POSCO (PKX) 20-F29 Apr 202019 FY Annual report (foreign)Financial data

Company Profile

Cover Page

Cover Page	12 Months Ended
Cover Page	Dec. 31, 2019shares
Document Information [Line Items]
Document Type	20-F
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Entity Registrant Name	POSCO
Entity Central Index Key	0000889132
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity File Number	1-13368
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	80,115,641
Entity Interactive Data Current	Yes
Document Annual Report	true
Document Transition Report	false
Document Shell Company Report	false
Entity Address, Country	KR
Entity Voluntary Filers	No
ADS [Member]
Document Information [Line Items]
Trading Symbol	PKX
Title of 12(b) Security	American Depositary Shares, each representing one-fourth of one share of common stock
Security Exchange Name	NYSE
Common Stock [Member]
Document Information [Line Items]
Trading Symbol	PKX
Title of 12(b) Security	Common Stock
Security Exchange Name	NYSE

Consolidated Statements of Fina

Consolidated Statements of Financial Position - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Assets
Cash and cash equivalents	₩ 3,514,872	₩ 2,643,865
Trade accounts and notes receivable, net	9,070,031	9,130,204
Other receivables, net	1,581,517	1,385,629
Other short-term financial assets	8,996,049	8,081,096
Inventories	11,230,759	12,153,303
Current income tax assets	45,930	51,557
Assets held for sale	74,158	21,854
Other current assets	631,177	684,464
Total current assets	35,144,493	34,151,972
Long-term trade accounts and notes receivable, net	198,785	427,125
Other receivables, net	1,140,879	863,240
Other long-term financial assets	1,669,389	1,647,898
Investments in associates and joint ventures	3,927,755	3,650,003
Investment property, net	878,227	928,615
Property, plant and equipment, net	29,925,973	30,018,273
Intangible assets, net	4,908,473	5,170,825
Defined benefit assets, net	4,280	1,489
Deferred tax assets	1,247,313	1,408,787
Other non-current assets	325,241	508,764
Total non-current assets	44,226,315	44,625,019
Total assets	79,370,808	78,776,991
Liabilities
Trade accounts and notes payable	3,422,922	4,006,135
Short-term borrowings and current installments of long-term borrowings	8,548,212	10,289,619
Other payables	1,879,508	1,720,097
Other short-term financial liabilities	77,827	77,800
Current income tax liabilities	396,616	948,166
Liabilities directly associated with the assets held for sale	8
Provisions	360,337	298,453
Other current liabilities	1,865,638	2,090,307
Total current liabilities	16,551,068	19,430,577
Long-term trade accounts and notes payable	20,067	29,825
Long-term borrowings, excluding current installments	11,893,401	9,919,651
Other payables	585,129	148,868
Other long-term financial liabilities	31,494	64,162
Defined benefit liabilities, net	181,011	140,933
Deferred tax liabilities	1,691,498	1,688,893
Long-term provisions	458,154	431,036
Other non-current liabilities	195,688	250,432
Total non-current liabilities	15,056,442	12,673,800
Total liabilities	31,607,510	32,104,377
Equity
Share capital	482,403	482,403
Capital surplus	1,385,707	1,420,007
Hybrid bonds	199,384	199,384
Reserves	(1,157,980)	(1,404,368)
Treasury shares	(1,508,303)	(1,532,728)
Retained earnings	45,054,077	44,160,660
Equity attributable to owners of the controlling company	44,455,288	43,325,358
Non-controllinginterests	3,308,010	3,347,256
Total equity	47,763,298	46,672,614
Total liabilities and equity	₩ 79,370,808	₩ 78,776,991

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of comprehensive income [abstract]
Revenue	₩ 64,785,709	₩ 65,154,636	₩ 60,186,867
Cost of sales	(58,462,100)	(57,129,060)	(51,915,597)
Gross profit	6,323,609	8,025,576	8,271,270
Selling and administrative expenses
Reversal of (Impairment loss) on trade accounts and notes receivable	28,105	(74,781)	(173,694)
Other administrative expenses	(2,041,286)	(1,985,755)	(2,003,106)
Selling expenses	(368,318)	(369,245)	(1,557,277)
Other operating income and expenses
Impairment loss on other receivables	(80,323)	(63,092)	(98,177)
Other operating income	450,891	523,586	448,481
Other operating expenses	(1,089,965)	(2,014,462)	(691,376)
Operating profit	3,222,713	4,041,827	4,196,121
Share of profit of equity-accounted investees, net	273,741	112,635	10,540
Finance income and costs
Finance income	1,872,143	1,705,970	2,372,667
Finance costs	(2,242,063)	(2,244,416)	(2,484,277)
Profit before income taxes	3,126,534	3,616,016	4,095,051
Income tax expense	(1,088,369)	(1,683,630)	(1,185,740)
Profit	2,038,165	1,932,386	2,909,311
Items that will not be reclassified subsequently to profit or loss :
Remeasurements of defined benefit plans	(117,152)	(173,489)	(47,543)
Net changes in fair value of equity investments at fair value through other comprehensive income	(10,541)	(149,188)
Items that are or may be reclassified subsequently to profit or loss :
Capital adjustment arising from investments in equity-accounted investees	66,134	(62,732)	(217,388)
Net changes in unrealized fair value of available-for-sale investments			(31,389)
Foreign currency translation differences	208,117	(42,908)	(264,695)
Losses on valuation of derivatives	(90)	(212)	(143)
Other comprehensive income (loss), net of tax	146,468	(428,529)	(561,158)
Total comprehensive income	2,184,633	1,503,857	2,348,153
Profit attributable to :
Owners of the controlling company	1,864,405	1,711,902	2,756,230
Non-controllinginterests	173,760	220,484	153,081
Profit	2,038,165	1,932,386	2,909,311
Total comprehensive income attributable to :
Owners of the controlling company	2,027,049	1,292,785	2,184,402
Non-controllinginterests	157,584	211,072	163,751
Total comprehensive income	₩ 2,184,633	₩ 1,503,857	₩ 2,348,153
Basic and diluted earnings per share (in Won)	₩ 23,189	₩ 21,177	₩ 34,040

Consolidated Statements of Chan

Consolidated Statements of Changes in Equity - KRW (₩) ₩ in Millions	Total	Final dividends [member]	Interim dividends [member]	Share capital [member]	Capital surplus [member]	Hybrid bonds [member]	Reserves [member]	Treasury shares [member]	Retained earnings [member]	Retained earnings [member]Final dividends [member]	Retained earnings [member]Interim dividends [member]	Attributable to owners of the controlling company [member]	Attributable to owners of the controlling company [member]Final dividends [member]	Attributable to owners of the controlling company [member]Interim dividends [member]	Non-controlling interests [member]	Non-controlling interests [member]Final dividends [member]
Beginning balance at Dec. 31, 2016	₩ 45,765,269			₩ 482,403	₩ 1,407,247	₩ 996,919	₩ (143,985)	₩ (1,533,468)	₩ 41,125,712			₩ 42,334,828			₩ 3,430,441
Comprehensive income (loss):
Profit	2,909,311								2,756,230			2,756,230			153,081
Other comprehensive income (loss)
Remeasurements of defined benefit plans, net of tax	(47,543)								(38,043)			(38,043)			(9,500)
Capital adjustment arising from investments in equity-accounted investees, net of tax	(217,388)						(214,794)					(214,794)			(2,594)
Net changes in the unrealized fair value of available-for-sale investments, net of tax	(31,389)						(45,953)					(45,953)			14,564
Foreign currency translation differences, net of tax	(264,695)						(272,902)					(272,902)			8,207
Gain or losses on valuation of derivatives, net of tax	(143)						(136)					(136)			(7)
Total comprehensive income	2,348,153						(533,785)		2,718,187			2,184,402			163,751
Transactions with owners of the controlling company, recognized directly in equity:
Dividends		₩ (502,896)	₩ (359,993)							₩ (459,987)	₩ (359,993)		₩ (459,987)	₩ (359,993)		₩ (42,909)
Changes in subsidiaries	(7,151)														(7,151)
Changes in ownership interests in subsidiaries	163,707				16,287							16,287			147,420
Interest of hybrid bonds	(67,787)								(43,600)			(43,600)			(24,187)
Disposal of treasury shares	540				126			414				540
Others	(13,117)				(1,639)		(4,786)		(5,661)			(12,086)			(1,031)
Total transactions with owners of the controlling company	(786,697)				14,774		(4,786)	414	(869,241)			(858,839)			72,142
Ending balance at Dec. 31, 2017	47,326,725			482,403	1,422,021	996,919	(682,556)	(1,533,054)	42,974,658			43,660,391			3,666,334
Adjustment on initial application of IFRS No. 15, net of tax	(129,883)								(70,907)			(70,907)			(58,976)
Adjustment on initial application of IFRS No. 9, net of tax	(86,204)						(498,517)		447,067			(51,450)			(34,754)
Comprehensive income (loss):
Profit	1,932,386								1,711,902			1,711,902			220,484
Other comprehensive income (loss)
Remeasurements of defined benefit plans, net of tax	(173,489)								(145,488)			(145,488)			(28,001)
Capital adjustment arising from investments in equity-accounted investees, net of tax	(62,732)						(76,587)					(76,587)			13,855
Net changes in fair value of equity investments at fair value through other comprehensive income, net of tax	(149,188)								(46,883)
Net changes in the unrealized fair value of available-for-sale investments, net of tax	(149,188)						(104,293)					(151,176)			1,988
Foreign currency translation differences, net of tax	(42,908)						(45,650)					(45,650)			2,742
Gain or losses on valuation of derivatives, net of tax	(212)						(216)					(216)			4
Total comprehensive income	1,503,857						(226,746)		1,519,531			1,292,785			211,072
Transactions with owners of the controlling company, recognized directly in equity:
Dividends		(334,239)	(400,003)							(279,999)	(400,003)		(279,999)	(400,003)		(54,240)
Changes in subsidiaries	(2,092)														(2,092)
Changes in ownership interests in subsidiaries	(2,151)				(1,497)							(1,497)			(654)
Repayment of hybrid bonds	(1,159,322)				(2,769)	(797,535)						(800,304)			(359,018)
Interest of hybrid bonds	(42,891)								(24,443)			(24,443)			(18,448)
Disposal of treasury shares	459				133			326				459
Others	(1,642)				2,119		3,451		(5,244)			326			(1,968)
Total transactions with owners of the controlling company	(1,941,881)				(2,014)	(797,535)	3,451	326	(709,689)			(1,505,461)			(436,420)
Ending balance (Adjusted balance [member]) at Dec. 31, 2018	47,110,638			482,403	1,422,021	996,919	(1,181,073)	(1,533,054)	43,350,818			43,538,034			3,572,604
Ending balance at Dec. 31, 2018	46,672,614			482,403	1,420,007	199,384	(1,404,368)	(1,532,728)	44,160,660			43,325,358			3,347,256
Comprehensive income (loss):
Profit	2,038,165								1,864,405			1,864,405			173,760
Other comprehensive income (loss)
Remeasurements of defined benefit plans, net of tax	(117,152)								(100,218)			(100,218)			(16,934)
Capital adjustment arising from investments in equity-accounted investees, net of tax	66,134						58,308					58,308			7,826
Net changes in fair value of equity investments at fair value through other comprehensive income, net of tax	(10,541)								(20,769)
Net changes in the unrealized fair value of available-for-sale investments, net of tax	(10,541)						10,228					(10,541)			0
Foreign currency translation differences, net of tax	208,117						215,181					215,181			(7,064)
Gain or losses on valuation of derivatives, net of tax	(90)						(86)					(86)			(4)
Total comprehensive income	2,184,633						283,631		1,743,418			2,027,049			157,584
Transactions with owners of the controlling company, recognized directly in equity:
Dividends		₩ (460,280)	₩ (480,694)							₩ (400,006)	₩ (480,694)		₩ (400,006)	₩ (480,694)		₩ (60,274)
Changes in subsidiaries	1,281														1,281
Changes in ownership interests in subsidiaries	(177,125)				(48,538)							(48,538)			(128,587)
Interest of hybrid bonds	(16,494)								(9,200)			(9,200)			(7,294)
Disposal of treasury shares	37,001				12,576			24,425				37,001
Others	2,362				1,662		(37,243)		39,899			4,318			(1,956)
Total transactions with owners of the controlling company	(1,093,949)				(34,300)		(37,243)	24,425	(850,001)			(897,119)			(196,830)
Ending balance at Dec. 31, 2019	₩ 47,763,298			₩ 482,403	₩ 1,385,707	₩ 199,384	₩ (1,157,980)	₩ (1,508,303)	₩ 45,054,077			₩ 44,455,288			₩ 3,308,010

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities
Profit	₩ 2,038,165	₩ 1,932,386	₩ 2,909,311
Adjustments for:
Depreciation	3,029,868	2,911,048	2,887,646
Amortization	431,247	356,581	409,774
Finance income	(855,382)	(737,745)	(1,376,324)
Finance costs	1,197,705	1,168,225	1,440,282
Income tax expense	1,088,369	1,683,630	1,185,740
Gain on disposal of property, plant and equipment	(49,367)	(53,139)	(32,145)
Loss on disposal of property, plant and equipment	120,227	117,614	151,343
Impairment losses on property, plant and equipment	442,700	1,004,704	117,231
Gain on disposal of intangible assets	(1,896)	(117,139)	(22,391)
Gain on disposal of investments in subsidiaries, associates and joint ventures	(27,836)	(45,241)	(81,794)
Loss on disposal of investments in subsidiaries, associates and joint ventures	6,539	5,226	19,985
Share of profit of equity-accounted investees	(273,741)	(112,635)	(10,540)
Expenses related to post-employment benefits	240,425	216,489	199,926
Increase to provisions	76,538	240,146	215,383
Impairment loss on trade and other receivables	52,218	137,873	271,871
Loss on valuation of inventories	96,201	141,799	78,560
Impairment losses on goodwill and intangible assets	191,021	337,519	167,995
Gain on disposal of assets held for sale	(37,461)	(27,171)	(1,180)
Impairment losses on assets held for sale	38,328	50,829
Others, net	894	77,945	(10,093)
Adjustments to reconcile profit (loss) other than changes in working capital	5,766,597	7,356,558	5,611,269
Changes in operating assets and liabilities	(114,045)	(2,105,726)	(1,841,633)
Interest received	320,336	352,337	244,980
Interest paid	(760,175)	(750,410)	(735,735)
Dividends received	266,774	224,410	225,514
Income taxes paid	(1,512,997)	(1,139,830)	(806,396)
Net cash provided by operating activities	6,004,655	5,869,725	5,607,310
Cash flows from investing activities
Acquisitions of short-term financial instruments	(36,063,406)	(32,173,134)	(20,843,530)
Proceeds from disposal of short-term financial instruments	35,415,822	31,105,544	19,146,634
Increase in loans	(450,638)	(627,783)	(1,055,895)
Collection of loans	398,838	941,962	667,045
Acquisitions of securities	(296,827)	(321,916)
Proceeds from disposal of securities	62,492	221,646
Acquisitions of available-for-sale investments			(66,278)
Proceeds from disposal of available-for-sale investments			1,006,856
Acquisitions of investments in associates and joint ventures	(160,404)	(47,355)	(60,277)
Proceeds from disposal of investments in associates and joint ventures	16,458	88,852	74,881
Acquisitions of property, plant and equipment	(2,519,219)	(2,135,550)	(2,287,580)
Proceeds from disposal of property, plant and equipment	51,800	90,412	39,183
Acquisitions of investment property	(19,344)	(44,106)	(69,169)
Proceeds from disposal of investment property	12,057	70,817	5,771
Acquisitions of intangible assets	(299,587)	(447,616)	(343,423)
Proceeds from disposal of intangible assets	24,161	77,654	28,502
Proceeds from disposal of assets held for sale	67,246	93,338	203,958
Increase in cash from (payment for) acquisition of business, net of cash acquired	(37,345)		(174,165)
Cash received (decrease in cash) from disposal of business, net of cash transferred	45,360	447,917	(75,540)
Collection of lease receivables	56,889
Others, net	12,788	11,348	(14,847)
Net cash used in investing activities	(3,682,859)	(2,647,970)	(3,817,874)
Cash flows from financing activities
Proceeds from borrowings	5,646,977	2,762,446	1,725,983
Repayment of borrowings	(3,746,845)	(3,136,308)	(3,136,016)
Proceeds from (repayment of) short-term borrowings, net	(2,194,727)	(854,554)	558,083
Payment of cash dividends	(946,218)	(723,934)	(863,450)
Repayment of hybrid bonds		(1,160,000)
Payment of interest of hybrid bonds	(16,494)	(46,166)	(67,783)
Capital contribution from non-controlling interests and proceeds from disposal of subsidiary while maintaining control	29,475	5,808	266,219
Capital deduction from non-controlling interests and additional acquisition of interests in subsidiaries	(123,304)	(3,823)	(26,288)
Repayment of lease liabilities	(167,427)	(30,481)	(10,536)
Others, net	6,384	(8,036)	(11,740)
Net cash used in financing activities	(1,512,179)	(3,195,048)	(1,565,528)
Effect of exchange rate fluctuation on cash held	61,764	4,628	(58,997)
Net increase in cash and cash equivalents	871,381	31,335	164,911
Cash and cash equivalents at beginning of the period	2,643,865	2,612,530	2,447,619
Cash and cash equivalents at end of the period	₩ 3,515,246	₩ 2,643,865	₩ 2,612,530

General Information

General Information	12 Months Ended
General Information	Dec. 31, 2019
Text block [abstract]
General Information	1. General Information General information about POSCO, its 32 domestic subsidiaries including POSCO ENGINEERING & CONSTRUCTION CO., LTD., 131 foreign subsidiaries including POSCO America Corporation (collectively “the Company”) and its 131 associates and joint ventures are as follows: (a) The controlling company POSCO, the controlling company, was incorporated on April 1, 1968, under the Commercial Code of the Republic of Korea to manufacture and sell steel rolled products and plates in the domestic and foreign markets. The shares of POSCO have been listed on the Korea Exchange since June 10, 1988. POSCO owns and operates two steel plants (Pohang and Gwangyang) and one office in Korea and it also operates internationally through six of its overseas liaison offices. As of December 31, 2019, POSCO’s shareholders are as follows: Shareholder’s name Number of shares Ownership (%) National Pension Service 10,291,670 11.80 BlackRock Fund Advisors(1,2,3) 5,429,071 6.23 Nippon Steel Corporation(1) 2,894,712 3.32 Samsung Group and subsidiaries(2) 2,401,789 2.75 GIC Private Limited 1,777,316 2.04 Others 64,392,277 73.86 87,186,835 100.00 (1) Includes American Depository Receipts (ADRs) of POSCO, each of which represents 0.25 share of POSCO’s common share which has par value of ￦ (2) Includes shares held by subsidiaries and others. (3) The number of shares held by the shareholder based on the information in the status report of large-scale shareholders filed with Korea Exchange on April 16, 2019. As of December 31, 2019, the shares of POSCO are listed on the Korea Exchange while its ADRs are listed on the New York Stock Exchange. (b) Consolidated subsidiaries Details of consolidated subsidiaries as of December 31, 2018 and 2019 are as follows: Principal operations Ownership (%) December 31, 2018 December 31, 2019 POSCO Subsidiaries Total POSCO Subsidiaries Total Region [Domestic] POSCO ENGINEERING & CONSTRUCTION., CO., LTD. Engineering and construction 52.80 — 52.80 52.80 — 52.80 Pohang POSCO COATED & COLOR STEEL Co., Ltd. Coated steel manufacturing 56.87 — 56.87 56.87 — 56.87 Pohang POSCO ICT Computer hardware and software distribution 65.38 — 65.38 65.38 — 65.38 Pohang POSCO Research Institute Economic research and consulting 100.00 — 100.00 100.00 — 100.00 Seoul POSCO O&M CO.,Ltd. Business facility maintenance 59.80 40.20 100.00 47.17 52.83 100.00 Seoul POSCO A&C Architecture and consulting 100.00 — 100.00 45.66 54.34 100.00 Seoul POSCO Venture Capital Co., Ltd. Investment in venture companies 95.00 — 95.00 95.00 — 95.00 Pohang eNtoB Corporation Electronic commerce 7.50 53.63 61.13 7.50 53.63 61.13 Seoul POSCO CHEMICAL CO., LTD. (formerly, POSCO CHEMTECH) Refractories manufacturing and sales 60.00 — 60.00 61.26 — 61.26 Pohang POSCO-Terminal Co., Ltd. Transporting and warehousing 51.00 — 51.00 51.00 — 51.00 Gwangyang POSCO M-TECH Packing materials manufacturing and sales 48.85 — 48.85 48.85 — 48.85 Pohang POSCO ENERGY CO., LTD. Generation of electricity 89.02 — 89.02 100.00 — 100.00 Seoul PNR Steel byproduct manufacturing and sales 70.00 — 70.00 70.00 — 70.00 Pohang Future Creation Fund Postech Early Stage account Investment in venture companies — 40.00 40.00 — 40.00 40.00 Seoul POSCO WOMAN’S FUND Investment in venture companies — 40.00 40.00 — 40.00 40.00 Seoul SPH Co, LTD. House manufacturing and management — 100.00 100.00 — 100.00 100.00 Incheon Posco Group University Education service and real estate business 100.00 — 100.00 100.00 — 100.00 Incheon Growth Ladder POSCO K-Growth Investment in venture companies — 50.00 50.00 — 50.00 50.00 Pohang 2015 POSCO New technology II Fund Investment in venture companies — 25.00 25.00 — 25.00 25.00 Pohang POSCO Research & Technology Intellectual Property Services and consulting 100.00 — 100.00 100.00 — 100.00 Seoul TANCHEON E&E Refuse derived fuel and power generation — 100.00 100.00 — 100.00 100.00 Seoul POSCO Humans Construction 90.30 — 90.30 75.49 24.51 100.00 Pohang Mapo Hibroad Parking Co., Ltd. Construction — 71.00 71.00 — 71.00 71.00 Seoul Busan E&E Co., Ltd. Refuse derived fuel and power generation 70.00 — 70.00 70.00 — 70.00 Busan POSCO Family Strategy Fund Investment in venture companies 69.91 30.09 100.00 69.91 30.09 100.00 Pohang POSCO INTERNATIONAL Corporation (formerly, POSCO DAEWOO Corporation) Trading, energy & resource development and others 62.90 0.04 62.94 62.91 0.03 62.94 Seoul Pohang Scrap Recycling Distribution Center Co., Ltd. Steel processing and sales — 51.00 51.00 — 51.00 51.00 Pohang PSC Energy Global Co., Ltd. Investment in energy industry — 100.00 100.00 — 100.00 100.00 Pohang Suncheon Eco Trans Co. LTD Train manufacturing and management 100.00 — 100.00 100.00 — 100.00 Suncheon Songdo Development PMC (Project Management Company) LLC. Housing business agency — 100.00 100.00 — 100.00 100.00 Incheon Korea Fuel Cell Fuel cell — — — — 100.00 100.00 Pohang POSCO GEM 1th Fund Investment in venture companies — — — 98.81 1.19 100.00 Pohang POSCO Processing&Service Steel sales and trading 93.95 0.45 94.40 — — — Seoul MegaAsset Co.,Ltd. Real estate rental and sales — 100.00 100.00 — — — Incheon HOTEL LAONZENA Hotel business — 100.00 100.00 — — — Daegu Posco e&c Songdo International Building Non-residental — 100.00 100.00 — — — Seoul POSCO ES MATERIALS CO., LTD. Secondary and storage battery manufacturing 90.00 — 90.00 — — — Gumi BLUE O&M Co.,Ltd. Engineering service — 100.00 100.00 — — — Pohang [Foreign] POSCO America Corporation Steel trading 99.45 0.55 100.00 99.45 0.55 100.00 USA POSCO AUSTRALIA PTY LTD Raw material sales & mine development 100.00 — 100.00 100.00 — 100.00 Australia POSCO Canada Ltd. Coal sales — 100.00 100.00 100.00 — 100.00 Canada POSCAN Elkview Coal sales — 100.00 100.00 — 100.00 100.00 Canada POSCO Asia Co., Ltd. Steel and raw material trading 100.00 — 100.00 100.00 — 100.00 China POSCO-CTPC Co., Ltd. Steel manufacturing and sales 61.91 38.09 100.00 100.00 — 100.00 China POSCO E&C Vietnam Co., Ltd. Steel structure manufacturing and sales — 100.00 100.00 — 100.00 100.00 Vietnam Zhangjiagang Pohang Stainless Steel Co., Ltd. Stainless steel manufacturing and sales 58.60 23.88 82.48 58.60 23.88 82.48 China POSCO (Thailand) Company Limited Steel manufacturing and sales 88.58 11.42 100.00 100.00 — 100.00 Thailand POSCO-MKPC SDN BHD Steel manufacturing and sales 44.69 25.31 70.00 70.00 — 70.00 Malaysia Qingdao Pohang Stainless Steel Co., Ltd. Stainless steel manufacturing and sales 70.00 30.00 100.00 70.00 30.00 100.00 China POSCO(Suzhou) Automotive Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China POSCO-China Qingdao Steel manufacturing and sales — 100.00 100.00 100.00 — 100.00 China POS-ORE Iron ore sales and sales — 100.00 100.00 — 100.00 100.00 Australia POSCO-China Holding Corp. Holding company 100.00 — 100.00 100.00 — 100.00 China POSCO JAPAN Co., Ltd. Steel trading 100.00 — 100.00 100.00 — 100.00 Japan POS-CD Coal sales — 100.00 100.00 — 100.00 100.00 Australia POS-GC Coal sales — 100.00 100.00 — 100.00 100.00 Australia POSCO-India Private Limited Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 India POSCO-India Pune Processing Center. Pvt. Ltd. Steel manufacturing and sales 65.00 — 65.00 65.00 — 65.00 India POSCO Japan PC CO., LTD Steel manufacturing and sales — 86.12 86.12 — 86.12 86.12 Japan POSCO-CFPC Co., Ltd. Steel manufacturing and sales 39.60 60.40 100.00 39.60 60.40 100.00 China POSCO E&C CHINA Co., Ltd. Civil engineering and construction — 100.00 100.00 — 100.00 100.00 China POSCO MPPC S.A. de C.V. Steel manufacturing and sales 21.02 75.29 96.31 21.02 75.29 96.31 Mexico Zhangjigang Pohang Port Co., Ltd. Loading and unloading service — 100.00 100.00 — 100.00 100.00 China POSCO-VIETNAM Co., Ltd. Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 Vietnam POSCO MEXICO S.A. DE C.V. Automotive steel sheet 83.28 14.88 98.16 83.28 14.88 98.16 Mexico POSCO-Poland Wroclaw Steel manufacturing and sales 60.00 — 60.00 60.00 — 60.00 Poland POS-NP Coal sales — 100.00 100.00 — 100.00 100.00 Australia POSCO DAEWOO WAIGAOQIAO Intermediary trade & bonded — 100.00 100.00 — 100.00 100.00 China PT. Bio Inti Agrindo Forest resources development — 85.00 85.00 — 85.00 85.00 Indonesia POSCO ENGINEERING AND CONSTRUCTION AUSTRALIA (POSCO E&C AUSTRALIA) PTY LTD Construction and engineering service — 100.00 100.00 — 100.00 100.00 Australia POSCO-TISCO (JILIN) Steel manufacturing and sales 50.00 10.00 60.00 50.00 10.00 60.00 China POSCO Thainox Public Company Limited STS cold-rolled steel manufacturing and sales 84.66 — 84.66 84.39 — 84.39 Thailand Hunchun Posco Hyundai Logistics Logistics — 80.00 80.00 — 80.00 80.00 China POSCO INTERNATIONAL VIETNAM COMPANY LIMITED Trading business — 100.00 100.00 — 100.00 100.00 Vietnam POSCO(Chongqing) Automotive Processing Center Co., Ltd. Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China SUZHOU POSCO-CORE TECHNOLOGY CO., LTD. Component manufacturing and sales — 100.00 100.00 84.85 15.15 100.00 China PT.Krakatau Posco Chemtech Calcination Quicklime manufacturing and sales — 80.00 80.00 — 80.00 80.00 Indonesia POSCO AFRICA (PROPRIETARY) LIMITED Mine development 100.00 — 100.00 100.00 — 100.00 South POSCO ICT BRASIL IT service and engineering — 100.00 100.00 — 100.00 100.00 Brazil LA-SRDC Scrap manufacturing — 100.00 100.00 — 100.00 100.00 USA POSCO Center Beijing Real estate development, rental and management — 100.00 100.00 — 100.00 100.00 China POSCO AMERICA COMERCIALIZADORA S DE RL DE CV Steel sales — 100.00 100.00 — 100.00 100.00 Mexico POSCO(Guangdong) Automotive Steel Co., Ltd. Steel manufacturing and sales 83.64 10.00 93.64 83.64 10.00 93.64 China POSCO-Malaysia SDN. BHD. Steel manufacturing and sales 81.79 13.63 95.42 81.79 13.63 95.42 Malaysia PT KRAKATAU BLUE WATER Wastewater treamtment facilities operation and maintenance — 67.00 67.00 — 67.00 67.00 Indonesia POSCO INTERNATIONAL MYANMAR CORPORATION LIMITED Trading business — 100.00 100.00 — 100.00 100.00 Myanmar POSCO-Italy Processing Center Stainless steel sheetmanufacturing and sales 80.00 10.00 90.00 88.89 11.11 100.00 Italy Myanmar POSCO C&C Company, Limited. Steel manufacturing and sales — 70.00 70.00 — 70.00 70.00 Myanmar POSCO ICT VIETNAM IT service and electric control engineering — 100.00 100.00 — 100.00 100.00 Vietnam Daewoo Global Development. Pte., Ltd Real estate development — 81.51 81.51 — 81.51 81.51 Singapore Myanmar POSCO Engineering & Construction Company, Limited. Construction and engineering service — 100.00 100.00 — 100.00 100.00 Myanmar POS-Minerals Mine development management and sales — 100.00 100.00 — 100.00 100.00 USA POSCO(Wuhu) Automotive Processing Center Co., Ltd. Steel manufacturing and sales 68.57 31.43 100.00 68.57 31.43 100.00 China POSCO Engineering and Construction India Private Limited Civil engineering and construction — 100.00 100.00 — 100.00 100.00 India POSCO COATED STEEL (THAILAND) CO., LTD. Automotive steel sheetmanufacturing and sales 100.00 — 100.00 100.00 — 100.00 Thailand [Foreign] Daewoo Amara Company Limited Real estate development — 85.00 85.00 — 85.00 85.00 Myanmar POSMATE-CHINA CO., LTD Business facility maintenance — 100.00 100.00 — 100.00 100.00 China POSCO-Mexico Villagran Wire-rod Steel manufacturing and sales 56.75 10.00 66.75 56.75 10.00 66.75 Mexico POSCO ChengDu Processing Center Steel manufacturing and sales 33.00 10.00 43.00 33.00 10.00 43.00 China POSCO SUZHOU PROCESSING CENTER CO., LTD. Steel manufacturing and sales 30.00 70.00 100.00 30.00 70.00 100.00 China POSCO E&C SMART S DE RL DE CV Civil engineering and construction — 100.00 100.00 — 100.00 100.00 Mexico POSCO Philippine Manila Processing Center, Inc. Steel manufacturing and sales — 100.00 100.00 100.00 — 100.00 Philippines POSCO E&C HOLDINGS CO., Ltd. Holding company — 100.00 100.00 — 100.00 100.00 Thailand POSCO INTERNATIONAL POWER (PNGLAE) LTD. Electricity production — 100.00 100.00 — 100.00 100.00 Papua New PT.Krakatau Posco Social Enterprise Social enterprise — 100.00 100.00 — 100.00 100.00 Indonesia Ventanas Philippines Construction Inc Construction — 100.00 100.00 — 100.00 100.00 Philippines POSCO E&C Mongolia Construction and engineering service — 100.00 100.00 — 100.00 100.00 Mongolia SANPU TRADING Co., Ltd. Raw material trading — 70.04 70.04 — 70.04 70.04 China Zhangjiagang BLZ Pohang Steel Intermediate trade — 100.00 100.00 — 100.00 100.00 China POSCO RU Limited Liability Company Trade and business development 100.00 — 100.00 100.00 — 100.00 Russia GOLDEN LACE POSCO Rice processing — 60.00 60.00 — 60.00 60.00 Myanmar POSCO ICT-China IT service and DVR business — 100.00 100.00 — 100.00 100.00 China Pos-Sea Steel Intermediate trade — 100.00 100.00 — 100.00 100.00 Singapore POSCO Europe Steel Distribution Center Logistics & Steel sales 50.00 20.00 70.00 50.00 20.00 70.00 Slovenia POSCO ENGINEERING (THAILAND) CO., LTD. Construction and engineering service — 100.00 100.00 — 100.00 100.00 Thailand POSCO VST CO., LTD. Stainless steel sheet 95.65 — 95.65 95.65 — 95.65 Vietnam POSCO INTERNATIONAL UKRAINE, LLC. Grain sales — 100.00 100.00 — 100.00 100.00 Ukraine Zhangjiagang Pohang Refractories Co., Ltd. Refractory materials sales & furnace maintenance — 51.00 51.00 — 51.00 51.00 China POSCO Maharashtra Steel Private Limited Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 India POSCO INDIA PROCESSING CENTER PRIVATE LIMITED Steel manufacturing and sales 93.34 1.98 95.32 93.34 1.98 95.32 India POSCO TNPC Otomotiv Celik San. Ve Tic. A.S Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 Turkey POSCO Vietnam Processing Center. Co., Ltd Steel manufacturing and sales 83.54 5.29 88.83 83.54 5.29 88.83 Vietnam POSCO(Liaoning) Automotive Processing Center Co., Ltd. Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China POSCO-Indonesia Jakarta Processing Center Steel manufacturing and sales 65.00 20.00 85.00 65.00 20.00 85.00 Indonesia PT.MRI Mine development 65.00 — 65.00 65.00 — 65.00 Indonesia POSCO TMC INDIA PRIVATE LIMITED Steel manufacturing and sales — 100.00 100.00 — 100.00 100.00 India POSCO AMERICA ALABAMA PROCESSING CENTER CO., LTD. Steel manufacturing and sales — 97.80 97.80 — 97.80 97.80 USA POSCO(Yantai Automotive Processing Center Co., Ltd. Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China POSCO India Steel Distribution Center Private Ltd. Steel logistics — 100.00 100.00 — 100.00 100.00 India POSCO China Dalian Plate Processing Center Co., Ltd. Plate manufacturing and sales 79.52 11.70 91.22 79.52 11.70 91.22 China POSCO SS VINA JOINT STOCK COMPANY (Formerly, POSCO SS VISA CO., Ltd.) Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 Vietnam PT.POSCO ICT INDONESIA IT service and electric control engineering — 66.99 66.99 — 66.99 66.99 Indonesia POSCO NCR Coal Ltd. Coal sales — 100.00 100.00 — 100.00 100.00 Canada POSCO WA PTY LTD Iron ore sales & mine development 100.00 — 100.00 100.00 — 100.00 Australia POSCO AUSTRALIA GP PTY LIMITED Resource development — 100.00 100.00 — 100.00 100.00 Australia POSCO INTERNATIONAL POWER(PNGPOM) LTD. Electricity production — 100.00 100.00 — 100.00 100.00 Papua New PT. KRAKATAU POSCO ENERGY Electricity production construction and operation — 90.00 90.00 — 90.00 90.00 Indonesia POSCO INTERNATIONAL AMERICA CORP. Trading business — 100.00 100.00 — 100.00 100.00 USA POSCO INTERNATIONAL Deutschland GMBH Trading business — 100.00 100.00 — 100.00 100.00 Germany POSCO INTERNATIONAL JAPAN CORP. Trading business — 100.00 100.00 — 100.00 100.00 Japan POSCO INTERNATIONAL SINGAPORE PTE. LTD. Trading business — 100.00 100.00 — 100.00 100.00 Singapore POSCO INTERNATIONAL ITALIA S.R.L. Trading business — 100.00 100.00 — 100.00 100.00 Italy POSCO INTERNATIONAL (CHINA) CO., LTD Trading business — 100.00 100.00 — 100.00 100.00 China POSCO INTERNATIONAL TEXTILE LLC. Textile manufacturing — 100.00 100.00 — 100.00 100.00 Uzbekistan POSCO INTERNATIONAL AUSTRALIA HOLDINGS PTY. LTD. Resource development — 100.00 100.00 — 100.00 100.00 Australia POSCO MAURITIUS LIMITED Coal development and sales — 100.00 100.00 — 100.00 100.00 Mauritius PT. KRAKATAU POSCO Steel manufacturing and sales 70.00 — 70.00 70.00 — 70.00 Indonesia POSCO INTERNATIONAL MEXICO S.A DE C.V. Trading business — 100.00 100.00 — 100.00 100.00 Mexico POSCO INTERNATIONAL MALAYSIA SDN BHD Trading business — 100.00 100.00 — 100.00 100.00 Malaysia PT.POSCO INDONESIA INTI Mine development 100.00 — 100.00 100.00 — 100.00 Indonesia POSCO INTERNATIONAL SHANGHAI CO., LTD. Trading business — 100.00 100.00 — 100.00 100.00 China PGSF, L.P. Investment in bio tech Industry — 100.00 100.00 — 100.00 100.00 USA POSCO INTERNATIONAL INDIA PVT. LTD Trading business — 100.00 100.00 — 100.00 100.00 India POSCO(Dalian) IT Center Development Co., Ltd. Real estate development and investment — 100.00 100.00 — 100.00 100.00 China PT. POSCO E&C INDONESIA Civil engineering and construction — 100.00 100.00 — 100.00 100.00 Indonesia HUME COAL PTY LTD Raw material manufacturing — 100.00 100.00 — 100.00 100.00 Australia Brazil Sao Paulo Steel Processing Center Steel manufacturing and sales — 76.00 76.00 — 76.00 76.00 Brazil DAESAN (CAMBODIA) Co., Ltd. Real estate development and investment — 100.00 100.00 — 100.00 100.00 Cambodia POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. Construction — 100.00 100.00 — 100.00 100.00 Brazil POSCO ASSAN TST STEEL INDUSTRY Steel manufacturing and sales 60.00 10.00 70.00 60.00 10.00 70.00 Turkey HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd. Real estate development and investment — 100.00 100.00 — 100.00 100.00 Hongkong JB CLARK HILLS(1) Apartment construction — 25.00 25.00 — 70.00 70.00 Philippines POS-LT Lithium mining investment — 100.00 100.00 — 100.00 100.00 Australia ZHEJIANG POSCO-HUAYOU ESM CO., LTD Anode material manufacturing 100.00 — 100.00 60.00 — 60.00 China POSCO Argentina S.A.U. Mineral exploration/manufacturing/sales 100.00 — 100.00 100.00 — 100.00 Argentina GRAIN TERMINAL HOLDING PTE. LTD. Trade — — — — 75.00 75.00 Singapore Mykolaiv Milling Works PJSC. Grain trading — — — — 100.00 100.00 Ukraine Yuzhnaya Stevedoring Company Limited LLC. Cargo handling — — — — 100.00 100.00 Ukraine Myanmar POSCO Steel Co., Ltd Steel manufacturing and sales — 70.00 70.00 — 70.00 70.00 Myanmar POSCO SINGAPORE LNG TRADING PTE. LTD. LNG trading 50.00 50.00 100.00 — — — Singapore POSCO DAEWOO E&P CANADA CORPORATION Crude oil and natural gas mining — 100.00 100.00 — — — Canada Daewoo Power and Infra (PTY) Limited Electricity — 100.00 100.00 — — — South Daewoo Precious Resources Co., Ltd. Resources development — 70.00 70.00 — — — Myanmar POSCO E&C (THAILAND) CO., Ltd. Construction and engineering — 100.00 100.00 — — — Thailand POSCO Gulf SFC LLC Steel manufacturing and sales — 65.72 65.72 — — — United Arab POSCO-South Asia Company Limited Steel sales 100.00 — 100.00 — — — Thailand POSCO(Guangdong) Coated Steel Co., Ltd. Steel manufacturing and sales 87.04 10.04 97.08 — — — China DAEWOO INTERNATIONAL GUANGZHOU CORP. Trading business — 100.00 100.00 — — — China (1) Reclassified from associate to subsidiary during the year ended December 31, 2019. The equity investment of controlling company decreased by ￦￦ Cash dividends paid to POSCO by subsidiaries in 2017, 2018 and 2019 amounted to ￦￦￦ As of December 31, 2019, there are no restrictions on the ability of subsidiaries to transfer funds to the controlling company, such as in the form of cash dividends, repayment of loans or payment of advances. (c) Details of non-controlling 1) December 31, 2017 (in millions of Won) POSCO PT. POSCO POSCO POSCO Others Total Current assets ￦ 4,483,544 557,041 441,325 4,878,251 1,054,538 8,579,813 19,994,512 Non-current 4,590,394 2,771,504 316,724 2,444,616 2,859,824 6,676,559 19,659,621 Current liabilities (4,221,443 ) (1,237,255 ) (145,649 ) (3,896,680 ) (785,462 ) (8,313,902 ) (18,600,391 ) Non-current (1,549,013 ) (1,933,247 ) (970 ) (833,403 ) (2,200,065 ) (2,048,454 ) (8,565,152 ) Equity 3,303,482 158,043 611,430 2,592,784 928,835 4,894,016 12,488,590 Non-controlling 1,224,303 47,413 244,572 1,223,816 762,390 974,941 4,477,435 Sales 20,891,526 1,635,837 1,163,918 5,794,532 1,578,026 23,547,072 54,610,911 Profit (loss) for the period 115,321 (117,729 ) 101,019 169,011 70,795 258,053 596,470 Profit (loss) attributable to non-controlling 42,739 (35,318 ) 40,408 79,775 7,770 39,605 174,979 Cash flows from operating activities 128,875 (27,817 ) 20,042 (84,840 ) 30,295 140,418 206,973 Cash flows from investing activities (86,365 ) (5,502 ) (18,699 ) (171,924 ) (2,792 ) (63,621 ) (348,903 ) Cash flows from financing activities (before dividends to non-controlling (19,295 ) 31,782 8 150,801 220,317 (38,090 ) 345,523 Dividend to non-controlling (22,597 ) — (7,088 ) — (24,183 ) (12,777 ) (66,645 ) Effect of exchange rate fluctuation on cash held (459 ) (147 ) (6 ) (3,541 ) — (15,532 ) (19,685 ) Net increase (decrease) in cash and cash equivalents 159 (1,684 ) (5,743 ) (109,504 ) 223,637 10,398 117,263 2) December 31, 2018 (in millions of Won) POSCO PT. POSCO POSCO POSCO Others Total Current assets ￦ 5,311,596 615,491 416,284 4,100,967 825,241 9,137,798 20,407,377 Non-current 4,363,490 2,730,865 460,905 1,911,844 2,767,203 5,493,324 17,727,631 Current liabilities (4,724,056 ) (1,368,498 ) (140,268 ) (3,007,029 ) (1,197,845 ) (8,026,474 ) (18,464,170 ) Non-current (1,563,107 ) (1,754,797 ) (10,767 ) (608,089 ) (1,445,288 ) (1,925,084 ) (7,307,132 ) Equity 3,387,923 223,061 726,154 2,397,693 949,311 4,679,564 12,363,706 Non-controlling 1,255,728 66,918 290,461 1,131,733 335,203 929,506 4,009,549 Sales 23,314,595 1,871,634 1,340,984 6,799,292 1,841,187 24,721,939 59,889,631 Profit (loss) for the period 113,196 54,257 142,918 290,131 (73,948 ) (56,151 ) 470,403 Profit (loss) attributable to non-controlling 41,956 16,277 57,167 136,944 (8,116 ) (101,156 ) 143,072 Cash flows from operating activities (61,173 ) 89,131 29,865 207,729 16,211 14,869 296,632 Cash flows from investing activities (12,780 ) (6,432 ) (15,801 ) 272,230 35,460 (13,199 ) 259,478 Cash flows from financing activities (before dividends to non-controlling 99,496 (82,295 ) — (400,499 ) (71,378 ) (16,094 ) (470,770 ) Dividend to non-controlling (22,862 ) — (8,270 ) — (19,813 ) (6,906 ) (57,851 ) Effect of exchange rate fluctuation on cash held 807 21 (17 ) 1,257 — 1,682 3,750 Net increase (decrease) in cash and cash equivalents 3,488 425 5,777 80,717 (39,520 ) (19,648 ) 31,239 3) December 31, 2019 (in millions of Won) POSCO PT. POSCO POSCO POSCO Others Total Current assets ￦ 4,396,683 520,057 624,017 4,242,954 441,208 8,062,428 18,287,347 Non-current 4,186,197 2,723,254 1,050,406 1,808,919 210,037 4,740,887 14,719,700 Current liabilities (3,013,269 ) (1,570,204 ) (236,968 ) (2,734,305 ) (262,265 ) (7,672,691 ) (15,489,702 ) Non-current (2,087,769 ) (1,590,810 ) (462,361 ) (786,191 ) (38,836 ) (2,095,797 ) (7,061,764 ) Equity 3,481,842 82,297 975,094 2,531,377 350,144 3,034,827 10,455,581 Non-controlling 1,290,600 24,689 377,770 1,194,833 121,213 1,124,381 4,133,486 Sales 22,745,239 1,906,302 1,434,507 7,625,389 925,551 22,975,605 57,612,593 Profit (loss) for the period 199,721 (146,975 ) 94,481 330,298 32,954 (587,146 ) (76,667 ) Profit (loss) attributable to non-controlling 74,030 (44,093 ) 36,604 155,904 11,408 (89,676 ) 144,177 Cash flows from operating activities 580,372 61,398 22,794 24,636 21,571 (16,324 ) 694,447 Cash flows from investing activities (40,264 ) (7,173 ) (111,996 ) (6,620 ) (2,129 ) 31,057 (137,125 ) Cash flows from financing activities (before dividends to non-controlling (502,801 ) (53,890 ) 134,609 (25,448 ) (336 ) (4,295 ) (452,161 ) Dividend to non-controlling (27,432 ) — (9,451 ) (9,867 ) (2,628 ) (11,079 ) (60,457 ) Effect of exchange rate fluctuation on cash held 1,736 25 (7 ) 1,401 (47 ) 3,931 7,039 Net increase (decrease) in cash and cash equivalents 11,611 360 35,949 (15,898 ) 16,431 3,290 51,743 (d) Details of associates and joint ventures 1) Associates Details of associates as of December 31, 2018 and 2019 are as follows: Ownership (%) Investee Category of business 2018 2019 Region [Domestic] New Songdo International City Development, LLC Real estate rental 29.90 29.90 Seoul Gale International Korea, LLC Real estate rental 29.90 29.90 Seoul SNNC Raw material manufacturing and sales 49.00 49.00 Gwangyang KONES, Corp. Technical service 41.67 41.67 Gyeongju CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd Real estate development 29.53 29.53 Chungju DAEHO GLOBAL MANAGEMENT CO., LTD. Investment advisory service 35.82 35.82 Pohang Mokpo Deayang Industrial Corporation Real estate development and rental 27.40 27.40 Mokpo Gunggi Green Energy(1) Electricity generation 19.00 19.00 Hwaseong Pohang Special Welding Co.,Ltd. Welding material and tools manufacturing and sales 50.00 50.00 Pohang KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund(1) Investment in new technologies 12.50 12.50 Seoul EQP POSCO Global NO1 Natural Resources Private Equity Fund Investment in new technologies 31.27 33.41 Seoul KC Chemicals CORP.(1) Machinery manufacturing 19.00 19.00 Hwaseong Garolim Tidal Power Plant Co.,Ltd Tidal power plant construction and management 32.13 32.13 Seosan POSTECH Social Enterprise Fund(1) Investment in new technologies 9.17 9.17 Seoul QSONE Co.,Ltd. Real estate rental and facility management 50.00 50.00 Seoul Chun-cheon Energy Co., Ltd Electricity generation 45.67 49.10 Chuncheon Keystone NO. 1 Private Equity Fund(6) Private equity financial 40.45 52.58 Seoul Noeul Green Energy(1) Electricity generation 10.00 10.00 Seoul Posco-IDV Investment in new technologies 17.86 17.86 Seoul Daesung Steel(1) Steel sales 17.54 17.54 Busan Pohang E&E Co., LTD Investment in waste energy 30.00 30.00 Pohang POSCO Energy Valley Fund Investment in new technologies 20.00 20.00 Pohang Hyundai Invest Guggenheim CLO Qualified Private Special Asset Trust No.2 Investment in new technologies 38.47 35.44 Seoul PoscoPlutus Bio Fund(1) Investment in new technologies 11.97 11.97 Seoul PoscoPlutus Project Fund(1) Investment in new technologies 11.91 11.91 Seoul Posco Agri-Food Export Fund Investment in new technologies 30.00 30.00 Seoul PoscoPlutus Project 2nd Project Fund(1) Investment in new technologies 0.61 0.61 Seoul Posco Culture Contents Fund Investment in new technologies 31.67 31.67 Seoul PCC_Centroid 1st Fund Investment in new technologies 24.10 24.10 Seoul PCC Amberstone Private Equity Fund 1(1) Investment in new technologies 8.80 8.80 Seoul UITrans LRT Co., Ltd. Transporting 38.19 38.19 Seoul POSCO Advanced Technical Staff Fund(1) Investment in new technologies 15.87 15.87 Seoul POSCO 4th Industrial Revolution Fund(1) Investment in new technologies 19.05 19.05 Seoul Incheon-Gimpo Expressway Co., Ltd.(1) Construction 18.26 18.26 Anyang Pureun Tongyeong Enviro Co., Ltd. Sewerage treatment 20.40 20.40 Tongyeong Pure Gimpo Co., Ltd. Construction 28.79 28.79 Seoul POSCO PLANTEC Co., Ltd.(2,6) Construction of industrial plant 73.94 73.94 Ulsan Posgreen Co., Ltd.(1) Lime and plaster manufacturing 19.00 19.00 Gwangyang Clean Iksan Co., Ltd. Construction 23.50 23.50 Iksan Innovalley Co., Ltd. Real estate development 28.77 28.77 Yongin Pohang Techno Valley PFV Corporation(6) Real estate development, supply and rental 57.39 57.39 Pohang BLUE OCEAN Private Equity Fund Private equity financial 27.52 27.52 Seoul Western Inland highway CO.,LTD. Construction 27.50 30.00 Incheon Metropolitan Outer Ring Expressway co., ltd. Investment in Expressway 47.58 21.27 Incheon IT ENGINEERING CO., LTD.(1) Vehicle engineering 10.84 4.99 Seoul PCC Bio 1ST Fund(1) Investment in new technologies 13.46 13.46 Seoul INNOPOLIS Job Creation Fund II(1) Investment in new technologies 6.43 6.21 Seoul POSPower Co., Ltd. Generation of electricity 34.00 34.00 Samcheok INKOTECH, INC.(1) Electricity generation and sales 10.00 10.00 Seoul PCC Social Enterprise Fund II(1) Investment in venture companies 16.67 16.67 Seoul PCC Amberstone Private Equity Fund II(1) Private equity trust 19.70 19.91 Seoul Synapse Fund(1) Investment in new technologies 16.26 16.26 Seoul NEXTRAIN Co.,Ltd Service maintenance and management 32.00 32.00 Incheon TK CHEMICAL CORPORATION(1) Chemical 8.80 5.01 Daegu Hanil-Daewoo Cement Co., Ltd.(1) Cement 15.00 15.00 Incheon PCC S/W 2nd Fund(1,3) Investment in new technologies business — 12.81 Pohang PCC-Conar Investment in venture — 13.64 Pohang Hyochun Co., Ltd(1,3) Screen door operation and other — 18.00 Seoul RPSD Project Co., Ltd(3) Real estate development — 29.00 Incheon PCC EV Fund(1,3) Investment in new technologies business — 18.18 Pohang IBKC-PCC Investment in new technologies business — 18.18 Pohang 2019 PCC Materials and Parts Fund(1,3) Investment in new technologies business — 8.70 Pohang Shinahn wind Power generation(1,3) Electric, gas, steam — 19.00 Suwon 2019 PCC New technology Fund(1,3) Investment in new technologies business — 4.76 Pohang PCC-Woori Investment in new technologies business — 18.85 Pohang 2016 Posco Plutus New technology Fund(4) New technology business investment 25.17 — Seoul Clean Gimpo Co., Ltd(5) Waste treatment and others 29.58 — Gimpo Postech Early Stage Fund(4) investment in New technology 10.00 — Pohang Appliedscience Co., Ltd(4) Machine manufacturing for semiconductor manufacturing 22.89 — Paju [Foreign] VSC POSCO Steel Corporation Steel processing and sales 50.00 50.00 Vietnam JB CLARK HILLS(7) Apartment Construction 25.00 70.00 Philippines POSCHROME (PROPRIETARY) LIMITED Raw material manufacturing and sales 50.00 50.00 South Africa CAML RESOURCES PTY LTD Raw material manufacturing and sales 33.34 33.34 Australia Nickel Mining Company SAS Raw material manufacturing and sales 49.00 49.00 New Caledonia PT. Wampu Electric Power Construction and civil engineering 20.00 20.00 Indonesia POSK(Pinghu) Steel Processing Center Co., Ltd. Steel processing and sales 20.00 20.00 China PT.INDONESIA POS CHEMTECH CHOSUN Ref Refractory manufacturing and sales 30.19 30.19 Indonesia NS-Thainox Steel manufacturing and sales 49.00 49.00 Vietnam Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd Tinplate manufacturing and sales 34.00 34.00 China PT. Tanggamus Electric Power(1) Construction and civil engineering 17.50 17.50 Indonesia LLP POSUK Titanium Titanium manufacturing and sales 36.83 35.30 Kazakhstan LI3 ENERGY INC Resource development 26.06 26.06 Peru IMFA ALLOYS FINLEASE LTD Raw material manufacturing and sales 24.00 24.00 India KRAKATAU POS-CHEM DONG-SUH Chemical by-product 19.00 19.00 Indonesia 7623704 Canada Inc.(1) Investments management 10.40 10.40 Canada Hamparan Mulya Resource development 45.00 45.00 Indonesia POS-SEAHSTEELWIRE(TIANJIN)CO.,Ltd. Steel manufacturing and sales 25.00 25.00 China Eureka Moly LLC Raw material manufacturing and sales 20.00 20.00 USA PT. Batutua Tembaga Raya Raw material manufacturing and sales 22.00 22.00 Indonesia KIRIN VIETNAM CO., LTD(1) Panel manufacturing 19.00 19.00 Vietnam POSCO SeAH Steel Wire(Nantong) Co., Ltd. Steel processing and sales 25.00 25.00 China POS-SeAH Steel manufacturing and sales 25.00 25.00 Thailand Jupiter Mines Limited(1) Resource development 6.93 6.93 Australia SAMHWAN VINA CO., LTD(1) Steel manufacturing and sales 19.00 19.00 Vietnam Saudi-Korean Company for Maintenance Properties Management LLC(1) Building management 19.00 19.00 Saudi NCR LLC Coal sales 29.41 29.40 Canada AMCI (WA) PTY LTD Iron ore sales & mine development 49.00 49.00 Australia SHANGHAI LANSHENG DAEWOO CORP. Trading 49.00 49.00 China SHANGHAI WAIGAOQIAO FREE TRADE ZONE LANSHENG DAEWOO IN’L TRADING CO., LTD. Trading 49.00 49.00 China General Medicines Company Ltd. Medicine manufacturing and sales 33.00 33.00 Sudan KOREA LNG LTD. Gas production and sales 20.00 20.00 England AES-VCM Electricity generation 30.00 30.00 Vietnam KG Power(M) SDN. BHD Resource development 20.00 20.00 Malaysia South-East Asia Gas Pipeline Company Ltd. Pipeline construction and management 25.04 25.04 Myanmar GLOBAL KOMSCO Daewoo LLC Cotton celluloid manufacturing and sales 35.00 35.00 Uzbekistan POSCO-Poggenamp Electrical Steel Pvt. Ltd. Steel processing and sales 26.00 26.00 India Qingdao Pohang DGENX Stainless SteelPipeCo., Ltd Exhaust meter manufacturing 40.00 40.00 China SHINPOONG DAEWOO PHARMA VIETNAM CO.,LTD(1) Medicine production 3.42 3.42 Vietnam ZHEJIANG HUAYOU-POSCO ESM(3) Produce — 40.00 China Sebang Steel(4) Scrap sale 49.00 — Japan ERAE Automotive Systems Mexico, S. DE R.L. DE C.V(4) Automobile parts manufacturing 7.65 — Mexico (*1) Considering the composition of board of directors, the Company is able to exercis

Statement of Compliance

Statement of Compliance	12 Months Ended
Statement of Compliance	Dec. 31, 2019
Text block [abstract]
Statement of Compliance	2. Statement of Compliance The consolidated financial statements have been prepared in accordance with International Financial Reporting Standards (“IFRS”), as issued by the International Accounting Standards Board. The consolidated financial statements were authorized for issue by the authorized directors on March 20, 2020. In 2019, the Company adopted IFRS No.16 “Leases” for the first time. Changes to significant accounting policies are described in Note 2 “Changes in Accounting Policies”. Basis of measurement The consolidated financial statements have been prepared on the historical cost basis, except for the following material items in the statement of financial position, as described in the accounting policy below. (a) Derivatives instruments measured at fair value (b) Financial instruments measured at fair value through profit or loss (c) Financial instruments measured at fair value through other comprehensive income (d) Defined benefit liabilities measured at the present value of the defined benefit obligation less the fair value of the plan assets Functional and presentation currency The financial statements of POSCO and subsidiaries are prepared in functional currency of each operation. These consolidated financial statements are presented in Korean Won, the POSCO’s functional currency, which is the currency of the primary economic environment in which POSCO operates. Use of estimates and judgments The preparation of the consolidated financial statements in conformity with IFRS requires management to make judgments, estimates and assumptions that affect the application of accounting policies and the reported amounts of assets, liabilities, income and expenses. Actual results may differ from these estimates. Estimates and underlying assumptions are reviewed on an ongoing basis. Revisions to accounting estimates are recognized prospectively. (a) Judgments Information about critical judgments in applying accounting policies that have the most significant effect on the amounts recognized in the consolidated financial statements is included in the following notes: • Note 1 - Subsidiaries, associates and joint ventures • Note 2 - Changes in accounting policies (leases) • Note 3 - Summary of significant accounting policies (leases) • Note 11 - Investments in associates and joint ventures • Note 12 - Joint operations • Note 25 - Hybrid bonds (b) Assumptions and estimation uncertainties Information about assumptions and estimation uncertainties that have a significant risk of resulting in a material adjustment within the next fiscal year is included in the following notes: • Note 9 - Inventory • Note 11 - Investments in associates and joint ventures • Note 14 - Property, plant and equipment, net • Note 15 - Goodwill and other intangible assets, net • Note 20 - Provisions • Note 21 - Employee benefits • Note 23 – Financial instruments • Note 29 – Revenue – contract balances • Note 35 - Income taxes • Note 38 - Commitments and contingencies (c) Measurement of fair value The Company’s accounting policies and disclosures require the measurement of fair values, for both financial and non-financial The valuation team regularly reviews significant unobservable inputs and valuation adjustments. If third party information, such as broker quotes or pricing services, is used to measure fair values, then the valuation team assesses the evidence obtained from the third parties to support the conclusion that such valuations meet the requirements of IFRS including the level in the fair value hierarchy in which such valuation techniques should be classified. Significant valuation issues are reported to the Company’s Audit Committee. When measuring the fair value of an asset or a liability, the Company uses market observable data as far as possible. Fair values are categorized into different levels in a fair value hierarchy based on the inputs used in the valuation techniques as follows. • Level 1 - unadjusted quoted prices in active markets for identical assets or liabilities. • Level 2 - inputs other than quoted prices included in Level 1 that are observable for the assets or liability, either directly or indirectly. • Level 3 - inputs for the assets or liability that are not based on observable market data. If the inputs used to measure the fair value of an asset or a liability might be categorized in different levels of the fair value hierarchy, then the fair value measurement is categorized in its entirety in the same level of the fair value hierarchy as the lowest level input that is significant to the entire measurement. The Company recognizes transfers between levels of the fair value hierarchy at the end of the reporting period during which the change has occurred. Information about the assumptions made in measuring fair values is included in the following note: • Note 23 - Financial instruments Changes in Accounting Policies The Company has initially adopted IFRS No.16 “Leases” from January 1, 2019. The other accounting standards adopted from January 1, 2019 had no significant effect on the Company’s consolidated financial statements. IFRS No.16 “Leases” introduced a single accounting model for lessees. As a result, the Company, as a lessee, recognized right-of-use The Company applied IFRS No.16 “Leases” using the modified retrospective approach by recognizing the cumulative effect of initial application as of January 1, 2019, the date of initial application. Accordingly, the comparative information presented for 2017 and 2018, has not been restated. (a) Definition of a lease Previously, the Company determined at contract inception whether an arrangement was or contained a lease under IFRIC No.4 “Determining Whether an Arrangement Contains a Lease”. The Company now assesses whether a contract is or contains a lease based on the new definition of a lease. Under IFRS No.16 “Leases”, a contract is, or contains, a lease if the contract conveys a right to control the use of an identified asset for a period of time in exchange for consideration. On transition to IFRS No.16 “Leases”, the Company elected to apply the practical expedient to grandfather the assessment of which transactions are leases. The Company applied IFRS No.16 only to contracts that were previously identified as leases. Contracts that were not identified as leases under IAS No.17 “Leases” and IFRIC No.4 “Determining Whether an Arrangement Contains a Lease” were not reassessed. Therefore, the definition of a lease under IFRS No.16 has been applied only to contracts entered into or changed on or after January 1, 2019. At inception or reassessment of a contract that contains a lease component, the Company allocates the consideration in the contract to each lease and non-lease (b) As a lessee The Company leases many assets, including land, warehouses, handling equipment and IT equipment. As a lessee, the Company previously classified leases as operating or finance leases based on its assessment of whether the lease transferred substantially all of the risks and rewards of ownership. Under IFRS No.16 “Leases”, the Company recognizes right-of-use However, the Company has elected not to recognize right-of-use low-value The Company measured lease liabilities and right-of-use right-of-use The Company used a number of practical expedients when applying IFRS No.16, to leases previously classified as operating leases under IAS No.17. In particular, the Company: • did not recognize right-of-use • excluded initial direct costs from the measurement of the right-of-use • used hindsight when determining the lease term For finance leases under IAS No.17, the carrying amounts of the right-of-use (c) As a lessor The Company leases out its investment properties. The Company classified these leases as operating leases, and the accounting policies applicable to the Company as a lessor are not different from those under IAS No.17 “Leases”. However, when the Company is an intermediate lessor the sub-leases right-of-use The Company provides sub-leases sub-leases ￦ In addition, the Company did not make any adjustments to leases for which the Company is a lessor, except for sub-leases (d) Impact on financial statements The Company recognized right-of-use (in millions of Won) The date of initial (January 1, 2019) Consolidated statement of financial position Right-of-use ￦ 704,458 Lease receivable 264,809 Lease liabilities 677,370 (*1) The prepaid lease payments of ￦ When measuring lease liabilities for leases previously classified as operating leases, the Company discounted lease payments using its incremental borrowing rates as of January 1, 2019, the date of initial application, and the weighted-average rates applied are 1.8 ~ 18.5%. The carrying amount of lease liabilities as of January 1, 2019, the date of initial application, is as follow: (in millions of Won) The date of initial (January 1, 2019) Operating lease commitments as of December 31, 2018 ￦ 913,630 Operating lease commitments not recognized as lease liabilities - Leases of low-value (50,364 ) - Leases with less than 12 months of lease term at transition (17,635 ) Operating lease commitments recognized as lease liabilities 845,631 Amount discounted using the incremental borrowing rate as of January 1, 2019, the date of initial application 677,370 Finance lease liabilities recognized as of December 31, 2018 94,754 Lease liabilities as of January 1, 2019, the date of initial application ￦ 772,124

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2019
Text block [abstract]
Summary of Significant Accounting Policies	3. Summary of Significant Accounting Policies The significant accounting policies applied by the Company in the preparation of its consolidated financial statements are included below. The accounting policies set out below have been applied consistently to all periods presented in these consolidated financial statements, except for the changes in accounting policies disclosed in Note 2. Basis of consolidation (a) Business combinations The Company accounts for business combinations using the acquisition method when control is transferred to the Company. The consideration transferred in the acquisition is generally measured at fair value, as are the identifiable net assets acquired. Any goodwill that arises is tested annually for impairment. Any gain on bargain purchase is recognized in profit or loss immediately. Transaction costs are expensed as incurred, except if related to the issue of debt or equity securities. The consideration transferred does not include amounts related to the settlement of pre-existing Any contingent consideration payable is measured at fair value at the acquisition date. If the contingent consideration is classified as equity, then it is not remeasured and settlement is accounted for within equity. Otherwise, subsequent changes in the fair value of the contingent consideration are recognized in profit or loss. If share-based payment awards (replacement awards) are required to be exchanged for awards held by the acquiree’s employees (acquiree’s awards), then all or a portion of the amount of the acquirer’s replacement awards is included in measuring the consideration transferred in the business combination. This determination is based on the market-based measure of the replacement awards compared with the market-based measure of the acquiree’s awards and the extent to which the replacement awards relate to pre-combination (b) Non-controlling Non-controlling (c) Subsidiaries Subsidiaries are entities controlled by the Company. The Company controls an entity when it is exposed to, or has rights to, variable returns from its involvement with the entity and has the ability to affect those returns through its power over the entity. The financial statements of subsidiaries are included in the consolidated financial statements from the date on which control commences until the date on which control ceases. (d) Loss of control When the Company loses control over a subsidiary, it derecognizes the assets and liabilities of the subsidiary, and any related non-controlling (e) Interests in equity-accounted investees The Company’s interests in equity-accounted investees comprise interests in associates and joint ventures. Associates are those entities in which the Company has significant influence, but not control or joint control, over the financial and operating policies. A joint venture is an arrangement in which the Company has joint control, whereby the Company has rights to the net assets of the arrangement, rather than rights to its assets and obligations for its liabilities. Interests in associates and joint ventures are accounted for using the equity method. They are recognized initially at cost, which includes transaction costs. Subsequent to initial recognition, the consolidated financial statements include the Company’s share of the profit or loss and other comprehensive income of equity-accounted investees, until the date on which significant influence or joint control ceases. (f) Transactions eliminated on consolidation Intra-group balances and transactions, and any unrealized income and expenses arising from intra-group transactions, are eliminated. Unrealized gains arising from transactions with equity-accounted investees are eliminated against the investment to the extent of the Company’s interest in the investee. Unrealized losses are eliminated in the same way as unrealized gains, but only to the extent that there is no evidence of impairment. Foreign currency transactions and translation (a) Foreign currency transactions Foreign currency transactions are initially recorded using the spot exchange rate between the functional currency and the foreign currency at the date of the transaction. At the end of each reporting period, foreign currency monetary items are translated using the closing rate. Non-monetary Exchange differences arising on the settlement of monetary items or on translating monetary items at rates different from those at which they were translated on initial recognition during the period or in previous period end are recognized in profit or loss in the period in which they arise. When gains or losses on non-monetary non-monetary (b) Foreign operations If the presentation currency of the Company is different from a foreign operation’s functional currency, the financial statements of the foreign operation are translated into the presentation currency using the following methods: The assets and liabilities of foreign operations, whose functional currency is not the currency of a hyperinflationary economy, are translated to presentation currency using exchange rates at the reporting date. The income and expenses of foreign operations are translated to functional currency at exchange rates at the dates of the transactions. Foreign currency differences are recognized in other comprehensive income. Any goodwill arising on the acquisition of a foreign operation and any fair value adjustments to the carrying amounts of assets and liabilities arising on the acquisition of that foreign operation are treated as assets and liabilities of the foreign operation. Thus, they are expressed in the functional currency of the foreign operation and translated to the presentation currency at the closing rate. When a foreign operation is disposed of, the relevant amount in the translation recognized in other comprehensive income is transferred to profit or loss as part of the profit or loss on disposal. On the partial disposal of a subsidiary that includes a foreign operation, the relevant proportion of such cumulative amount is reattributed to non-controlling Cash and cash equivalents Cash and cash equivalents comprise cash on hand, demand deposits, and short-term investments in highly liquid securities that are readily convertible to known amounts of cash with maturities of three months or less from the acquisition date and which are subject to an insignificant risk of changes in value. Equity investments are excluded from cash and cash equivalents. Non-derivative Trade receivables and debt securities issued are initially recognized when they are originated. All other financial assets are initially recognized when the Company becomes a party to the contractual provisions of the instruments. A financial asset (unless it is a trade receivable without a significant financing component) is initially measured at fair value plus, for an item not at financial assets measured at fair value through profit or loss, transaction costs that are directly attributable to its acquisition or issue. A trade receivable without a significant financing component is initially measured at the transaction price. On initial recognition, a financial asset is classified as measured at amortized cost, debt instruments measured at fair value through other comprehensive income, equity instruments measured at fair value through other comprehensive income or financial assets measured at fair value through profit or loss. Financial assets are not reclassified subsequent to their initial recognition unless the Company changes its business model for managing financial assets, in which case all affected financial assets are reclassified on the first day of the reporting period following the change in the business model. (a) Financial assets measured at amortized cost A financial asset is measured at amortized cost if it meets both of the following conditions and is not designated as at fair value through profit or loss. • it is held within a business model whose objective is to hold assets to collect contractual cash flows, and • its contractual terms give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. Financial assets measured at amortized cost are subsequently measured at amortized cost using the effective interest method. The amortized cost is reduced by impairment losses. Interest income, gains and losses on foreign currency translation and impairment losses are recognized in profit or loss. Any gain or loss on derecognition is recognized in profit or loss. (b) Debt instruments measured at fair value through other comprehensive income A debt instrument is measured at fair value through other comprehensive income if it meets both of the following conditions and is not designated as at fair value through profit or loss. • it is held within a business model whose objective is achieved by both collection contractual cash flows and selling financial assets, and • its contractual terms give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. Debt instruments measured at fair value through other comprehensive income are subsequently measured at fair value. Interest income which is calculated using the effective interest method, gains and losses from foreign currency translation and impairment losses are recognized in profit or loss and other net profit or loss is recognized in other comprehensive income. At the time of elimination, other accumulated comprehensive income is reclassified to profit or loss. (c) Equity instruments measured at fair value through other comprehensive income On initial recognition of an equity investment that is not held for trading, the Company may irrevocably elect to present subsequent changes in the investment’s fair value in other comprehensive income. This election is made on an investment-by-investment Equity instruments measured at fair value through other comprehensive income are subsequently measured at fair value. Dividends are recognized as income in profit or loss unless the dividend clearly represents a recovery of part of the cost of the investment. Other net gains and losses are recognized in other comprehensive income and never reclassified to profit or loss. (d) Financial assets measured at fair value through profit or loss All financial assets not classified as measured at amortized cost or fair value through other comprehensive income as described above are measured at fair value through profit or loss. This includes all derivative financial assets. On initial recognition, the Company may irrevocably designate a financial asset that otherwise meets the requirements to be measured at amortized cost or fair value through other comprehensive income as at fair value through profit or loss if doing so eliminates or significantly reduces an accounting mismatch that would otherwise arise. Financial assets measured at fair value through profit or loss are subsequently measured at fair value. Net gains and losses, including any interest or dividend income, are recognized in profit or loss. (e) Offsetting a financial asset and a financial liability Financial assets and financial liabilities are offset and the net amount is presented in the consolidated statement of financial position only when the Company currently has a legally enforceable right to offset the recognized amounts, and there is the intention to settle on a net basis or to realize the asset and settle the liability simultaneously. Inventories Inventory costs, except materials-in-transit Inventories are measured at the lower of cost or net realizable value. The amount of any write-down of inventories to net realizable value and all losses of inventories are recognized as an expense in the period the write-down or loss occurs. The amount of any reversal of any write-down of inventories arising from an increase in net realizable value is recognized as a reduction in the amount of inventories recognized as cost of goods sold in the period in which the reversal occurs. The carrying amount of those inventories sold is recognized as cost of goods sold in the period in which the related revenue is recognized. Non-current Non-current non-current The Company recognizes an impairment loss for any initial or subsequent write-down of an asset or disposal group to fair value less costs to sell, and a gain for any subsequent increase in fair value less costs to sell, up to the cumulative impairment loss previously recognized. A non-current Investment property Property held to earn rentals or for capital appreciation or both is classified as investment property. Investment property is measured initially at its cost. Transaction costs are included in the initial measurement. Subsequently, investment property is carried at depreciated cost less any accumulated impairment losses. Subsequent costs are recognized in the carrying amount of investment property at cost or, if appropriate, as separate items if it is probable that future economic benefits associated with the item will flow to the Company and the cost of the item can be measured reliably. The carrying amount of the replaced part is derecognized. The costs of the day-to-day Depreciation methods, useful lives and residual values are reviewed at the end of each reporting date and adjusted, if appropriate. The change is accounted for as a change in an accounting estimate. Property, plant and equipment Property, plant and equipment are initially measured at cost and after initial recognition, are carried at cost less accumulated depreciation and any accumulated impairment losses. The cost of property, plant and equipment includes expenditures arising directly from the construction or acquisition of the asset, any costs directly attributable to bringing the asset to the location and condition necessary for it to be capable of operating in the manner intended by management and, when the Company has an obligation to remove the asset or restore the site, an estimate of the costs of dismantling and removing the item and restoring the site on which it is located. The cost of replacing a part of an item is recognized in the carrying amount of the item of property, plant and equipment, if the following recognition criteria are met: (a) it is probable that future economic benefits associated with the item will flow to the Company, and (b) the cost can be measured reliably. The carrying amount of the replaced part is derecognized at the time the replacement part is recognized. The costs of the day-to-day Items of property, plant and equipment are depreciated from the date they are available for use or, in respect of self-constructed assets, from the date that the asset is completed and ready for use. Other than land, the costs of an asset less its estimated residual value are depreciated. Depreciation of property, plant and equipment is recognized in profit or loss on a straight-line basis, which most closely reflects the expected pattern of consumption of the future economic benefits embodied in the asset, over the estimated useful lives of each component of an item of property, plant and equipment. Land is not depreciated. Each part of an item of property, plant and equipment with a cost that is significant in relation to the total cost of the item is depreciated separately. The gain or loss arising from the derecognition of an item of property, plant and equipment is included in profit or loss when the item is derecognized. The estimated useful lives for the current and comparative periods are as follows: Buildings 5-50 years Structures 4-50 Machinery and equipment 4-25 Vehicles 3-20 Tools 3-10 Furniture and fixtures 3-20 Lease assets 2-30 Bearer plants 20 years The estimated residual value, useful lives and the depreciation method are reviewed at least at the end of each reporting period and, if expectations differ from previous estimates, the changes are accounted for as changes in accounting estimates. Borrowing costs The Company capitalizes borrowing costs directly attributable to the acquisition, construction or production of a qualifying asset as part of the cost of that asset. Other borrowing costs are recognized in expense as incurred. A qualifying asset is an asset that requires a substantial period of time to get ready for its intended use or sale. Financial assets and inventories that are manufactured or otherwise produced over a short period of time are not qualifying assets. Assets that are ready for their intended use or sale when acquired are not qualifying assets. To the extent that the Company borrows funds specifically for the purpose of obtaining a qualifying asset, the Company determines the amount of borrowing costs eligible for capitalization as the actual borrowing costs incurred on that borrowing during the period less any investment income on the temporary investment of those borrowings. The Company immediately recognizes other borrowing costs as an expense. To the extent that the Company borrows funds generally and uses them for the purpose of obtaining a qualifying asset, the Company determines the amount of borrowing costs eligible for capitalization by applying a capitalization rate to the expenditures on that asset. The capitalization rate is the weighted average of the borrowing costs applicable to the borrowings of the Company that are outstanding during the period, other than borrowings made specifically for the purpose of obtaining a qualifying asset. The amount of borrowing costs that the Company capitalizes during a period does not exceed the amount of borrowing costs incurred during that period. Intangible assets Intangible assets are measured initially at cost and, subsequently, are carried at cost less accumulated amortization and accumulated impairment losses. Amortization of intangible assets except for goodwill is calculated on a straight-line basis over the estimated useful lives of intangible assets from the date that they are available for use. The residual value of intangible assets is zero. However, as there are no foreseeable limits to the periods over which club memberships are expected to be available for use, this intangible asset is determined as having an indefinite useful life and not amortized. Intellectual property rights 4-25 years Development expense 3-5 Port facilities usage rights 4-75 Other intangible assets 2-15 years Amortization periods and the amortization methods for intangible assets with finite useful lives are reviewed at the end of each reporting period. The useful lives of intangible assets that are not being amortized are reviewed at the end of each reporting period to determine whether events and circumstances continue to support indefinite useful life assessments for those assets. Changes are accounted for as changes in accounting estimates. Expenditures on research activities, undertaken with the prospect of gaining new scientific or technical knowledge and understanding, are recognized in profit or loss as incurred. Development expenditures are capitalized only if development costs can be measured reliably, the product or process is technically and commercially feasible, future economic benefits are probable, and the Company intends to and has sufficient resources to complete development and to use or sell the asset. Other development expenditures are recognized in profit or loss as incurred. Subsequent expenditures are capitalized only when they increase the future economic benefits embodied in the specific asset to which they relate. All other expenditures, including expenditures on internally generated goodwill and brands, are recognized in profit or loss as incurred. Exploration for and evaluation of mineral resources POSCO is engaged in exploration projects for mineral resources through subsidiaries, associates and joint ventures or other contractual arrangements. Expenditures related to the development of mineral resources are recognized as exploration or development intangible assets. The nature of these intangible assets are as follows: (a) Exploration and evaluation assets Exploration and evaluation assets consist of expenditures for topographical studies, geophysical studies and trenching. These assets are reclassified as development assets when it is proved that the exploration has identified commercially viable mineral deposit. (b) Development assets When proved reserves are determined and development is sanctioned, development expenditures incurred are capitalized. These expenditures include evaluation of oil fields, construction of oil/gas wells, drilling for viability and others. On completion of development and inception of extraction for commercial production of developed proved reserves, the development assets are reclassified as either property, plant and equipment or as intellectual property rights (mining rights) under intangible assets based on the nature of the capitalized expenditures. The respective property, plant and equipment and intellectual property (mining rights) are each depreciated and amortized based on proved reserves on a unit of production basis. Government grants Government grants are not recognized unless there is reasonable assurance that the Company will comply with the grant’s conditions and that the grant will be received. (a) Grants related to assets Government grants whose primary condition is that the Company purchase, construct or otherwise acquire long-term assets are deducted from the carrying amount of the assets and recognized in profit or loss on a systematic and rational basis over the life of the depreciable assets. (b) Grants related to income Government grants which are intended to compensate the Company for expenses incurred are deducted from the related expenses. Leases The Company applied IFRS No.16 “Leases” using the modified retrospective approach by recognizing the cumulative effect of initial application as of January 1, 2019, the date of initial application. Therefore, the comparative information has not been restated and continues to be reported under IAS No.17 “Lease” and IFRIC No.4 “Determining Whether an Arrangement Contains a Lease”. 1) As a lessee: policy applicable from January 1, 2019 The Company recognizes a right-of-use right-of-use The right-of-use right-of-use right-of-use right-of-use The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted using the interest rate implicit in the lease or, if that rate cannot be readily determined the Company’s incremental borrowing rate. Generally, the Company uses its incremental borrowing rate as the discount rate. In determining the lease term and assessing the length of the non-cancellable period of a lease, The Company determines the period for which the contract is enforceable. When the Company determining the enforceable period of the lease period, it considers (a) if either party has an economic incentive not to terminate the lease such that it would incur a penalty on termination that is more than insignificant, the contract is enforceable beyond the date on which the contract can be terminated; and (b) whether each of the parties has the right to terminate the lease without permission from the other party with no more than an insignificant penalty. In addition, a lease is no longer enforceable only when both parties have such a right. The Company determines its incremental borrowing rate by obtaining interest rates from various external sources and makes certain adjustments to reflect the terms of the lease and type of the asset leased. Lease payments included in the measurement of the lease liability comprise the followings: • fixed payments • variable lease payments that depend on an index or a rate • amounts expected to be payable under a residual value guarantee; and • the exercise price under a purchase option that the Company is reasonably certain to exercise, lease payments in an optional renewal period if the Company is reasonably certain to exercise an extension option, and penalties for early termination of a lease unless the Company is reasonably certain not to terminate early. The lease liability is measured at amortized cost using the effective interest method. When the lease liability is remeasured, a corresponding adjustment is made to the carrying amount of the right-of-use right-of-use • a revised in-substance • a change in future lease payments arising from a change in an index or rate, • a change in the Company’s estimate of the amount expected to be payable under a residual value guarantee, or • a change in the Company’s assessment of whether it will exercise a purchase, extension or termination option The Company presents right-of-use The Company has elected not to recognize right-of-use low-value 2) As a lessee: policy applicable before January 1, 2019 The Company classifies and accounts for leases as either a finance or operating lease, depending on the terms. Leases where the Company assumes substantially all of the risks and rewards of ownership are classified as finance leases. All other leases are classified as operating leases. In the case of finance leases, the Company recognizes as finance assets and finance liabilities the lower amount of the fair value of the leased property and the present value of the minimum lease payments, each determined at the inception of the lease at the commencement of the lease term. Any initial direct costs are added to the amount recognized as an asset. The minimum lease payment is recognized by dividing the financial cost and the repayment amount of the lease liabilities. The financial cost is allocated to the remaining balance for each reporting period so that a fixed interest rate is calculated. Contingent rents are charged as expenses in the period in which they are incurred. The depreciable amount of a leased asset is allocated to each accounting period during the period of expected use on a systematic basis consistent with the depreciation policy the Company adopts for similar depreciable assets that are owned. If there is no reasonable certainty that the Company will obtain ownership by the end of the lease term, the asset is fully depreciated over the shorter of the lease term and its useful life. In the case of an operating lease, the Company recognizes the lease payment as an expense on a straight-line basis over the lease term. Contingent rents are charged as expenses in the periods in which they are incurred. 3) As a lessor When the Company acts as a lessor, it determines at lease inception whether each lease is a finance lease or an operating lease. To the Company classifies the lease that transfers substantially all of the risks and rewards incidental to ownership of the underlying asset as a finance lease, and all other leases as operating leases. As part of this assessment, the Company considers certain indicators such as whether the lease is for the major part of the economic life of the asset. The Company leases out its investment properties. The Company classified these leases as operating leases, and the accounting policies applicable to the Company as a lessor are not different from those under IAS No.17 “Leases”. However, when the Company is an intermediate lessor, the sub-leases right-of-use The Company provides sub-leases sub-leases ￦ sub-leases, Impairment for financial assets The Company recognizes loss allowances for expected credit losses on: • financial assets measured at amortized cost; • debt instruments measured at fair value through other comprehensive income; and • lease receivables, contractual assets, loan commitments, and financial guarantee contracts If credit risk has increased significantly since the initial recognition, a loss allowance for lifetime expected credit loss is measured at the end of every reporting period. If credit risk has not increased significantly since the initial recognition, a loss allowance is measured based on 12-month If the financial instrument has low credit risk at the end of the reporting period, the Company may assume that the credit risk has not increased significantly since initial recognition. However, a loss allowance for lifetime expected credit losses is measured for contract assets or trade receivables that do not contain a significant financing component. (a) Judgments on credit risk When determining whether the credit risk of a financial asset has increased significantly since initial recognition and when estimating expected credit losses, the Company considers reasonable and supportable information that is relevant and available without undue cost or effort. This includes both quantitative and qualitative information and analysis, based on the Company’s historical experience and informed credit assessment including forward-looking information. The Company assumes that the credit risk on a financial asset has increased significantly if it is more than 30 days past due. The Company considers a financial asset to be in default when the borrower is unlikely to pay its credit obligations to the Company in full, without recourse by the Company to actions such as realizing security (if any is held). The Company considers a debt security to have low credit risk when its credit risk rating is equivalent to the globally understood definition of investment grade. (b) Measurement of expected credit losses Lifetime expected credit losses are the expected credit losses that result from all possible default events over the expected life of a financial instrument. 12-month Expected credit losses are a probability-weighted estimate of credit losses. Credit losses are measured as the present value of all cash shortfalls such as the difference between the cash flows due to the entity in accordance with the contract and the cash flows that the Company expects to receive. Expected credit losses for financial assets measured at amortized cost are recognized in profit or loss. Loss allowances for financial assets measured at amortized cost are deducted from carrying amount of the assets. For debt instruments measured at fair value through other comprehensive income, the loss allowance is charged to profit or loss and is recognized in other comprehensive income. (c) Credit-impaired financial assets At each reporting date, the Company assesses whether financial assets measured at amortized cost and debt instrument measured at fair value through other comprehensive income are credit-impaired. A financial asset is ‘credit-impaired’ when one or more events that have a detrimental impact on the estimated future cash flows of the financial asset have occurred. Objective evidence that a financial asset or group of financial assets are impaired includes: • significant financial difficulty of the issuer or borrower • a breach of contract, such as a default or delinquency in interest or principal payments • the lender, for economic or legal reasons relating to the borrower’s financial difficulty, granting to the borrower a concession that the lender would not otherwise consider • becoming probable that the borrower will enter bankruptcy or other financial reorganization • the disappearance of an active market for that financial asset because of financial difficulties (d) Write-off The gross carrying amount of a financial asset is written off when the Company has no reasonable expectations of recovering a financial asset in entirety or a portion. The Company individually makes an assessment with respect to the timing and amount of write-off Impairment for non-financial The carrying amounts of the Company’s non-financial non-current Management estimates the recoverable amount of an individual asset. If it is impossible to measure the individual recoverable amount of an asset, then management estimates the recoverable amount of cash-generating unit (“CGU”). A CGU is the smallest identifiable group of assets that generates cash inflows that are largely independent of the cash inflows from other assets or groups of assets. The Company determined that individual operating entities are CGUs. The recoverable amount of an asset or CGU is the greater of its value-in-use value-in-use pre-tax An impairment loss is recognized if the carrying amount of an asset or a CGU exceeds its recoverable amount. Impairment losses are recognized in profit or loss. Goodwill acquired in a business combination is allocated to each CGU that is expected to benefit from the synergies arising from the goodwill acquired. Any impairment identified at the CGU level will first reduce the carrying amount of goodwill and th

Financial risk management

Financial risk management	12 Months Ended
Financial risk management	Dec. 31, 2019
Text block [abstract]
Financial risk management	4. Financial risk management The Company has exposure to the following risks in relation to its of financial instruments: • credit risk • liquidity risk • market risk • capital risk This note presents information about the Company’s exposure to each of the above risks, the Company’s objectives, policies and processes for measuring and managing risk, and the Company’s management of capital. Further quantitative disclosures are included throughout these consolidated financial statements. (a) Financial risk management 1) Risk management framework The Board of Directors has overall responsibility for the establishment and oversight of the Company’s risk management framework. The Company’s risk management policies are established to identify and analyze the risks faced by the Company, to set appropriate risk limits and controls, and to monitor risks and adherence to limits. Risk management policies and systems are reviewed regularly to reflect changes in market conditions and the Company’s activities. The Company, through its training and management standards and procedures, aims to develop a disciplined and constructive control environment in which all employees understand their roles and obligations. 2) Credit risk Credit risk is the risk of financial loss to the Company if a customer or counterparty to a financial instrument fails to meet its contractual obligations, and arises principally from the Company’s receivables from customers and debt securities. In addition, credit risk arises from finance guarantees which are provided by the Company. The Company implements a credit risk management policy under which the Company only transacts business with counterparties that have a certain level of credit rate evaluated based on financial condition, historical experience, and other factors. The Company’s exposure to credit risk is influenced mainly by the individual characteristics of each customer. The default risk of a nation or an industry in which a customer operates its business does not have a significant influence on credit risk. The Company has established a credit policy under which each new customer is analyzed individually for creditworthiness. The Company establishes an allowance for impairment that represents its estimate of expected losses in respect of trade and other receivables. The main components of this allowance are a specific loss component that relates to individually significant exposures, and a collective loss component based on group of financial assets with similar risk characteristics in respect of losses that have been incurred. Credit risk also arises from transactions with financial institutions, and such transactions include transactions of cash and cash equivalents, various deposits, and financial instruments including derivative contracts. The Company manages its exposure to this credit risk by only entering into transactions with banks that have high international credit ratings. The Company’s treasury department authorizes, manages, and overseas new transactions with financial institutions with whom the Company has no previous relationship. Furthermore, the Company limits its exposure to credit risk of financial guarantee contracts by strictly evaluating their necessity based on internal decision making processes, such as the approval of the board of directors. 3) Liquidity risk Liquidity risk is the risk that the Company will encounter difficulty in meeting the obligations associated with its financial liabilities that are settled by delivering cash or other financial asset. The Company’s approach to managing liquidity is to ensure, as far as possible, that it will always have sufficient liquidity to meet its liabilities when due, under both normal and stressed conditions, without incurring unacceptable losses or risking damage to the Company’s reputation. The Company’s cash flow from operations, borrowing or financing is sufficient to meet the cash requirements for the Company’s strategic investments. Management believes that the Company is capable of raising funds by borrowing or financing if the Company is not able to generate cash flow requirements from its operations. The Company has committed borrowing facilities with various banks. 4) Market risk Market risk means that the fair value or future cash flows of a financial instrument will fluctuate because of changes in market prices. The goal of market risk management is optimization of profit and controlling the exposure to market risk within acceptable limits. ① Currency risk The Company’s policy in respect of foreign currency risks is a natural hedge whereby foreign currency income is offset with foreign currency expenditures. The remaining net exposures after the natural hedge have been hedged using derivative contracts such as forward exchange contracts. In addition, the Company’s derivative transactions are limited to hedging actual foreign currency transactions and speculative transactions is not permitted. Based on this policy, the Company has manages currency risk considering characteristics of respective segments. The entities in the steel segment reduce the foreign currency exposure by repayment of foreign currency borrowings related to investment in overseas when they mature. The entities in the engineering and construction segment have hedged foreign currency risks by using forward exchange contracts. Entities in the trading segment have hedged foreign currency risks by using forward exchange contracts when the foreign currencies receivables and payables are different. ② Interest rate risk The Company manages the exposure to interest rate risk by adjusting borrowing structure between borrowings at fixed interest rates and variable interest rates. The Company monitors interest rate risks regularly in order to avoid exposure to interest rate risk on borrowings at variable interest rate. ③ Other market price risk Equity price risk arises from fluctuation of market price of listed equity securities. The Company’s management measures regularly the fair value of listed equity securities and the risk of variance in future cash flows caused by market price fluctuations. All buy and sell decisions related to significant investments are managed and approved by the Company’s management. (b) Management of capital The fundamental goal of capital management is the maximization of shareholders’ value by means of the stable dividend policy and retirement of treasury shares. The capital structure of the Company consists of equity and net borrowings (borrowings less cash and cash equivalents). The Company applied the same capital risk management strategy that was applied in the previous period. Net borrowing-to-equity (in millions of Won) 2018 2019 Total borrowings ￦ 20,209,270 20,441,613 Less: Cash and cash equivalents 2,643,865 3,514,872 Net borrowings 17,565,405 16,926,741 Total equity 46,759,551 47,794,707 Net borrowings-to-equity 37.57 % 35.42 %

Cash and Cash Equivalents

Cash and Cash Equivalents	12 Months Ended
Cash and Cash Equivalents	Dec. 31, 2019
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Cash and Cash Equivalents	5. Cash and Cash Equivalents Cash and cash equivalents as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Cash ￦ 1,668 2,081 Demand deposits and checking accounts 1,471,891 1,581,428 Time deposits 538,130 701,865 Other cash equivalents 632,176 1,229,498 ￦ 2,643,865 3,514,872 In connection with the jointly held accounts of joint operations and others, as of December 31, 2019, cash and cash equivalents amounting to ￦

Trade Accounts and Notes Receiv

Trade Accounts and Notes Receivable	12 Months Ended
Trade Accounts and Notes Receivable	Dec. 31, 2019
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Trade Accounts and Notes Receivable	6. Trade Accounts and Notes Receivable (a) Trade accounts and notes receivable as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Trade accounts and notes receivable ￦ 8,648,250 8,352,968 Finance lease receivables 57,487 221 Unbilled due from customers for contract work 810,655 1,128,116 Less: Allowance for doubtful accounts (386,188 ) (411,274 ) ￦ 9,130,204 9,070,031 Non-current Trade accounts and notes receivable ￦ 583,797 209,310 Finance lease receivables 45,873 43,725 Less: Allowance for doubtful accounts (202,545 ) (54,250 ) ￦ 427,125 198,785 Trade accounts and notes receivable sold to financial institutions, for which the derecognition conditions were not met, amounted to ￦￦ (b) Finance lease receivables are as follows: (in millions of Won) Customer Contents 2018 2019 Officers and employees Songdo apartment rental ￦ 103,360 43,445 ZHAOHUUI PROSPERITY INT’L LTD Office rental — 501 ￦ 103,360 43,946 (c) As of December 31, 2018 and 2019, the Company’s gross investment and net investment in the leases are as follows: (in millions of Won) 2018 2019 Less than 1 year ￦ 57,820 237 1 year - 3 years 49,678 46,161 Undiscounted lease payments 107,498 46,398 Unrealized interest income (4,138 ) (2,452 ) Present value of minimum lease payment ￦ 103,360 43,946

Other Receivables

Other Receivables	12 Months Ended
Other Receivables	Dec. 31, 2019
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Other Receivables	7. Other Receivables (1) The details of other receivables as of December 31, 2019 and 2018, are as follows: (in millions of Won) 2018 2019 Current Loans ￦ 236,782 367,580 Other accounts receivable 954,030 971,845 Accrued income 220,066 272,528 Deposits 108,640 86,519 Lease receivables — 48,744 Others 16,201 14,510 Less: Allowance for doubtful accounts (150,090 ) (180,209 ) ￦ 1,385,629 1,581,517 Non-current Loans ￦ 731,344 701,529 Other accounts receivable 155,936 209,039 Accrued income 1,855 65,275 Deposits 152,072 238,261 Lease receivables — 179,315 Less: Allowance for doubtful accounts (177,967 ) (252,540 ) ￦ 863,240 1,140,879 (2) The details of lease receivables are as follows: (in millions of Won) Customer Content of lease agreement 2019 HEUNG-A SHIPPING CO., LTD., MSC KOGAS, ONGC Videsh Limited, 6 Container Ships, 4 Tankers ￦ 212,933 GAIL(India) Limited,Myanma Oil and Gas Enterprise Helicopter, Ship, Office, Jetty 15,126 ￦ 228,059 (3) As of December 31, 2019, gross investment and net investment in the leases are as follows: (in millions of Won) total lease investment and lease net investment - Undiscounted contractual cash flows 2019 Less than 1 year ￦ 56,796 1 year - 3 years 107,955 3 year - 5 years 70,742 Over 5 years 16,089 Undiscounted lease payments 251,582 Unrealized interest income (23,523 ) Present value of minimum lease payment ￦ 228,059

Other Financial Assets

Other Financial Assets	12 Months Ended
Other Financial Assets	Dec. 31, 2019
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Other Financial Assets	8. Other Financial Assets Other financial assets as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Derivatives assets ￦ 47,288 47,541 Debt securities 2,987 342,371 Deposit instruments(1,2) 1,931,518 1,744,895 Short-term financial instruments(2) 6,099,303 6,861,242 ￦ 8,081,096 8,996,049 Non-current Derivatives assets ￦ 1,795 64,737 Equity securities(3) 1,238,630 1,204,902 Debt securities 34,327 22,380 Other securities(3) 338,106 343,183 Deposit instruments(2) 35,040 34,187 ￦ 1,647,898 1,669,389 (1) As of December 31, 2018 and 2019, ￦￦ (2) As of December 31, 2018 and 2019, financial instruments amounting to ￦￦ (3) As of December 31, 2018 and 2019, ￦￦

Inventories

Inventories	12 Months Ended
Inventories	Dec. 31, 2019
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Inventories	9. Inventories (a) Inventories as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Finished goods ￦ 1,886,040 1,655,228 Merchandise 1,131,416 1,058,874 Semi-finished goods 1,945,567 2,097,289 Raw materials 2,821,972 2,656,341 Fuel and materials 888,941 1,026,133 Construction inventories 1,372,259 1,045,088 Materials-in-transit 2,245,740 1,824,044 Others 68,150 83,905 12,360,085 11,446,902 Less: Allowance for inventories valuation (206,782 ) (216,143 ) ￦ 12,153,303 11,230,759 (b) The changes in allowance for inventories valuation for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Beginning ￦ 203,164 135,631 206,782 Loss on valuation of inventories 78,560 141,799 96,201 Realization on disposal of inventories (138,967 ) (69,426 ) (79,419 ) Others (7,126 ) (1,222 ) (7,421 ) Ending ￦ 135,631 206,782 216,143

Assets Held for Sale

Assets Held for Sale	12 Months Ended
Assets Held for Sale	Dec. 31, 2019
Text block [abstract]
Assets Held for Sale	10. Assets Held for Sale Details of assets held for sale as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Subsidiaries(2) Controlling Subsidiaries Total Assets Cash and cash equivalents(3) ￦ — — 374 374 Other financial assets 778 — 185 185 Property, plant and equipment 21,076 36,321 32,972 69,293 Others — — 4,306 4,306 ￦ 21,854 36,321 37,837 74,158 Liabilities Others ￦ — — 8 8 (1) During the year ended December 31, 2019, the Company decided to dispose individual assets for which use was suspended, such as CEM plants, and classified the assets as held for sale. During the year ended December 31, 2019, the Company recognized impairment loss of ￦ (2) During the year ended December 31, 2018, the subsidiary, DAESAN (CAMBODIA) Co., Ltd., decided to sell its land and classified the property, plant and equipment as held for sale. As of December 31, 2019 the sale is completed and gain on disposal of ￦ (*3) Cash and cash equivalents in the statement of cash flows include cash and cash equivalents that are classified as assets held for sale.

Investments in Associates and J

Investments in Associates and Joint ventures	12 Months Ended
Investments in Associates and Joint ventures	Dec. 31, 2019
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Investments in Associates and Joint ventures	11. Investments in Associates and Joint ventures (a) Investments in associates and joint ventures as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Investments in associates ￦ 1,738,692 1,864,509 Investments in joint ventures 1,911,311 2,063,246 ￦ 3,650,003 3,927,755 (b) Details of investments in associates as of December 31, 2018 and 2019 are as follows: (in millions of Won) Number of shares Ownership (%) Acquisition cost Book value Company 2018 2019 [Domestic] EQP POSCO Global NO1 Natual Resources Private Equity Fund 178,787,468,209 33.41 ￦ 178,787 ￦ 174,123 175,907 POSPower Co., Ltd(2) 4,507,138 34.00 179,410 161,477 161,280 SNNC 18,130,000 49.00 90,650 116,922 142,602 QSONE Co.,Ltd. 200,000 50.00 84,395 85,550 85,887 Chun-cheon Energy Co., Ltd(2) 17,308,143 49.10 86,541 62,478 56,679 Nextrain Co., Ltd. 8,321,920 32.00 41,610 10 41,447 Keystone NO. 1. Private Equity Fund(5) 22,523,123 52.58 22,523 11,183 19,438 CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd 2,008,000 29.53 10,040 17,382 17,824 Daesung Steel(4) 108,038 17.54 14,000 15,644 15,375 Incheon-Gimpo Expressway Co., Ltd.(2,4) 9,032,539 18.26 45,163 13,329 7,904 KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund(4) 6,485 12.50 6,485 5,739 6,177 KONES, Corp. 3,250,000 41.67 6,893 2,849 2,473 Others (53 companies)(2) 123,724 112,621 790,410 845,614 [Foreign] AES-VCM — 30.00 164,303 209,936 178,892 South-East Asia Gas Pipeline Company Ltd. 135,219,000 25.04 135,899 179,459 225,933 7623704 Canada Inc.(4) 114,452,000 10.40 124,341 126,885 131,529 Eureka Moly LLC — 20.00 240,123 82,447 85,349 AMCI (WA) PTY LTD 49 49.00 209,664 71,086 72,937 Nickel Mining Company SAS 3,234,698 49.00 157,585 41,712 37,940 KOREA LNG LTD. 2,400 20.00 135,205 43,554 46,557 NCR LLC — 29.40 49,744 37,602 46,391 ZHEJIANG HUAYOU-POSCO ESM CO., LTD(1) 134,400,000 40.00 22,423 — 22,356 PT. Batutua Tembaga Raya 128,285 22.00 21,824 20,479 14,717 PT. Wampu Electric Power(2) 8,708,400 20.00 10,054 14,120 13,363 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 10,200,000 34.00 9,517 14,796 15,128 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 50 25.00 4,723 6,478 6,755 Others (26 companies)(2) 99,728 121,048 948,282 1,018,895 ￦ 1,738,692 1,864,509 (1) During the year ended December 31, 2019, ZHEJIANG HUAYOU-POSCO ESM CO., LTD was established and classified as investment in an associate. (2) As of December 31, 2018 and 2019, investments in associates amounting to ￦￦ (3) As of December 31, 2018, shares of PSC Energy Global Co., Ltd., a subsidiary of the Company, are provided as collateral in relation to the associate’s borrowings. (4) As of December 31, 2019, it was classified as an associate even though the Company’s ownership percentage is less than 20% of ownership percentage since the Company has significant influence over the investee when considering its structure of the associate’s Board of Directors and others. (5) Although the Company’s shareholding exceeds 50%, the entity is classified as an associate because the Company does not have control when considering the structure of the Board of Directors. (c) Details of investments in joint ventures as of December 31, 2018 and 2019 are as follows: (in millions of Won) Number of shares Ownership (%) Acquisition cost Book value Company 2018 2019 [Domestic] POSCO MITSUBISHI CARBON TECHNOLOGY 11,568,000 60.00 ￦ 115,680 ￦ 180,192 182,648 Others (8 companies) 9,124 10,305 189,316 192,953 [Foreign] Roy Hill Holdings Pty Ltd(1) 13,117,972 12.50 1,528,672 1,041,600 1,235,682 POSCO-NPS 325,050,000 50.00 364,609 363,506 376,410 KOBRASCO 2,010,719,185 50.00 32,950 133,449 115,641 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. — 25.00 61,961 88,391 88,935 DMSA/AMSA(1) — 4.00 346,278 26,709 12,189 CSP - Compania Siderurgica do Pecem 1,221,586,532 20.00 594,173 24,832 — Others (12 companies) 43,508 41,436 1,721,995 1,870,293 ￦ 1,911,311 2,063,246 (1) As of December 31, 2018 and 2019, the investments in joint ventures are provided as collateral in relation to the joint ventures’ borrowings. (d) The changes in investments in associates and joint ventures for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Company December 31, Book value Acquisition Dividends Share profits Other (decrease)(1) December 31, Book value [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 175,553 — — (1,430 ) — 174,123 POSPower Co., Ltd — 176,731 — (3,198 ) (12,056 ) 161,477 SNNC 110,424 — — 6,624 (126 ) 116,922 QSONE Co.,Ltd. 85,049 — (550 ) 1,051 — 85,550 Chun-cheon Energy Co., Ltd 74,378 — — (11,900 ) — 62,478 CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd 17,252 — — 130 — 17,382 BLUE OCEAN Private Equity Fund 19,620 — — (17,930 ) (1,690 ) — Daesung Steel 15,500 — — 144 — 15,644 Incheon-Gimpo Expressway Co., Ltd. 31,660 — — (18,331 ) — 13,329 Keystone NO. 1. Private Equity Fund 12,379 — — (1,295 ) 99 11,183 UITrans LRT Co., Ltd. 15,841 — — (15,841 ) — — KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 6,828 — — (1,089 ) — 5,739 KONES, Corp. 2,827 — — 29 (7 ) 2,849 POSCO MITSUBISHI CARBON TECHNOLOGY 110,760 — — 69,594 (162 ) 180,192 Others (52 companies) 73,419 44,629 (784 ) 18,942 (3,348 ) 132,858 751,490 221,360 (1,334 ) 25,500 (17,290 ) 979,726 [Foreign] AES-VCM 142,348 — (26,108 ) 30,096 63,600 209,936 South-East Asia Gas Pipeline Company Ltd. 197,069 — (29,301 ) 17,709 (6,018 ) 179,459 7623704 Canada Inc. 121,702 — (4,509 ) 4,373 5,319 126,885 Eureka Moly LLC 79,398 — — (406 ) 3,455 82,447 AMCI (WA) PTY LTD 63,378 — — (3,412 ) 11,120 71,086 Nickel Mining Company SAS 45,905 — — (4,268 ) 75 41,712 KOREA LNG LTD. 33,422 — (10,544 ) 10,542 10,134 43,554 NCR LLC 33,738 2,505 — (5,909 ) 7,268 37,602 PT. Batutua Tembaga Raya 21,823 — — (1,817 ) 473 20,479 PT. Wampu Electric Power 13,391 — — 177 552 14,120 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 15,617 — — (735 ) (86 ) 14,796 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 6,517 — — 23 (62 ) 6,478 Roy Hill Holdings Pty Ltd 1,125,133 — — 59,095 (142,628 ) 1,041,600 POSCO-NPS 348,836 — (22,254 ) 21,536 15,388 363,506 KOBRASCO 108,485 — (37,710 ) 75,170 (12,496 ) 133,449 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 88,305 — — 540 (454 ) 88,391 DMSA/AMSA 56,735 17,973 — (48,802 ) 803 26,709 CSP - Compania Siderurgica do Pecem 146,427 — — (109,714 ) (11,881 ) 24,832 Others (42 companies) 158,213 2,771 (22,588 ) 42,937 (38,097 ) 143,236 2,806,442 23,249 (153,014 ) 87,135 (93,535 ) 2,670,277 ￦ 3,557,932 244,609 (154,348 ) 112,635 (110,825 ) 3,650,003 (1) Other increase or decrease represents the changes in investments in associates and joint ventures due to disposals, change in capital adjustments from translations of financial statements of foreign investees and others. 2) For the year ended December 31, 2019 (in millions of Won) Company December 31, Book value Acquisition Dividends Share of profits Other (decrease)(1) December 31, Book value [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 174,123 — — (976 ) 2,760 175,907 POSPower Co., Ltd 161,477 — — (4,744 ) 4,547 161,280 SNNC 116,922 — (1,450 ) 27,655 (525 ) 142,602 QSONE Co.,Ltd. 85,550 — (950 ) 1,287 — 85,887 Chun-cheon Energy Co., Ltd 62,478 6,050 — (11,849 ) — 56,679 Nextrain Co., Ltd. 10 41,600 — (163 ) — 41,447 Keystone NO. 1. Private Equity Fund 11,183 8,723 — (342 ) (126 ) 19,438 CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd 17,382 — — 442 — 17,824 Daesung Steel 15,644 — — (269 ) — 15,375 Incheon-Gimpo Expressway Co., Ltd. 13,329 — — (5,425 ) — 7,904 KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 5,739 — — 438 — 6,177 KONES, Corp. 2,849 — — (403 ) 27 2,473 POSCO MITSUBISHI CARBON TECHNOLOGY 180,192 — (16,369 ) 19,377 (552 ) 182,648 Others (61 companies) 132,848 30,973 (1,392 ) (18,146 ) (21,357 ) 122,926 979,726 87,346 (20,161 ) 6,882 (15,226 ) 1,038,567 [Foreign] AES-VCM 209,936 — (18,099 ) 24,126 (37,071 ) 178,892 South-East Asia Gas Pipeline Company Ltd. 179,459 — (24,267 ) 63,749 6,992 225,933 7623704 Canada Inc. 126,885 — (9,902 ) 9,912 4,634 131,529 Eureka Moly LLC 82,447 — — (25 ) 2,927 85,349 AMCI (WA) PTY LTD 71,086 — — (4,377 ) 6,228 72,937 Nickel Mining Company SAS 41,712 — — (4,250 ) 478 37,940 KOREA LNG LTD. 43,554 — (13,404 ) 13,501 2,906 46,557 NCR LLC 37,602 9,605 — (822 ) 6 46,391 ZHEJIANG HUAYOU-POSCO ESM CO., LTD — 22,423 — 61 (128 ) 22,356 PT. Batutua Tembaga Raya 20,479 — — (6,209 ) 447 14,717 PT. Wampu Electric Power 14,120 — — (1,247 ) 490 13,363 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 14,796 — — 10 322 15,128 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 6,478 — — 80 197 6,755 Roy Hill Holdings Pty Ltd 1,041,600 — — 158,562 35,520 1,235,682 POSCO-NPS 363,506 — (24,933 ) 24,543 13,294 376,410 KOBRASCO 133,449 — (74,716 ) 56,474 434 115,641 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 88,391 — (1,574 ) 665 1,453 88,935 DMSA/AMSA 26,709 23,682 — (40,415 ) 2,213 12,189 CSP - Compania Siderurgica do Pecem 24,832 35,352 — (57,647 ) (2,537 ) — Others (38 companies) 143,236 552 (19,430 ) 30,168 7,958 162,484 2,670,277 91,614 (186,325 ) 266,859 46,763 2,889,188 ￦ 3,650,003 178,960 (206,486 ) 273,741 31,537 3,927,755 (*1) Other increase or decrease represents the changes in investments in associates and joint ventures due to disposals, change in capital adjustments effect from translations of financial statements of foreign investees and others. (e) Summarized financial information of associates and joint ventures as of and for the years ended December 31, 2018 and 2019 are as follows: 1) December 31, 2018 (in millions of Won) Company Assets Liabilities Equity Sales Net income (loss) [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 552,760 783 551,977 — 10,249 POSPower Co., Ltd 425,632 35,761 389,871 — (4,536 ) SNNC 645,013 384,586 260,427 656,320 14,229 QSONE Co., Ltd. 249,384 78,285 171,099 16,597 2,101 Chun-cheon Energy Co., Ltd 667,454 525,308 142,146 320,950 (18,796 ) Nextrain Co., Ltd. 30 — 30 — — CHUNGJU ENTERPRISE CITY DEVELOPMENT Co., Ltd 63,554 35,003 28,551 16,237 439 BLUE OCEAN Private Equity Fund 305,876 174,640 131,236 459,491 (5,294 ) Daesung Steel 169,305 111,502 57,803 75,474 824 Incheon-Gimpo Expressway Co., Ltd. 1,049,629 931,937 117,692 45,566 (92,202 ) Keystone NO. 1. Private Equity Fund 177,024 144,186 32,838 15,507 (3,962 ) UITrans LRT Co., Ltd. 430,227 435,699 (5,472 ) 12,929 (85,344 ) KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 59,464 1,061 58,403 2,401 (12,313 ) KONES, Corp. 2,618 1,414 1,204 5,167 70 POSCO MITSUBISHI CARBON TECHNOLOGY 537,138 237,563 299,575 300,986 116,049 [Foreign] South-East Asia Gas Pipeline Company Ltd. 1,726,410 1,009,731 716,679 343,471 70,717 7623704 Canada Inc. 1,232,208 1 1,232,207 — 44,320 Nickel Mining Company SAS 465,463 329,084 136,379 207,956 (4,569 ) KOREA LNG LTD. 217,883 110 217,773 54,357 52,720 PT. Batutua Tembaga Raya 332,305 274,580 57,725 128,609 (8,451 ) PT. Wampu Electric Power 223,009 155,407 67,602 13,461 887 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 73,515 24,264 49,251 121,104 (2,231 ) POSCO SeAH Steel Wire (Nantong) Co., Ltd. 61,782 34,740 27,042 85,619 78 Roy Hill Holdings Pty Ltd 9,666,619 6,043,492 3,623,127 3,259,256 497,469 POSCO-NPS 726,810 — 726,810 — 41,812 KOBRASCO 317,842 50,945 266,897 229,340 150,550 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 710,518 384,572 325,946 1,341,849 2,159 DMSA/AMSA 5,562,877 4,171,896 1,390,981 731,127 (529,844 ) CSP - Compania Siderurgica do Pecem 4,194,242 4,192,867 1,375 1,860,198 (542,865 ) 2) December 31, 2019 (in millions of Won) Company Assets Liabilities Equity (deficit) Sales Net income (loss) [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 516,659 786 515,873 — 7,479 POSPower Co., Ltd 707,051 199,846 507,205 — (5,294 ) SNNC 677,508 357,843 319,665 738,977 63,269 QSONE Co., Ltd. 250,364 78,589 171,775 17,591 2,576 Chun-cheon Energy Co., Ltd 610,089 492,620 117,469 313,438 (24,677 ) Nextrain Co., Ltd. 136,203 7,322 128,881 — (509 ) Keystone NO. 1. Private Equity Fund 187,156 138,219 48,937 18,342 (887 ) CHUNGJU ENTERPRISE CITY DEVELOPMENT Co., Ltd 53,019 22,971 30,048 17,824 1,497 Daesung Steel 164,708 108,441 56,267 85,537 (1,536 ) Incheon-Gimpo Expressway Co., Ltd. 1,014,410 951,321 63,089 50,575 (36,449 ) KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 50,479 1,062 49,417 2,841 3,502 KONES, Corp. 1,950 1,648 302 4,416 (966 ) POSCO MITSUBISHI CARBON TECHNOLOGY 474,387 170,678 303,709 216,648 32,334 [Foreign] South-East Asia Gas Pipeline Company Ltd. 1,808,529 906,254 902,275 555,075 254,582 7623704 Canada Inc. 1,276,857 1 1,276,856 — 95,306 Nickel Mining Company SAS 471,377 331,194 140,183 245,509 2,432 ZHEJIANG HUAYOU-POSCO ESM CO., LTD 73,604 17,765 55,839 641 153 KOREA LNG LTD. 232,935 147 232,788 69,577 67,507 PT. Batutua Tembaga Raya 423,608 392,226 31,382 112,568 (28,360 ) PT. Wampu Electric Power 222,266 158,451 63,815 18,163 (6,233 ) Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 65,413 15,232 50,181 101,101 28 POSCO SeAH Steel Wire (Nantong) Co., Ltd. 61,847 33,989 27,858 77,371 327 Roy Hill Holdings Pty Ltd 11,143,705 5,718,152 5,425,553 5,037,471 1,660,577 POSCO-NPS 752,617 — 752,617 — 47,521 KOBRASCO 268,139 36,857 231,282 167,022 112,949 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 969,280 637,478 331,802 1,145,794 1,704 DMSA/AMSA 5,703,501 4,202,704 1,500,797 638,797 (504,077 ) CSP - Compania Siderurgica do Pecem 3,959,365 4,249,083 (289,718 ) 1,623,843 (465,853 )

Joint Operations

Joint Operations	12 Months Ended
Joint Operations	Dec. 31, 2019
Investments accounted for using equity method [abstract]
Joint Operations	12. Joint Operations Details of significant joint operations that the Company is participating in as a party to a joint arrangement as of December 31, 2019 are as follows: Joint operations Operation Ownership (%) Location Myanmar A-1/A-3 Mine development and gas production 51.00 Myanmar Offshore midstream Gas transportation facility 51.00 Myanmar Greenhills mine Mine development 20.00 Canada Arctos Anthracite coal project Mine development 50.00 Canada Mt. Thorley J/V Mine development 20.00 Australia POSMAC J/V Mine development 20.00 Australia RUM J/V Mine development 10.00 Australia Hanam-Gamil package public housing project Construction 7.70 Korea Hanam-Gamil district B6, C2, C3 Block public housing lot development project Construction 27.00 Korea Yangsan-Sasong district public housing project (private-participation) Construction 13.08 Korea Yangsan-Sasong district public housing project Construction 49.00 Korea Sejong 2-1 Construction 37.00 Korea Yongin-Giheung Station area city development project Construction 61.00 Korea Korean Wave World Complex land multi-purpose building development project Construction 33.30 Korea Sejong 4-1 Construction 60.00 Korea

Investment Property, Net

Investment Property, Net	12 Months Ended
Investment Property, Net	Dec. 31, 2019
Text block [abstract]
Investment Property, Net	13. Investment Property, Net (a) Investment property as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Acquisition cost Accumulated depreciation impairment Book value Acquisition cost Accumulated depreciation impairment Book value Land ￦ 295,328 (16,743 ) 278,585 295,183 (16,718 ) 278,465 Buildings 681,518 (110,183 ) 571,335 778,816 (180,657 ) 598,159 Structures 3,327 (1,919 ) 1,408 3,455 (2,277 ) 1,178 Right of use assets — — — 434 (9 ) 425 Construction-in-progress 101,665 (24,378 ) 77,287 — — — ￦ 1,081,838 (153,223 ) 928,615 1,077,888 (199,661 ) 878,227 As of December 31, 2019, the fair value of investment property is ￦ (b) Changes in the carrying amount of investment property for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Acquisitions Disposals Depreciation(1) Others(2) Ending Land ￦ 360,402 1,327 (26,826 ) (16,743 ) (39,575 ) 278,585 Buildings 634,040 727 (32,807 ) (28,358 ) (2,267 ) 571,335 Structures 6,281 — — (603 ) (4,270 ) 1,408 Construction-in-progress 64,191 42,052 — (24,948 ) (4,008 ) 77,287 ￦ 1,064,914 44,106 (59,633 ) (70,652 ) (50,120 ) 928,615 (1) Includes impairment loss on investment property recognized by each of the consolidated subsidiaries, including the office lease of POSCO (Dalian) IT Center Development Co., Ltd. amounting to ￦ (2) Includes reclassification resulting from changing the purpose of use, adjustment of foreign currency translation difference and others. 2) For the year ended December 31, 2019 (in millions of Won) Beginning Acquisitions Disposals Depreciation(1) Others(2) Ending Land ￦ 278,585 — (5,921 ) — 5,801 278,465 Buildings 571,335 1,548 (5,343 ) (52,416 ) 83,035 598,159 Structures 1,408 — (50 ) (625 ) 445 1,178 Right of use assets — — — — 425 425 Construction-in-progress 77,287 18,644 — — (95,931 ) — ￦ 928,615 20,192 (11,314 ) (53,041 ) (6,225 ) 878,227 (1) Includes impairment loss on investment property recognized by POSCO (Dalian) IT Center Development Co., Ltd., a subsidiary, in relation to its office lease amounting to ￦ (2) Includes reclassification resulting from changing the purpose of use, adjustment of foreign currency translation difference and others.

Property, Plant and Equipment,

Property, Plant and Equipment, Net	12 Months Ended
Property, Plant and Equipment, Net	Dec. 31, 2019
Text block [abstract]
Property, Plant and Equipment, Net	14. Property, Plant and Equipment, Net (a) Property, plant and equipment as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Acquisition Accumulated depreciation and impairment Government Book value Acquisition cost Accumulated depreciation and impairment Government Book value Land ￦ 2,553,957 (5,955 ) — 2,548,002 2,527,972 (1,913 ) — 2,526,059 Buildings 9,146,294 (4,743,449 ) (393 ) 4,402,452 9,227,064 (5,010,770 ) (840 ) 4,215,454 Structures 5,884,277 (2,966,304 ) (49 ) 2,917,924 6,066,000 (3,161,453 ) (41 ) 2,904,506 Machinery and equipment 47,610,225 (29,091,754 ) (342 ) 18,518,129 47,548,589 (30,326,324 ) (4,001 ) 17,218,264 Vehicles 302,767 (271,381 ) (45 ) 31,341 305,275 (272,977 ) (13 ) 32,285 Tools 399,638 (333,387 ) (87 ) 66,164 418,829 (348,032 ) (46 ) 70,751 Furniture and fixtures 638,553 (502,215 ) (51 ) 136,287 658,467 (528,066 ) (269 ) 130,132 Finance lease assets 213,873 (76,309 ) — 137,564 970,891 (196,309 ) — 774,582 Bearer plants 88,773 (8,002 ) — 80,771 138,818 (14,625 ) — 124,193 Construction-in- 1,964,267 (778,373 ) (6,255 ) 1,179,639 2,800,412 (856,548 ) (14,117 ) 1,929,747 ￦ 68,802,624 (38,777,129 ) (7,222 ) 30,018,273 70,662,317 (40,717,017 ) (19,327 ) 29,925,973 (b) Changes in the carrying amount of property, plant and equipment for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Acquisitions Disposals Depreciation Impairment loss(1,2) Others(3) Ending Land ￦ 2,527,650 28,998 (26,157 ) — 6,399 11,112 2,548,002 Buildings 4,877,018 46,129 (21,501 ) (331,688 ) (73,523 ) (93,983 ) 4,402,452 Structures 2,765,852 18,749 (2,834 ) (220,218 ) (6,652 ) 363,027 2,917,924 Machinery and equipment 19,367,957 145,220 (62,135 ) (2,224,000 ) (143,293 ) 1,434,380 18,518,129 Vehicles 32,861 8,538 (1,149 ) (14,835 ) (56 ) 5,982 31,341 Tools 63,640 21,337 (1,867 ) (26,421 ) (206 ) 9,681 66,164 Furniture and fixtures 145,439 32,258 (577 ) (51,835 ) (1,494 ) 12,496 136,287 Finance lease assets 145,257 28,466 (420 ) (19,224 ) — (16,515 ) 137,564 Bearer plants 65,515 — — (3,636 ) — 18,892 80,771 Construction-in-progress 1,892,346 1,884,125 (23,814 ) — (778,373 ) (1,794,645 ) 1,179,639 ￦ 31,883,535 2,213,820 (140,454 ) (2,891,857 ) (997,198 ) (49,573 ) 30,018,273 (1) During 2018, the Controlling Company evaluated future economic performance of its Synthetic Natural Gas (SNG) facility that was still in trial run stage. Considering the continuous decline in LNG price, increase in coal prices and the need for additional capital investment in the SNG facility, the Controlling Company concluded that the profitability for the SNG facility is unlikely to be sustainable and decided to terminate the operation of SNG facility as of December 31, 2018. The property, plant and equipment in the SNG facility are primarily comprised of machinery and equipment, among which assets with a carrying value of ￦ re-used For the assets for which sale is probable, the recoverable amount is determined based on fair value less cost of disposal. Fair value was measured using cost approach, which is based on an estimation of the current cost to purchase or replace the asset less applicable depreciation and obsolescence. Specifically, the Controlling Company used indirect cost approach to estimate the replacement cost for a new asset by applying asset specific inflation factors to the asset’s historical cost. Then the Controlling Company estimated and deducted depreciation for physical deterioration. Depreciation factors are applied primarily based on estimated useful life of the asset and declining balance depreciation method. The fair value measurement of assets in SNG facility is considered to be level 3 because significant inputs used in the estimate, such as asset specific inflation factors and estimated useful lives, are unobservable. As a result of the impairment test, the Company recognized an impairment loss of ￦ The Controlling Company also has recognized an impairment loss amounting to ￦ (2) As of December 31, 2018, POSCO ENERGY CO., LTD., a subsidiary, performed an impairment test due to the continued operating losses of the fuel cell business, and recognized impairment losses amounting to ￦ (3) Represents assets transferred from construction-in-progress 2) For the year ended December 31, 2019 (in millions of Won) Beginning Acquisitions Business Combination Disposals Depreciation Impairment loss(1,2) Others(3) Ending Land ￦ 2,548,002 6,550 — (2,128 ) — — (26,365 ) 2,526,059 Buildings 4,402,452 39,551 22,836 (10,376 ) (314,107 ) (90,036 ) 165,134 4,215,454 Structures 2,917,924 49,931 2 (3,350 ) (228,616 ) (27,217 ) 195,832 2,904,506 Machinery and equipment 18,518,129 175,743 1,216 (78,236 ) (2,250,022 ) (309,604 ) 1,161,038 17,218,264 Vehicles 31,341 8,027 189 (742 ) (15,057 ) (559 ) 9,086 32,285 Tools 66,164 19,178 5,792 (1,340 ) (28,537 ) (2,106 ) 11,600 70,751 Furniture and fixtures 136,287 34,618 252 (1,630 ) (36,309 ) (1,808 ) (1,278 ) 130,132 Lease assets(4) 137,564 72,640 490 (8,401 ) (130,905 ) — 703,194 774,582 Bearer plants 80,771 — — — (5,916 ) — 49,338 124,193 Construction-in-progress 1,179,639 2,261,663 17,697 (24,840 ) — (10,150 ) (1,494,262 ) 1,929,747 ￦ 30,018,273 2,667,901 48,474 (131,043 ) (3,009,469 ) (441,480 ) 773,317 29,925,973 (1) During the year ended December 31, 2019, the Controlling Company estimated recoverable amount of individual assets in CEM and Fe-Si ￦ (2) As of December 31, 2019, POSCO SS VINA JOINT STOCK COMPANY (formerly, POSCO SS VINA Co., Ltd.), a subsidiary, performed impairment test due to the continued operating losses and recognized impairment losses amounting to ￦ value-in-use (3) Represents assets transferred from construction-in-progress (4) On the date of initial application of IFRS No.16 “Leases” (January 1, 2019), recognition of ￦ right-of-use (c) Borrowing costs capitalized and the capitalized interest rate for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Weighted average expenditure ￦ 628,595 587,628 Borrowing costs capitalized 22,619 22,775 Capitalization rate (%) 2.51 ~ 3.90 3.57 ~ 5.46 (d) Property, plant and equipment and investment property pledged as collateral as of December 31, 2018 and 2019 are as follows: (in millions of Won) Collateral right holder Book value 2018 2019 Land Korean Development Bank and others ￦ 769,843 765,307 Buildings and structures Korean Development Bank and others 1,522,129 1,363,709 Machinery and equipment Korean Development Bank and others 3,419,528 2,440,777 ￦ 5,711,500 4,569,793 As of December 31, 2019, assets pledged as collateral related to the Company’s borrowings and others amounting to ￦ (e) Changes in the carrying amount of right of use assets presented as property, plant and equipment for the year ended December 31, 2019 were as follows: (in millions of Won) Beginning (Initial Right of use Acquisitions Depreciation Others Ending Land ￦ 340,107 22,850 (11,461 ) (10,154 ) 341,342 Buildings and structures 209,455 23,015 (38,853 ) (22,505 ) 171,112 Machinery and equipment 219,877 14,610 (33,751 ) 15,092 215,828 Vehicles 20,555 8,735 (10,050 ) (5,135 ) 14,105 others 52,028 3,430 (36,790 ) 13,527 32,195 ￦ 842,022 72,640 (130,905 ) (9,175 ) 774,582 (f) The amount recognized in profit or loss related to leases for the year ended December 31, 2019 are as follows: (in millions of Won) 2019 Interest on lease liabilities ￦ 35,483 Expenses related to short-term leases 41,974 Expenses related to leases of low-value 14,150 ￦ 91,607

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets, Net	12 Months Ended
Goodwill and Other Intangible Assets, Net	Dec. 31, 2019
Text block [abstract]
Goodwill and Other Intangible Assets, Net	15. Goodwill and Other Intangible Assets, Net (a) Goodwill and other intangible assets as of December 31, 2018 and 2019 are as follows: 2018 2019 (in millions of Won) Acquisition Accumulated Government Book value Acquisition Accumulated Government Book value Goodwill ￦ 1,603,308 (478,159 ) — 1,125,149 1,631,413 (533,604 ) — 1,097,809 Intellectual property rights 3,300,638 (901,113 ) — 2,399,525 3,449,796 (1,170,586 ) — 2,279,210 Premium in rental 158,338 (23,545 ) — 134,793 170,247 (22,169 ) — 148,078 Development expense 445,752 (346,589 ) — 99,163 483,539 (389,200 ) — 94,339 Port facilities usage rights 724,375 (419,294 ) — 305,081 686,525 (405,127 ) — 281,398 Exploration and evaluation assets 285,845 (93,715 ) — 192,130 294,874 (217,603 ) — 77,271 Customer relationships 860,951 (439,178 ) — 421,773 865,821 (490,946 ) — 374,875 Other intangible assets 1,115,742 (622,417 ) (114 ) 493,211 1,220,641 (665,026 ) (122 ) 555,493 ￦ 8,494,949 (3,324,010 ) (114 ) 5,170,825 8,802,856 (3,894,261 ) (122 ) 4,908,473 (b) The changes in carrying amount of goodwill and other intangible assets for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Acquisitions Disposals Amortization Impairment loss Others(3) Ending Goodwill ￦ 1,349,838 — — — (223,709 ) (980 ) 1,125,149 Intellectual property rights 2,449,193 334,667 (18,619 ) (198,282 ) (96,475 ) (70,959 ) 2,399,525 Premium in rental(1) 118,310 36,196 (15,675 ) (330 ) (4,218 ) 510 134,793 Development expense 80,218 4,248 (32 ) (37,305 ) (411 ) 52,445 99,163 Port facilities usage rights 309,373 — — (22,975 ) — 18,683 305,081 Exploration and evaluation assets 205,944 2,654 — — (3,339 ) (13,129 ) 192,130 Customer relationships 466,945 — — (48,499 ) — 3,327 421,773 Power generation permit(2) 539,405 — — — — (539,405 ) — Other intangible assets 433,043 164,594 (1,644 ) (49,190 ) (8,844 ) (44,748 ) 493,211 ￦ 5,952,269 542,359 (35,970 ) (356,581 ) (336,996 ) (594,256 ) 5,170,825 (1) Premium in rental includes memberships with indefinite useful lives. (2) During the year ended December 31, 2018, the Company disposed of a portion of shares of its subsidiary, POSPower Co., Ltd, which resulted in the Company’s loss of control, and derecognition of corresponding intangible assets. (3) Represents assets transferred from construction-in-progress 2) For the year ended December 31, 2019 (in millions of Won) Beginning Acquisitions Business Combination Disposals Amortization Impairment loss(2) Others(3) Ending Goodwill ￦ 1,125,149 — 26,256 — — (55,445 ) 1,849 1,097,809 Intellectual property rights 2,399,525 127,479 — (6,566 ) (271,694 ) (2 ) 30,468 2,279,210 Premium in rental(1) 134,793 15,636 — (3,326 ) (181 ) 24 1,132 148,078 Development expense 99,163 4,484 — (35 ) (44,418 ) (666 ) 35,811 94,339 Port facilities usage rights 305,081 — — (4,674 ) (22,923 ) — 3,914 281,398 Exploration and evaluation assets 192,130 9,642 — — — (123,888 ) (613 ) 77,271 Customer relationships 421,773 — — — (51,768 ) — 4,870 374,875 Other intangible assets 493,211 141,578 74 (10,718 ) (40,263 ) (10,111 ) (18,278 ) 555,493 — — — — — — — — ￦ 5,170,825 298,819 26,330 (25,319 ) (431,247 ) (190,088 ) 59,153 4,908,473 (1) Premium in rental includes memberships with indefinite useful lives. (2) From exploration and evaluation of natural gas in the AD-7 ￦ (3) Represents assets transferred from construction-in-progress (c) For the purpose of impairment testing, goodwill is allocated to individually operating entities which are determined to be CGUs. The goodwill amounts as of December 31, 2018 and 2019 are as follows: (in millions of Won) Reportable segments Total number of 2018 2019 CGUs 2018 2019 Steel 7 7 POSCO VST CO., LTD. ￦ 36,955 36,955 Others 12,484 13,721 Trading 2 3 POSCO INTERNATIONAL CORPORATION(1) 1,006,879 951,434 GRAIN TERMINAL HOLDING(2) — 26,256 PT. Bio Inti Agrindo 6,902 7,468 Others 16 — E&C 2 2 POSCO ENGINEERING & CONSTRUCTION CO., LTD. 24,868 24,868 POSCO Center Beijing 155 158 POSCO ENERGY CO., LTD. 26,471 26,471 Others 5 5 Others 10,419 10,478 16 17 ￦ 1,125,149 1,097,809 (1) Recoverable amounts of POSCO INTERNATIONAL Corporation are determined based on its value in use. As of December 31, 2019, value in use is estimated by applying a 6.84% discount rate and a 1.9% terminal growth rate after 5 years, based on management’s business plan. The terminal growth rate does not exceed long-term growth rate of its industry. Impairment loss on goodwill of ￦ Value in use of the CGU was affected by the assumptions such as discount rate, terminal growth rate and estimated sales used in discounted cash flow model. When the discount rate increases by 0.25%, value in use will be decreased by ￦￦ (2) In connection with the acquisition of Grain Terminal Holding, the Company recognized goodwill of ￦

Other Assets

Other Assets	12 Months Ended
Other Assets	Dec. 31, 2019
Text block [abstract]
Other Assets	16. Other Assets Other current assets and other non-current (in millions of Won) 2018 2019 Current Advance payment ￦ 539,894 453,538 Prepaid expenses 123,770 145,834 Firm commitment asset 11,246 17,490 Others 9,553 14,315 684,463 631,177 Non-current Long-term advance payment 24,280 21,950 Long-term prepaid expenses 334,918 41,256 Others(1) 149,566 262,036 ￦ 508,764 325,242 (1) ) As of December 31, 2018 and 2019 the Company recognized tax assets amounting to ￦￦

Borrowings

Borrowings	12 Months Ended
Borrowings	Dec. 31, 2019
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Borrowings	17. Borrowings (a) Short-term borrowings and current portion of long-term borrowings as of December 31, 2018 and 2019 are as follows: (in millions of Won) Bank Issuance date Maturity date Interest 2018 2019 Short-term borrowings Bank overdrafts JP Morgan and others January, 2019~ December, 2019 January, 2020~ December, 2020 0.5~8.9 ￦ 294,364 159,075 Short-term borrowings HSBC and others January, 2019~ December, 2019 January, 2020~ December, 2020 0.2~12.7 7,193,416 5,327,258 7,487,780 5,486,333 Current portion of long-term liabilities Current portion of long-term borrowings Export-Import Bank of Korea and others November, 2004~ October, 2019 January, 2020~ December, 2020 0.7~6.6 1,234,915 1,491,934 Current portion of debentures Korea Development Bank and others October, 2010~ September, 2018 April, 2020~ October, 2020 1.5~4.3 1,568,108 1,571,194 Less: Current portion of discount on debentures issued (1,184 ) (1,249 ) 2,801,839 3,061,879 ￦ 10,289,619 8,548,212 (b) Long-term borrowings, excluding current portion as of December 31, 2018 and 2019 are as follows: (in millions of Won) Bank Issuance date Maturity date Interest 2018 2019 Long-term borrowings Export-Import Bank of Korea and others September, 2001~ December, 2019 February, 2021~ March, 2037 0.2~12.5 ￦ 4,499,199 3,827,152 Less: Present value discount (30,526 ) (24,374 ) Bonds KB Securities co.,Ltd. and others April, 2011~ November, 2019 February, 2021~ October, 2029 1.6~5.3 5,469,580 8,124,194 Less: Discount on debentures issued (18,602 ) (33,571 ) ￦ 9,919,651 11,893,401 (c) Assets pledged as collateral in regard to the borrowings as of December 31, 2019 are as follows: (in millions of Won) Bank Book value Pledged Cash and cash equivalents Sinhan Bank and others 26,923 26,923 Property, plant and equipment and Investment property Korea Development Bank and others 4,420,551 4,967,168 Trade accounts and notes receivable Korea Development Bank and others 7,498 7,498 Inventories Export-Import Bank of Korea and others 118,824 12,650 Financial instruments KB Kookmin Bank and others 46,217 45,017 ￦ 4,620,013 5,059,256

Other Payables

Other Payables	12 Months Ended
Other Payables	Dec. 31, 2019
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Other Payables	18. Other Payables Other payables as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Accounts payable ￦ 783,562 832,845 Accrued expenses 720,773 742,370 Dividend payable 8,673 3,106 Lease liabilities(1) 10,152 149,176 Withholdings 196,937 152,011 ￦ 1,720,097 1,879,508 Non-current Accounts payable ￦ 1,624 2,718 Accrued expenses 19,021 4,805 Lease liabilities(1) 84,602 526,294 Long-term withholdings 43,621 51,312 ￦ 148,868 585,129 (*1) As of December 31, 2019, the Company recognized additional lease liabilities of ￦

Other Financial Liabilities

Other Financial Liabilities	12 Months Ended
Other Financial Liabilities	Dec. 31, 2019
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Other Financial Liabilities	19. Other Financial Liabilities Other financial liabilities as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Derivatives liabilities ￦ 27,328 28,021 Financial guarantee liabilities 50,472 49,806 ￦ 77,800 77,827 Non-current Derivatives liabilities ￦ 46,429 17,033 Financial guarantee liabilities 17,733 14,461 ￦ 64,162 31,494

Provisions

Provisions	12 Months Ended
Provisions	Dec. 31, 2019
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Provisions	20. Provisions (a) Provisions as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Non-current Current Non-current Provision for bonus payments ￦ 46,514 26,964 76,432 47,237 Provision for construction warranties 11,842 130,391 7,655 162,773 Provision for legal contingencies and claims(1) 16,981 94,169 6,996 77,488 Provision for the restoration(2) 9,379 79,789 6,783 80,520 Others(3,4) 213,737 99,723 262,471 90,136 ￦ 298,453 431,036 360,337 458,154 (1) The Company recognized probable outflow of resources amounting to ￦￦ (2) Due to contamination of lands near the Company’s magnesium smelting plant located in Gangneung province and others, the Company recognized present values of estimated costs for recovery of ￦ (3) As of December 31, 2018 and 2019, POSCO ENERGY CO., LTD., and Korea Fuel Cell, recognized ￦￦ (4) The Company has recognized emission liabilities of ￦ (b) The following are the key assumptions concerning the future and other key sources of estimation uncertainties at the end of the reporting period. Key assumptions for the estimation Provision for bonus payments Estimations based on financial performance and service provided Provision for construction warranties Estimations based on historical warranty data Provision for legal contingencies and claims Estimations based on the degree of probability of an unfavorable outcome and the ability to make a sufficient reliable estimate of the amount of loss (c) Changes in provisions for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Increase Utilization Reversal Others(1) Ending Provision for bonus payments ￦ 49,171 88,879 (60,723 ) (3,856 ) 7 73,478 Provision for construction warranties 118,036 56,560 (24,608 ) (7,660 ) (95 ) 142,233 Provision for legal contingencies and claims 36,764 84,242 (6,066 ) (3,399 ) (391 ) 111,150 Provision for the restoration 134,190 14,912 (9,212 ) (47,682 ) (3,040 ) 89,168 Others 249,957 328,879 (118,388 ) (216,668 ) 69,680 313,460 ￦ 573,472 (218,997) (279,265) 66,161 729,489 (1) Includes adjustments of foreign currency translation differences and others. 2) For the year ended December 31, 2019 (in millions of Won) Beginning Increase Utilization Reversal Others(1) Ending Provision for bonus payments ￦ 73,478 122,714 (86,084 ) (3,077 ) 16,638 123,669 Provision for construction warranties 142,233 53,203 (22,858 ) (3,444 ) 1,294 170,428 Provision for legal contingencies and claims 111,150 26,407 (37,087 ) (18,098 ) 2,112 84,484 Provision for the restoration 89,168 23,559 (13,411 ) (14,379 ) 2,366 87,303 Others 313,460 95,747 (38,260 ) (86,458 ) 68,118 352,607 ￦ 321,630 (197,700) (125,456) 90,528 818,491 (*1) Includes adjustments of foreign currency translation differences and others.

Employee Benefits

Employee Benefits	12 Months Ended
Employee Benefits	Dec. 31, 2019
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Employee Benefits	21. Employee Benefits (a) Defined contribution plans The expenses related to post-employment benefit plans under defined contribution plans for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Expense related to post-employment benefit plans under defined contribution plans ￦ 35,538 42,825 46,846 (b) Defined benefit plans 1) The amounts recognized in relation to net defined benefit liabilities in the statements of financial position as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Present value of funded obligations ￦ 2,117,829 2,416,203 Fair value of plan assets(1) (1,997,717 ) (2,255,149 ) Present value of non-funded 19,332 15,677 Net defined benefit liabilities ￦ 139,444 176,731 (1) As of December 31, 2018 and 2019, the Company recognized net defined benefit assets amounting to ￦￦ 2) Changes in present value of defined benefit obligations for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Defined benefit obligations at the beginning of year ￦ 1,843,135 2,137,161 Current service costs 212,323 236,735 Interest costs 54,950 51,900 Remeasurements : 212,678 152,713 - Gain from change in financial assumptions 173,084 103,850 - Loss (gain) from change in demographic assumptions 526 (492 ) - Others 39,068 49,355 Benefits paid (189,165 ) (152,275 ) Others 3,240 5,646 Defined benefit obligations at the end of year ￦ 2,137,161 2,431,880 3) Changes in fair value of plan assets for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Fair value of plan assets at the beginning of year ￦ 1,714,166 1,997,717 Interest on plan assets 50,784 48,210 Remeasurement of plan assets (19,761 ) (8,692 ) Contributions to plan assets 408,326 342,915 Benefits paid (163,112 ) (124,962 ) Others 7,314 (39 ) Fair value of plan assets at the end of year ￦ 1,997,717 2,255,149 The Company expects to make an estimated contribution of ￦ 4) The fair value of plan assets as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Equity instruments ￦ 3,151 10,386 Debt instruments 692,825 1,013,716 Deposits 1,244,802 1,159,455 Others 56,939 71,592 ￦ 1,997,717 2,255,149 5) The amounts recognized in consolidated statements of comprehensive income for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Current service costs ￦ 209,612 212,323 236,735 Net interest costs(1) (9,686 ) 4,166 3,690 ￦ 199,926 216,489 240,425 (1) The actual return on plan assets amounted to ￦￦￦ The expenses by function were as follows: (in millions of Won) 2017 2018 2019 Cost of sales ￦ 131,724 150,822 169,206 Selling and administrative expenses 67,424 64,505 70,060 Others 778 1,162 1,159 ￦ 199,926 216,489 240,425 6) Accumulated actuarial gains (losses), net of tax recognized in other comprehensive income for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Beginning ￦ (251,612 ) (299,155 ) (472,644 ) Current actuarial gains (losses) (47,543 ) (173,489 ) (117,152 ) Ending ￦ (299,155 ) (472,644 ) (589,796 ) 7) The principal actuarial assumptions as of December 31, 2018 and 2019 are as follows: (%) 2018 2019 Discount rate 2.24~10.03 1.72 ~ 13.00 Expected future increase in salaries(1) 2.54~10.00 2.00 ~ 11.00 (1) The expected future increase in salaries is based on the average salary increase rate for the past 3 years. All assumptions are reviewed at the end of the reporting period. Additionally, to determine the present value of defined benefit obligations, the Company uses actuarial assumptions associated with the long-term characteristics of the defined benefit plan. 8) Reasonably possible changes at the reporting date to one of the relevant actuarial assumptions, holding the other assumptions constant, would have affected the defined benefit obligation by the amounts shown below: (in millions of Won) 1% Increase 1% Decrease Amount Percentage(%) Amount Percentage(%) Discount rate ￦ (167,767 ) (6.9 ) 194,809 8.0 Expected future increase in salaries 195,098 8.0 (170,997 ) (7.0 ) 9) As of December 31, 2019, the maturity of the expected benefit payments are as follows: (in millions of Won) Within 1 year - 5 years 5 years - 10 years 10 years - 20 years After 20 years Total Benefits paid ￦ 279,554 928,288 513,133 771,500 409,976 2,902,451 The maturity analysis of the defined benefit obligation is based on nominal amounts according to expected remaining working lives of employees.

Other Liabilities

Other Liabilities	12 Months Ended
Other Liabilities	Dec. 31, 2019
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Other Liabilities	22. Other Liabilities Other liabilities as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Due to customers for contract work ￦ 641,064 644,947 Advances received 1,130,910 746,169 Unearned revenue 49,805 61,795 Withholdings 233,981 388,486 Firm commitment liability 24,373 15,637 Others 10,174 8,604 ￦ 2,090,307 1,865,638 Non-current Advances received 123,071 116,178 Unearned revenue 42,992 27,161 Others 84,369 52,349 ￦ 250,432 195,688

Financial Instruments

Financial Instruments	12 Months Ended
Financial Instruments	Dec. 31, 2019
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Financial Instruments	23. Financial Instruments (a) Classification and fair value of financial instruments 1) The carrying amount and the fair values of financial assets and financial liabilities by fair value hierarchy as of December 31, 2018 and 2019 are as follows: ① (in millions of Won) Fair value Book value Level 1 Level 2 Level 3 Total Financial assets Fair value through profit or loss Derivative assets ￦ 16,662 — 16,662 — 16,662 Short-term financial instruments 6,099,303 — 6,099,303 — 6,099,303 Debt securities 27,229 — — 27,229 27,229 Other securities 338,106 1,224 5,205 331,677 338,106 Other receivables 2,000 — — 2,000 2,000 Derivative hedging instruments(2) 32,421 — 32,421 — 32,421 Fair value through other comprehensive income Equity securities 1,238,630 891,514 — 347,116 1,238,630 Debt securities 1,638 — — 1,638 1,638 Financial assets measured at amortized cost(1) — Cash and cash Equivalents 2,643,865 — — — — Trade accounts and notes receivable 8,819,617 — — — — Other receivables 1,843,381 — — — — Debt securities 8,447 — — — — Deposit instruments 1,966,558 — — — — ￦ 23,037,857 892,738 6,153,591 709,660 7,755,989 Financial liabilities Fair value through profit or loss Derivative liabilities ￦ 60,047 — 60,047 — 60,047 Derivative hedging instruments(2) 13,710 — 13,710 — 13,710 Financial liabilities measured at amortized cost(1) Trade accounts and notes payable 4,035,960 — — — — Borrowings 20,209,270 — 20,377,105 — 20,377,105 Financial guarantee liabilities 68,205 — — — — Others 1,803,353 — — — — ￦ 26,190,545 — 20,450,862 — 20,450,862 (1) Fair value of financial assets and liabilities measured at amortized cost except borrowings approximates carrying amounts. ② (in millions of Won) Fair value Book value Level 1 Level 2 Level 3 Total Financial assets Fair value through profit or loss Derivative assets ￦ 106,104 — 106,104 — 106,104 Short-term financial instruments 6,861,242 — 6,861,242 — 6,861,242 Debt securities 28,087 — — 28,087 28,087 Other securities 340,008 1,222 3,330 335,456 340,008 Other receivables 2,000 — — 2,000 2,000 Derivative hedging instruments(2) 6,174 — 6,174 — 6,174 Fair value through other comprehensive income Equity securities 1,204,902 782,108 73 422,721 1,204,902 Debt securities 5,686 — — 5,686 5,686 Financial assets measured at amortized cost(1) Cash and cash Equivalents 3,514,872 — — — — Trade accounts and notes receivable 8,214,459 — — — — Other receivables 2,193,700 — — — — Debt securities 334,153 — — — — Deposit instruments 1,779,082 — — — — ￦ 24,590,469 783,330 6,976,923 793,950 8,554,203 Financial liabilities Fair value through profit or loss Derivative liabilities ￦ 32,193 — 32,193 — 32,193 Derivative hedging instruments(2) 12,861 — 12,861 — 12,861 Financial liabilities measured at amortized cost(1) Trade accounts and notes payable 3,442,989 — — — — Borrowings 20,441,613 — 20,666,476 — 20,666,476 Financial guarantee liabilities 64,267 — — — — Others 2,401,382 — — — — ￦ 26,395,305 — 20,711,530 — 20,711,530 (1) Fair value of financial assets and liabilities measured at amortized cost except borrowings approximates carrying amounts. (2) The Company applies fair value hedge for certain forward contracts utilized in hedging the risk of changes in fair value of product prices regarding firm commitments or purchase commitments. Also, the Company applies cash flow hedge for certain currency swap utilized in hedging the risk of changes in foreign currency which influences cash flow from borrowings. 2) Financial assets and financial liabilities classified as fair value hierarchy Level 2 Fair values of derivatives are measured using valuation models such as discounted cash flow method and others. Inputs of the valuation model include forward rate, interest rate and others. It may change depending on the type of derivatives and the nature of the underlying assets. 3) Financial assets and financial liabilities classified as fair value hierarchy Level 3 ① Fair value measurement method and significant but not observable inputs for the financial assets classified as fair value hierarchy Level 3 as of December 31, 2019 are as follows: (in millions of Won) Fair value Valuation technique Inputs Range of inputs Effect on fair value with unobservable input Financial assets at fair value ￦ 417,683 Discounted cash flows Growth rate 0% ~ 0.5% As growth rate increases, fair value increases Discount rate 6.0% ~ 18.4% As discount rate increases, fair value decreases 17,931 Proxy firm valuation method Price multiples 0.621 ~ 2.645 As price multiples increases, fair value increases 358,336 Asset value approach — — — ② Sensitivity analysis of financial assets and financial liabilities classified as Level 3 of fair value hierarchy If other inputs remain constant as of December 31, 2019 and one of the significant but not observable input is changed, the effect on fair value measurement is as follows: (in millions of Won) Input variable Favorable Unfavorable changes Financial assets at fair value Fluctuation 0.5% of growth rate ￦ 1,325 1,224 Fluctuation 0.5% of discount rate 24,766 21,845 ③ Changes in fair value of financial assets and financial liabilities classified as Level 3 for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Beginning ￦ 880,012 709,660 Acquisition 134,325 68,461 Loss on valuation of financial assets (34,555 ) (9,412 ) Other comprehensive income 26,771 106,586 Disposal and others (296,893 ) (81,345 ) Ending ￦ 709,660 793,950 4) Finance income and costs by category of financial instrument for the years ended December 31, 2017, 2018 and 2019 were as follows: ① For the year ended December 31, 2017 Finance income and costs Other (in millions of Won) Interest Gain and Gain and Gain and Impairment Others Total Financial assets held for trading ￦ — 16 — — — — 16 — Derivatives assets — (99,942 ) — 206,362 — — 106,420 (143 ) Available-for-sale 60 — — 418,789 (123,214 ) 92,961 388,596 (31,389 ) Held-to-maturity 236 — — — — 7 243 — Loans and receivables 212,155 — (607,837 ) (32,456 ) — (304 ) (428,442 ) — Derivatives liabilities — (61,809 ) — (231,908 ) — — (293,717 ) — Financial liabilities measured at amortized cost (653,115 ) — 777,935 — — (9,546 ) 115,274 — ￦ (440,664 ) (161,735 ) 170,098 360,787 (123,214 ) 83,118 (111,610 ) (31,532 ) ② For the year ended December 31, 2018 Finance income and costs Other comprehensive (in millions of Won) Interest Gain and Gain and Gain and Others Total Financial assets at fair value through profit or loss ￦ 140,116 (43,293 ) — 11,919 3,644 112,386 — Derivative assets — 47,720 — 233,187 — 280,907 — Financial assets at fair value through other comprehensive income — — — — 59,701 59,701 (149,188 ) Financial assets measured at amortized cost 197,142 — 234,606 (39,970 ) (370 ) 391,408 — Derivative liabilities — 8,592 — (194,446 ) — (185,854 ) (212 ) Financial liabilities measured at amortized cost (741,296 ) — (438,708 ) — (16,990 ) (1,196,994 ) — ￦ (404,038 ) 13,019 (204,102 ) 10,690 45,985 (538,446 ) (149,400 ) ③ For the year ended December 31, 2019 Finance income and costs Other comprehensive (in millions of Won) Interest Gain and Gain and Gain and Others Total Financial assets at fair value through profit or loss ￦ 142,873 (23,551 ) — 5,556 630 125,508 — Derivative assets — 123,538 — 184,861 — 308,399 — Financial assets at fair value through other comprehensive income — — — — 74,825 74,825 (10,541 ) Financial assets measured at amortized cost 209,511 — 295,319 (36,935 ) (8,042 ) 459,853 — Derivative liabilities — (7,494 ) — (217,072 ) — (224,566 ) (90 ) Financial liabilities measured at amortized cost (755,711 ) — (330,808 ) (2,432 ) (24,988 ) (1,113,939 ) — ￦ (403,327 ) 92,493 (35,489 ) (66,022 ) 42,425 (369,920 ) (10,631 ) (b) Credit risk 1) Credit risk exposure The carrying amount of financial assets represents the Company’s maximum exposure to credit risk. The maximum exposure to credit risk as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Cash and cash equivalents ￦ 2,643,865 3,514,872 Derivative assets 49,083 112,278 Short-term financial instrument 6,099,303 6,861,242 Debt securities 37,314 367,926 Other securities 338,106 340,008 Other receivables 1,845,381 2,195,700 Trade accounts and nores receivable 8,819,617 8,214,459 Deposit instruments 1,966,558 1,779,082 ￦ 21,799,227 23,385,567 The Company provided financial guarantee for the repayment of loans of associates, joint ventures and third parties. As of December 31, 2018 and 2019, the maximum exposure to credit risk related to the financial guarantee amounted to ￦￦ 2) Impairment losses on financial assets The Company assesses expected credit losses by estimating the default rate based on the credit loss experience of prior periods and current overdue conditions and considers the credit default swap (CDS) premium to reflect changes in credit risk by sector. For credit-impaired assets and significant receivables where the credit risk is significantly increased, credit losses are individually assessed. ① Allowance for doubtful accounts as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Trade accounts and notes receivable ￦ 588,733 465,524 Other accounts receivable 160,729 210,313 Loans 147,980 195,339 Other assets 19,348 27,098 ￦ 916,790 898,274 ② Impairment losses on financial assets for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Bad debt expenses ￦ 74,781 (28,105 ) Other bad debt expenses(1) 81,353 88,787 Less: Recovery of allowance for other bad debt accounts (18,261 ) (8,464 ) ￦ 137,873 52,218 (1) Other bad debt expenses are mainly related to loans and other accounts receivable. ③ The aging and allowance for doubtful accounts of trade accounts and notes receivable as of December 31, 2018 and 2019 are as follows: 2018 2019 (in millions of Won) Trade accounts and Impairment Trade accounts and Impairment Current (not past due) ￦ 8,021,110 70,418 7,528,607 75,324 Over due less than 1 month 632,082 14,434 876,753 9,395 1 month - 3 months 226,082 4,116 228,115 6,647 3 months - 12 months 118,094 11,774 134,888 7,954 Over 12 months 1,148,694 487,991 965,977 366,204 ￦ 10,146,062 588,733 9,734,340 465,524 ④ The aging and allowance for doubtful accounts of other receivables as of December 31, 2018 and 2019 are as follows: 2018 2019 (in millions of Won) Loans and other Impairment Loans and other account receivable Impairment Current (not past due) ￦ 1,754,293 140,072 1,220,756 56,354 Over due less than 1 month 100,102 4,307 432,220 1,546 1 month - 3 months 28,351 851 91,521 239 3 months - 12 months 59,946 12,411 271,814 10,846 over 12 months 230,746 170,416 612,139 363,765 ￦ 2,173,438 328,057 2,628,450 432,750 ⑤ Changes in the allowance for doubtful accounts for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Beginning ￦ 977,771 1,094,464 916,790 Initial application of IFRS No.9 — 107,454 — Bad debt expenses 173,694 74,781 (28,105 ) Other bad debt expenses 98,177 63,092 80,323 Others(1) (155,178 ) (423,001 ) (70,735 ) Ending ￦ 1,094,464 916,790 898,273 (1) Others for the years ended December 31, 2017, 2018 and 2019, included decreases mainly due to write-off ￦￦￦ (c) Liquidity risk 1) Contractual maturities of non-derivative (in millions of Won) Book value Contractual cash flow Within 1 year 1 year - 5 years After 5 years Trade accounts and notes payable ￦ 3,442,989 3,444,596 3,422,957 21,639 — Borrowings 20,441,613 22,161,306 9,262,808 11,171,927 1,726,571 Financial guarantee liabilities(1) 64,267 3,406,609 3,406,609 — — Lease liabilities 675,470 858,662 166,854 502,674 189,134 Other financial liabilities 1,725,912 1,797,765 1,667,087 130,678 — ￦ 26,350,251 31,668,938 17,926,315 11,826,918 1,915,705 (*1) For issued financial guarantee contracts, the maximum amount of the guarantee is allocated to the earliest period in which the guarantee could be called. 2) Contractual maturities of derivative financial liabilities are as follows: (in millions of Won) Within 1 year - 5 years After 5 years Total Currency forward ￦ 11,779 10,132 — 21,911 Currency swap 570 1,687 3,845 6,102 Interest rate swap 1,525 1,368 — 2,893 Others 14,148 — — 14,148 ￦ 28,022 13,187 3,845 45,054 (d) Currency risk 1) The Company has exposure to the risk that the fair value or future cash flows of a financial instrument will fluctuate because of the changes in foreign exchange rates. The exposure to currency risk as of December 31, 2018 and 2019 is as follows: (in millions of Won) 2018 2019 Assets Liabilities Assets Liabilities USD ￦ 4,346,481 6,389,276 4,423,107 6,166,765 EUR 657,690 509,437 592,381 180,816 JPY 97,722 389,625 79,664 253,542 Others 259,949 142,868 481,455 319,046 2) As of December 31, 2018 and 2019, provided that functional currency against foreign currencies other than functional currency hypothetically strengthens or weakens by 10%, the changes in gain or loss for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 10% increase 10% decrease 10% increase 10% decrease USD ￦ (204,280 ) 204,280 (174,366 ) 174,366 EUR 14,825 (14,825 ) 41,156 (41,156 ) JPY (29,190 ) 29,190 (17,388 ) 17,388 (e) Interest rate risk 1) The carrying amount of interest-bearing financial instruments as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Fixed rate Financial assets ￦ 11,565,519 13,391,637 Financial liabilities (11,781,701 ) (13,264,607 ) (216,182 ) 127,030 Variable rate Financial liabilities ￦ (8,522,323 ) (7,852,476 ) 2) Sensitivity analysis on the cash flows of financial instruments with variable interest rate The Company’s interest rate risk mainly arises from borrowings with variable interest rate. As of December 31, 2018 and 2019, provided that other factors remain the same and the interest rate of borrowings with floating rates increases or decreases by 1%, the changes in interest expense for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 1% increase 1% decrease 1% increase 1% decrease Variable rate financial instruments ￦ (85,223 ) 85,223 (78,525 ) 78,525

Share Capital and Capital Surpl

Share Capital and Capital Surplus	12 Months Ended
Share Capital and Capital Surplus	Dec. 31, 2019
Text block [abstract]
Share Capital and Capital Surplus	24. Share Capital and Capital Surplus (a) Share capital as of December 31, 2018 and 2019 are as follows: (Share, in Won) 2018 2019 Authorized shares 200,000,000 200,000,000 Par value ￦ 5,000 5,000 Issued shares(1) 87,186,835 87,186,835 Shared capital(2) ￦ 482,403,125,000 482,403,125,000 (1) As of December 31, 2019, total shares of ADRs of 34,827,912 outstanding in overseas stock market are equivalent to 8,706,978 of common stock. (2) As of December 31, 2019, the difference between the ending balance of common stock and the par value of issued common stock is ￦ (b) The changes in issued common stock for the years ended December 31, 2018 and 2019 were as follows: (share) 2018 2019 Issued shares Treasury shares Number of Issued shares Treasury shares Number of Beginning 87,186,835 (7,187,231 ) 79,999,604 87,186,835 (7,185,703 ) 80,001,132 Disposal of treasury shares — 1,528 1,528 — 114,509 114,509 Ending 87,186,835 (7,185,703 ) 80,001,132 87,186,835 (7,071,194 ) 80,115,641 (c) Capital surplus as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Share premium ￦ 463,825 463,825 Gain on disposal of treasury shares 784,047 796,623 Other capital deficit 172,135 125,259 ￦ 1,420,007 1,385,707 (d) POSCO Energy Co., Ltd., a subsidiary of the Company, issued redeemable convertible preferred shares which are classified as non-controlling (Share, in Won) Redeemable Convertible Preferred Shares Issue date February 25, 2017 Number of shares issued 8,643,193 shares Price per share ￦ Voting rights No voting rights for 3 years from issue date Dividend rights Cumulative, Non-participating · Minimum dividend rate for 1 year : 3.98% · Dividend rate for 2~3 years : 4.48% · Minimum dividend rate after 4 years : Comparative rate + Issuance spread + 2% Details about Redemption Issuer can demand redemption of all or part of redeemable convertible preferred shares every year after the issue date, for a period of 10 years from the issue date. Details about Conversion Stockholders of redeemable convertible preferred shares can convert them to common shares from 3 years after the issue date to the end of the redemption period (10 years). Conversion price is equal to issue price, which could be adjusted according to anti-dilution clause. Redeemable convertible preferred shares are classified as non-controlling

Hybrid Bonds

Hybrid Bonds	12 Months Ended
Hybrid Bonds	Dec. 31, 2019
Text block [abstract]
Hybrid Bonds	25. Hybrid Bonds (a) Hybrid bonds classified as equity as of December 31, 2018 and 2019 are as follows: (in millions of Won) Date of issue Date of Interest 2018 2019 Hybrid bond 1-2(1) 2013-06-13 2043-06-13 4.60 ￦ 200,000 200,000 Issuance cost (616 ) (616 ) ￦ 199,384 199,384 (1) Details of issuance of hybrid bonds as of December 31, 2019 are as follows: Hybrid bond 1-2 Maturity date 30 years (POSCO has a right to extend the maturity date) Interest rate Issue date ~ 2023-06-12 Reset every 10 years as follows; · After 10 years : return on government bond (10 years) + 1.40% · After 10 years : additionally +0.25% according to Step-up · After 30 years : additionally +0.75% Interest payments condition Quarterly (Optional deferral of interest payment is available to POSCO) Others POSCO can call the hybrid bond at year 10 and interest payment date afterwards The hybrid bond holder’s preference in the event of liquidation is senior to the common shareholders, but subordinate to other creditors. The interest accumulated but not paid on the hybrid bonds as of December 31, 2019 amounts to ￦ (b) POSCO ENERGY CO., LTD., a subsidiary of the Company, issued hybrid bonds, which are classified as non-controlling (in millions of Won) Date of issue Date of maturity Interest rate (%) 2018 2019 Hybrid bond 1-4(1) 2013-08-29 2043-08-29 5.21 140,000 140,000 Issuance cost (429 ) (429 ) ￦ 139,571 139,571 (1) Details of issuance of hybrid bonds of POSCO ENERGY Co., Ltd .as of December 31, 2019 are as follows: Hybrid bond 1-4 Maturity date 30 years (The Company has a right to extend the maturity date) Interest rate Issue date ~ 2023-08-29 Reset every 10 years as follows; · After 10 years : return on government bond (10 years) + 1.55% · After 10 years : additionally +0.25% according to Step-up · After 30 years : additionally +0.75% Interest payments condition Quarterly (Optional deferral of interest payment is available to the issuer) Others The issuer can call the hybrid bond at year 10 and interest payment date afterwards The hybrid bond holders’ preference in the event of liquidation is senior to the common shareholders, but subordinate to other creditors. The interest accumulated but not paid on the hybrid bonds as of December 31, 2019 amounts to ￦

Reserves

Reserves	12 Months Ended
Reserves	Dec. 31, 2019
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Reserves	26. Reserves (a) Reserves as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Accumulated comprehensive loss of investments in associates and joint ventures ￦ (670,435 ) (648,712 ) Changes in fair value of equity investments at fair value through other comprehensive income (295,300 ) (285,073 ) Foreign currency translation differences (417,817 ) (202,636 ) Gain or losses on valuation of derivatives (352 ) (438 ) Others (20,464 ) (21,121 ) ￦ (1,404,368 ) (1,157,980 ) (b) Changes in unrealized fair value of available-for-sale (in millions of Won) 2018 2019 Beginning balance ￦ 230,190 (295,300 ) Initial application of IFRS No. 9 (421,525 ) — Changes in unrealized fair value of equity investments (139,226 ) (9,422 ) Reclassification upon disposal 45,737 21,902 Others (10,476 ) (2,253 ) Ending balance ￦ (295,300 ) (285,073 )

Treasury Shares

Treasury Shares	12 Months Ended
Treasury Shares	Dec. 31, 2019
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Treasury Shares	27. Treasury Shares Based on the Board of Directors’ resolution, POSCO holds treasury shares for business purposes including its share price stabilization. The changes in treasury shares for the years ended December 31, 2018 and 2019 were as follows: (shares, in millions of Won) 2018 2019 Number of shares Amount Number of shares Amount Beginning 7,187,231 ￦ 1,533,054 7,185,703 ￦ 1,532,728 Disposal of treasury shares (1,528 ) (326 ) (114,509 ) (24,425 ) Ending 7,185,703 ￦ 1,532,728 7,071,194 ￦ 1,508,303

Revenue

Revenue	12 Months Ended
Revenue	Dec. 31, 2019
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Revenue	28. Revenue (a) Disaggregation of revenue 1) Details of revenue disaggregated by types of revenue and timing of revenue recognition for the years ended December 31, 2017, 2018 and 2019 were as follows: ① For the year ended December 31, 2017 (in millions of Won) Steel Trading Construction Others Total Types of revenue Revenue from sales of goods ￦ 30,064,680 20,655,267 20,368 617,394 51,357,709 Revenue from services 111,494 28,793 48,408 1,876,179 2,064,874 Revenue from construction contract — — 6,262,038 37,154 6,299,192 Others 54,194 118,147 87,559 205,192 465,092 ￦ 30,230,368 20,802,207 6,418,373 2,735,919 60,186,867 Timing of revenue recognition Revenue recognized at a point in time ￦ 30,118,874 20,773,414 334,345 832,369 52,059,002 Revenue recognized over time 111,494 28,793 6,084,028 1,903,550 8,127,865 ￦ 30,230,368 20,802,207 6,418,373 2,735,919 60,186,867 ② For the year ended December 31, 2018 (in millions of Won) Steel Trading Construction Others Total Types of revenue Revenue from sales of goods ￦ 31,733,609 21,632,183 3,568 605,206 53,974,566 Revenue from services 583,359 611,752 63,922 2,274,606 3,533,639 Revenue from construction contract — — 6,860,995 272,778 7,133,773 Others 41,041 163,782 17,784 290,051 512,658 ￦ 32,358,009 22,407,717 6,946,269 3,442,641 65,154,636 Timing of revenue recognition Revenue recognized at a point in time ￦ 31,774,650 21,795,965 743,448 906,120 55,220,183 Revenue recognized over time 583,359 611,752 6,202,821 2,536,521 9,934,453 ￦ 32,358,009 22,407,717 6,946,269 3,442,641 65,154,636 ③ For the year ended December 31, 2019 (in millions of Won) Steel Trading Construction Others Total Types of revenue Revenue from sales of goods ￦ 31,456,714 21,629,838 — 712,196 53,798,748 Revenue from services 573,463 369,730 49,696 2,217,862 3,210,751 Revenue from construction contract — — 7,308,401 30,998 7,339,399 Others 48,276 157,564 5,393 225,578 436,811 ￦ 32,078,453 22,157,132 7,363,490 3,186,634 64,785,709 Timing of revenue recognition Revenue recognized at a point in time ￦ 31,504,990 21,787,402 747,917 943,037 54,983,346 Revenue recognized over time 573,463 369,730 6,615,573 2,243,597 9,802,363 ￦ 32,078,453 22,157,132 7,363,490 3,186,634 64,785,709 (b) Details of contract assets and liabilities from contracts with customers as of December 31, 2018 and 2019, are as follows. (in millions of Won) 2018 2019 Receivables Account receivables ￦ 8,819,617 8,214,459 Contract assets Due from customers for contract work 737,712 1,054,357 Contract liabilities Advance received 1,278,731 864,480 Due to customers for contract work 641,064 644,947 Unearned revenue 91,872 88,733

Revenue - Contract Balances

Revenue - Contract Balances	12 Months Ended
Revenue - Contract Balances	Dec. 31, 2019
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Revenue - Contract Balances	29. Revenue – Contract Balances (a) Details of in-progress (in millions of Won) 2018 2019 Accumulated cost ￦ 26,153,452 27,281,031 Accumulated contract profit 1,848,718 2,462,008 Accumulated contract loss (804,538 ) (1,185,200 ) Accumulated contract revenue 27,197,632 28,557,839 (b) Details of due from customers for contract work and due to customers for contract work as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Unbilled due from customers for contract work ￦ 810,655 1,128,116 Due to customers for contract work (641,064 ) (644,947 ) ￦ 169,591 483,169 (c) Due to the factors causing the variation of costs for the years ended December 31, 2018 and 2019, the estimated total contract costs have changed. Details of changes in estimated total contract costs and the impact on profit before income taxes for the years ended December 31, 2018, 2019 and future periods are as follows: (in millions of Won) 2018 2019 Changes in estimated total contract costs ￦ 427,812 533,639 Changes in profit before income taxes of construction contract : - Current period (38,720 ) (166,077 ) - Future periods 69,428 (43,584 ) The effect on the current and future profit is estimated based on the circumstances that have occurred from the commencement date of the contract to the end of period. The estimation is evaluated for the total contract costs and expected total contract revenue as of the end of the period. Also, it may change during future periods. (d) Uncertainty of estimates 1) Total contract revenues Total contract revenues are measured based on contractual amount initially agreed. However, the contract revenues can increase due to additional contract work, claims and incentive payments, or decrease due to penalty when the completion of contract is delayed due to the Company’s fault. Therefore, the measurement of contract revenues is affected by the uncertainty of the occurrence of future events. 2) Total contract costs Contract revenues are recognized based on the percentage of completion, which is measured on the basis of the gross cost amount incurred to date. Total contract costs are estimated based on estimates of future material costs, labor costs, outsourcing cost and others. There is uncertainty in estimates on future contract costs due to various internal and external factors such as fluctuation of market, the risk of business partner and the experience of project performance and others. The significant assumptions including uncertainty of the estimate of total contract costs are as follows: Method of significant assumption Material cost Assumption based on recent purchasing price and quoted market price Labor cost Assumption based on standard monthly and daily labor cost Outsourcing cost Assumption based on the past experience rate of similar project and market price Management reviews the assumptions used in estimated contract costs at each reporting period end and adjusts them, if necessary. (e) As of December 31, 2019, revenue expected to be recognized in the future in relation to performance obligations that have not been fulfilled (or partially fulfilled) is as follows: (in millions of Won) 2020 2021 2022 After 2023 Total Expected Revenue ￦ 6,387,124 4,279,557 2,105,577 1,965,478 14,737,736

Selling and Administrative Expe

Selling and Administrative Expenses	12 Months Ended
Selling and Administrative Expenses	Dec. 31, 2019
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Selling and Administrative Expenses	30. Selling and Administrative Expenses (a) Other administrative expenses Other administrative expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Wages and salaries ￦ 774,900 813,467 840,599 Expenses related to post-employment benefits 78,654 73,290 88,880 Other employee benefits 159,920 176,240 177,908 Travel 39,790 40,929 42,692 Depreciation 97,261 101,274 131,337 Amortization 146,314 112,418 112,171 Communication 11,740 10,616 11,150 Electricity 7,050 8,309 8,799 Taxes and public dues 72,826 71,973 78,932 Rental 69,976 69,516 39,886 Repairs 9,859 15,291 13,454 Entertainment 11,582 11,816 11,123 Advertising 119,724 106,875 82,574 Research & development 125,795 108,352 110,315 Service fees 193,387 165,938 193,486 Vehicles maintenance 8,211 8,942 7,660 Industry association fee 10,140 9,571 9,609 Conference 14,494 14,510 15,104 Increase to provisions 10,990 14,433 18,071 Others 40,493 51,995 47,536 ￦ 2,003,106 1,985,755 2,041,286 (b) Selling expenses Selling expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Freight and custody(1) ￦ 1,336,969 184,675 180,341 Operating expenses for distribution center 10,503 10,614 9,222 Sales commissions 115,925 79,080 73,941 Sales advertising 3,800 4,821 1,552 Sales promotion 12,414 13,792 9,989 Sample 1,989 2,716 2,287 Sales insurance premium 36,546 37,251 32,632 Contract cost 23,061 16,992 38,081 Others 16,070 19,304 20,273 ￦ 1,557,277 369,245 368,318 (1) From the year ended December 31, 2018, upon adoption of IFRS No. 15, the Company recognized the freight expenses included in selling expenses incurred for the delivery of transportation services identified as a separate performance obligations in cost of sales.

Research and Development Expend

Research and Development Expenditures Recognized as Expenses	12 Months Ended
	Dec. 31, 2019
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Research and Development Expenditures Recognized as Expenses	31. Research and Development Expenditures Recognized as Expenses Research and development expenditures recognized as expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Administrative expenses ￦ 125,795 108,352 110,315 Cost of sales 361,093 418,250 389,460 ￦ 486,888 526,602 499,775

Other Operating Income and Expe

Other Operating Income and Expenses	12 Months Ended
Other Operating Income and Expenses	Dec. 31, 2019
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Other Operating Income and Expenses	32. Other Operating Income and Expenses Details of other operating income and expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Other operating income Gain on disposals of assets held for sale ￦ 1,180 27,171 37,461 Gain on disposals of investment in subsidiaries, associates and joint ventures 81,794 45,241 27,836 Gain on disposals of property, plant and equipment 32,145 53,139 49,367 Gain on disposals of intangible assets 23,391 117,139 1,896 Gain on valuation of firm commitment 56,301 39,028 60,201 Gain on valuation of emission rights — — 25,440 Gain on disposals of emission rights — — 11,141 Reversal of other provisions — 3,557 36,522 Others(1,3) 253,670 238,311 201,027 ￦ 448,481 523,586 450,891 Other operating expenses Impairment loss on assets held for sale ￦ — (50,829 ) (38,328 ) Loss on disposals of investments in subsidiaries, associates and joint ventures (19,985 ) (5,226 ) (6,539 ) Loss on disposals of property, plant and equipment (151,343 ) (117,614 ) (120,227 ) Impairment loss on property, plant and equipment (117,231 ) (1,004,704 ) (442,700 ) Impairment loss on investment property — (51,461 ) (32,642 ) Impairment loss on intangible assets (167,995 ) (337,519 ) (191,021 ) Loss on valuation of firm commitment (43,164 ) (66,281 ) (37,685 ) Idle tangible asset expenses (10,490 ) (9,257 ) (34,152 ) Increase to provisions (33,964 ) (134,632 ) (23,074 ) Donations (51,424 ) (52,074 ) (51,567 ) Others(2) (95,780 ) (184,865 ) (112,029 ) ￦ (691,376 ) (2,014,462 ) (1,089,964 ) (1) During the year ended December 31, 2019, the Company recognized other operating income of ￦ (2) During the 2018, the Company recognized the other-operating expenses of ￦ (*3) During the year ended December 31, 2018, the Company recognized other operating income of ￦

Finance Income and Costs

Finance Income and Costs	12 Months Ended
Finance Income and Costs	Dec. 31, 2019
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Finance Income and Costs	33. Finance Income and Costs Details of finance income and costs for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Finance income Interest income(1) ￦ 212,451 337,258 352,384 Dividend income 92,962 63,345 75,455 Gain on foreign currency transactions 785,616 716,060 824,565 Gain on foreign currency translations 564,016 212,443 206,019 Gain on derivatives transactions 210,727 247,513 195,933 Gain on valuations of derivatives 64,735 96,986 163,491 Gain on disposals of financial assets at fair value through profit of loss — 8,742 8,525 Gain on disposals of available-for-sale 425,684 — — Gain on valuations of financial assets at fair value through profit or loss — 16,149 42,297 Others 16,476 7,474 3,474 ￦ 2,372,667 1,705,970 1,872,143 Finance costs Interest expenses ￦ (653,115 ) (741,296 ) (755,711 ) Loss on foreign currency transactions (756,654 ) (810,857 ) (746,603 ) Loss on foreign currency translations (422,880 ) (321,748 ) (319,470 ) Loss on derivatives transactions (236,273 ) (208,772 ) (228,144 ) Loss on valuations of derivatives (226,487 ) (40,674 ) (47,447 ) Loss on disposals of trade accounts and notes receivable (32,456 ) (39,970 ) (36,935 ) Impairment loss on available-for-sale (123,214 ) — — Loss on disposals of financial assets at fair value through profit or loss — (1,474 ) (2,969 ) Loss on valuations of financial assets at fair value through profit or loss — (59,442 ) (65,848 ) Others (33,198 ) (20,183 ) (38,936 ) ￦ (2,484,277 ) (2,244,416 ) (2,242,063 ) (1) Interest income calculated using the effective interest method for the years ended December 31, 2017, 2018 and 2019 were ￦￦￦

Expenses by Nature

Expenses by Nature	12 Months Ended
Expenses by Nature	Dec. 31, 2019
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Expenses by Nature	34. Expenses by Nature Expenses that are recorded by nature as cost of sales, selling and administrative expenses, impairment loss on other receivables and other operating expenses in the statements of comprehensive income for the years ended December 31, 2017, 2018 and 2019 were as follows (excluding finance costs and income tax expense): (in millions of Won) 2017 2018 2019 Raw material used, changes in inventories and others ￦ 35,584,184 38,884,690 39,279,866 Employee benefits(2) 3,357,861 3,639,192 3,623,611 Outsourced processing cost 7,074,948 7,462,656 8,250,372 Electricity 933,045 949,435 912,832 Depreciation(1) 2,887,646 2,911,048 3,029,868 Amortization 409,774 356,581 431,247 Freight and custody 1,336,969 1,414,940 1,446,628 Sales commissions 115,925 79,080 73,941 Loss on disposal of property, plant and equipment 151,343 117,614 120,227 Impairment loss on property, plant and equipment 117,231 1,004,704 442,700 Impairment loss on goodwill and intangible assets 167,995 337,519 191,021 Donations 51,424 52,074 51,567 Other 4,253,625 4,445,124 4,168,470 ￦ 56,441,970 61,654,657 62,022,350 (1) Includes depreciation of investment property. (2) The details of employee benefits expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Wages and salaries ￦ 3,105,364 3,372,831 3,313,642 Expenses related to post-employment benefits 252,497 266,361 309,969 ￦ 3,357,861 3,639,192 3,623,611

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2019
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Income Taxes	35. Income Taxes (a) Income tax expense for the years ended December 31, 2017, 2018 and 2019 was as follows: (in millions of Won) 2017 2018 2019 Current income taxes(1) ￦ 864,143 1,577,581 913,286 Deferred income tax due to temporary differences 300,037 (38,851 ) 164,078 Items recorded directly in equity 21,560 144,900 11,005 Income tax expense ￦ 1,185,740 1,683,630 1,088,369 (1) Refund (additional payment) of income taxes when filing a final corporation tax return credited (charged) directly to current income taxes. (b) The income taxes credited (charged) directly to equity for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Net changes in the unrealized fair value of available-for-sale ￦ 1,271 47,423 (26,744 ) Gain on disposal of treasury shares (40 ) (50 ) — Others 20,329 97,527 37,749 ￦ 21,560 144,900 11,005 (c) The following table reconciles the calculated income tax expense based on POSCO’s statutory rate (27.5%) to the actual amount of taxes recorded by the Company for the years ended December 31, 2017, 2018 and 2019. (in millions of Won) 2017 2018 2019 Profit before income tax expense ￦ 4,095,051 3,616,016 3,126,534 Income tax expense computed at statutory rate 990,540 982,287 847,017 Adjustments: Tax credits (40,757 ) (32,103 ) (39,709 ) Additional income tax expense for prior years (over provisions from prior years) (20,912 ) 44,336 (35,389 ) Tax effect from tax audit — 130,196 14,775 Investment in subsidiaries, associates and joint ventures (12,510 ) 114,856 317,977 Tax effects due to permanent differences 72,421 64,708 (5,588 ) Effect of tax rate change(1) 175,647 — — Others(2) 21,311 379,350 (10,714 ) 195,200 701,343 241,352 Income tax expense ￦ 1,185,740 1,683,630 1,088,369 Effective tax rate (%) 28.96 % 46.56 % 34.81 % (1) During the year ended 31, 2017, the statutory rate changed from 24.2% to 27.5% for taxable income in excess of ￦ (2) Includes the effect of undeductible impairment loss related to Synthetic Natural Gas (SNG) facility for the year ended December 31, 2018. (d) The movements in deferred tax assets (liabilities) for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Beginning Inc. Ending Beginning Inc. Ending Deferred income tax due to temporary differences Allowance for doubtful accounts ￦ 273,994 (92,851 ) 181,143 181,143 (28,007 ) 153,136 Reserve for technology developments (37,987 ) 37,987 — — — — PP&E - Depreciation 14,641 (4,804 ) 9,837 9,837 12,374 22,211 Share of profit or loss of equity-accounted investees 196,042 31,552 227,594 227,594 (108,480 ) 119,114 Allowance for inventories valuation 10,780 (104 ) 10,676 10,676 (1,231 ) 9,445 PP&E - Revaluation (1,828,164 ) (33,548 ) (1,861,712 ) (1,861,712 ) 43,251 (1,818,461 ) Prepaid expenses 20,000 (2,741 ) 17,259 17,259 (2,047 ) 15,212 PP&E - Impairment loss 5,540 (927 ) 4,613 4,613 (208 ) 4,405 Gain or loss on foreign currency translation (48,472 ) 10,462 (38,010 ) (38,010 ) 45,046 7,036 Defined benefit liabilities (36,754 ) (36,835 ) (73,589 ) (73,589 ) (22,094 ) (95,683 ) Provision for construction losses 441 6,964 7,405 7,405 (102 ) 7,303 Provision for construction warranty 28,717 41,601 70,318 70,318 (8,517 ) 61,801 Accrued income (12,915 ) (179 ) (13,094 ) (13,094 ) (17,722 ) (30,816 ) Impairment loss on AFS 202,795 (126,876 ) 75,919 75,919 36,636 112,555 Difference in acquisition costs of treasury shares 70,547 (15 ) 70,532 70,532 (1,124 ) 69,408 Others 490,225 (65,906 ) 424,319 424,319 (30,535 ) 393,784 (650,570 ) (236,220 ) (886,790 ) (886,790 ) (82,760 ) (969,550 ) Deferred income taxes recognized directly to equity Net changes in fair value of equity investments at fair value through other comprehensive income(1) (49,236 ) 206,121 156,885 156,885 (26,744 ) 130,141 Others 72,161 58,111 130,272 130,272 37,749 168,021 22,925 264,232 287,157 287,157 11,005 298,162 Deferred tax from tax credit Tax credit carry-forward and others 118,032 (2,443 ) 115,589 115,589 (23,750 ) 91,839 Investments in subsidiaries, associates and joint ventures Investments in subsidiaries, associates and joint ventures 68,426 135,512 203,938 203,938 (68,574 ) 135,364 ￦ (441,187 ) 161,081 (280,106 ) (280,106 ) (164,079 ) (444,185 ) (1) These changes include the cumulative impact of initial application of IFRS No. 15 and IFRS No. 9 from the year ended December 31, 2018. (e) Deferred tax assets and liabilities for the years ended December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Assets Liabilities Net Assets Liabilities Net Deferred income tax due to temporary differences Allowance for doubtful accounts ￦ 181,143 — 181,143 153,136 — 153,136 Reserve for technology developments — — — — — — PP&E - Depreciation 55,354 (45,517 ) 9,837 68,649 (46,438 ) 22,211 Share of profit or loss of equity-accounted investees 278,466 (50,872 ) 227,594 177,467 (58,353 ) 119,114 Allowance for inventories valuation 10,676 — 10,676 9,445 — 9,445 PP&E - Revaluation — (1,861,712 ) (1,861,712 ) — (1,818,461 ) (1,818,461 ) Prepaid expenses 17,259 — 17,259 15,212 — 15,212 PP&E - Impairment loss 5,240 (627 ) 4,613 4,405 — 4,405 Gain or loss on foreign currency translation 121,797 (159,807 ) (38,010 ) 136,360 (129,324 ) 7,036 Defined benefit liabilities 390,972 (464,561 ) (73,589 ) 426,930 (522,613 ) (95,683 ) Provision for construction losses 7,405 — 7,405 7,303 — 7,303 Provision for construction warranty 70,318 — 70,318 61,801 — 61,801 Accrued income — (13,094 ) (13,094 ) — (30,816 ) (30,816 ) Impairment loss on AFS 75,919 — 75,919 112,555 — 112,555 Difference in acquisition costs of treasury shares 70,532 — 70,532 69,408 — 69,408 Others 820,611 (396,292 ) 424,319 471,621 (77,836 ) 393,784 2,105,692 (2,992,482 ) (886,790 ) 1,714,292 (2,683,841 ) (969,550 ) Deferred income taxes recognized directly to equity Net changes in fair value of equity investments at fair value through other comprehensive income 247,921 (91,036 ) 156,885 220,276 (90,135 ) 130,141 Others 153,609 (23,337 ) 130,272 193,384 (25,363 ) 168,021 401,530 (114,373 ) 287,157 413,660 (115,498 ) 298,162 Deferred tax from tax credit Tax credit carry-forward and others 115,589 — 115,589 91,839 — 91,839 Investments in subsidiaries, associates and joint ventures Investments in subsidiaries, associates and joint ventures 547,662 (343,724 ) 203,938 441,172 (305,808 ) 135,364 ￦ 3,170,473 (3,450,579 ) (280,106 ) 2,660,963 (3,105,147 ) (444,185 ) (f) As of December 31, 2019, deductible temporary differences of ￦￦￦ (g) The Company recognized current tax payable or receivable at the best of the tax amount expected to be paid or received that reflects uncertainty related to income taxes.

Earnings per Share

Earnings per Share	12 Months Ended
Earnings per Share	Dec. 31, 2019
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Earnings per Share	36. Earnings per Share Basic and diluted earnings per share for the years ended December 31, 2017, 2018 and 2019 were as follows: (in Won, except per share 2017 2018 2019 Profit attribute to controlling interest ￦ 2,756,230,487,872 1,711,901,875,666 1,864,405,092,477 Interests of hybrid bonds (33,048,799,997 ) (17,720,986,299 ) (6,669,999,999 ) Weighted-average number of common shares outstanding(1) 79,998,600 80,000,606 80,113,759 Basic and diluted earnings per share ￦ 34,040 21,177 23,189 (1) The weighted-average number of common shares used to calculate basic and diluted earnings per share are as follows: (shares) 2017 2018 2019 Total number of common shares issued 87,186,835 87,186,835 87,186,835 Weighted-average number of treasury shares (7,188,235 ) (7,186,229 ) (7,073,076 ) Weighted-average number of common shares outstanding 79,998,600 80,000,606 80,113,759 Since there were no potential shares of common stock which had dilutive effects as of December 31, 2017, 2018 and 2019, diluted earnings per share is equal to basic earnings per share.

Related Party Transactions

Related Party Transactions	12 Months Ended
Related Party Transactions	Dec. 31, 2019
Text block [abstract]
Related Party Transactions	37. Related Party Transactions (a) Significant transactions between the controlling company and related companies for the years ended December 31, 2017, 2018 and 2019 were as follows: 1) For the year ended December 31, 2017 (in millions of Won) Sales and others(1) Purchase and others (2) Sales Others Purchase of Purchase of Outsourced Others Subsidiaries(3) POSCO ENGINEERING & CONSTRUCTION CO.,LTD. ￦ 3,328 71 — 151,639 32 18,352 POSCO Processing&Service 298,781 1 113,628 4,595 8,309 404 POSCO COATED & COLOR STEEL Co., Ltd. 417,369 3,533 — — 8,483 106 POSCO ICT(4) 1,697 5,097 — 315,748 29,773 183,226 eNtoB Corporation 1 30 330,921 8,215 139 26,023 POSCO CHEMICAL CO., LTD 359,862 33,076 479,896 23,043 296,296 6,860 POSCO ENERGY CO., LTD. 179,966 1,456 — — — 2 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 5,214,127 35,182 550,258 221 44,108 1,948 POSCO Thainox Public Company Limited 218,005 9,780 10,168 — — — POSCO America Corporation 345,225 — 90 — — 1,776 POSCO Canada Ltd. 439 690 278,915 — — — POSCO Asia Co., Ltd. 1,949,354 1,454 365,025 337 1,625 4,982 Qingdao Pohang Stainless Steel Co., Ltd. 161,803 — — — — 176 POSCO JAPAN Co., Ltd. 1,436,159 20 26,256 621 — 44,829 POSCO-VIETNAM Co., Ltd. 212,883 — — — — 7 POSCO MEXICO S.A. DE C.V. 276,387 — — — — 1,749 POSCO Maharashtra Steel Private Limited 467,206 — — — — 65 POSCO(Suzhou) Automotive Processing Center Co., Ltd. 192,467 — — — — — Others 932,048 10,073 262,828 25,270 240,687 118,665 12,667,107 100,463 2,417,985 529,689 629,452 409,170 Associates and joint ventures(3) POSCO PLANTEC Co., Ltd. 2,947 112 5,487 300,041 20,718 19,763 SNNC 6,734 712 554,151 — — 4 POSCO-SAMSUNG-Slovakia Processing Center 52,779 — — — — — Roy Hill Holdings Pty Ltd — — 697,096 — — — CSP - Compania Siderurgica do Pecem 7,384 — 159,501 — — — Others 14,943 52,583 79,103 — — 3 84,787 53,407 1,495,338 300,041 20,718 19,770 ￦ 12,751,894 153,870 3,913,323 829,730 650,170 428,940 (1) Sales and others mainly consist of sales of steel products to subsidiaries, associates and joint ventures. These are priced on an arm’s length basis. (2) Purchases and others mainly consist of subsidiaries’ purchases of construction services and purchases of raw materials to manufacture steel products. These are priced on an arm`s length basis. (3) As of December 31, 2017, the Company provided guarantees to related parties (Note 38). (4) Others (purchase) mainly consist of service fees related to maintenance and repair of ERP System. 2) For the year ended December 31, 2018 (in millions of Won) Sales and others(1) Purchase and others(2) Sales Others Purchase of Purchase of fixed assets Outsourced Others Subsidiaries(3) POSCO ENGINEERING & CONSTRUCTION CO., LTD. ￦ 7,827 97 — 322,924 47 36,428 POSCO COATED & COLOR STEEL Co., Ltd. 476,105 2,725 — — 9,211 1,434 POSCO ICT(4) 2,624 7,479 — 341,472 34,376 196,252 eNtoB Corporation 12 60 377,198 27,508 390 31,455 POSCO CHEMICAL CO., LTD 417,957 35,762 531,452 21,730 319,868 2,802 POSCO ENERGY CO., LTD. 206,638 1,445 — — — — POSCO INTERNATIONAL Corporation 5,835,226 42,888 690,345 — 57,624 4,318 POSCO Thainox Public Company Limited 299,450 5,335 10,115 — — 71 POSCO America Corporation 336,366 — — — — 2,486 POSCO Canada Ltd. — 2,155 300,982 — — — POSCO Asia Co., Ltd. 1,857,665 253 536,280 650 2,449 6,524 Qingdao Pohang Stainless Steel Co., Ltd. 188,252 7 — — — 34 POSCO JAPAN Co., Ltd. 1,353,313 6 25,773 4,204 — 5,411 POSCO-VIETNAM Co., Ltd. 273,573 156 — — — 8 POSCO MEXICO S.A. DE C.V. 299,276 17 — — — 35 POSCO Maharashtra Steel Private Limited 563,618 584 — — — 156 POSCO(Suzhou) Automotive Processing Center Co., Ltd. 196,095 — 2,616 — — 5 Others(5) 1,158,122 44,098 456,804 31,787 264,060 140,869 13,472,119 143,067 2,931,565 750,275 688,025 428,288 Associates and joint ventures(3) POSCO PLANTEC Co., Ltd. 10,904 240 3,166 215,023 24,192 10,257 SNNC 5,105 4,108 558,425 — — 80 POSCO-SAMSUNG-Slovakia Processing Center 61,981 — — — — — Roy Hill Holdings Pty Ltd — — 810,196 — — — Others 14,199 54,747 64,335 — — 6 92,189 59,095 1,436,122 215,023 24,192 10,343 ￦ 13,564,308 202,162 4,367,687 965,298 712,217 438,631 (1) Sales and others mainly consist of sales of steel products to subsidiaries, associates and joint ventures. (2) Purchases and others mainly consist of subsidiaries’ purchases of construction services and purchases of raw materials to manufacture steel products. (3) As of December 31, 2018, the Company provided guarantees to related parties (Note 38). (4) Others (purchase) mainly consist of service fees related to maintenance and repair of ERP System. (5) During the year ended December 31, 2018, the Company made loans of ￦ 3) For the year ended December 31, 2019 (in millions of Won) Sales and others(1) Purchase and others(2) Sales Others Purchase of Purchase of Outsourced Others Subsidiaries(3) POSCO ENGINEERING & CONSTRUCTION CO., LTD. ￦ 6,688 11,137 4,725 416,734 57 24,174 POSCO COATED & COLOR STEEL Co., Ltd. 468,070 2,014 95 — 20,298 724 POSCO ICT(4) 2,924 4,994 — 344,977 34,638 181,128 eNtoB Corporation 15 60 304,846 64,845 126 25,754 POSCO CHEMICAL CO., LTD (Formerly, POSCO CHEMTECH) 389,731 35,592 522,493 17,549 315,530 4,561 POSCO ENERGY CO., LTD. 148,205 2,211 5,123 94 — 7,561 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 6,025,938 46,661 541,002 — 49,506 7,149 POSCO Thainox Public Company Limited 265,374 13,795 10,037 — — 3 POSCO America Corporation 300,598 — — — — 2,994 POSCO Canada Ltd. 1,067 1,833 306,552 — — — POSCO Asia Co., Ltd. 1,781,841 1,352 390,056 1,338 1,574 7,561 Qingdao Pohang Stainless Steel Co., Ltd. 146,468 — — — — 110 POSCO JAPAN Co., Ltd. 1,509,631 36 38,631 6,269 — 5,835 POSCO-VIETNAM Co., Ltd. 265,849 368 — — — 66 POSCO MEXICO S.A. DE C.V. 303,924 159 — — — 809 POSCO Maharashtra Steel Private Limited 644,652 311 — — — 800 POSCO(Suzhou) Automotive Processing Center Co., Ltd. 121,633 27 2,189 — — — POSCO VST CO., LTD. 299,307 — — — — 114 POSCO INTERNATIONAL SINGAPORE PTE LTD. — 154 694,600 — — — Others 964,532 20,679 134,296 34,444 246,184 169,849 13,646,447 141,383 2,954,645 886,250 667,913 439,192 Associates and joint ventures(3) POSCO PLANTEC Co., Ltd. 1,364 86 2,882 306,927 15,089 30,317 SNNC 5,527 4,100 588,276 — — 9 POSCO-SAMSUNG-Slovakia Processing Center 65,688 — — — — — Roy Hill Holdings Pty Ltd — — 1,272,878 — — — Others 16,084 112,390 76,427 — — 85,167 88,663 116,576 1,940,463 306,927 15,089 115,493 ￦ 13,735,110 257,959 4,895,108 1,193,177 683,002 554,685 (1) Sales and others mainly consist of sales of steel products to subsidiaries, associates and joint ventures. (2) Purchases and others mainly consist of subsidiaries’ purchases of construction services and purchases of raw materials to manufacture steel products. (3) As of December 31, 2019, the company provided guarantees to related parties (Note 38) (4) Others (purchase) mainly consist of service fees related to maintenance and repair of ERP System. (b) The related account balances of receivables and payables resulting from significant transactions between the controlling company and related companies as of December 31, 2018 and 2019 are as follows: 1) December 31, 2018 (in millions of Won) Receivables Payables Trade accounts receivable Others Total Trade accounts Accounts Others Total Subsidiaries POSCO ENGINEERING & CONSTRUCTION CO., LTD. ￦ 57 5,181 5,238 — 52,775 438 53,213 POSCO COATED & COLOR STEEL Co., Ltd. 55,598 317 55,915 — 25 1,194 1,219 POSCO ICT — 229 229 1,572 112,960 8,717 123,249 eNtoB Corporation — — — 10,860 22,072 11 32,943 POSCO CHEMICAL CO., LTD (Formerly, POSCO CHEMTECH) 40,258 3,883 44,141 19,911 58,725 19,012 97,648 POSCO ENERGY CO., LTD. 22,163 1,700 23,863 — — 1,425 1,425 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 437,554 1,056 438,610 161 1,881 5,304 7,346 POSCO Thainox Public Company Limited 71,189 — 71,189 467 71 — 538 POSCO America Corporation 14,338 — 14,338 — 221 — 221 POSCO Asia Co., Ltd. 480,205 1,047 481,252 7,839 — — 7,839 Qingdao Pohang Stainless Steel Co., Ltd. 52,037 — 52,037 — — — — POSCO MEXICO S.A. DE C.V. 101,179 218 101,397 — — — — POSCO Maharashtra Steel Private Limited 390,413 1,428 391,841 — — — — Others 379,950 54,407 434,357 33,183 36,591 85,745 155,519 2,044,941 69,466 2,114,407 73,993 285,321 121,846 481,160 Associates and joint ventures POSCO PLANTEC Co., Ltd. 249 10 259 3,275 34,803 — 38,078 SNNC 541 61 602 22,188 — — 22,188 Roy Hill Holdings Pty Ltd — — — 22,997 — — 22,997 Others 918 910 1,828 217 76 — 293 1,708 981 2,689 48,677 34,879 — 83,556 ￦ 2,046,649 70,447 2,117,096 122,670 320,200 121,846 564,716 2) December 31, 2019 (in millions of Won) Receivables Payables Trade accounts Others Total Trade accounts Accounts Others Total Subsidiaries POSCO ENGINEERING & CONSTRUCTION CO.,LTD. ￦ 5,702 65 5,767 — 78,512 385 78,897 POSCO COATED & COLOR STEEL Co., Ltd. 57,792 — 57,792 — 11 3,828 3,839 POSCO ICT 225 1 226 1,147 129,424 42,844 173,415 eNtoB Corporation — — — 3,459 27,431 — 30,890 POSCO CHEMICAL CO., LTD (Formerly, POSCO CHEMTECH) 35,102 3,578 38,680 17,839 52,710 19,369 89,918 POSCO ENERGY CO., LTD. 1,876 4 1,880 — 3,229 14,912 18,141 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 633,073 — 633,073 345 2,218 3,839 6,402 POSCO Thainox Public Company Limited 52,826 2 52,828 916 — — 916 POSCO America Corporation 8,448 — 8,448 — — — — POSCO Asia Co., Ltd. 508,962 748 509,710 12,784 171 — 12,955 Qingdao Pohang Stainless Steel Co., Ltd. 29,842 — 29,842 — — — — POSCO MEXICO S.A. DE C.V. 90,351 702 91,053 — — — — POSCO Maharashtra Steel Private Limited 235,917 444 236,361 — — — — Others(1) 470,734 33,851 504,585 14,397 40,233 87,652 142,282 2,130,850 39,395 2,170,245 50,887 333,939 172,829 557,655 Associates and joint ventures POSCO PLANTEC Co., Ltd. 84 10 94 471 49,511 — 49,982 SNNC 297 65 362 19,769 — — 19,769 Roy Hill Holdings Pty Ltd — — — 93,383 — — 93,383 Others 942 706 1,648 3,447 586 — 4,033 1,323 781 2,104 117,070 50,097 — 167,167 ￦ 2,132,173 40,176 2,172,349 167,957 384,036 172,829 724,822 (1) During the year ended December 31, 2018, the Company made loans of ￦ (c) Significant transactions between the Company, excluding the controlling company, and related companies for the years ended December 31, 2017, 2018 and 2019 were as follows: 1) For the year ended December 31, 2017 (in millions of Won) Sales and others Purchase and others Sales Others Purchase of Others Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 19,513 — 98 8,113 New Songdo International City Development, LLC 223,567 13,207 — 49 SNNC 26,288 — 3,578 17,985 Chuncheon Energy Co., Ltd. 42,147 — — — Noeul Green Energy Co., Ltd. 11,863 — — 2,178 VSC POSCO Steel Corporation 19,404 — 188 — USS-POSCO 26,899 107 2,222 — CSP - Compania Siderurgica do Pecem 241,299 — 101,018 21,154 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 38,484 — 47,241 — LLP POSUK Titanium — — 3,972 — BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 4 — 20,145 — POS-SEAHSTEELWIRE(TIANJIN)CO., 20,004 — — — PT. Batutua Tembaga Raya — — 21,024 — POSCO SeAH Steel Wire (Nantong) Co., Ltd. 34,088 — 192 — Zhangjiagang Pohang Refractories Co., Ltd. — — 87 1,632 Sebang Steel 441 — 23,778 — SHANGHAI WAIGAOQIAO FREE TRADE ZONE LANSHENG DAEWOO IN’L TRADING CO., LTD. 43,764 — — — DMSA/AMSA — 99 47,092 — South-East Asia Gas Pipeline Company Ltd. — 62,423 — — Others 272,107 43,126 19,520 19,483 ￦ 1,019,872 118,962 290,155 70,594 2) For the year ended December 31, 2018 (in millions of Won) Sales and others Purchase and others Sales Others Purchase of Others Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 19,394 — 83 24,103 New Songdo International City Development, LLC 30,997 53,316 — 97 SNNC 66,075 128 2,395 71,421 Chuncheon Energy Co., Ltd. 25,693 — — — Noeul Green Energy Co., Ltd. 6,444 — — 587 VSC POSCO Steel Corporation 12,504 — 2,314 — USS-POSCO — — 2,595 — CSP - Compania Siderurgica do Pecem 239,922 9,678 346,602 26,324 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 46,538 — 62,851 — BX STEEL POSCO Cold Rolled Sheet Co., Ltd. — — 10,572 — POS-SEAHSTEELWIRE(TIANJIN)CO., 12,244 — — — PT. Batutua Tembaga Raya — 168 15,663 — POSCO SeAH Steel Wire(Nantong) Co., Ltd. 30,417 — 249 — Sebang Steel — — 13,571 — DMSA/AMSA — — 46,293 — South-East Asia Gas Pipeline Company Ltd. — 50,789 — — Others 359,124 62,375 20,136 50,918 ￦ 849,352 176,454 523,324 173,450 3) For the year ended December 31, 2019 (in millions of Won) Sales and others Purchase and others Sales Others Purchase of Others Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 15,637 — 39 14,778 New Songdo International City Development, LLC 33,885 44,131 — 36 SNNC 74,034 — 35,910 65,503 Chuncheon Energy Co., Ltd. 1,156 — — — Noeul Green Energy Co., Ltd. 6,579 — — 1,217 USS-POSCO 4 — 1,835 — CSP - Compania Siderurgica do Pecem 98,330 12,718 416,541 23,398 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 34,895 — 39,733 — BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 10 — 4,222 — POS-SEAHSTEELWIRE(TIANJIN)CO., 11,500 — — — PT. Batutua Tembaga Raya — 772 45,841 — POSCO SeAH Steel Wire(Nantong) Co., Ltd. 30,083 — 353 — Sebang Steel — — 4,862 — DMSA/AMSA — — 71,275 — South-East Asia Gas Pipeline Company Ltd. 64 42,010 — — POSCO MITSUBISHI CARBON TECHNOLOGY 88,506 16,424 4,769 2,144 POSPower Co., Ltd. 163,167 — — — TK CHEMICAL CORPORATION 172,133 — 63,836 — Others 252,125 53,596 31,460 28,039 ￦ 982,108 169,651 720,676 135,115 (d) The related account balances of receivables and payables resulting from significant transactions between the Company, excluding the controlling company, and related companies as of December 31, 2018 and December 31, 2019 are as follows: 1) December 31, 2018 (in millions of Won) Receivables(1) Payables Trade accounts Loan Others Total Trade accounts Others Total Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 3,593 — 6 3,599 6,160 217 6,377 New Songdo International City Development, LLC 233,157 — — 233,157 — — — Chuncheon Energy Co., Ltd — — — — — 1,758 1,758 POSPower Co.,Ltd 13,703 — — 13,703 — 66,856 66,856 Nickel Mining Company SAS — 59,664 118 59,782 — — — CSP - Compania Siderurgica do Pecem 364,190 — 9,669 373,859 62,578 — 62,578 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 10,836 — — 10,836 2,101 — 2,101 PT. Batutua Tembaga Raya — 35,100 171 35,271 — — — POSCO SeAH Steel Wire(Nantong) Co., Ltd. 6,274 3,354 27 9,655 66 — 66 DMSA/AMSA — 64,297 — 64,297 — — — South-East Asia Gas Pipeline Company Ltd. — 191,107 — 191,107 — — — Others 75,382 136,117 83,786 295,285 7,768 5,363 13,131 ￦ 707,135 489,639 93,777 1,290,551 78,673 74,194 152,867 (1) As of December 31, 2018, the Company recognizes bad debt allowance for receivables amounting to ￦ 2) December 31, 2019 (in millions of Won) Receivables(1) Payables Trade accounts Loan Others Total Trade accounts Others Total Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 4,121 — 205 4,326 791 8 799 New Songdo International City Development, LLC 23,626 — 20,592 44,218 — 10 10 Chuncheon Energy Co., Ltd. — 8,234 — 8,234 657 — 657 POSPower Co., Ltd. 34,945 — — 34,945 — 67,543 67,543 Nickel Mining Company SAS — 60,516 120 60,636 — — — CSP - Compania Siderurgica do Pecem 244,700 — 14,264 258,964 — 33 33 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 10,273 — — 10,273 633 — 633 PT. Batutua Tembaga Raya — 36,291 19,993 56,284 56 — 56 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 7,035 — — 7,035 101 — 101 DMSA/AMSA — 57,999 1,672 59,671 — — — South-East Asia Gas Pipeline Company Ltd. 14 147,367 — 147,381 — — — POSCO MITSUBISHI CARBON TECHNOLOGY 8,078 — — 8,078 916 — 916 TK CHEMICAL CORPORATION 37,373 — — 37,373 110 — 110 Others 94,914 138,663 97,804 331,381 7,128 13,379 20,507 ￦ 465,079 449,070 154,650 1,068,799 10,392 80,973 91,365 (1) As of December 31, 2019, the Company recognizes bad debt allowance for receivables amounting to ￦ (e) Significant financial transactions between the Company, excluding the controlling company, and related companies for the years ended December 31, 2018 and 2019 were as follows: 1) December 31, 2018 (in millions of Won) Beginning Lend Collect Others(2) Ending Associates and joint ventures New Songdo International City Development, LLC ￦ 282,775 150 (252,759 ) (30,166 ) — GALE International Korea, LLC 2,000 8,500 (10,500 ) — — UITrans LRT Co., Ltd. — 5,695 — — 5,695 DMSA/AMSA(1) 69,713 9,965 (342 ) (15,039 ) 64,297 South-East Asia Gas Pipeline Company Ltd. 229,880 — (47,569 ) 8,796 191,107 PT. Batutua Tembaga Raya 29,048 4,678 — 1,374 35,100 PT. Tanggamus Electric Power 3,197 — — 1,226 4,423 PT. Wampu Electric Power 5,107 — — 223 5,330 PT. POSMI Steel Indonesia 4,286 — (2,200 ) 150 2,236 Nickel Mining Company SAS 59,668 — — (4 ) 59,664 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 5,357 — (5,357 ) — — KRAKATAU POS-CHEM DONG-SUH 6,428 — — 281 6,709 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 5,357 4,451 (6,454 ) — 3,354 POS-SeAH 6,428 — — 281 6,709 AMCI (WA) PTY LTD 92,061 3,795 — (5,376 ) 90,480 POS-AUSTEM 5,357 5,564 (5,357 ) 26 5,590 POS-AUSTEM 8,571 8,902 (8,571 ) 43 8,945 SAMHWAN VINA CO., LTD 1,071 — (1,071 ) — — ￦ 816,304 51,700 (340,180 ) (38,185 ) 489,639 (1) During the year ended December 31, 2018, loans amounting to ￦ (2) Includes adjustments of foreign currency translation differences and others. 2) December 31, 2019 (in millions of Won) Beginning Lend Collect Others(2) Ending Associates and joint ventures UITrans LRT Co., Ltd. ￦ 5,695 4,884 — — 10,579 DMSA/AMSA(1) 64,297 15,451 — (21,749 ) 57,999 South-East Asia Gas Pipeline Company Ltd. 191,107 — (48,027 ) 4,287 147,367 PT. Batutua Tembaga Raya 35,100 — — 1,191 36,291 PT. Tanggamus Electric Power 4,423 — — 157 4,580 PT. Wampu Electric Power 5,330 — — 189 5,519 PT. POSMI Steel Indonesia 2,236 — — 80 2,316 Nickel Mining Company SAS 59,664 — — 852 60,516 KRAKATAU POS-CHEM DONG-SUH 6,709 — — 238 6,947 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 3,354 — (3,354 ) — — POS-SeAH 6,709 — — 238 6,947 AMCI (WA) PTY LTD 90,480 4,669 — (16,596 ) 78,553 POS-AUSTEM 5,590 — — 199 5,789 POS-AUSTEM 8,945 — — 317 9,262 Hyo-chun — — — 2,382 2,382 Chuncheon Energy Co., Ltd. — 8,234 — — 8,234 POS-AUSTEM — 5,827 — (38 ) 5,789 ￦ 489,639 39,065 (51,381 ) (28,253 ) 449,070 (1) During the year ended December 31, 2019, loans amounting to ￦ (2) Includes adjustments of foreign currency translation differences and others. (3) During the year ended December 31, 2019, it was newly classified to associates. (f) For the years ended December 31, 2017, 2018 and 2019, details of compensation to key management officers were as follows: (in millions of Won) 2017 2018 2019 Short-term benefits ￦ 112,688 115,618 119,658 Long-term benefits 8,632 13,400 13,562 Retirement benefits 20,422 21,658 21,231 ￦ 141,742 150,676 154,451 Key management officers include directors (including non-standing

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2019
Text block [abstract]
Commitments and Contingencies	38. Commitments and Contingencies (a) Contingent liabilities Contingent liabilities may develop in a way not initially expected. Therefore, management continuously assesses contingent liabilities to determine whether an outflow of resources embodying economic benefits has become probable. If it becomes probable that an outflow of future economic benefits will be required for an item previously dealt with as a contingent liability, a provision is recognized in the consolidated financial statements of the period in which the change in probability occurs (except in the extremely rare circumstances where no reliable estimate can be made). Management makes estimates and assumptions that affect disclosures of commitments and contingencies. All estimates and assumptions are based on the evaluation of current circumstances and appraisals with the supports of internal specialists or external consultants. Management regularly analyzes current information about these matters and provides for probable contingent losses including the estimate of legal expense to resolve the matters. Internal and external lawyers are used for these assessments. In making the decision regarding the need for a provision, management considers whether the Company has an obligation as a result of a past event, whether it is probable that an outflow of cash or other resources embodying economic benefits will be required to settle the obligation and the ability to make a reliable estimate of the amount of the obligation. (b) Details of guarantees Contingent liabilities on outstanding guarantees and others provided by the Company as of December 31, 2019 are as follows. (in millions of Won) Guarantee limit Guarantee amount Guarantor Guarantee Financial Foreign currency Won Foreign Won [The Company] POSCO POSCO Asia Co., Ltd. BOC and others USD 100,000,000 115,780 100,000,000 115,780 POSCO ASSAN TST STEEL INDUSTRY SMBC and others USD 146,527,500 169,650 131,874,750 152,685 POSCO COATED STEEL (THAILAND) CO., LTD. The Great & CO Co., Ltd.(SPC) THB 5,501,000,000 212,669 5,501,000,000 212,669 POSCO Maharashtra Steel Private Limited Export-Import Bank of Korea and others USD 83,784,000 97,005 83,784,000 97,005 POSCO MEXICO S.A. DE C.V. BOA and others USD 120,000,000 138,936 120,000,000 138,936 POSCO SS VINA Co., Ltd. Export-Import Bank of Korea and others USD 298,000,000 345,024 298,000,000 345,024 POSCO-VIETNAM Co., Ltd. SMBC and others USD 156,000,000 180,617 156,000,000 180,617 PT. KRAKATAU POSCO Export-Import Bank of Korea and others USD 1,350,300,000 1,563,377 940,488,348 1,088,897 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) Daewoo Global Development. Pte., Ltd Export-Import Bank of Korea and others USD 199,884,500 231,426 183,992,000 213,026 Daewoo Power PNG Ltd. Export-Import Bank of Korea USD 53,517,404 61,962 41,167,234 47,663 POSCO ASSAN TST STEEL INDUSTRY ING and others USD 14,652,750 16,965 14,652,750 16,965 Songdo Posco family Housing SHINYOUNG SECURITIES CO., LTD. KRW 10,000 10,000 — — PT. Bio Inti Agrindo Export-Import Bank of Korea and others IDR 150,000,000,000 12,465 150,000,000,000 12,465 KEB Hana Bank USD 135,000,000 156,303 134,224,401 155,405 Golden Lace DAEWOO Company Limited Shinhan Bank USD 11,000,000 12,736 11,000,000 12,736 POSCO INTERNATIONAL AMERICA Corp. POSCO INTERNATIONAL SINGAPORE Pte. Ltd. POSCO INTERNATIONAL MEXICO S.A. de C.V. POSCO INTERNATIONAL Japan Corp. Bank Mendes Gans USD 50,000,000 57,890 5,602,997 6,487 POSCO INTERNATIONAL Malaysia SDN BHD POSCO INTERNATIONAL Deutschland GmbH POSCO INTERNATIONAL Italia S.R.L. Mykolaiv Milling Works PJSC. Black Sea Trade and Development Bank EUR 23,250,000 30,165 23,250,000 30,165 POSCO ENGINEERING & CONSTRUCTION CO., LTD. POSCO E&C Vietnam Co., Ltd. Export-Import Bank of Korea and others USD 47,000,000 54,417 47,000,000 54,417 HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd. Woori bank and others USD 160,000,000 185,248 149,740,000 173,369 POSCO Engineering and Construction India Private Limited KEB Hana Bank INR 221,000,000 3,587 171,200,000 2,779 PT. POSCO E&C INDONESIA POSCO Asia Co., Ltd. and others USD 10,900,000 12,620 10,900,000 12,620 JB CLARK HILLS Korea Investment & Securities Co., Ltd. KRW 60,000 60,000 55,000 55,000 Daewoo Global Development. Pte., Ltd SMBC and others USD 163,633,000 189,454 163,633,000 189,454 Songdo Posco family Housing SHINYOUNG SECURITIES CO., LTD. KRW 10,000 10,000 — — POSCO ICT PT.POSCO ICT INDONESIA POSCO Asia Co., Ltd. USD 1,500,000 1,737 1,500,000 1,737 POSCO CHEMCAL CO., LTD (Formerly, POSCO CHEMTECH) PT.Krakatau Posco Chemtech Calcination POSCO Asia Co., Ltd. USD 15,200,000 17,599 12,000,000 13,894 POSCO COATED & COLOR STEEL Co.,Ltd. Myanmar POSCO C&C Company, Limited. POSCO Asia Co., Ltd. USD 13,986,947 16,194 13,986,947 16,194 POSCO ENERGY CO., LTD. PT. KRAKATAU POSCO ENERGY Export-Import Bank of Korea and others USD 193,900,000 224,497 105,067,663 121,647 POSCO Asia Co., Ltd. POSCO America Corporation SMBC USD 70,000,000 81,046 70,000,000 81,046 [Associates and joint ventures] POSCO CSP - Compania Siderurgica do Pecem Export-Import Bank of Korea and others USD 420,000,000 486,276 373,565,631 432,514 BNDES BRL 464,060,000 133,672 464,060,000 133,672 LLP POSUK Titanium SMBC USD 15,000,000 17,367 15,000,000 17,367 Nickel Mining Company SAS SMBC EUR 46,000,000 59,682 46,000,000 59,682 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) GLOBAL KOMSCO Daewoo LLC KEB Hana Bank USD 8,225,000 9,523 8,050,000 9,320 POSCO ENGINEERING & CONSTRUCTION CO., LTD. New Songdo International City Development, LLC Others KRW 386,000 386,000 386,000 386,000 RPSD Project Co., Ltd Others KRW 45,000 45,000 35,000 35,000 Chun-cheon Energy Co., Ltd Kookmin Bank and others KRW 12,430 12,430 8,234 8,234 Pohang E&E Co., Ltd Heungkuk Life Insurance Co., Ltd. KRW 71,930 71,930 64,592 64,592 Incheon-Gimpo Expressway Co, Ltd. Kookmin Bank and others KRW 28,940 28,940 — — PT. Wampu Electric Power KEB Hana Bank USD 2,365,099 2,738 2,365,099 2,738 PT.Tanggamus Electric Power KEB Hana Bank USD 1,936,699 2,242 1,936,699 2,242 Metropolitan Outer Ring Expressway co., ltd. Others KRW 276,521 276,521 14,486 14,486 UITrans LRT Co., Ltd. Kookmin Bank and others KRW 121,750 121,750 107,176 107,176 NEXTRAIN Co., Ltd Others KRW 634,752 634,752 — — Pureun Tongyeong Enviro Co., Ltd. KDB Bank and others KRW 22,714 22,714 16,017 16,017 Pure Gimpo Co., Ltd. KDB Bank and others KRW 44,740 44,740 32,847 32,847 Clean Iksan Co., Ltd. Samsung Fire & Marine Insurance Co., Ltd. KRW 44,054 44,054 31,062 31,062 POSCO ICT Incheon-Gimpo Expressway Co, Ltd. KDB Bank KRW 100,000 100,000 100,000 100,000 UITrans LRT Co., Ltd. Kookmin Bank KRW 76,000 76,000 76,000 76,000 Hyochun CO., LTD KYOBO SECURITIES CO., LTD. 39,575 39,575 39,575 39,575 Metropolitan Outer Ring Expressway co., ltd. Woori bank and others KRW 193,700 193,700 7,748 7,748 POSCO CHEMCAL CO., LTD (Formerly, POSCO CHEMTECH) KRAKATAU POS-CHEM DONG-SUH KEB Hana Bank USD 1,140,000 1,320 506,667 587 POSCO(Suzhou) Automotive Processing Center Co.,Ltd. POS-InfraAuto KDB Bank USD 769,500 891 769,500 891 [Others] POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) Ambatovy Project Investments Ltd. and others Export-Import Bank of Korea USD 21,818,182 25,261 3,451,287 3,996 POSCO ICT Soosungenc and others KEB Hana Bank KRW 1,198,724 1,198,724 1,198,724 1,198,724 POSCO ENGINEERING & CONSTRUCTION CO., LTD. Ecocity CO., LTD and others Others KRW 3,616,714 3,616,714 2,156,506 2,156,506 POSCO AUSTRALIA PTY LTD Department of Trade and Investment (NSW Government) and others Woori bank and others AUD 26,525,154 21,495 26,525,154 21,495 AUD 26,525,154 21,495 26,525,154 21,495 BRL 464,060,000 133,672 464,060,000 133,672 EUR 69,250,000 89,847 69,250,000 89,847 IDR 150,000,000,000 12,465 150,000,000,000 12,465 INR 221,000,000 3,587 171,200,000 2,779 KRW 6,993,544 6,993,544 4,329,507 4,329,507 THB 5,501,000,000 212,669 5,501,000,000 212,669 USD 3,866,040,581 4,476,101 3,200,258,973 3,705,259 (c) Other commitments Details of other commitments of the Company as of December 31, 2019 are as follows: Company Description POSCO POSCO entered into long-term contracts to purchase iron ore, coal, nickel and others. The contracts of iron ore and coal generally have terms of more than three years and the contracts of nickel have terms of more than one year. These contracts provide for periodic price adjustments based on the market price. As of December 31, 2019, 102 million tons of iron ore and 11 million tons of coal remained to be purchased under such long-term contracts. POSCO entered into an agreement with Tangguh Liquefied Natural Gas (LNG) Consortium in Indonesia to purchase 550 thousand tons of LNG annually for 20 years commencing in August 2005. The purchase price is subject to change, based on changes of the monthly standard oil price (JCC) and with a price ceiling. POSCO has long-term service contracts for the transportation of raw materials. As of December 31, 2019, there are 39 vessels under contracts, and the average remaining contract period is about 10 years. As of December 31, 2019, POSCO entered into a commitment with KOREA ENERGY AGENCY for long-term foreign currency borrowings, which are limited up to the amount of USD 4.12 million. The borrowing is related to the exploration of gas hydrates in Western Fergana-Chinabad. The repayment of the borrowings depends on the success of the projects. POSCO is not liable for the repayment in full or in part of the amount borrowed if the respective projects fail. POSCO has agreed to pay a certain portion of its profits under certain conditions, as defined by the borrowing agreements. As of December 31, 2019, the ending balance of the borrowing amounts to USD 1.02 million. POSCO provides a ￦ POSCO has provided a supplemental funding agreement, as the largest shareholder, as requested from the creditors, including Norddeutsche Landesbank, for seamless funding to POSCO ENERGY Co., LTD., a subsidiary of the Company, under construction of new power plant. POSCO ENGINEERING & CONSTRUCTION CO., LTD. As of December 31, 2019, POSCO ENGINEERING & CONSTRUCTION CO., LTD. has foreign currency guarantee of up to USD 2,425 million and uses USD 710 million with Woori Bank and others. As of December 31, 2019, The out standing balance of loans related to major liability compliance agreements is ￦ POSCO ICT As of December 31, 2019, the company is provided with a guarantee of ￦￦￦ In connection with 15 projects, including the construction of the Bundang Center of Doosan Co.,LTD, the company is responsible for fulfilling its obligations, and as of the end of the current quarter, outstanding loans related to the liability compliance agreement are worth ￦ (d) Litigation in progress 1) Request for Arbitration of NSC Investment and TGC In March 2019, NSC Investment and TGC(“Applicant”), a joint venture former partner of POSCO E&C, in connection with the Songdo International City Development Project in Incheon, have filed an arbitration (mediation price: about USD 2 billion) for violations of POSCO E&C. In addition, the Applicants filed an appeal in the United States District Court for the Southern District of New York in March 2019, confirming that all claims specified in the above arbitration application must be resolved by ICC arbitration. As of December 31, 2019, the Company has determined that the applicant’s claim is not legally valid, and did not recognize a provision because it believes that the present obligation does not exist. 2) Other litigations As of December 31, 2019, litigations in progress that POSCO and certain subsidiaries are defendants in legal actions arising from the normal course of business are as follows: (in millions of Won, in thousands of Company Legal Claim amount Won Descrioption POSCO 23 KRW 39,500 39,500 Lawsuit on claim for employee right and others(1) POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 1 CAD 79,000 70,038 Lawsuit on claim for damages 5 INR 4,518,694 73,338 Lawsuit on claim for payment on guarantees and others(1) 8 KRW 18,786 18,786 Litigation for confirmation of deposit bond and others 4 USD 22,813 26,413 Lawsuit on claim for damages and others 1 PKR 124,775 931 Lawsuit on claim for damages POSCO ENGINEERING & CONSTRUCTION CO., LTD. 123 KRW 2,838,122 2,838,122 Lawsuit on claim for damages and others(1) POSCO ICT 1 BRL 10,244 2,951 Lawsuit on revocation of claim for damage(1) 11 KRW 8,500 8,500 Lawsuit on claim for damages and others(1) POSCO A&C 10 KRW 6,043 6,043 Lawsuit on claim for payment on construction and others POSCO ENERGY CO., LTD. 3 KRW 3,669 3,669 Lawsuit on claim for damages and others POSCO E&C CHINA CO., LTD. 5 CNY 66,655 11,047 Lawsuit over contract dispute and others POSCO COATED & COLOR STEEL Co., Ltd. 1 KRW 1,400 1,400 Lawsuit on claim for damages POSCO ENGINEERING (THAILAND) CO., LTD. 2 THB 160,929 6,222 Lawsuit on claim for payment on construction and others 1 USD 1,046 1,211 Lawsuit on claim for payment on construction PT. KRAKATAU POSCO 1 IDR 211,407,872 17,568 Lawsuit on claim for payment on construction POSCO E&C Vietnam Co., Ltd. 3 USD 5,131 5,941 Lawsuit on claim for payment on construction Pos-Sea 1 USD 12,700 14,704 Lawsuit over contract dispute POSCO TNPC Otomotiv Celik San. Ve Tic. A.S 7 TRY 102 20 Lawsuit over industrial accidents and others POSCO India Steel Distribution Center Private Ltd. 1 INR 223,795 3,632 Lawsuit on claim for tax restitution Brazil Sao Paulo Steel Processing Center 3 BRL 4,321 1,245 Lawsuit on claim for labor and others POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. 104 BRL 152,077 43,806 Lawsuit on claim for payment on construction and others(1) POSCO ASSAN TST STEEL INDUSTRY 1 TRY 1,965 383 Lawsuit on compensation POSCO Asia Co., Ltd. 1 USD 950 1,099 Lawsuit on claim for receivable ZHANGJIAGANG POHANG STAINLESS STEEL CO., LTD. 1 CNY 807 134 Lawsuit on claim for labor POSCO CHEMCAL CO., LTD (Formerly, POSCO CHEMTECH) 1 KRW 15,383 15,383 Calculation of stock purchase value POSCO M-TECH 2 KRW 425 425 Lawsuit on claim for damages POSCO Engineering and Construction India Private Limited 3 INR 27,995 454 Lawsuit on claim for payment POSCO INTERNATIONAL AMERICA Corp. 1 USD 150 174 Lawsuit over injury HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd. 1 KRW 3,305 3,305 Lawsuit on claim for payment (*1) The Company made a reliable estimate in 105 lawsuits by considering the possibility and estimated amount of outflow of resources and recognized ￦ For all the other lawsuits and claims, management does not believe the Company has any present obligations and the Company has not recognized any provisions. (e) Other contingent circumstances Other major contingencies for the Company for the years ended December 31, 2019 are as follows: Company Description POSCO POSCO has provided 3 blank checks to Korea Energy Agency as collateral for long-term foreign currency borrowings. POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) As of December 31, 2019, POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) has provided 33 blank promissory notes and 20 blank checks to Korea Energy Agency and others as collateral for the guarantee on performance for contracts and others. POSCO ENGINEERING & CONSTRUCTION Co., LTD. As of December 31, 2019, POSCO ENGINEERING & CONSTRUCTION CO., LTD. has provided 26 blank checks and 4 blank promissory notes as collateral for agreements and outstanding loans, and has provided joint guarantee of ￦ POSCO ICT As of December 31, 2019, POSCO ICT has provided 2 blank promissory notes and 6 blank checks to financial institutions as collateral for the guarantee on performance for contracts and others.

Additional Information of Cash

Additional Information of Cash Flow Statements	12 Months Ended
Additional Information of Cash Flow Statements	Dec. 31, 2019
Text block [abstract]
Additional Information of Cash Flow Statements	39. Additional Information of Cash Flow Statements (a) Changes in operating assets and liabilities for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Trade accounts and notes receivable ￦ 63,075 17,806 286,121 Other receivables 113,740 (20,786 ) (163,234 ) Inventories (1,435,170 ) (1,451,009 ) 1,136,819 Other current assets 110,688 1,118 42,337 Other non-current 12,455 5,974 (30,010 ) Trade accounts and notes payable (607,999 ) 379,742 (732,741 ) Other payables (26,922 ) (111,893 ) 2,762 Other current liabilities 338,273 (197,154 ) (173,762 ) Provisions (145,763 ) (119,617 ) (75,514 ) Payments of severance benefits (185,220 ) (189,165 ) (152,275 ) Plan assets 3,815 (245,214 ) (217,953 ) Other non-current (82,605 ) (175,528 ) (36,595 ) ￦ (1,841,633 ) (2,105,726 ) (114,045 ) (b) Changes in liabilities arising from financial activities for the years ended December 31, 2018 and 2019 were as follows: 1) December 31, 2018 (in millions of Won) Liabilities Derivatives that hedge Short-term borrowings long-term borrowings Dividend payable Finance lease liabilities Beginning ￦ 8,174,818 12,888,839 7,213 93,018 119,320 Changes from financing cash flows (854,554 ) (373,862 ) (770,099 ) (14,955 ) (17,237 ) Changes arising from obtaining or losing control of subsidiaries or other business (342 ) — — — — The effect of changes in foreign exchange rates 167,858 200,308 (5,573 ) (7,766 ) — Changes in fair values — — — — (58,666 ) Other changes: — Decrease in retained earnings — — 704,444 — — Decrease in non-controlling — — 72,688 — — Amortization of discount on debentures issued — 6,205 — — — Increase in finance lease assets — — — 24,457 — Ending ￦ 7,487,780 12,721,490 8,673 94,754 43,417 2) December 31, 2019 (in millions of Won) Liabilities Derivatives that hedge Short-term borrowings Long-term borrowings Dividend payable Lease liabilities Beginning ￦ 7,487,780 12,721,490 8,673 94,754 43,417 Changes from financing cash flows (2,194,727 ) 1,900,132 (962,712 ) (167,427 ) 7,657 Changes arising from obtaining or losing control of subsidiaries or other business (45,589 ) (88,966 ) 324 — — The effect of changes in foreign exchange rates 238,869 415,028 (649 ) (1,867 ) — Changes in fair values — — — — (117,023 ) Other changes: Decrease in retained earnings — — 889,900 — — Decrease in non-controlling — — 67,569 — — Amortization of discount on debentures issued — 7,596 — — — Initial application of IFRS No.16 — — — 677,370 — Increase in lease assets — — — 72,640 — Ending ￦ 5,486,333 14,955,280 3,105 675,470 (65,949 )

Operating Segments and Geograph

Operating Segments and Geographic Information	12 Months Ended
Operating Segments and Geographic Information	Dec. 31, 2019
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Operating Segments and Geographic Information	40. Operating Segments and Geographic Information (a) The Company’s operating segments are organized based on the nature of markets and customers. The Company has four reportable operating segments—steel, construction, trading and others. The steel segment includes production of steel products and revenue of such products. The construction segment includes planning, designing and construction of industrial plants, civil engineering projects and commercial and residential buildings, both in Korea and overseas. The trading segment consists of exporting and importing a wide range of steel products and raw materials that are both obtained from and supplied to POSCO, as well as between other suppliers and purchasers in Korea and overseas. Other segments include power generation, network and system integration and logistics. The policies of classification and measurement on operating segments were the same for all periods presented. (b) Information about reportable segments as of and for the years ended December 31, 2017, 2018 and 2019 were as follows: 1) As of and for the year ended December 31, 2017 (in millions of Won) Steel Trading Construction Others Total External revenues ￦ 30,230,368 20,802,207 6,886,606 2,735,919 60,655,100 Internal revenues 17,381,010 14,075,996 398,924 2,548,674 34,404,604 Including inter segment revenue 12,004,614 8,043,643 329,215 2,446,029 22,823,501 Total revenues 47,611,378 34,878,203 7,285,530 5,284,593 95,059,704 Interest income 128,827 32,799 100,922 17,940 280,488 Interest expenses (422,357 ) (121,967 ) (112,983 ) (100,656 ) (757,963 ) Depreciation and amortization (2,856,133 ) (206,490 ) (42,123 ) (255,620 ) (3,360,366 ) Impairment loss on property, plant and equipment and others (149,840 ) (140,839 ) (37,476 ) (8,564 ) (336,719 ) Impairment loss on available-for-sale (95,261 ) — (18,637 ) (13,421 ) (127,319 ) Share of profit or loss of investment in associates and JVs 8,352 — (8,555 ) (1,518 ) (1,721 ) Income tax expense (977,853 ) (109,710 ) (109,961 ) (77,172 ) (1,274,696 ) Segment profit (loss) 2,790,855 112,661 24,545 232,700 3,160,761 Segment assets 70,017,816 14,139,098 8,609,753 8,776,090 101,542,757 Investment in associates 16,116,654 1,134,798 668,392 1,193,895 19,113,739 Acquisition of non-current 2,033,184 286,185 99,190 251,665 2,670,224 Segment liabilities 19,057,249 10,386,294 5,744,693 4,620,902 39,809,138 2) As of and for the year ended December 31, 2018 (in millions of Won) Steel Trading Construction Others Total External revenues ￦ 32,358,009 22,407,717 6,769,410 3,442,641 64,977,777 Internal revenues 18,063,213 15,911,138 551,324 2,755,176 37,280,851 Including inter segment revenue 12,496,287 8,743,666 465,057 2,639,561 24,344,571 Total revenues 50,421,222 38,318,855 7,320,734 6,197,817 102,258,628 Interest income 199,016 36,437 115,019 23,454 373,926 Interest expenses (468,681 ) (189,165 ) (111,101 ) (94,613 ) (863,560 ) Depreciation and amortization (2,812,666 ) (210,493 ) (36,840 ) (265,416 ) (3,325,415 ) Impairment loss on property, plant and equipment and others (1,057,474 ) (86,085 ) (82,521 ) (117,280 ) (1,343,360 ) Impairment loss on investment in associates and JVs (733,879 ) (160,085 ) (155,371 ) — (1,049,335 ) Income tax expense (1,307,292 ) (52,914 ) (238,441 ) (65,611 ) (1,664,258 ) Segment profit (loss) 1,268,313 49,264 234 13,608 1,331,419 Segment assets 70,976,493 15,550,854 7,333,221 8,017,433 101,878,001 Investment in subsidiaries, associates and joint ventures 16,099,692 1,379,045 511,230 932,107 18,922,074 Acquisition of non-current 2,239,467 132,017 49,095 232,281 2,652,860 Segment liabilities 20,289,037 11,454,079 4,386,852 4,134,352 40,264,320 3) As of and for the year ended December 31, 2019 (in millions of Won) Steel Trading Construction Others Total External revenues ￦ 32,078,453 22,157,131 6,944,629 3,186,635 64,366,848 Internal revenues 17,729,990 15,467,687 743,376 2,796,306 36,737,359 Including inter segment revenue 12,184,743 8,130,503 686,881 2,638,449 23,640,576 Total revenues 49,808,443 37,624,818 7,688,005 5,982,941 101,104,207 Interest income 211,715 41,739 118,102 28,036 399,592 Interest expenses (529,743 ) (183,129 ) (77,005 ) (81,778 ) (871,655 ) Depreciation and amortization (2,892,901 ) (276,817 ) (29,266 ) (226,693 ) (3,425,677 ) Impairment loss on property, plant and equipment and others (497,583 ) (131,914 ) (1,490 ) (3,758 ) (634,745 ) Share of loss of equity-accounted investees, net (865,769 ) (76,038 ) (85,628 ) — (1,027,435 ) Income tax expense (725,448 ) (119,044 ) (86,106 ) (105,171 ) (1,035,769 ) Segment profit 585,948 165,348 27,789 544,961 1,324,046 Segment assets 71,153,809 14,482,538 7,653,637 9,212,225 102,502,209 Investment in subsidiaries, — — — — — associates and joint ventures 15,650,654 1,409,764 527,418 1,062,215 18,650,051 Acquisition of non-current 2,275,103 192,805 30,563 404,963 2,903,434 Segment liabilities 21,101,474 10,184,521 4,584,423 4,454,502 40,324,920 (c) Reconciliations of total segment revenues, profit or loss, assets and liabilities, and other significant items to their respective consolidated financial statement line items are as follows: 1) Revenues (in millions of Won) 2017 2018 2019 Total revenue for reportable segments ￦ 95,059,704 102,258,628 101,104,207 Elimination of inter-segment revenue (34,404,604 ) (37,280,851 ) (36,737,359 ) Basis difference(2) (468,233 ) 176,859 418,861 ￦ 60,186,867 65,154,636 64,785,709 2) Profit (in millions of Won) 2017 2018 2019 Total profit (loss) for reportable segments ￦ 3,160,761 1,331,419 1,324,046 Goodwill and corporate FV adjustments (84,370 ) (77,756 ) (80,218 ) Elimination of inter-segment profits (102,922 ) 638,401 738,809 Income tax expense 1,206,223 1,670,757 1,070,641 Basis difference(2) (84,641 ) 53,195 73,256 Profit before income tax expense ￦ 4,095,051 3,616,016 3,126,534 3) Assets (in millions of Won) 2018 2019 Total assets for reportable segments(1) ￦ 101,878,001 102,502,209 Equity-accounted investees (15,272,243 ) (14,400,831 ) Goodwill and corporate FV adjustments 2,722,115 2,622,409 Elimination of inter-segment assets (11,079,608 ) (11,665,126 ) Basis difference(2) 528,726 312,147 ￦ 78,776,991 79,370,808 (1) As segment assets and liabilities are determined based on separate financial statements, for subsidiaries which are in a different segment from that of its immediate parent company, their carrying amount in separate financial statements is eliminated upon consolidation. In addition, adjustments are made to adjust the amount of investment in associates and joint ventures from the amount reflected in segment assets to that determined using equity method in consolidated financial statements. 4) Liabilities (in millions of Won) 2018 2019 Total liabilities for reportable segments ￦ 40,264,320 40,324,920 Corporate FV adjustments 321,320 292,124 Elimination of inter-segment liabilities (9,096,926 ) (9,353,090 ) Basis difference(2) 615,663 343,556 ￦ 32,104,377 31,607,510 5) Other significant items a) December 31, 2017 (in millions of Won) Total segment corporate FV Elimination of inter-segment Basis Consolidated Interest income ￦ 280,488 — (68,037 ) — 212,451 Interest expenses (757,963 ) 1,304 103,544 — (653,115 ) Depreciation and amortization (3,360,366 ) (106,195 ) 169,141 — (3,297,420 ) Share of profit or loss of investment in associates (1,721 ) — 12,261 — 10,540 Income tax expense (1,274,696 ) 21,270 47,203 20,483 (1,185,740 ) Impairment loss on property, plant and equipment and others (336,719 ) (867 ) 34,619 — (302,967 ) Impairment loss on available-for-sale (127,319 ) — 4,105 — (123,214 ) ￦ (5,578,296 ) (84,488 ) 302,836 20,483 (5,339,465 ) b) December 31, 2018 (in millions of Won) Total corporate FV Elimination of inter-segment Basis Consolidated Interest income ￦ 373,926 — (36,668 ) — 337,258 Interest expenses (863,560 ) 1,035 121,229 — (741,296 ) Depreciation and amortization (3,325,415 ) (103,932 ) 161,718 — (3,267,629 ) Share of profit or loss of investment in associates (1,049,335 ) — 1,161,970 — 112,635 Income tax expense (1,664,258 ) 25,921 (32,420 ) (12,873 ) (1,683,630 ) Impairment loss on property, plant and equipment and others (1,343,360 ) (779 ) (107,258 ) — (1,451,397 ) ￦ (7,872,002 ) (77,755 ) 1,268,571 (12,873 ) (6,694,059 ) c) December 31, 2019 (in millions of Won) Total segment Goodwill and Elimination of inter-segment Basis Consolidated Interest income ￦ 399,592 — (47,208 ) — 352,384 Interest expenses (871,655 ) 806 115,138 — (755,711 ) Depreciation and amortization (3,425,677 ) (109,941 ) 74,503 — (3,461,115 ) Share of profit of equity-accounted investees, net (1,027,435 ) — 1,301,176 — 273,741 Income tax expense (1,035,769 ) 28,917 (63,789 ) (17,728 ) (1,088,369 ) Impairment loss on property, plant and equipment and others (634,745 ) — (70,011 ) — (704,756 ) ￦ (6,595,689 ) (80,218 ) 1,309,809 (17,728 ) (5,383,826 ) (*2) Basis difference is related to the difference in recognizing revenue and expenses in connection with development and sale of certain residential real estate between the report reviewed by the CEO and the consolidated financial statements. (d) Revenue by geographic area for the years ended December 31, 2017, 2018 and 2019 was as follows: (in millions of Won) 2017 2018 2019 Domestic ￦ 38,882,220 41,671,930 40,890,972 Japan 2,200,405 2,084,061 2,202,075 China 6,731,214 6,945,266 7,165,271 Asia-other 7,750,553 8,904,532 8,976,593 North America 1,725,120 1,834,534 1,711,859 Others 3,365,588 3,537,454 3,420,078 60,655,100 64,977,777 64,366,848 Basis difference (468,233 ) 176,859 418,861 ￦ 60,186,867 65,154,636 64,785,709 In presenting information on the basis of geography, segment revenue is based on the geographical location of customers. (e) Non-current (in millions of Won) 2018 2019 Domestic ￦ 28,298,293 27,742,370 Japan 146,490 175,719 China 1,185,828 1,307,847 Asia-other 5,067,936 4,916,775 North America 173,914 221,565 Others 1,245,252 1,348,397 ￦ 36,117,713 35,712,673 Non-current (f) There are no customers whose revenue is 10% or more of the consolidated revenue.

Events after the Reporting Peri

Events after the Reporting Period	12 Months Ended
Events after the Reporting Period	Dec. 31, 2019
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Disclosure of events after reporting period [text block]	41. Events after the Reporting Period (a) On January 17, 2020, the Company issued non-guaranteed senior dollar bonds (issued at USD 500 million and USD 440 million) and non-guaranteed senior euro bonds (issued at EUR 500 million). The maturity of the bonds is January 17, 2023, January 17, 2025, and January 17, 2024. (b) POSCO ENERGY, a subsidiary, resolved to repay the convertible preferred stock at the Board of Directors meeting on February 17, 2020 and the Extraordinary Shareholders’ meeting on February 21, 2020. The repayment of ￦ (c) POSCO ENGINEERING & CONSTRUCTION CO., LTD., a subsidiary, decided to refinance funds in February 2020, to raise funds for repayment of principal funds and minimize financial expenses of Chun-cheon Energy Co., Ltd, an associate. In doing so, POSCO ENGINEERING & CONSTRUCTION CO., LTD. expects to enter into a guarantee arrangement to provide payment guarantees of about ￦￦

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2019
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Basis of consolidation	Basis of consolidation (a) Business combinations The Company accounts for business combinations using the acquisition method when control is transferred to the Company. The consideration transferred in the acquisition is generally measured at fair value, as are the identifiable net assets acquired. Any goodwill that arises is tested annually for impairment. Any gain on bargain purchase is recognized in profit or loss immediately. Transaction costs are expensed as incurred, except if related to the issue of debt or equity securities. The consideration transferred does not include amounts related to the settlement of pre-existing Any contingent consideration payable is measured at fair value at the acquisition date. If the contingent consideration is classified as equity, then it is not remeasured and settlement is accounted for within equity. Otherwise, subsequent changes in the fair value of the contingent consideration are recognized in profit or loss. If share-based payment awards (replacement awards) are required to be exchanged for awards held by the acquiree’s employees (acquiree’s awards), then all or a portion of the amount of the acquirer’s replacement awards is included in measuring the consideration transferred in the business combination. This determination is based on the market-based measure of the replacement awards compared with the market-based measure of the acquiree’s awards and the extent to which the replacement awards relate to pre-combination (b) Non-controlling Non-controlling (c) Subsidiaries Subsidiaries are entities controlled by the Company. The Company controls an entity when it is exposed to, or has rights to, variable returns from its involvement with the entity and has the ability to affect those returns through its power over the entity. The financial statements of subsidiaries are included in the consolidated financial statements from the date on which control commences until the date on which control ceases. (d) Loss of control When the Company loses control over a subsidiary, it derecognizes the assets and liabilities of the subsidiary, and any related non-controlling (e) Interests in equity-accounted investees The Company’s interests in equity-accounted investees comprise interests in associates and joint ventures. Associates are those entities in which the Company has significant influence, but not control or joint control, over the financial and operating policies. A joint venture is an arrangement in which the Company has joint control, whereby the Company has rights to the net assets of the arrangement, rather than rights to its assets and obligations for its liabilities. Interests in associates and joint ventures are accounted for using the equity method. They are recognized initially at cost, which includes transaction costs. Subsequent to initial recognition, the consolidated financial statements include the Company’s share of the profit or loss and other comprehensive income of equity-accounted investees, until the date on which significant influence or joint control ceases. (f) Transactions eliminated on consolidation Intra-group balances and transactions, and any unrealized income and expenses arising from intra-group transactions, are eliminated. Unrealized gains arising from transactions with equity-accounted investees are eliminated against the investment to the extent of the Company’s interest in the investee. Unrealized losses are eliminated in the same way as unrealized gains, but only to the extent that there is no evidence of impairment.
Foreign currency transactions and translation	Foreign currency transactions and translation (a) Foreign currency transactions Foreign currency transactions are initially recorded using the spot exchange rate between the functional currency and the foreign currency at the date of the transaction. At the end of each reporting period, foreign currency monetary items are translated using the closing rate. Non-monetary Exchange differences arising on the settlement of monetary items or on translating monetary items at rates different from those at which they were translated on initial recognition during the period or in previous period end are recognized in profit or loss in the period in which they arise. When gains or losses on non-monetary non-monetary (b) Foreign operations If the presentation currency of the Company is different from a foreign operation’s functional currency, the financial statements of the foreign operation are translated into the presentation currency using the following methods: The assets and liabilities of foreign operations, whose functional currency is not the currency of a hyperinflationary economy, are translated to presentation currency using exchange rates at the reporting date. The income and expenses of foreign operations are translated to functional currency at exchange rates at the dates of the transactions. Foreign currency differences are recognized in other comprehensive income. Any goodwill arising on the acquisition of a foreign operation and any fair value adjustments to the carrying amounts of assets and liabilities arising on the acquisition of that foreign operation are treated as assets and liabilities of the foreign operation. Thus, they are expressed in the functional currency of the foreign operation and translated to the presentation currency at the closing rate. When a foreign operation is disposed of, the relevant amount in the translation recognized in other comprehensive income is transferred to profit or loss as part of the profit or loss on disposal. On the partial disposal of a subsidiary that includes a foreign operation, the relevant proportion of such cumulative amount is reattributed to non-controlling
Cash and cash equivalents	Cash and cash equivalents Cash and cash equivalents comprise cash on hand, demand deposits, and short-term investments in highly liquid securities that are readily convertible to known amounts of cash with maturities of three months or less from the acquisition date and which are subject to an insignificant risk of changes in value. Equity investments are excluded from cash and cash equivalents.
Non-derivative financial assets	Non-derivative Trade receivables and debt securities issued are initially recognized when they are originated. All other financial assets are initially recognized when the Company becomes a party to the contractual provisions of the instruments. A financial asset (unless it is a trade receivable without a significant financing component) is initially measured at fair value plus, for an item not at financial assets measured at fair value through profit or loss, transaction costs that are directly attributable to its acquisition or issue. A trade receivable without a significant financing component is initially measured at the transaction price. On initial recognition, a financial asset is classified as measured at amortized cost, debt instruments measured at fair value through other comprehensive income, equity instruments measured at fair value through other comprehensive income or financial assets measured at fair value through profit or loss. Financial assets are not reclassified subsequent to their initial recognition unless the Company changes its business model for managing financial assets, in which case all affected financial assets are reclassified on the first day of the reporting period following the change in the business model. (a) Financial assets measured at amortized cost A financial asset is measured at amortized cost if it meets both of the following conditions and is not designated as at fair value through profit or loss. • it is held within a business model whose objective is to hold assets to collect contractual cash flows, and • its contractual terms give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. Financial assets measured at amortized cost are subsequently measured at amortized cost using the effective interest method. The amortized cost is reduced by impairment losses. Interest income, gains and losses on foreign currency translation and impairment losses are recognized in profit or loss. Any gain or loss on derecognition is recognized in profit or loss. (b) Debt instruments measured at fair value through other comprehensive income A debt instrument is measured at fair value through other comprehensive income if it meets both of the following conditions and is not designated as at fair value through profit or loss. • it is held within a business model whose objective is achieved by both collection contractual cash flows and selling financial assets, and • its contractual terms give rise on specified dates to cash flows that are solely payments of principal and interest on the principal amount outstanding. Debt instruments measured at fair value through other comprehensive income are subsequently measured at fair value. Interest income which is calculated using the effective interest method, gains and losses from foreign currency translation and impairment losses are recognized in profit or loss and other net profit or loss is recognized in other comprehensive income. At the time of elimination, other accumulated comprehensive income is reclassified to profit or loss. (c) Equity instruments measured at fair value through other comprehensive income On initial recognition of an equity investment that is not held for trading, the Company may irrevocably elect to present subsequent changes in the investment’s fair value in other comprehensive income. This election is made on an investment-by-investment Equity instruments measured at fair value through other comprehensive income are subsequently measured at fair value. Dividends are recognized as income in profit or loss unless the dividend clearly represents a recovery of part of the cost of the investment. Other net gains and losses are recognized in other comprehensive income and never reclassified to profit or loss. (d) Financial assets measured at fair value through profit or loss All financial assets not classified as measured at amortized cost or fair value through other comprehensive income as described above are measured at fair value through profit or loss. This includes all derivative financial assets. On initial recognition, the Company may irrevocably designate a financial asset that otherwise meets the requirements to be measured at amortized cost or fair value through other comprehensive income as at fair value through profit or loss if doing so eliminates or significantly reduces an accounting mismatch that would otherwise arise. Financial assets measured at fair value through profit or loss are subsequently measured at fair value. Net gains and losses, including any interest or dividend income, are recognized in profit or loss. (e) Offsetting a financial asset and a financial liability Financial assets and financial liabilities are offset and the net amount is presented in the consolidated statement of financial position only when the Company currently has a legally enforceable right to offset the recognized amounts, and there is the intention to settle on a net basis or to realize the asset and settle the liability simultaneously.
Inventories	Inventories Inventory costs, except materials-in-transit Inventories are measured at the lower of cost or net realizable value. The amount of any write-down of inventories to net realizable value and all losses of inventories are recognized as an expense in the period the write-down or loss occurs. The amount of any reversal of any write-down of inventories arising from an increase in net realizable value is recognized as a reduction in the amount of inventories recognized as cost of goods sold in the period in which the reversal occurs. The carrying amount of those inventories sold is recognized as cost of goods sold in the period in which the related revenue is recognized.
Non-current assets held for sale	Non-current Non-current non-current The Company recognizes an impairment loss for any initial or subsequent write-down of an asset or disposal group to fair value less costs to sell, and a gain for any subsequent increase in fair value less costs to sell, up to the cumulative impairment loss previously recognized. A non-current
Investment property	Investment property Property held to earn rentals or for capital appreciation or both is classified as investment property. Investment property is measured initially at its cost. Transaction costs are included in the initial measurement. Subsequently, investment property is carried at depreciated cost less any accumulated impairment losses. Subsequent costs are recognized in the carrying amount of investment property at cost or, if appropriate, as separate items if it is probable that future economic benefits associated with the item will flow to the Company and the cost of the item can be measured reliably. The carrying amount of the replaced part is derecognized. The costs of the day-to-day Depreciation methods, useful lives and residual values are reviewed at the end of each reporting date and adjusted, if appropriate. The change is accounted for as a change in an accounting estimate.
Property, plant and equipment	Property, plant and equipment Property, plant and equipment are initially measured at cost and after initial recognition, are carried at cost less accumulated depreciation and any accumulated impairment losses. The cost of property, plant and equipment includes expenditures arising directly from the construction or acquisition of the asset, any costs directly attributable to bringing the asset to the location and condition necessary for it to be capable of operating in the manner intended by management and, when the Company has an obligation to remove the asset or restore the site, an estimate of the costs of dismantling and removing the item and restoring the site on which it is located. The cost of replacing a part of an item is recognized in the carrying amount of the item of property, plant and equipment, if the following recognition criteria are met: (a) it is probable that future economic benefits associated with the item will flow to the Company, and (b) the cost can be measured reliably. The carrying amount of the replaced part is derecognized at the time the replacement part is recognized. The costs of the day-to-day Items of property, plant and equipment are depreciated from the date they are available for use or, in respect of self-constructed assets, from the date that the asset is completed and ready for use. Other than land, the costs of an asset less its estimated residual value are depreciated. Depreciation of property, plant and equipment is recognized in profit or loss on a straight-line basis, which most closely reflects the expected pattern of consumption of the future economic benefits embodied in the asset, over the estimated useful lives of each component of an item of property, plant and equipment. Land is not depreciated. Each part of an item of property, plant and equipment with a cost that is significant in relation to the total cost of the item is depreciated separately. The gain or loss arising from the derecognition of an item of property, plant and equipment is included in profit or loss when the item is derecognized. The estimated useful lives for the current and comparative periods are as follows: Buildings 5-50 years Structures 4-50 Machinery and equipment 4-25 Vehicles 3-20 Tools 3-10 Furniture and fixtures 3-20 Lease assets 2-30 Bearer plants 20 years The estimated residual value, useful lives and the depreciation method are reviewed at least at the end of each reporting period and, if expectations differ from previous estimates, the changes are accounted for as changes in accounting estimates.
Borrowing costs	Borrowing costs The Company capitalizes borrowing costs directly attributable to the acquisition, construction or production of a qualifying asset as part of the cost of that asset. Other borrowing costs are recognized in expense as incurred. A qualifying asset is an asset that requires a substantial period of time to get ready for its intended use or sale. Financial assets and inventories that are manufactured or otherwise produced over a short period of time are not qualifying assets. Assets that are ready for their intended use or sale when acquired are not qualifying assets. To the extent that the Company borrows funds specifically for the purpose of obtaining a qualifying asset, the Company determines the amount of borrowing costs eligible for capitalization as the actual borrowing costs incurred on that borrowing during the period less any investment income on the temporary investment of those borrowings. The Company immediately recognizes other borrowing costs as an expense. To the extent that the Company borrows funds generally and uses them for the purpose of obtaining a qualifying asset, the Company determines the amount of borrowing costs eligible for capitalization by applying a capitalization rate to the expenditures on that asset. The capitalization rate is the weighted average of the borrowing costs applicable to the borrowings of the Company that are outstanding during the period, other than borrowings made specifically for the purpose of obtaining a qualifying asset. The amount of borrowing costs that the Company capitalizes during a period does not exceed the amount of borrowing costs incurred during that period.
Intangible assets	Intangible assets Intangible assets are measured initially at cost and, subsequently, are carried at cost less accumulated amortization and accumulated impairment losses. Amortization of intangible assets except for goodwill is calculated on a straight-line basis over the estimated useful lives of intangible assets from the date that they are available for use. The residual value of intangible assets is zero. However, as there are no foreseeable limits to the periods over which club memberships are expected to be available for use, this intangible asset is determined as having an indefinite useful life and not amortized. Intellectual property rights 4-25 years Development expense 3-5 Port facilities usage rights 4-75 Other intangible assets 2-15 years Amortization periods and the amortization methods for intangible assets with finite useful lives are reviewed at the end of each reporting period. The useful lives of intangible assets that are not being amortized are reviewed at the end of each reporting period to determine whether events and circumstances continue to support indefinite useful life assessments for those assets. Changes are accounted for as changes in accounting estimates. Expenditures on research activities, undertaken with the prospect of gaining new scientific or technical knowledge and understanding, are recognized in profit or loss as incurred. Development expenditures are capitalized only if development costs can be measured reliably, the product or process is technically and commercially feasible, future economic benefits are probable, and the Company intends to and has sufficient resources to complete development and to use or sell the asset. Other development expenditures are recognized in profit or loss as incurred. Subsequent expenditures are capitalized only when they increase the future economic benefits embodied in the specific asset to which they relate. All other expenditures, including expenditures on internally generated goodwill and brands, are recognized in profit or loss as incurred.
Exploration for and evaluation of mineral resources	Exploration for and evaluation of mineral resources POSCO is engaged in exploration projects for mineral resources through subsidiaries, associates and joint ventures or other contractual arrangements. Expenditures related to the development of mineral resources are recognized as exploration or development intangible assets. The nature of these intangible assets are as follows: (a) Exploration and evaluation assets Exploration and evaluation assets consist of expenditures for topographical studies, geophysical studies and trenching. These assets are reclassified as development assets when it is proved that the exploration has identified commercially viable mineral deposit. (b) Development assets When proved reserves are determined and development is sanctioned, development expenditures incurred are capitalized. These expenditures include evaluation of oil fields, construction of oil/gas wells, drilling for viability and others. On completion of development and inception of extraction for commercial production of developed proved reserves, the development assets are reclassified as either property, plant and equipment or as intellectual property rights (mining rights) under intangible assets based on the nature of the capitalized expenditures. The respective property, plant and equipment and intellectual property (mining rights) are each depreciated and amortized based on proved reserves on a unit of production basis.
Government grants	Government grants Government grants are not recognized unless there is reasonable assurance that the Company will comply with the grant’s conditions and that the grant will be received. (a) Grants related to assets Government grants whose primary condition is that the Company purchase, construct or otherwise acquire long-term assets are deducted from the carrying amount of the assets and recognized in profit or loss on a systematic and rational basis over the life of the depreciable assets. (b) Grants related to income Government grants which are intended to compensate the Company for expenses incurred are deducted from the related expenses.
Leases	Leases The Company applied IFRS No.16 “Leases” using the modified retrospective approach by recognizing the cumulative effect of initial application as of January 1, 2019, the date of initial application. Therefore, the comparative information has not been restated and continues to be reported under IAS No.17 “Lease” and IFRIC No.4 “Determining Whether an Arrangement Contains a Lease”. 1) As a lessee: policy applicable from January 1, 2019 The Company recognizes a right-of-use right-of-use The right-of-use right-of-use right-of-use right-of-use The lease liability is initially measured at the present value of the lease payments that are not paid at the commencement date, discounted using the interest rate implicit in the lease or, if that rate cannot be readily determined the Company’s incremental borrowing rate. Generally, the Company uses its incremental borrowing rate as the discount rate. In determining the lease term and assessing the length of the non-cancellable period of a lease, The Company determines the period for which the contract is enforceable. When the Company determining the enforceable period of the lease period, it considers (a) if either party has an economic incentive not to terminate the lease such that it would incur a penalty on termination that is more than insignificant, the contract is enforceable beyond the date on which the contract can be terminated; and (b) whether each of the parties has the right to terminate the lease without permission from the other party with no more than an insignificant penalty. In addition, a lease is no longer enforceable only when both parties have such a right. The Company determines its incremental borrowing rate by obtaining interest rates from various external sources and makes certain adjustments to reflect the terms of the lease and type of the asset leased. Lease payments included in the measurement of the lease liability comprise the followings: • fixed payments • variable lease payments that depend on an index or a rate • amounts expected to be payable under a residual value guarantee; and • the exercise price under a purchase option that the Company is reasonably certain to exercise, lease payments in an optional renewal period if the Company is reasonably certain to exercise an extension option, and penalties for early termination of a lease unless the Company is reasonably certain not to terminate early. The lease liability is measured at amortized cost using the effective interest method. When the lease liability is remeasured, a corresponding adjustment is made to the carrying amount of the right-of-use right-of-use • a revised in-substance • a change in future lease payments arising from a change in an index or rate, • a change in the Company’s estimate of the amount expected to be payable under a residual value guarantee, or • a change in the Company’s assessment of whether it will exercise a purchase, extension or termination option The Company presents right-of-use The Company has elected not to recognize right-of-use low-value 2) As a lessee: policy applicable before January 1, 2019 The Company classifies and accounts for leases as either a finance or operating lease, depending on the terms. Leases where the Company assumes substantially all of the risks and rewards of ownership are classified as finance leases. All other leases are classified as operating leases. In the case of finance leases, the Company recognizes as finance assets and finance liabilities the lower amount of the fair value of the leased property and the present value of the minimum lease payments, each determined at the inception of the lease at the commencement of the lease term. Any initial direct costs are added to the amount recognized as an asset. The minimum lease payment is recognized by dividing the financial cost and the repayment amount of the lease liabilities. The financial cost is allocated to the remaining balance for each reporting period so that a fixed interest rate is calculated. Contingent rents are charged as expenses in the period in which they are incurred. The depreciable amount of a leased asset is allocated to each accounting period during the period of expected use on a systematic basis consistent with the depreciation policy the Company adopts for similar depreciable assets that are owned. If there is no reasonable certainty that the Company will obtain ownership by the end of the lease term, the asset is fully depreciated over the shorter of the lease term and its useful life. In the case of an operating lease, the Company recognizes the lease payment as an expense on a straight-line basis over the lease term. Contingent rents are charged as expenses in the periods in which they are incurred. 3) As a lessor When the Company acts as a lessor, it determines at lease inception whether each lease is a finance lease or an operating lease. To the Company classifies the lease that transfers substantially all of the risks and rewards incidental to ownership of the underlying asset as a finance lease, and all other leases as operating leases. As part of this assessment, the Company considers certain indicators such as whether the lease is for the major part of the economic life of the asset. The Company leases out its investment properties. The Company classified these leases as operating leases, and the accounting policies applicable to the Company as a lessor are not different from those under IAS No.17 “Leases”. However, when the Company is an intermediate lessor, the sub-leases right-of-use The Company provides sub-leases sub-leases ￦ sub-leases,
Impairment for financial assets	Impairment for financial assets The Company recognizes loss allowances for expected credit losses on: • financial assets measured at amortized cost; • debt instruments measured at fair value through other comprehensive income; and • lease receivables, contractual assets, loan commitments, and financial guarantee contracts If credit risk has increased significantly since the initial recognition, a loss allowance for lifetime expected credit loss is measured at the end of every reporting period. If credit risk has not increased significantly since the initial recognition, a loss allowance is measured based on 12-month If the financial instrument has low credit risk at the end of the reporting period, the Company may assume that the credit risk has not increased significantly since initial recognition. However, a loss allowance for lifetime expected credit losses is measured for contract assets or trade receivables that do not contain a significant financing component. (a) Judgments on credit risk When determining whether the credit risk of a financial asset has increased significantly since initial recognition and when estimating expected credit losses, the Company considers reasonable and supportable information that is relevant and available without undue cost or effort. This includes both quantitative and qualitative information and analysis, based on the Company’s historical experience and informed credit assessment including forward-looking information. The Company assumes that the credit risk on a financial asset has increased significantly if it is more than 30 days past due. The Company considers a financial asset to be in default when the borrower is unlikely to pay its credit obligations to the Company in full, without recourse by the Company to actions such as realizing security (if any is held). The Company considers a debt security to have low credit risk when its credit risk rating is equivalent to the globally understood definition of investment grade. (b) Measurement of expected credit losses Lifetime expected credit losses are the expected credit losses that result from all possible default events over the expected life of a financial instrument. 12-month Expected credit losses are a probability-weighted estimate of credit losses. Credit losses are measured as the present value of all cash shortfalls such as the difference between the cash flows due to the entity in accordance with the contract and the cash flows that the Company expects to receive. Expected credit losses for financial assets measured at amortized cost are recognized in profit or loss. Loss allowances for financial assets measured at amortized cost are deducted from carrying amount of the assets. For debt instruments measured at fair value through other comprehensive income, the loss allowance is charged to profit or loss and is recognized in other comprehensive income. (c) Credit-impaired financial assets At each reporting date, the Company assesses whether financial assets measured at amortized cost and debt instrument measured at fair value through other comprehensive income are credit-impaired. A financial asset is ‘credit-impaired’ when one or more events that have a detrimental impact on the estimated future cash flows of the financial asset have occurred. Objective evidence that a financial asset or group of financial assets are impaired includes: • significant financial difficulty of the issuer or borrower • a breach of contract, such as a default or delinquency in interest or principal payments • the lender, for economic or legal reasons relating to the borrower’s financial difficulty, granting to the borrower a concession that the lender would not otherwise consider • becoming probable that the borrower will enter bankruptcy or other financial reorganization • the disappearance of an active market for that financial asset because of financial difficulties (d) Write-off The gross carrying amount of a financial asset is written off when the Company has no reasonable expectations of recovering a financial asset in entirety or a portion. The Company individually makes an assessment with respect to the timing and amount of write-off
Impairment for non-financial assets	Impairment for non-financial The carrying amounts of the Company’s non-financial non-current Management estimates the recoverable amount of an individual asset. If it is impossible to measure the individual recoverable amount of an asset, then management estimates the recoverable amount of cash-generating unit (“CGU”). A CGU is the smallest identifiable group of assets that generates cash inflows that are largely independent of the cash inflows from other assets or groups of assets. The Company determined that individual operating entities are CGUs. The recoverable amount of an asset or CGU is the greater of its value-in-use value-in-use pre-tax An impairment loss is recognized if the carrying amount of an asset or a CGU exceeds its recoverable amount. Impairment losses are recognized in profit or loss. Goodwill acquired in a business combination is allocated to each CGU that is expected to benefit from the synergies arising from the goodwill acquired. Any impairment identified at the CGU level will first reduce the carrying amount of goodwill and then be used to reduce the carrying amount of the other assets in the CGU on a pro rata basis. Except for impairment losses in respect of goodwill which are never reversed, an impairment loss is reversed if there has been a change in the estimates used to determine the recoverable amount. An impairment loss is reversed only to the extent that the asset’s carrying amount does not exceed the carrying amount that would have been determined, net of depreciation or amortization, if no impairment loss had been recognized.
Derivative financial instruments, including hedge accounting	Derivative financial instruments, including hedge accounting Derivatives are initially recognized at fair value. Subsequent to initial recognition, derivatives are measured at fair value, and changes therein are recognized as describe below. (a) Hedge accounting The Company holds forward exchange contracts, currency swaps and commodity future contracts to manage foreign exchange risk and commodity fair value risk. The Company designated derivatives as hedging instruments to hedge the risk of changes in the fair value of assets, liabilities or firm commitments (a fair value hedge) and foreign currency risk of highly probable forecasted transactions or firm commitments (a cash flow hedge). On initial designation of the hedge, the Company formally documents the relationship between the hedging instruments and hedged items, including the risk management objectives and strategy in undertaking the hedge transaction, together with the methods that will be used to assess the effectiveness of the hedging relationship. ① Fair value hedge Changes in the fair value of a derivative hedging instrument designated as a fair value hedge are recognized in profit or loss. The gain or loss from remeasuring the hedging instrument at fair value for a derivative hedging instrument and the gain or loss on the hedged item attributable to the hedged risk are recognized in profit or loss in the same line item of the consolidated statement of comprehensive income. The Company discontinues fair value hedge accounting if the hedging instrument expires or is sold, terminated or exercised, or if the hedge no longer meets the criteria for hedge accounting. Any adjustment arising from gain or loss on the hedged item attributable to the hedged risk is amortized to profit or loss from the date the hedge accounting is discontinued. ② Cash flow hedge When a derivative is designated to hedge the variability in cash flows attributable to a particular risk associated with a recognized asset or liability or a highly probable forecasted transaction that could affect profit or loss, the effective portion of changes in the fair value of the derivative is recognized in other comprehensive income, net of tax, and presented in the hedging reserve in equity. Any ineffective portion of changes in the fair value of the derivative is recognized immediately in profit or loss. If the hedging instrument no longer meets the criteria for hedge accounting, expires or is sold, terminated, exercised, or the designation is revoked, then hedge accounting is discontinued prospectively. The cumulative gain or loss on the hedging instrument that has been recognized in other comprehensive income is reclassified to profit or loss in the periods during which the forecasted transaction occurs. If the forecasted transaction is no longer expected to occur, then the balance in other comprehensive income is recognized immediately in profit or loss. (b) Other derivatives Changes in the fair value of a derivative that is not designated as a hedging instrument are recognized immediately in profit or loss.
Non-derivative financial liabilities	Non-derivative The Company classifies non-derivative (a) Financial liabilities measured at fair value through profit or loss A financial liability is classified as at fair value through profit or loss if it is classified as held-for-trading, (b) Financial liabilities measured at amortized cost Non-derivative (c) Derecognition of financial liabilities The Company derecognizes a financial liability when its contractual obligations are discharged or cancelled, or expire. The Company also derecognizes a financial liability when its terms are modified and the cash flows of the modified liability are substantially different, in which case a new financial liability based on the modified terms is recognized at fair value. On derecognition of a financial liability, the difference between the carrying amount extinguished and the consideration paid (including any non-cash
Construction work in progress	Construction work in progress The gross amount due from customers for contract work is presented for all contracts in which profits multiply cumulative percentage-of-completion percentage-of-completion, The Company accounts for the remaining rights and performance obligation on the contract with each customer on a net basis. Due from customers for contract work and due to customers for contract work for a contract are offset and presented on a net basis.
Employee benefits	Employee benefits (a) Short-term employee benefits Short-term employee benefits are employee benefits that are due to be settled within twelve months after the end of the period in which the employees render the related service. When an employee has rendered service to the Company during an accounting period, the Company recognizes the undiscounted amount of short-term employee benefits expected to be paid in exchange for that service as profit or loss. If the Company has a legal or constructive obligation which can be reliably measured, the Company recognizes the amount of expected payment for profit-sharing and bonuses payable as liabilities. (b) Other long-term employee benefits Other long-term employee benefits include employee benefits that are settled beyond twelve months after the end of the period in which the employees render the related service, and are calculated at the present value of the amount of future benefit that employees have earned in return for their service in the current and prior periods, less the fair value of any related assets. Any actuarial gains and losses are recognized in profit or loss in the period in which they arise. (c) Retirement benefits: Defined contribution plans For defined contribution plans, when an employee has rendered service to the Company during a period, the Company recognizes the contribution payable to a defined contribution plan in exchange for that service as an accrued expense, after deducting any contributions already paid. If the contributions already paid exceed the contribution due for service before the end of the reporting period, the Company recognizes that excess as an asset (prepaid expense) to the extent that the prepayment will lead to a reduction in future payments or a cash refund. (d) Retirement benefits: Defined benefit plans A defined benefit plan is a post-employment benefit plan other than a defined contribution plan. The Company’s net obligation in respect of defined benefit plans is calculated by estimating the amount of future benefit that employees have earned in return for their service in the current and prior periods; that benefit is discounted to determine its present value. The fair value of plan assets is deducted. The calculation is performed annually by an independent actuary using the projected unit credit method. The discount rate is the yield at the reporting date on corporate bonds that have maturity dates approximating the terms of the Company’s obligations and that are denominated in the same currency in which the benefits are expected to be paid. The Company recognizes all actuarial gains and losses arising from actuarial assumption changes and experiential adjustments in other comprehensive income when incurred. When the fair value of plan assets exceeds the present value of the defined benefit obligation, the Company recognizes an asset, to the extent of the present value of the total of cumulative any economic benefits available in the form of refunds from the plan or reduction in the future contributions to the plan. Remeasurements of net defined benefit liabilities, which comprise actuarial gains and losses, the return on plan assets (excluding interest) and the effect of the asset ceiling (if any, excluding interest), are recognized immediately in other comprehensive income. The Company determines the net interest expense (income) on the net defined benefit liability (asset) for the period by applying the discount rate used to measure the defined benefit obligation at the beginning of the annual period to the then-net When the benefits of a plan are changed or when a plan is curtailed, the resulting change in benefit that relates to past service or the gain or loss in curtailment is recognized immediately in profit or loss. The Company recognizes gains and losses on the settlement of a defined benefit plan when the settlement occurs.
Provisions	Provisions Provisions are recognized when the Company has a present legal or constructive obligation as a result of a past event, it is probable that an outflow of resources embodying economic benefits will be required to settle the obligation and a reliable estimate can be made of the amount of the obligation. The risks and uncertainties that inevitably surround events and circumstances are taken into account in reaching the best estimate of a provision. Where the effect of the time value of money is material, provisions are determined at the present value of the expected future cash flows. Where some or all of the expenditures required to settle a provision are expected to be reimbursed by another party, the reimbursement is recognized when, and only when, it is virtually certain that reimbursement will be received if the entity settles the obligation. The reimbursement is treated as a separate asset. Provisions are reviewed at the end of each reporting period and adjusted to reflect the current best estimates. If it is no longer probable that an outflow of resources embodying economic benefits will be required to settle the obligation, the provision is reversed. A provision for warranties is recognized when the underlying products are sold. The provision is based on historical warranty. Regarding provision for construction warranties, warranty period starts from the completion of construction in accordance with construction contracts. If the Company has an obligation for warranties, provision for warranties which are estimated based on historical warranty data are recorded as cost of construction during the construction period. If the estimated total contract cost of the construction contract exceeds the total contract revenue, the estimated contract cost exceeding the contract revenue is recognized as a provision for construction losses for incomplete construction projects. A provision for restoration regarding contamination of land is recognized in accordance with the Company’s announced Environment Policy and legal requirement as needed. A provision is used only for expenditures for which the provision was originally recognized.
Emission Rights	Emission Rights The Company accounts for greenhouse gases emission right and the relevant liability as follows pursuant to the Act on Allocation and Trading of Greenhouse Gas Emission (a) Greenhouse Gases Emission Right Greenhouse Gases Emission Right consists of emission allowances which are allocated from the government free of charge and those purchased from the market. The cost includes any directly attributable costs incurred during the normal course of business. Emission rights held for the purpose of performing the obligation are classified as intangible asset and initially measured at cost and subsequently carried at cost less accumulated impairment losses. Emission rights held for short-swing profits are classified as current asset and are measured at fair value with any changes in fair value recognized as profit or loss in the respective reporting period. The Company derecognizes an emission right asset when the emission allowance is unusable, disposed or submitted to government and when the future economic benefits are no longer expected to be probable. (b) Emission liability Emission liability is a present obligation of submitting emission rights to the government with regard to emission of greenhouse gas. Emission liability is recognized when there is a high possibility of outflows of resources in performing the obligation and the costs required to perform the obligation are reliably estimable. Emission liability is an amount of estimated obligations for emission rights to be submitted to the government for the performing period. The emission liability is measured based on the expected quantity of emission for the performing period in excess of emission allowance in possession and the unit price for such emission rights in the market at the end of the reporting period.
Equity instruments	Equity instruments (a) Share capital Common stock is classified as equity and the incremental costs directly attributable to the issuance of common stock less their tax effects are deducted from equity. If the Company reacquires its own equity instruments, the amount of those instruments (“treasury shares”) are presented as a contra-equity account. No gain or loss is recognized in profit or loss on the purchase, sale, issuance or cancellation of its own equity instruments. When treasury shares are sold or reissued subsequently, the amount received is recognized as an increase to equity, and the resulting surplus or deficit on the transaction is recorded in capital surplus. (b) Hybrid Bonds Debt and equity instruments issued by the Company are classified as either financial liabilities or as equity in accordance with the substance of the contractual arrangements and the definitions of financial liability and equity. When the Company has an unconditional right to avoid delivering cash or other financial asset to settle a contractual obligation, the instruments are classified as equity instruments.
Revenue from contracts with customers	Revenue from contracts with customers The Company has initially applied IFRS No. 15 “Revenue from Contracts with Customers” from January 1, 2018. The Company applied the modified retrospective approach by recognizing the cumulative impact of initially applying the revenue standard as of January 1, 2018, the date of initial application of IFRS No. 15, and the Company also decided to apply the practical expedients as allowed by IFRS No. 15 by applying the new standard only to those contracts that are not considered as completed contracts at the date of initial application. Revenue is measured based on the consideration promised in a contract with a customer. The Company recognizes revenue when the control over a good or service is transferred to the customer. The following are the revenue recognition policies for performance obligations in the contracts with customers. (a) Sale of good The goods sold by the Company consist mainly of steel products from the steel segment and products such as steel, chemicals, auto parts and machinery in the trade segment. For domestic sales, the control of the product is usually transferred to the customer when the product is delivered to the customer, at which point revenue is recognized. Invoices are generally payable within 10 to 90 days. When a customer makes payment prior to the due date, they are offered a discount at certain percentage of the invoice amount. For export sales, revenue is recognized at the time when control of the product is transferred to the customer based on the “International Incoterms for Interpretation of Trade Terms” prescribed in the respective contracts, which is generally when the products are loaded to the transportation vessels. Invoices are usually issued at the date of bill of lading and payments are settled by the terms of Letter of Credit (L / C), Document against Acceptance (D / A), Document against Payment (D / P), Telegraphic Transfer (T / T) and others. The Company provides certain discount when the customer prepays according to the payment terms. The Company recognized revenue only to the extent that it is highly probable that a significant reversal in the amount of cumulative revenue recognized will not occur when discount period expires. (b) Transportation service For the performance obligation for transportation services included in the Company’s product sales contracts, revenue is recognized over the period when the services are provided and the revenue is measured by reference to examining the degree to which the service has been completed. The billing date and payment terms for the service charge are the same as the billing date and payment terms for sale of goods. (c) Construction contracts In the case of construction contracts where the Company renders construction services for plants, etc., the customer controls the assets as they are being constructed. Under those contracts, the Company performs construction or design services to meet the customer’s specifications, and if a contract is terminated by the customer, the Company is entitled to reimbursement of all costs incurred to date, including a reasonable margin. When the contract can be reliably estimated, the company recognizes the contract revenue and contract cost as revenue and costs based on the progress of the contract activity as of the end of the reporting period. The percentage of completion is determined based on the proportion that contract costs incurred for work performed, excluding contract cost incurred that do not reflect the progress of construction, to the estimated total contract costs. If the outcome of the contract cannot be reliably estimated, the revenue is recognized only to the extent of the contract costs that are probable to be recovered. If the total contract cost is likely to exceed the total contract revenue, expected losses are immediately recognized as a cost. The Company issues an invoice when the customer has completed a progress confirmation and generally the payment is made within 45 days from the invoice date. (d) Certain construction contracts for condominiums For certain construction service contracts for condominiums where the criterion of an enforceable right to payment for performance is met under IFRS No.15, even if the legal ownership or physical occupancy of the incomplete construction is not transferred to the customer during the construction period, revenue is recognized based on percentage of completion by considering the terms and conditions described in the relevant law and contracts such as the guarantee for sale policy, government approval on business plan, payment and termination terms. For certain construction contracts for condominiums and shopping centers where the criterion of an enforceable right to payment for performance is not met during the construction period, the Company recognizes revenue upon completion of construction when the control of the condominiums and shopping centers are transferred to customers. The timing of the billing and the payment terms of the sales contracts are different according to the terms of the contracts.
Finance income and finance costs	Finance income and finance costs The Company’s finance income and finance costs include: • interest income; • interest expense; • dividend income; • foreign currency gain or loss on financial assets and financial liabilities; • net gain or loss on financial assets measured at fair value through profit or loss; • hedge ineffectiveness recognized in profit or loss; and • net gain or loss on disposal of investments in debt securities measured at fair value through other comprehensive income. Interest income or expense is recognized using the effective interest method. Dividend income is recognized in profit or loss on the date on which the Company’s right to receive payment is established. The ‘effective interest rate’ is the rate that exactly discounts estimated future cash payments or receipts through the expected life of the financial instrument to: • the gross carrying amount of the financial asset; or • the amortized cost of the financial liability. In calculating interest income and expense, the effective interest rate is applied to the gross carrying amount of the asset (when the asset is not credit-impaired) or to the amortized cost of the liability. However, for financial assets that have become credit-impaired subsequent to initial recognition, interest income is calculated by applying the effective interest rate to the amortized cost of the financial asset. If the asset is no longer credit-impaired, then the calculation of interest income reverts to the gross basis.
Income taxes	Income taxes Income tax expense comprises current and deferred tax. Current tax and deferred tax are recognized in profit or loss except to the extent that it relates to a business combination, or items recognized directly in equity or in other comprehensive income. The Company recognizes interest and penalties related to corporate tax as the income taxes in accordance with IAS No.12 “Income Taxes”, otherwise, the Company applies IAS No.37 “Provisions Contingent Liabilities and Contingent Assets”. If there is an uncertainty on tax treatment such as dispute of a particular tax treatment by the taxation authority, the Company determines whether it is probable that the taxation authority will accept an uncertain tax treatment in determining taxable profit, tax bases, unused tax losses, unused tax credits or tax rates. If the Company concludes it is probable that the taxation authority will accept an uncertain tax treatment, the Company determines the taxable profit (tax loss), tax bases, unused tax losses, unused tax credits or tax rates consistently with the tax treatment used or planned to be used in its income tax filings. If the Company concludes it is not probable that the taxation authority will accept an uncertain tax treatment, the Company reflects the effect of uncertainty for each uncertain tax treatment by using either of the most likely amount or the expected value depending on which method the entity expects to better predict the resolution of the uncertainty. (a) Current income tax Current income tax is the expected income tax payable or receivable on the taxable profit or loss for the year, using tax rates enacted or substantively enacted at the end of the reporting period and any adjustment to tax payable in respect of previous years. The taxable profit is different from the accounting profit for the period since the taxable profit is calculated excluding the temporary differences, which will be taxable or deductible in determining taxable profit of future periods, and non-taxable non-deductible The Company offsets current tax assets and current tax liabilities if, and only if, the Company: • has a legally enforceable right to set off the recognized amounts, and • intends either to settle on a net basis, or to realize the asset and settle the liability simultaneously. (b) Deferred income tax The measurement of deferred income tax liabilities and deferred tax assets reflects the tax consequences that would follow from the manner in which the Company expects, at the end of the reporting period, to recover or settle the carrying amount of its assets and liabilities. The Company recognizes deferred income tax liabilities for all taxable temporary differences associated with investments in subsidiaries, associates, and joint ventures, except to the extent that the Company is able to control the timing of the reversal of the temporary difference and it is probable that the temporary difference will not reverse in the foreseeable future. The Company recognizes deferred income tax assets for deductible temporary differences arising from investments in subsidiaries, associates and joint ventures, to the extent that it is probable that the temporary difference will reverse in the foreseeable future and taxable profit will be available against which the temporary difference can be utilized. However, deferred tax is not recognized for the following temporary differences: taxable temporary differences arising on the initial recognition of goodwill, or the initial recognition of assets or liabilities in a transaction that is not a business combination and that affects neither accounting profit or loss nor taxable income. A deferred income tax asset is recognized for the carryforward of unused tax losses, tax credits and deductible temporary differences to the extent that it is probable that future taxable profit will be available against which the unused tax losses, tax credits and deductible temporary differences can be utilized. The future taxable profit depends on reversing taxable temporary differences. When there are insufficient taxable temporary differences, the probability of future taxable profit (including the reversal of temporary differences) should be considered. The carrying amount of a deferred income tax asset is reviewed at the end of each reporting period and is reduced to the extent that it is no longer probable that sufficient taxable profit will be available to allow the benefit of part or all of that deferred income tax asset to be utilized. Deferred income tax assets and liabilities are measured at the tax rates that are expected to apply to the period when the asset is realized or the liability is settled, based on tax rates (and tax laws) that have been enacted or substantively enacted by the end of the reporting period. Deferred income tax assets and liabilities are offset only if there is a legally enforceable right to offset the related current income tax liabilities and assets, and they relate to income taxes levied by the same tax authority and they intend to settle current income tax liabilities and assets on a net basis.
Earnings per share	Earnings per share Management calculates basic earnings per share (“EPS”) data for POSCO’s ordinary shares, which is presented at the end of the statement of comprehensive income. Basic EPS is calculated by dividing profit attributable to ordinary shareholders of POSCO by the weighted average number of ordinary shares outstanding during the period, adjusted for own shares held.
Operating segments	Operating segments An operating segment is a component of the Company that: a) engages in business activities from which it may earn revenues and incur expenditures, including revenues and expenses that relate to transactions with any of the Company’s other components, b) whose operating results are regularly reviewed by the Company’s chief operating decision maker (“CODM”) to make decisions about resources to be allocated to the segment and assess its performance and for which discrete financial information is available. Management has determined that the CODM of the Company is the CEO. With regard to construction segment, segment profit and loss is determined in the same way that consolidated profit after tax for the period is generally determined under IFRS except that revenues and expenses from the development and sale of certain residential real estate are determined by reference to the stage of completion of the contact activity at the end of the reporting period, while in the consolidated financial statements, they are recognized when an individual unit of residential real estate is delivered to the buyer. No adjustments are made for corporate allocations to segment profit and loss. In addition, segment assets and liabilities are generally measured based on total assets and liabilities in accordance with IFRS without any adjustment for corporate allocations, except that assets and liabilities in connection with the construction and sale of residential real estate are determined by reference to the stage of completion of the contract activity at the end of each period. For the other segments, segment profit and loss is determined the same way that consolidated net after tax profit for the period is generally determined under IFRS without any adjustment for corporate allocations. The accounting policies used by each segment are consistent with the accounting policies used in the preparation of the consolidated financial statements. Segment assets and liabilities are generally measured based on total assets and liabilities in accordance with IFRS without any adjustment for corporate allocations. Also, segment assets and liabilities are based on the separate financial statements of the entities instead of on consolidated basis. In addition, there are varying levels of transactions amongst the reportable segments. These transactions include sales of property, plant and assets, and rendering of construction service and so on. Segment results that are reported to the CEO include items directly attributable to a segment and items allocated on a reasonable basis. Segment capital expenditure is the total cost incurred during the period to acquire property, plant and equipment, and intangible assets other than goodwill.
New standards and interpretations not yet adopted	New standards and interpretations not yet adopted The following new standards have been published but are not mandatory for the Company for annual period beginning on January 1, 2019, and the Company has not early adopted them. (a) IAS No.1 “Presentation of Financial Statements” and IAS No.8 “Accounting Policies, Changes in Accounting Estimates and Errors” The definition of materiality has been clarified, and IAS No.1 “Presentation of Financial Statements” and IAS No.8 “Accounting Policies, Changes in Accounting Estimates and Errors” have been amended according to the clarified definition. In determining the materiality, information is material if omitting, misstating or obscuring it could reasonably be expected to influence decisions that the primary users of general purpose financial statements make on the basis of those financial statements, which provide financial information about a specific reporting entity. The Company believes that the effect of the amendments to the consolidated financial statements is not significant. (b) IFRS No.3 “Business Combinations” The amendment clarifies the definition of business when it includes input and process together significantly contribute to ability to create output and requires a simplified assessment that result in an asset acquisition if substantially all of the fair value of the gross assets is concentrated in a single identifiable asset or a group of similar identifiable assets. The Company expects that the amendments will not have a material impact on its consolidated financial statements.

General Information (Tables)

General Information (Tables)	12 Months Ended
General Information (Tables)	Dec. 31, 2019
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POSCO's Shareholders	As of December 31, 2019, POSCO’s shareholders are as follows: Shareholder’s name Number of shares Ownership (%) National Pension Service 10,291,670 11.80 BlackRock Fund Advisors(1,2,3) 5,429,071 6.23 Nippon Steel Corporation(1) 2,894,712 3.32 Samsung Group and subsidiaries(2) 2,401,789 2.75 GIC Private Limited 1,777,316 2.04 Others 64,392,277 73.86 87,186,835 100.00 (1) Includes American Depository Receipts (ADRs) of POSCO, each of which represents 0.25 share of POSCO’s common share which has par value of ￦ (2) Includes shares held by subsidiaries and others. (3) The number of shares held by the shareholder based on the information in the status report of large-scale shareholders filed with Korea Exchange on April 16, 2019.
Details of Consolidated Subsidiaries	As of December 31, 2019, the shares of POSCO are listed on the Korea Exchange while its ADRs are listed on the New York Stock Exchange. (b) Consolidated subsidiaries Details of consolidated subsidiaries as of December 31, 2018 and 2019 are as follows: Principal operations Ownership (%) December 31, 2018 December 31, 2019 POSCO Subsidiaries Total POSCO Subsidiaries Total Region [Domestic] POSCO ENGINEERING & CONSTRUCTION., CO., LTD. Engineering and construction 52.80 — 52.80 52.80 — 52.80 Pohang POSCO COATED & COLOR STEEL Co., Ltd. Coated steel manufacturing 56.87 — 56.87 56.87 — 56.87 Pohang POSCO ICT Computer hardware and software distribution 65.38 — 65.38 65.38 — 65.38 Pohang POSCO Research Institute Economic research and consulting 100.00 — 100.00 100.00 — 100.00 Seoul POSCO O&M CO.,Ltd. Business facility maintenance 59.80 40.20 100.00 47.17 52.83 100.00 Seoul POSCO A&C Architecture and consulting 100.00 — 100.00 45.66 54.34 100.00 Seoul POSCO Venture Capital Co., Ltd. Investment in venture companies 95.00 — 95.00 95.00 — 95.00 Pohang eNtoB Corporation Electronic commerce 7.50 53.63 61.13 7.50 53.63 61.13 Seoul POSCO CHEMICAL CO., LTD. (formerly, POSCO CHEMTECH) Refractories manufacturing and sales 60.00 — 60.00 61.26 — 61.26 Pohang POSCO-Terminal Co., Ltd. Transporting and warehousing 51.00 — 51.00 51.00 — 51.00 Gwangyang POSCO M-TECH Packing materials manufacturing and sales 48.85 — 48.85 48.85 — 48.85 Pohang POSCO ENERGY CO., LTD. Generation of electricity 89.02 — 89.02 100.00 — 100.00 Seoul PNR Steel byproduct manufacturing and sales 70.00 — 70.00 70.00 — 70.00 Pohang Future Creation Fund Postech Early Stage account Investment in venture companies — 40.00 40.00 — 40.00 40.00 Seoul POSCO WOMAN’S FUND Investment in venture companies — 40.00 40.00 — 40.00 40.00 Seoul SPH Co, LTD. House manufacturing and management — 100.00 100.00 — 100.00 100.00 Incheon Posco Group University Education service and real estate business 100.00 — 100.00 100.00 — 100.00 Incheon Growth Ladder POSCO K-Growth Investment in venture companies — 50.00 50.00 — 50.00 50.00 Pohang 2015 POSCO New technology II Fund Investment in venture companies — 25.00 25.00 — 25.00 25.00 Pohang POSCO Research & Technology Intellectual Property Services and consulting 100.00 — 100.00 100.00 — 100.00 Seoul TANCHEON E&E Refuse derived fuel and power generation — 100.00 100.00 — 100.00 100.00 Seoul POSCO Humans Construction 90.30 — 90.30 75.49 24.51 100.00 Pohang Mapo Hibroad Parking Co., Ltd. Construction — 71.00 71.00 — 71.00 71.00 Seoul Busan E&E Co., Ltd. Refuse derived fuel and power generation 70.00 — 70.00 70.00 — 70.00 Busan POSCO Family Strategy Fund Investment in venture companies 69.91 30.09 100.00 69.91 30.09 100.00 Pohang POSCO INTERNATIONAL Corporation (formerly, POSCO DAEWOO Corporation) Trading, energy & resource development and others 62.90 0.04 62.94 62.91 0.03 62.94 Seoul Pohang Scrap Recycling Distribution Center Co., Ltd. Steel processing and sales — 51.00 51.00 — 51.00 51.00 Pohang PSC Energy Global Co., Ltd. Investment in energy industry — 100.00 100.00 — 100.00 100.00 Pohang Suncheon Eco Trans Co. LTD Train manufacturing and management 100.00 — 100.00 100.00 — 100.00 Suncheon Songdo Development PMC (Project Management Company) LLC. Housing business agency — 100.00 100.00 — 100.00 100.00 Incheon Korea Fuel Cell Fuel cell — — — — 100.00 100.00 Pohang POSCO GEM 1th Fund Investment in venture companies — — — 98.81 1.19 100.00 Pohang POSCO Processing&Service Steel sales and trading 93.95 0.45 94.40 — — — Seoul MegaAsset Co.,Ltd. Real estate rental and sales — 100.00 100.00 — — — Incheon HOTEL LAONZENA Hotel business — 100.00 100.00 — — — Daegu Posco e&c Songdo International Building Non-residental — 100.00 100.00 — — — Seoul POSCO ES MATERIALS CO., LTD. Secondary and storage battery manufacturing 90.00 — 90.00 — — — Gumi BLUE O&M Co.,Ltd. Engineering service — 100.00 100.00 — — — Pohang [Foreign] POSCO America Corporation Steel trading 99.45 0.55 100.00 99.45 0.55 100.00 USA POSCO AUSTRALIA PTY LTD Raw material sales & mine development 100.00 — 100.00 100.00 — 100.00 Australia POSCO Canada Ltd. Coal sales — 100.00 100.00 100.00 — 100.00 Canada POSCAN Elkview Coal sales — 100.00 100.00 — 100.00 100.00 Canada POSCO Asia Co., Ltd. Steel and raw material trading 100.00 — 100.00 100.00 — 100.00 China POSCO-CTPC Co., Ltd. Steel manufacturing and sales 61.91 38.09 100.00 100.00 — 100.00 China POSCO E&C Vietnam Co., Ltd. Steel structure manufacturing and sales — 100.00 100.00 — 100.00 100.00 Vietnam Zhangjiagang Pohang Stainless Steel Co., Ltd. Stainless steel manufacturing and sales 58.60 23.88 82.48 58.60 23.88 82.48 China POSCO (Thailand) Company Limited Steel manufacturing and sales 88.58 11.42 100.00 100.00 — 100.00 Thailand POSCO-MKPC SDN BHD Steel manufacturing and sales 44.69 25.31 70.00 70.00 — 70.00 Malaysia Qingdao Pohang Stainless Steel Co., Ltd. Stainless steel manufacturing and sales 70.00 30.00 100.00 70.00 30.00 100.00 China POSCO(Suzhou) Automotive Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China POSCO-China Qingdao Steel manufacturing and sales — 100.00 100.00 100.00 — 100.00 China POS-ORE Iron ore sales and sales — 100.00 100.00 — 100.00 100.00 Australia POSCO-China Holding Corp. Holding company 100.00 — 100.00 100.00 — 100.00 China POSCO JAPAN Co., Ltd. Steel trading 100.00 — 100.00 100.00 — 100.00 Japan POS-CD Coal sales — 100.00 100.00 — 100.00 100.00 Australia POS-GC Coal sales — 100.00 100.00 — 100.00 100.00 Australia POSCO-India Private Limited Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 India POSCO-India Pune Processing Center. Pvt. Ltd. Steel manufacturing and sales 65.00 — 65.00 65.00 — 65.00 India POSCO Japan PC CO., LTD Steel manufacturing and sales — 86.12 86.12 — 86.12 86.12 Japan POSCO-CFPC Co., Ltd. Steel manufacturing and sales 39.60 60.40 100.00 39.60 60.40 100.00 China POSCO E&C CHINA Co., Ltd. Civil engineering and construction — 100.00 100.00 — 100.00 100.00 China POSCO MPPC S.A. de C.V. Steel manufacturing and sales 21.02 75.29 96.31 21.02 75.29 96.31 Mexico Zhangjigang Pohang Port Co., Ltd. Loading and unloading service — 100.00 100.00 — 100.00 100.00 China POSCO-VIETNAM Co., Ltd. Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 Vietnam POSCO MEXICO S.A. DE C.V. Automotive steel sheet 83.28 14.88 98.16 83.28 14.88 98.16 Mexico POSCO-Poland Wroclaw Steel manufacturing and sales 60.00 — 60.00 60.00 — 60.00 Poland POS-NP Coal sales — 100.00 100.00 — 100.00 100.00 Australia POSCO DAEWOO WAIGAOQIAO Intermediary trade & bonded — 100.00 100.00 — 100.00 100.00 China PT. Bio Inti Agrindo Forest resources development — 85.00 85.00 — 85.00 85.00 Indonesia POSCO ENGINEERING AND CONSTRUCTION AUSTRALIA (POSCO E&C AUSTRALIA) PTY LTD Construction and engineering service — 100.00 100.00 — 100.00 100.00 Australia POSCO-TISCO (JILIN) Steel manufacturing and sales 50.00 10.00 60.00 50.00 10.00 60.00 China POSCO Thainox Public Company Limited STS cold-rolled steel manufacturing and sales 84.66 — 84.66 84.39 — 84.39 Thailand Hunchun Posco Hyundai Logistics Logistics — 80.00 80.00 — 80.00 80.00 China POSCO INTERNATIONAL VIETNAM COMPANY LIMITED Trading business — 100.00 100.00 — 100.00 100.00 Vietnam POSCO(Chongqing) Automotive Processing Center Co., Ltd. Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China SUZHOU POSCO-CORE TECHNOLOGY CO., LTD. Component manufacturing and sales — 100.00 100.00 84.85 15.15 100.00 China PT.Krakatau Posco Chemtech Calcination Quicklime manufacturing and sales — 80.00 80.00 — 80.00 80.00 Indonesia POSCO AFRICA (PROPRIETARY) LIMITED Mine development 100.00 — 100.00 100.00 — 100.00 South POSCO ICT BRASIL IT service and engineering — 100.00 100.00 — 100.00 100.00 Brazil LA-SRDC Scrap manufacturing — 100.00 100.00 — 100.00 100.00 USA POSCO Center Beijing Real estate development, rental and management — 100.00 100.00 — 100.00 100.00 China POSCO AMERICA COMERCIALIZADORA S DE RL DE CV Steel sales — 100.00 100.00 — 100.00 100.00 Mexico POSCO(Guangdong) Automotive Steel Co., Ltd. Steel manufacturing and sales 83.64 10.00 93.64 83.64 10.00 93.64 China POSCO-Malaysia SDN. BHD. Steel manufacturing and sales 81.79 13.63 95.42 81.79 13.63 95.42 Malaysia PT KRAKATAU BLUE WATER Wastewater treamtment facilities operation and maintenance — 67.00 67.00 — 67.00 67.00 Indonesia POSCO INTERNATIONAL MYANMAR CORPORATION LIMITED Trading business — 100.00 100.00 — 100.00 100.00 Myanmar POSCO-Italy Processing Center Stainless steel sheetmanufacturing and sales 80.00 10.00 90.00 88.89 11.11 100.00 Italy Myanmar POSCO C&C Company, Limited. Steel manufacturing and sales — 70.00 70.00 — 70.00 70.00 Myanmar POSCO ICT VIETNAM IT service and electric control engineering — 100.00 100.00 — 100.00 100.00 Vietnam Daewoo Global Development. Pte., Ltd Real estate development — 81.51 81.51 — 81.51 81.51 Singapore Myanmar POSCO Engineering & Construction Company, Limited. Construction and engineering service — 100.00 100.00 — 100.00 100.00 Myanmar POS-Minerals Mine development management and sales — 100.00 100.00 — 100.00 100.00 USA POSCO(Wuhu) Automotive Processing Center Co., Ltd. Steel manufacturing and sales 68.57 31.43 100.00 68.57 31.43 100.00 China POSCO Engineering and Construction India Private Limited Civil engineering and construction — 100.00 100.00 — 100.00 100.00 India POSCO COATED STEEL (THAILAND) CO., LTD. Automotive steel sheetmanufacturing and sales 100.00 — 100.00 100.00 — 100.00 Thailand [Foreign] Daewoo Amara Company Limited Real estate development — 85.00 85.00 — 85.00 85.00 Myanmar POSMATE-CHINA CO., LTD Business facility maintenance — 100.00 100.00 — 100.00 100.00 China POSCO-Mexico Villagran Wire-rod Steel manufacturing and sales 56.75 10.00 66.75 56.75 10.00 66.75 Mexico POSCO ChengDu Processing Center Steel manufacturing and sales 33.00 10.00 43.00 33.00 10.00 43.00 China POSCO SUZHOU PROCESSING CENTER CO., LTD. Steel manufacturing and sales 30.00 70.00 100.00 30.00 70.00 100.00 China POSCO E&C SMART S DE RL DE CV Civil engineering and construction — 100.00 100.00 — 100.00 100.00 Mexico POSCO Philippine Manila Processing Center, Inc. Steel manufacturing and sales — 100.00 100.00 100.00 — 100.00 Philippines POSCO E&C HOLDINGS CO., Ltd. Holding company — 100.00 100.00 — 100.00 100.00 Thailand POSCO INTERNATIONAL POWER (PNGLAE) LTD. Electricity production — 100.00 100.00 — 100.00 100.00 Papua New PT.Krakatau Posco Social Enterprise Social enterprise — 100.00 100.00 — 100.00 100.00 Indonesia Ventanas Philippines Construction Inc Construction — 100.00 100.00 — 100.00 100.00 Philippines POSCO E&C Mongolia Construction and engineering service — 100.00 100.00 — 100.00 100.00 Mongolia SANPU TRADING Co., Ltd. Raw material trading — 70.04 70.04 — 70.04 70.04 China Zhangjiagang BLZ Pohang Steel Intermediate trade — 100.00 100.00 — 100.00 100.00 China POSCO RU Limited Liability Company Trade and business development 100.00 — 100.00 100.00 — 100.00 Russia GOLDEN LACE POSCO Rice processing — 60.00 60.00 — 60.00 60.00 Myanmar POSCO ICT-China IT service and DVR business — 100.00 100.00 — 100.00 100.00 China Pos-Sea Steel Intermediate trade — 100.00 100.00 — 100.00 100.00 Singapore POSCO Europe Steel Distribution Center Logistics & Steel sales 50.00 20.00 70.00 50.00 20.00 70.00 Slovenia POSCO ENGINEERING (THAILAND) CO., LTD. Construction and engineering service — 100.00 100.00 — 100.00 100.00 Thailand POSCO VST CO., LTD. Stainless steel sheet 95.65 — 95.65 95.65 — 95.65 Vietnam POSCO INTERNATIONAL UKRAINE, LLC. Grain sales — 100.00 100.00 — 100.00 100.00 Ukraine Zhangjiagang Pohang Refractories Co., Ltd. Refractory materials sales & furnace maintenance — 51.00 51.00 — 51.00 51.00 China POSCO Maharashtra Steel Private Limited Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 India POSCO INDIA PROCESSING CENTER PRIVATE LIMITED Steel manufacturing and sales 93.34 1.98 95.32 93.34 1.98 95.32 India POSCO TNPC Otomotiv Celik San. Ve Tic. A.S Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 Turkey POSCO Vietnam Processing Center. Co., Ltd Steel manufacturing and sales 83.54 5.29 88.83 83.54 5.29 88.83 Vietnam POSCO(Liaoning) Automotive Processing Center Co., Ltd. Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China POSCO-Indonesia Jakarta Processing Center Steel manufacturing and sales 65.00 20.00 85.00 65.00 20.00 85.00 Indonesia PT.MRI Mine development 65.00 — 65.00 65.00 — 65.00 Indonesia POSCO TMC INDIA PRIVATE LIMITED Steel manufacturing and sales — 100.00 100.00 — 100.00 100.00 India POSCO AMERICA ALABAMA PROCESSING CENTER CO., LTD. Steel manufacturing and sales — 97.80 97.80 — 97.80 97.80 USA POSCO(Yantai Automotive Processing Center Co., Ltd. Steel manufacturing and sales 90.00 10.00 100.00 90.00 10.00 100.00 China POSCO India Steel Distribution Center Private Ltd. Steel logistics — 100.00 100.00 — 100.00 100.00 India POSCO China Dalian Plate Processing Center Co., Ltd. Plate manufacturing and sales 79.52 11.70 91.22 79.52 11.70 91.22 China POSCO SS VINA JOINT STOCK COMPANY (Formerly, POSCO SS VISA CO., Ltd.) Steel manufacturing and sales 100.00 — 100.00 100.00 — 100.00 Vietnam PT.POSCO ICT INDONESIA IT service and electric control engineering — 66.99 66.99 — 66.99 66.99 Indonesia POSCO NCR Coal Ltd. Coal sales — 100.00 100.00 — 100.00 100.00 Canada POSCO WA PTY LTD Iron ore sales & mine development 100.00 — 100.00 100.00 — 100.00 Australia POSCO AUSTRALIA GP PTY LIMITED Resource development — 100.00 100.00 — 100.00 100.00 Australia POSCO INTERNATIONAL POWER(PNGPOM) LTD. Electricity production — 100.00 100.00 — 100.00 100.00 Papua New PT. KRAKATAU POSCO ENERGY Electricity production construction and operation — 90.00 90.00 — 90.00 90.00 Indonesia POSCO INTERNATIONAL AMERICA CORP. Trading business — 100.00 100.00 — 100.00 100.00 USA POSCO INTERNATIONAL Deutschland GMBH Trading business — 100.00 100.00 — 100.00 100.00 Germany POSCO INTERNATIONAL JAPAN CORP. Trading business — 100.00 100.00 — 100.00 100.00 Japan POSCO INTERNATIONAL SINGAPORE PTE. LTD. Trading business — 100.00 100.00 — 100.00 100.00 Singapore POSCO INTERNATIONAL ITALIA S.R.L. Trading business — 100.00 100.00 — 100.00 100.00 Italy POSCO INTERNATIONAL (CHINA) CO., LTD Trading business — 100.00 100.00 — 100.00 100.00 China POSCO INTERNATIONAL TEXTILE LLC. Textile manufacturing — 100.00 100.00 — 100.00 100.00 Uzbekistan POSCO INTERNATIONAL AUSTRALIA HOLDINGS PTY. LTD. Resource development — 100.00 100.00 — 100.00 100.00 Australia POSCO MAURITIUS LIMITED Coal development and sales — 100.00 100.00 — 100.00 100.00 Mauritius PT. KRAKATAU POSCO Steel manufacturing and sales 70.00 — 70.00 70.00 — 70.00 Indonesia POSCO INTERNATIONAL MEXICO S.A DE C.V. Trading business — 100.00 100.00 — 100.00 100.00 Mexico POSCO INTERNATIONAL MALAYSIA SDN BHD Trading business — 100.00 100.00 — 100.00 100.00 Malaysia PT.POSCO INDONESIA INTI Mine development 100.00 — 100.00 100.00 — 100.00 Indonesia POSCO INTERNATIONAL SHANGHAI CO., LTD. Trading business — 100.00 100.00 — 100.00 100.00 China PGSF, L.P. Investment in bio tech Industry — 100.00 100.00 — 100.00 100.00 USA POSCO INTERNATIONAL INDIA PVT. LTD Trading business — 100.00 100.00 — 100.00 100.00 India POSCO(Dalian) IT Center Development Co., Ltd. Real estate development and investment — 100.00 100.00 — 100.00 100.00 China PT. POSCO E&C INDONESIA Civil engineering and construction — 100.00 100.00 — 100.00 100.00 Indonesia HUME COAL PTY LTD Raw material manufacturing — 100.00 100.00 — 100.00 100.00 Australia Brazil Sao Paulo Steel Processing Center Steel manufacturing and sales — 76.00 76.00 — 76.00 76.00 Brazil DAESAN (CAMBODIA) Co., Ltd. Real estate development and investment — 100.00 100.00 — 100.00 100.00 Cambodia POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. Construction — 100.00 100.00 — 100.00 100.00 Brazil POSCO ASSAN TST STEEL INDUSTRY Steel manufacturing and sales 60.00 10.00 70.00 60.00 10.00 70.00 Turkey HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd. Real estate development and investment — 100.00 100.00 — 100.00 100.00 Hongkong JB CLARK HILLS(1) Apartment construction — 25.00 25.00 — 70.00 70.00 Philippines POS-LT Lithium mining investment — 100.00 100.00 — 100.00 100.00 Australia ZHEJIANG POSCO-HUAYOU ESM CO., LTD Anode material manufacturing 100.00 — 100.00 60.00 — 60.00 China POSCO Argentina S.A.U. Mineral exploration/manufacturing/sales 100.00 — 100.00 100.00 — 100.00 Argentina GRAIN TERMINAL HOLDING PTE. LTD. Trade — — — — 75.00 75.00 Singapore Mykolaiv Milling Works PJSC. Grain trading — — — — 100.00 100.00 Ukraine Yuzhnaya Stevedoring Company Limited LLC. Cargo handling — — — — 100.00 100.00 Ukraine Myanmar POSCO Steel Co., Ltd Steel manufacturing and sales — 70.00 70.00 — 70.00 70.00 Myanmar POSCO SINGAPORE LNG TRADING PTE. LTD. LNG trading 50.00 50.00 100.00 — — — Singapore POSCO DAEWOO E&P CANADA CORPORATION Crude oil and natural gas mining — 100.00 100.00 — — — Canada Daewoo Power and Infra (PTY) Limited Electricity — 100.00 100.00 — — — South Daewoo Precious Resources Co., Ltd. Resources development — 70.00 70.00 — — — Myanmar POSCO E&C (THAILAND) CO., Ltd. Construction and engineering — 100.00 100.00 — — — Thailand POSCO Gulf SFC LLC Steel manufacturing and sales — 65.72 65.72 — — — United Arab POSCO-South Asia Company Limited Steel sales 100.00 — 100.00 — — — Thailand POSCO(Guangdong) Coated Steel Co., Ltd. Steel manufacturing and sales 87.04 10.04 97.08 — — — China DAEWOO INTERNATIONAL GUANGZHOU CORP. Trading business — 100.00 100.00 — — — China (1) Reclassified from associate to subsidiary during the year ended December 31, 2019.
Details of Non-controlling Interest	(c) Details of non-controlling 1) December 31, 2017 (in millions of Won) POSCO PT. POSCO POSCO POSCO Others Total Current assets ￦ 4,483,544 557,041 441,325 4,878,251 1,054,538 8,579,813 19,994,512 Non-current 4,590,394 2,771,504 316,724 2,444,616 2,859,824 6,676,559 19,659,621 Current liabilities (4,221,443 ) (1,237,255 ) (145,649 ) (3,896,680 ) (785,462 ) (8,313,902 ) (18,600,391 ) Non-current (1,549,013 ) (1,933,247 ) (970 ) (833,403 ) (2,200,065 ) (2,048,454 ) (8,565,152 ) Equity 3,303,482 158,043 611,430 2,592,784 928,835 4,894,016 12,488,590 Non-controlling 1,224,303 47,413 244,572 1,223,816 762,390 974,941 4,477,435 Sales 20,891,526 1,635,837 1,163,918 5,794,532 1,578,026 23,547,072 54,610,911 Profit (loss) for the period 115,321 (117,729 ) 101,019 169,011 70,795 258,053 596,470 Profit (loss) attributable to non-controlling 42,739 (35,318 ) 40,408 79,775 7,770 39,605 174,979 Cash flows from operating activities 128,875 (27,817 ) 20,042 (84,840 ) 30,295 140,418 206,973 Cash flows from investing activities (86,365 ) (5,502 ) (18,699 ) (171,924 ) (2,792 ) (63,621 ) (348,903 ) Cash flows from financing activities (before dividends to non-controlling (19,295 ) 31,782 8 150,801 220,317 (38,090 ) 345,523 Dividend to non-controlling (22,597 ) — (7,088 ) — (24,183 ) (12,777 ) (66,645 ) Effect of exchange rate fluctuation on cash held (459 ) (147 ) (6 ) (3,541 ) — (15,532 ) (19,685 ) Net increase (decrease) in cash and cash equivalents 159 (1,684 ) (5,743 ) (109,504 ) 223,637 10,398 117,263 2) December 31, 2018 (in millions of Won) POSCO PT. POSCO POSCO POSCO Others Total Current assets ￦ 5,311,596 615,491 416,284 4,100,967 825,241 9,137,798 20,407,377 Non-current 4,363,490 2,730,865 460,905 1,911,844 2,767,203 5,493,324 17,727,631 Current liabilities (4,724,056 ) (1,368,498 ) (140,268 ) (3,007,029 ) (1,197,845 ) (8,026,474 ) (18,464,170 ) Non-current (1,563,107 ) (1,754,797 ) (10,767 ) (608,089 ) (1,445,288 ) (1,925,084 ) (7,307,132 ) Equity 3,387,923 223,061 726,154 2,397,693 949,311 4,679,564 12,363,706 Non-controlling 1,255,728 66,918 290,461 1,131,733 335,203 929,506 4,009,549 Sales 23,314,595 1,871,634 1,340,984 6,799,292 1,841,187 24,721,939 59,889,631 Profit (loss) for the period 113,196 54,257 142,918 290,131 (73,948 ) (56,151 ) 470,403 Profit (loss) attributable to non-controlling 41,956 16,277 57,167 136,944 (8,116 ) (101,156 ) 143,072 Cash flows from operating activities (61,173 ) 89,131 29,865 207,729 16,211 14,869 296,632 Cash flows from investing activities (12,780 ) (6,432 ) (15,801 ) 272,230 35,460 (13,199 ) 259,478 Cash flows from financing activities (before dividends to non-controlling 99,496 (82,295 ) — (400,499 ) (71,378 ) (16,094 ) (470,770 ) Dividend to non-controlling (22,862 ) — (8,270 ) — (19,813 ) (6,906 ) (57,851 ) Effect of exchange rate fluctuation on cash held 807 21 (17 ) 1,257 — 1,682 3,750 Net increase (decrease) in cash and cash equivalents 3,488 425 5,777 80,717 (39,520 ) (19,648 ) 31,239 3) December 31, 2019 (in millions of Won) POSCO PT. POSCO POSCO POSCO Others Total Current assets ￦ 4,396,683 520,057 624,017 4,242,954 441,208 8,062,428 18,287,347 Non-current 4,186,197 2,723,254 1,050,406 1,808,919 210,037 4,740,887 14,719,700 Current liabilities (3,013,269 ) (1,570,204 ) (236,968 ) (2,734,305 ) (262,265 ) (7,672,691 ) (15,489,702 ) Non-current (2,087,769 ) (1,590,810 ) (462,361 ) (786,191 ) (38,836 ) (2,095,797 ) (7,061,764 ) Equity 3,481,842 82,297 975,094 2,531,377 350,144 3,034,827 10,455,581 Non-controlling 1,290,600 24,689 377,770 1,194,833 121,213 1,124,381 4,133,486 Sales 22,745,239 1,906,302 1,434,507 7,625,389 925,551 22,975,605 57,612,593 Profit (loss) for the period 199,721 (146,975 ) 94,481 330,298 32,954 (587,146 ) (76,667 ) Profit (loss) attributable to non-controlling 74,030 (44,093 ) 36,604 155,904 11,408 (89,676 ) 144,177 Cash flows from operating activities 580,372 61,398 22,794 24,636 21,571 (16,324 ) 694,447 Cash flows from investing activities (40,264 ) (7,173 ) (111,996 ) (6,620 ) (2,129 ) 31,057 (137,125 ) Cash flows from financing activities (before dividends to non-controlling (502,801 ) (53,890 ) 134,609 (25,448 ) (336 ) (4,295 ) (452,161 ) Dividend to non-controlling (27,432 ) — (9,451 ) (9,867 ) (2,628 ) (11,079 ) (60,457 ) Effect of exchange rate fluctuation on cash held 1,736 25 (7 ) 1,401 (47 ) 3,931 7,039 Net increase (decrease) in cash and cash equivalents 11,611 360 35,949 (15,898 ) 16,431 3,290 51,743
Details of Associates	(d) Details of associates and joint ventures 1) Associates Details of associates as of December 31, 2018 and 2019 are as follows: Ownership (%) Investee Category of business 2018 2019 Region [Domestic] New Songdo International City Development, LLC Real estate rental 29.90 29.90 Seoul Gale International Korea, LLC Real estate rental 29.90 29.90 Seoul SNNC Raw material manufacturing and sales 49.00 49.00 Gwangyang KONES, Corp. Technical service 41.67 41.67 Gyeongju CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd Real estate development 29.53 29.53 Chungju DAEHO GLOBAL MANAGEMENT CO., LTD. Investment advisory service 35.82 35.82 Pohang Mokpo Deayang Industrial Corporation Real estate development and rental 27.40 27.40 Mokpo Gunggi Green Energy(1) Electricity generation 19.00 19.00 Hwaseong Pohang Special Welding Co.,Ltd. Welding material and tools manufacturing and sales 50.00 50.00 Pohang KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund(1) Investment in new technologies 12.50 12.50 Seoul EQP POSCO Global NO1 Natural Resources Private Equity Fund Investment in new technologies 31.27 33.41 Seoul KC Chemicals CORP.(1) Machinery manufacturing 19.00 19.00 Hwaseong Garolim Tidal Power Plant Co.,Ltd Tidal power plant construction and management 32.13 32.13 Seosan POSTECH Social Enterprise Fund(1) Investment in new technologies 9.17 9.17 Seoul QSONE Co.,Ltd. Real estate rental and facility management 50.00 50.00 Seoul Chun-cheon Energy Co., Ltd Electricity generation 45.67 49.10 Chuncheon Keystone NO. 1 Private Equity Fund(6) Private equity financial 40.45 52.58 Seoul Noeul Green Energy(1) Electricity generation 10.00 10.00 Seoul Posco-IDV Investment in new technologies 17.86 17.86 Seoul Daesung Steel(1) Steel sales 17.54 17.54 Busan Pohang E&E Co., LTD Investment in waste energy 30.00 30.00 Pohang POSCO Energy Valley Fund Investment in new technologies 20.00 20.00 Pohang Hyundai Invest Guggenheim CLO Qualified Private Special Asset Trust No.2 Investment in new technologies 38.47 35.44 Seoul PoscoPlutus Bio Fund(1) Investment in new technologies 11.97 11.97 Seoul PoscoPlutus Project Fund(1) Investment in new technologies 11.91 11.91 Seoul Posco Agri-Food Export Fund Investment in new technologies 30.00 30.00 Seoul PoscoPlutus Project 2nd Project Fund(1) Investment in new technologies 0.61 0.61 Seoul Posco Culture Contents Fund Investment in new technologies 31.67 31.67 Seoul PCC_Centroid 1st Fund Investment in new technologies 24.10 24.10 Seoul PCC Amberstone Private Equity Fund 1(1) Investment in new technologies 8.80 8.80 Seoul UITrans LRT Co., Ltd. Transporting 38.19 38.19 Seoul POSCO Advanced Technical Staff Fund(1) Investment in new technologies 15.87 15.87 Seoul POSCO 4th Industrial Revolution Fund(1) Investment in new technologies 19.05 19.05 Seoul Incheon-Gimpo Expressway Co., Ltd.(1) Construction 18.26 18.26 Anyang Pureun Tongyeong Enviro Co., Ltd. Sewerage treatment 20.40 20.40 Tongyeong Pure Gimpo Co., Ltd. Construction 28.79 28.79 Seoul POSCO PLANTEC Co., Ltd.(2,6) Construction of industrial plant 73.94 73.94 Ulsan Posgreen Co., Ltd.(1) Lime and plaster manufacturing 19.00 19.00 Gwangyang Clean Iksan Co., Ltd. Construction 23.50 23.50 Iksan Innovalley Co., Ltd. Real estate development 28.77 28.77 Yongin Pohang Techno Valley PFV Corporation(6) Real estate development, supply and rental 57.39 57.39 Pohang BLUE OCEAN Private Equity Fund Private equity financial 27.52 27.52 Seoul Western Inland highway CO.,LTD. Construction 27.50 30.00 Incheon Metropolitan Outer Ring Expressway co., ltd. Investment in Expressway 47.58 21.27 Incheon IT ENGINEERING CO., LTD.(1) Vehicle engineering 10.84 4.99 Seoul PCC Bio 1ST Fund(1) Investment in new technologies 13.46 13.46 Seoul INNOPOLIS Job Creation Fund II(1) Investment in new technologies 6.43 6.21 Seoul POSPower Co., Ltd. Generation of electricity 34.00 34.00 Samcheok INKOTECH, INC.(1) Electricity generation and sales 10.00 10.00 Seoul PCC Social Enterprise Fund II(1) Investment in venture companies 16.67 16.67 Seoul PCC Amberstone Private Equity Fund II(1) Private equity trust 19.70 19.91 Seoul Synapse Fund(1) Investment in new technologies 16.26 16.26 Seoul NEXTRAIN Co.,Ltd Service maintenance and management 32.00 32.00 Incheon TK CHEMICAL CORPORATION(1) Chemical 8.80 5.01 Daegu Hanil-Daewoo Cement Co., Ltd.(1) Cement 15.00 15.00 Incheon PCC S/W 2nd Fund(1,3) Investment in new technologies business — 12.81 Pohang PCC-Conar Investment in venture — 13.64 Pohang Hyochun Co., Ltd(1,3) Screen door operation and other — 18.00 Seoul RPSD Project Co., Ltd(3) Real estate development — 29.00 Incheon PCC EV Fund(1,3) Investment in new technologies business — 18.18 Pohang IBKC-PCC Investment in new technologies business — 18.18 Pohang 2019 PCC Materials and Parts Fund(1,3) Investment in new technologies business — 8.70 Pohang Shinahn wind Power generation(1,3) Electric, gas, steam — 19.00 Suwon 2019 PCC New technology Fund(1,3) Investment in new technologies business — 4.76 Pohang PCC-Woori Investment in new technologies business — 18.85 Pohang 2016 Posco Plutus New technology Fund(4) New technology business investment 25.17 — Seoul Clean Gimpo Co., Ltd(5) Waste treatment and others 29.58 — Gimpo Postech Early Stage Fund(4) investment in New technology 10.00 — Pohang Appliedscience Co., Ltd(4) Machine manufacturing for semiconductor manufacturing 22.89 — Paju [Foreign] VSC POSCO Steel Corporation Steel processing and sales 50.00 50.00 Vietnam JB CLARK HILLS(7) Apartment Construction 25.00 70.00 Philippines POSCHROME (PROPRIETARY) LIMITED Raw material manufacturing and sales 50.00 50.00 South Africa CAML RESOURCES PTY LTD Raw material manufacturing and sales 33.34 33.34 Australia Nickel Mining Company SAS Raw material manufacturing and sales 49.00 49.00 New Caledonia PT. Wampu Electric Power Construction and civil engineering 20.00 20.00 Indonesia POSK(Pinghu) Steel Processing Center Co., Ltd. Steel processing and sales 20.00 20.00 China PT.INDONESIA POS CHEMTECH CHOSUN Ref Refractory manufacturing and sales 30.19 30.19 Indonesia NS-Thainox Steel manufacturing and sales 49.00 49.00 Vietnam Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd Tinplate manufacturing and sales 34.00 34.00 China PT. Tanggamus Electric Power(1) Construction and civil engineering 17.50 17.50 Indonesia LLP POSUK Titanium Titanium manufacturing and sales 36.83 35.30 Kazakhstan LI3 ENERGY INC Resource development 26.06 26.06 Peru IMFA ALLOYS FINLEASE LTD Raw material manufacturing and sales 24.00 24.00 India KRAKATAU POS-CHEM DONG-SUH Chemical by-product 19.00 19.00 Indonesia 7623704 Canada Inc.(1) Investments management 10.40 10.40 Canada Hamparan Mulya Resource development 45.00 45.00 Indonesia POS-SEAHSTEELWIRE(TIANJIN)CO.,Ltd. Steel manufacturing and sales 25.00 25.00 China Eureka Moly LLC Raw material manufacturing and sales 20.00 20.00 USA PT. Batutua Tembaga Raya Raw material manufacturing and sales 22.00 22.00 Indonesia KIRIN VIETNAM CO., LTD(1) Panel manufacturing 19.00 19.00 Vietnam POSCO SeAH Steel Wire(Nantong) Co., Ltd. Steel processing and sales 25.00 25.00 China POS-SeAH Steel manufacturing and sales 25.00 25.00 Thailand Jupiter Mines Limited(1) Resource development 6.93 6.93 Australia SAMHWAN VINA CO., LTD(1) Steel manufacturing and sales 19.00 19.00 Vietnam Saudi-Korean Company for Maintenance Properties Management LLC(1) Building management 19.00 19.00 Saudi NCR LLC Coal sales 29.41 29.40 Canada AMCI (WA) PTY LTD Iron ore sales & mine development 49.00 49.00 Australia SHANGHAI LANSHENG DAEWOO CORP. Trading 49.00 49.00 China SHANGHAI WAIGAOQIAO FREE TRADE ZONE LANSHENG DAEWOO IN’L TRADING CO., LTD. Trading 49.00 49.00 China General Medicines Company Ltd. Medicine manufacturing and sales 33.00 33.00 Sudan KOREA LNG LTD. Gas production and sales 20.00 20.00 England AES-VCM Electricity generation 30.00 30.00 Vietnam KG Power(M) SDN. BHD Resource development 20.00 20.00 Malaysia South-East Asia Gas Pipeline Company Ltd. Pipeline construction and management 25.04 25.04 Myanmar GLOBAL KOMSCO Daewoo LLC Cotton celluloid manufacturing and sales 35.00 35.00 Uzbekistan POSCO-Poggenamp Electrical Steel Pvt. Ltd. Steel processing and sales 26.00 26.00 India Qingdao Pohang DGENX Stainless SteelPipeCo., Ltd Exhaust meter manufacturing 40.00 40.00 China SHINPOONG DAEWOO PHARMA VIETNAM CO.,LTD(1) Medicine production 3.42 3.42 Vietnam ZHEJIANG HUAYOU-POSCO ESM(3) Produce — 40.00 China Sebang Steel(4) Scrap sale 49.00 — Japan ERAE Automotive Systems Mexico, S. DE R.L. DE C.V(4) Automobile parts manufacturing 7.65 — Mexico (1) Considering the composition of board of directors, the Company is able to exercise significant influence even though the Company’s percentage of ownership is below 20%. (2) On September 30, 2015, in order to improve its financial standing and normalize operation, the associates reached a workout agreement with its Creditor Financial Institutions Committee. As a result, the Company lost its control and classified its shares as investment in associate. (3) During the year ended December 31, 2019, the entity was newly classified to associates. (4) During the year ended December 31, 2019, the entity was excluded from associates due to liquidation. (5) During the year ended December 31, 2019, the entity was excluded from associates due to sale of interest. (6) Considering the composition of board of directors, the Company has no control even though the Company’s percentage of ownership if above 50%. (*7) During the year ended December 31, 2019, the Company reclassified to subsidiaries from associates.
Details of Joint Ventures	2) Joint ventures Details of joint ventures as of December 31, 2018 and 2019 are as follows: Ownership (%) Investee Category of business 2018 2019 Region [Domestic] POSCO MITSUBISHI CARBON TECHNOLOGY Steel processing and sales 60.00 60.00 Gwangyang POSCO-SGI Investment in new technologies 24.55 24.55 Seoul POSCO-KB Investment in new technologies 18.75 18.75 Seoul POSCO-NSC Investment in new technologies 16.67 16.67 Seoul PoscoPlutus Project 3rd Project fund Investment in new technologies 5.96 5.96 Seoul PCC Bio 2nd Fund Investment in new technologies 19.72 19.72 Seoul PCC Material 3rd Fund Investment in new technologies 2.38 2.38 Seoul Union PCC Portfolio Fund(1) Investment in venture — 14.12 Seoul PCC S/W FUND(1) Investment in new technologies — 0.46 Seoul [Foreign] KOBRASCO Steel materials manufacturing and sales 50.00 50.00 Brazil USS-POSCO Cold-rolled steel manufacturing and sales 50.00 50.00 USA PT. POSMI Steel Indonesia Steel processing and sales 36.69 36.69 Indonesia United Spiral Pipe, LLC Material manufacturing and sales 35.00 35.00 USA CSP - Compania Siderurgica do Pecem Steel manufacturing and sales 20.00 20.00 Brazil BX STEEL POSCO Cold Rolled Sheet Co., Ltd. Steel processing and sales 25.00 25.00 China POSCO-SAMSUNG-Slovakia Processing Center Steel processing and sales 30.00 30.00 Slovakia YULCHON MEXICO S.A. DE C.V. Tube for automobile manufacturing 19.00 19.00 Mexico Hyunson Engineering & Construction HYENCO Construction 4.89 4.89 Algeria POSCO E&C Saudi Arabia Civil engineering and construction 40.00 40.00 Saudi Pos-Austem Automotive parts manufacturing 19.90 19.90 China POS-InfraAuto Automotive parts manufacturing 16.20 16.20 China POS-AUSTEM Automotive parts manufacturing 11.10 11.10 China POS-AUSTEM Automotive parts manufacturing 13.00 13.00 China Kwanika Copper Corporation Energy & resource development 35.00 35.00 Canada DMSA/AMSA Energy & resource development 4.00 4.00 Madagascar Roy Hill Holdings Pty Ltd Energy & resource development 12.50 12.50 Australia POSCO-NPS Mine development 50.00 50.00 USA VNS-DAEWOO Fabricate and sell iron scraps 50.00 — Vietnam (1) These joint ventures were newly established in 2019. (2) Excluded from joint ventures due to liquidation during the year ended December 31, 2019.
Consolidated Subsidiaries Acquired or Newly Established	(e) Newly included subsidiaries Consolidated subsidiaries acquired or newly established during the year ended December 31, 2019 are as follows: Company Date of addition Ownership (%) Reason GRAIN TERMINAL HOLDING PTE. LTD. June 2019 75.00 Acquisition of control Mykolaiv Milling Works PJSC. June 2019 100.00 Acquisition of control Yuzhnaya Stevedoring Company Limited LLC. June 2019 100.00 Acquisition of control Chargev Co., Ltd September 2019 100.00 New establishment Korea Fuel Cell November 2019 100.00 New establishment JB CLARK HILLS December 2019 70.00 Reclassified to subsidiary from associate POSCO GEM 1th Fund December 2019 100.00 New establishment
Subsidiaries That Were Excluded From Consolidation	(f) Excluded subsidiaries Subsidiaries that were excluded from consolidation during the year ended December 31, 2019 are as follows: Company Date of exclusion Reason POSCO Processing & Service Co., Ltd. January 2019 Merged into POSCO Co.,Ltd Daewoo Precious Resources Co., Ltd. January 2019 Liquidation BLUE O&M Co.,Ltd. February 2019 Merged into POSCO O&M CO.,Ltd. Mega asset Co.,Ltd. February 2019 Merged into POSCO O&M CO.,Ltd. POSCO ESM Co.,Ltd. April 2019 Merged into POSCO Chemical CO.,Ltd. Daewoo International Guangzhou Corp. April 2019 Merged into POSCO INTERNATIONAL(CHINA) CO.,Ltd. POSCO(Guangdong) Coated Steel Co., Ltd. June 2019 Disposal POSCO E&C (THAILAND) CO.,Ltd. June 2019 Liquidation POSCO Gulf SFC LLC June 2019 Liquidation Hotel laonzena July 2019 Disposal Daewoo Power and Infra (PTY) Limited July 2019 Liquidation POSCO SINGAPORE LNG TRADING PTE. LTD. September 2019 Liquidation POSCO-South Asia Co., Ltd. September 2019 Liquidation PSIB CO.,Ltd. October 2019 Liquidation Chargev Co., Ltd December 2019 Disposal POSCO DAEWOO E&P CANADA CORPORATION December 2019 Liquidation

Statement of Compliance (Tables

Statement of Compliance (Tables)	12 Months Ended
Statement of Compliance (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of additional right of use assets and liabilities recognized	The Company recognized right-of-use (in millions of Won) The date of initial (January 1, 2019) Consolidated statement of financial position Right-of-use ￦ 704,458 Lease receivable 264,809 Lease liabilities 677,370 (*1) The prepaid lease payments of ￦ When measuring lease liabilities for leases previously classified as operating leases, the Company discounted lease payments using its incremental borrowing rates as of January 1, 2019, the date of initial application, and the weighted-average rates applied are 1.8 ~ 18.5%. The carrying amount of lease liabilities as of January 1, 2019, the date of initial application, is as follow: (in millions of Won) The date of initial (January 1, 2019) Operating lease commitments as of December 31, 2018 ￦ 913,630 Operating lease commitments not recognized as lease liabilities - Leases of low-value (50,364 ) - Leases with less than 12 months of lease term at transition (17,635 ) Operating lease commitments recognized as lease liabilities 845,631 Amount discounted using the incremental borrowing rate as of January 1, 2019, the date of initial application 677,370 Finance lease liabilities recognized as of December 31, 2018 94,754 Lease liabilities as of January 1, 2019, the date of initial application ￦ 772,124
Summary of carrying amount of lease liabilities	The carrying amount of lease liabilities as of January 1, 2019, the date of initial application, is as follow: (in millions of Won) The date of initial (January 1, 2019) Operating lease commitments as of December 31, 2018 ￦ 913,630 Operating lease commitments not recognized as lease liabilities - Leases of low-value (50,364 ) - Leases with less than 12 months of lease term at transition (17,635 ) Operating lease commitments recognized as lease liabilities 845,631 Amount discounted using the incremental borrowing rate as of January 1, 2019, the date of initial application 677,370 Finance lease liabilities recognized as of December 31, 2018 94,754 Lease liabilities as of January 1, 2019, the date of initial application ￦ 772,124

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
Summary of Significant Accounting Policies (Tables)	Dec. 31, 2019
Text block [abstract]
Estimated Useful Lives of Property, Plant and Equipment	The estimated useful lives for the current and comparative periods are as follows: Buildings 5-50 years Structures 4-50 Machinery and equipment 4-25 Vehicles 3-20 Tools 3-10 Furniture and fixtures 3-20 Lease assets 2-30 Bearer plants 20 years
Estimated Useful Lives of Intangible Assets	Amortization of intangible assets except for goodwill is calculated on a straight-line basis over the estimated useful lives of intangible assets from the date that they are available for use. The residual value of intangible assets is zero. However, as there are no foreseeable limits to the periods over which club memberships are expected to be available for use, this intangible asset is determined as having an indefinite useful life and not amortized. Intellectual property rights 4-25 years Development expense 3-5 Port facilities usage rights 4-75 Other intangible assets 2-15 years

Financial risk management (Tabl

Financial risk management (Tables)	12 Months Ended
Financial risk management (Tables)	Dec. 31, 2019
Text block [abstract]
Net Borrowing-to-Equity Ratio	Net borrowing-to-equity (in millions of Won) 2018 2019 Total borrowings ￦ 20,209,270 20,441,613 Less: Cash and cash equivalents 2,643,865 3,514,872 Net borrowings 17,565,405 16,926,741 Total equity 46,759,551 47,794,707 Net borrowings-to-equity 37.57 % 35.42 %

Cash and Cash Equivalents (Tabl

Cash and Cash Equivalents (Tables)	12 Months Ended
Cash and Cash Equivalents (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Cash and Cash Equivalents	Cash and cash equivalents as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Cash ￦ 1,668 2,081 Demand deposits and checking accounts 1,471,891 1,581,428 Time deposits 538,130 701,865 Other cash equivalents 632,176 1,229,498 ￦ 2,643,865 3,514,872

Trade Accounts and Notes Rece_2

Trade Accounts and Notes Receivable (Tables)	12 Months Ended
Trade Accounts and Notes Receivable (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of lease investment and net lease investment	(c) As of December 31, 2018 and 2019, the Company’s gross investment and net investment in the leases are as follows: (in millions of Won) 2018 2019 Less than 1 year ￦ 57,820 237 1 year - 3 years 49,678 46,161 Undiscounted lease payments 107,498 46,398 Unrealized interest income (4,138 ) (2,452 ) Present value of minimum lease payment ￦ 103,360 43,946

Other Receivables (Tables)

Other Receivables (Tables)	12 Months Ended
Other Receivables (Tables)	Dec. 31, 2019
Statement [LineItems]
Summary of lease investment and net lease investment	(c) As of December 31, 2018 and 2019, the Company’s gross investment and net investment in the leases are as follows: (in millions of Won) 2018 2019 Less than 1 year ￦ 57,820 237 1 year - 3 years 49,678 46,161 Undiscounted lease payments 107,498 46,398 Unrealized interest income (4,138 ) (2,452 ) Present value of minimum lease payment ￦ 103,360 43,946
Other receivables [member]
Statement [LineItems]
Summary of Financial Assets	(1) The details of other receivables as of December 31, 2019 and 2018, are as follows: (in millions of Won) 2018 2019 Current Loans ￦ 236,782 367,580 Other accounts receivable 954,030 971,845 Accrued income 220,066 272,528 Deposits 108,640 86,519 Lease receivables — 48,744 Others 16,201 14,510 Less: Allowance for doubtful accounts (150,090 ) (180,209 ) ￦ 1,385,629 1,581,517 Non-current Loans ￦ 731,344 701,529 Other accounts receivable 155,936 209,039 Accrued income 1,855 65,275 Deposits 152,072 238,261 Lease receivables — 179,315 Less: Allowance for doubtful accounts (177,967 ) (252,540 ) ￦ 863,240 1,140,879
Summary of lease investment and net lease investment	(3) As of December 31, 2019, gross investment and net investment in the leases are as follows: (in millions of Won) total lease investment and lease net investment - Undiscounted contractual cash flows 2019 Less than 1 year ￦ 56,796 1 year - 3 years 107,955 3 year - 5 years 70,742 Over 5 years 16,089 Undiscounted lease payments 251,582 Unrealized interest income (23,523 ) Present value of minimum lease payment ￦ 228,059
Others [member]
Statement [LineItems]
Summary of Financial Assets	Other financial assets as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Derivatives assets ￦ 47,288 47,541 Debt securities 2,987 342,371 Deposit instruments(1,2) 1,931,518 1,744,895 Short-term financial instruments(2) 6,099,303 6,861,242 ￦ 8,081,096 8,996,049 Non-current Derivatives assets ￦ 1,795 64,737 Equity securities(3) 1,238,630 1,204,902 Debt securities 34,327 22,380 Other securities(3) 338,106 343,183 Deposit instruments(2) 35,040 34,187 ￦ 1,647,898 1,669,389 (1) As of December 31, 2018 and 2019, ￦￦ (2) As of December 31, 2018 and 2019, financial instruments amounting to ￦￦ (3) As of December 31, 2018 and 2019, ￦￦
Trade accounts and notes receivables, net [member]
Statement [LineItems]
Summary of Financial Assets	(a) Trade accounts and notes receivable as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Trade accounts and notes receivable ￦ 8,648,250 8,352,968 Finance lease receivables 57,487 221 Unbilled due from customers for contract work 810,655 1,128,116 Less: Allowance for doubtful accounts (386,188 ) (411,274 ) ￦ 9,130,204 9,070,031 Non-current Trade accounts and notes receivable ￦ 583,797 209,310 Finance lease receivables 45,873 43,725 Less: Allowance for doubtful accounts (202,545 ) (54,250 ) ￦ 427,125 198,785
Finance lease receivables [member]
Statement [LineItems]
Summary of Financial Assets	(b) Finance lease receivables are as follows: (in millions of Won) Customer Contents 2018 2019 Officers and employees Songdo apartment rental ￦ 103,360 43,445 ZHAOHUUI PROSPERITY INT’L LTD Office rental — 501 ￦ 103,360 43,946
Lease receivables [member]
Statement [LineItems]
Summary of Financial Assets	(1) The details of other receivables as of December 31, 2019 and 2018, are as follows: (in millions of Won) 2018 2019 Current Loans ￦ 236,782 367,580 Other accounts receivable 954,030 971,845 Accrued income 220,066 272,528 Deposits 108,640 86,519 Lease receivables — 48,744 Others 16,201 14,510 Less: Allowance for doubtful accounts (150,090 ) (180,209 ) ￦ 1,385,629 1,581,517 Non-current Loans ￦ 731,344 701,529 Other accounts receivable 155,936 209,039 Accrued income 1,855 65,275 Deposits 152,072 238,261 Lease receivables — 179,315 Less: Allowance for doubtful accounts (177,967 ) (252,540 ) ￦ 863,240 1,140,879 (2) The details of lease receivables are as follows: (in millions of Won) Customer Content of lease agreement 2019 HEUNG-A SHIPPING CO., LTD., MSC KOGAS, ONGC Videsh Limited, 6 Container Ships, 4 Tankers ￦ 212,933 GAIL(India) Limited,Myanma Oil and Gas Enterprise Helicopter, Ship, Office, Jetty 15,126 ￦ 228,059

Inventories (Tables)

Inventories (Tables)	12 Months Ended
Inventories (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Inventories	(a) Inventories as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Finished goods ￦ 1,886,040 1,655,228 Merchandise 1,131,416 1,058,874 Semi-finished goods 1,945,567 2,097,289 Raw materials 2,821,972 2,656,341 Fuel and materials 888,941 1,026,133 Construction inventories 1,372,259 1,045,088 Materials-in-transit 2,245,740 1,824,044 Others 68,150 83,905 12,360,085 11,446,902 Less: Allowance for inventories valuation (206,782 ) (216,143 ) ￦ 12,153,303 11,230,759
Changes of Allowance for Inventories Valuation	(b) The changes in allowance for inventories valuation for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Beginning ￦ 203,164 135,631 206,782 Loss on valuation of inventories 78,560 141,799 96,201 Realization on disposal of inventories (138,967 ) (69,426 ) (79,419 ) Others (7,126 ) (1,222 ) (7,421 ) Ending ￦ 135,631 206,782 216,143

Assets Held for Sale (Tables)

Assets Held for Sale (Tables)	12 Months Ended
Assets Held for Sale (Tables)	Dec. 31, 2019
Text block [abstract]
Details of Assets Held For Sale and Related Liabilities	Details of assets held for sale as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Subsidiaries(2) Controlling Subsidiaries Total Assets Cash and cash equivalents(3) ￦ — — 374 374 Other financial assets 778 — 185 185 Property, plant and equipment 21,076 36,321 32,972 69,293 Others — — 4,306 4,306 ￦ 21,854 36,321 37,837 74,158 Liabilities Others ￦ — — 8 8 (1) During the year ended December 31, 2019, the Company decided to dispose individual assets for which use was suspended, such as CEM plants, and classified the assets as held for sale. During the year ended December 31, 2019, the Company recognized impairment loss of ￦ (2) During the year ended December 31, 2018, the subsidiary, DAESAN (CAMBODIA) Co., Ltd., decided to sell its land and classified the property, plant and equipment as held for sale. As of December 31, 2019 the sale is completed and gain on disposal of ￦ (*3) Cash and cash equivalents in the statement of cash flows include cash and cash equivalents that are classified as assets held for sale.

Investments in Associates and_2

Investments in Associates and Joint ventures (Tables)	12 Months Ended
Investments in Associates and Joint ventures (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Investments in Associates and Joint Ventures	(a) Investments in associates and joint ventures as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Investments in associates ￦ 1,738,692 1,864,509 Investments in joint ventures 1,911,311 2,063,246 ￦ 3,650,003 3,927,755
Details of Investments in Associates	(b) Details of investments in associates as of December 31, 2018 and 2019 are as follows: (in millions of Won) Number of shares Ownership (%) Acquisition cost Book value Company 2018 2019 [Domestic] EQP POSCO Global NO1 Natual Resources Private Equity Fund 178,787,468,209 33.41 ￦ 178,787 ￦ 174,123 175,907 POSPower Co., Ltd(2) 4,507,138 34.00 179,410 161,477 161,280 SNNC 18,130,000 49.00 90,650 116,922 142,602 QSONE Co.,Ltd. 200,000 50.00 84,395 85,550 85,887 Chun-cheon Energy Co., Ltd(2) 17,308,143 49.10 86,541 62,478 56,679 Nextrain Co., Ltd. 8,321,920 32.00 41,610 10 41,447 Keystone NO. 1. Private Equity Fund(5) 22,523,123 52.58 22,523 11,183 19,438 CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd 2,008,000 29.53 10,040 17,382 17,824 Daesung Steel(4) 108,038 17.54 14,000 15,644 15,375 Incheon-Gimpo Expressway Co., Ltd.(2,4) 9,032,539 18.26 45,163 13,329 7,904 KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund(4) 6,485 12.50 6,485 5,739 6,177 KONES, Corp. 3,250,000 41.67 6,893 2,849 2,473 Others (53 companies)(2) 123,724 112,621 790,410 845,614 [Foreign] AES-VCM — 30.00 164,303 209,936 178,892 South-East Asia Gas Pipeline Company Ltd. 135,219,000 25.04 135,899 179,459 225,933 7623704 Canada Inc.(4) 114,452,000 10.40 124,341 126,885 131,529 Eureka Moly LLC — 20.00 240,123 82,447 85,349 AMCI (WA) PTY LTD 49 49.00 209,664 71,086 72,937 Nickel Mining Company SAS 3,234,698 49.00 157,585 41,712 37,940 KOREA LNG LTD. 2,400 20.00 135,205 43,554 46,557 NCR LLC — 29.40 49,744 37,602 46,391 ZHEJIANG HUAYOU-POSCO ESM CO., LTD(1) 134,400,000 40.00 22,423 — 22,356 PT. Batutua Tembaga Raya 128,285 22.00 21,824 20,479 14,717 PT. Wampu Electric Power(2) 8,708,400 20.00 10,054 14,120 13,363 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 10,200,000 34.00 9,517 14,796 15,128 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 50 25.00 4,723 6,478 6,755 Others (26 companies)(2) 99,728 121,048 948,282 1,018,895 ￦ 1,738,692 1,864,509 (1) During the year ended December 31, 2019, ZHEJIANG HUAYOU-POSCO ESM CO., LTD was established and classified as investment in an associate. (2) As of December 31, 2018 and 2019, investments in associates amounting to ￦￦ (3) As of December 31, 2018, shares of PSC Energy Global Co., Ltd., a subsidiary of the Company, are provided as collateral in relation to the associate’s borrowings. (4) As of December 31, 2019, it was classified as an associate even though the Company’s ownership percentage is less than 20% of ownership percentage since the Company has significant influence over the investee when considering its structure of the associate’s Board of Directors and others. (5) Although the Company’s shareholding exceeds 50%, the entity is classified as an associate because the Company does not have control when considering the structure of the Board of Directors.
Details of Investments in Joint Ventures	(c) Details of investments in joint ventures as of December 31, 2018 and 2019 are as follows: (in millions of Won) Number of shares Ownership (%) Acquisition cost Book value Company 2018 2019 [Domestic] POSCO MITSUBISHI CARBON TECHNOLOGY 11,568,000 60.00 ￦ 115,680 ￦ 180,192 182,648 Others (8 companies) 9,124 10,305 189,316 192,953 [Foreign] Roy Hill Holdings Pty Ltd(1) 13,117,972 12.50 1,528,672 1,041,600 1,235,682 POSCO-NPS 325,050,000 50.00 364,609 363,506 376,410 KOBRASCO 2,010,719,185 50.00 32,950 133,449 115,641 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. — 25.00 61,961 88,391 88,935 DMSA/AMSA(1) — 4.00 346,278 26,709 12,189 CSP - Compania Siderurgica do Pecem 1,221,586,532 20.00 594,173 24,832 — Others (12 companies) 43,508 41,436 1,721,995 1,870,293 ￦ 1,911,311 2,063,246 (*1) As of December 31, 2018 and 2019, the investments in joint ventures are provided as collateral in relation to the joint ventures’ borrowings.
Changes in Investments in Associates and Joint Ventures	(d) The changes in investments in associates and joint ventures for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Company December 31, Book value Acquisition Dividends Share profits Other (decrease)(1) December 31, Book value [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 175,553 — — (1,430 ) — 174,123 POSPower Co., Ltd — 176,731 — (3,198 ) (12,056 ) 161,477 SNNC 110,424 — — 6,624 (126 ) 116,922 QSONE Co.,Ltd. 85,049 — (550 ) 1,051 — 85,550 Chun-cheon Energy Co., Ltd 74,378 — — (11,900 ) — 62,478 CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd 17,252 — — 130 — 17,382 BLUE OCEAN Private Equity Fund 19,620 — — (17,930 ) (1,690 ) — Daesung Steel 15,500 — — 144 — 15,644 Incheon-Gimpo Expressway Co., Ltd. 31,660 — — (18,331 ) — 13,329 Keystone NO. 1. Private Equity Fund 12,379 — — (1,295 ) 99 11,183 UITrans LRT Co., Ltd. 15,841 — — (15,841 ) — — KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 6,828 — — (1,089 ) — 5,739 KONES, Corp. 2,827 — — 29 (7 ) 2,849 POSCO MITSUBISHI CARBON TECHNOLOGY 110,760 — — 69,594 (162 ) 180,192 Others (52 companies) 73,419 44,629 (784 ) 18,942 (3,348 ) 132,858 751,490 221,360 (1,334 ) 25,500 (17,290 ) 979,726 [Foreign] AES-VCM 142,348 — (26,108 ) 30,096 63,600 209,936 South-East Asia Gas Pipeline Company Ltd. 197,069 — (29,301 ) 17,709 (6,018 ) 179,459 7623704 Canada Inc. 121,702 — (4,509 ) 4,373 5,319 126,885 Eureka Moly LLC 79,398 — — (406 ) 3,455 82,447 AMCI (WA) PTY LTD 63,378 — — (3,412 ) 11,120 71,086 Nickel Mining Company SAS 45,905 — — (4,268 ) 75 41,712 KOREA LNG LTD. 33,422 — (10,544 ) 10,542 10,134 43,554 NCR LLC 33,738 2,505 — (5,909 ) 7,268 37,602 PT. Batutua Tembaga Raya 21,823 — — (1,817 ) 473 20,479 PT. Wampu Electric Power 13,391 — — 177 552 14,120 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 15,617 — — (735 ) (86 ) 14,796 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 6,517 — — 23 (62 ) 6,478 Roy Hill Holdings Pty Ltd 1,125,133 — — 59,095 (142,628 ) 1,041,600 POSCO-NPS 348,836 — (22,254 ) 21,536 15,388 363,506 KOBRASCO 108,485 — (37,710 ) 75,170 (12,496 ) 133,449 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 88,305 — — 540 (454 ) 88,391 DMSA/AMSA 56,735 17,973 — (48,802 ) 803 26,709 CSP - Compania Siderurgica do Pecem 146,427 — — (109,714 ) (11,881 ) 24,832 Others (42 companies) 158,213 2,771 (22,588 ) 42,937 (38,097 ) 143,236 2,806,442 23,249 (153,014 ) 87,135 (93,535 ) 2,670,277 ￦ 3,557,932 244,609 (154,348 ) 112,635 (110,825 ) 3,650,003 (1) Other increase or decrease represents the changes in investments in associates and joint ventures due to disposals, change in capital adjustments from translations of financial statements of foreign investees and others. 2) For the year ended December 31, 2019 (in millions of Won) Company December 31, Book value Acquisition Dividends Share of profits Other (decrease)(1) December 31, Book value [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 174,123 — — (976 ) 2,760 175,907 POSPower Co., Ltd 161,477 — — (4,744 ) 4,547 161,280 SNNC 116,922 — (1,450 ) 27,655 (525 ) 142,602 QSONE Co.,Ltd. 85,550 — (950 ) 1,287 — 85,887 Chun-cheon Energy Co., Ltd 62,478 6,050 — (11,849 ) — 56,679 Nextrain Co., Ltd. 10 41,600 — (163 ) — 41,447 Keystone NO. 1. Private Equity Fund 11,183 8,723 — (342 ) (126 ) 19,438 CHUNGJU ENTERPRISE CITY DEVELOPMENT Co.,Ltd 17,382 — — 442 — 17,824 Daesung Steel 15,644 — — (269 ) — 15,375 Incheon-Gimpo Expressway Co., Ltd. 13,329 — — (5,425 ) — 7,904 KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 5,739 — — 438 — 6,177 KONES, Corp. 2,849 — — (403 ) 27 2,473 POSCO MITSUBISHI CARBON TECHNOLOGY 180,192 — (16,369 ) 19,377 (552 ) 182,648 Others (61 companies) 132,848 30,973 (1,392 ) (18,146 ) (21,357 ) 122,926 979,726 87,346 (20,161 ) 6,882 (15,226 ) 1,038,567 [Foreign] AES-VCM 209,936 — (18,099 ) 24,126 (37,071 ) 178,892 South-East Asia Gas Pipeline Company Ltd. 179,459 — (24,267 ) 63,749 6,992 225,933 7623704 Canada Inc. 126,885 — (9,902 ) 9,912 4,634 131,529 Eureka Moly LLC 82,447 — — (25 ) 2,927 85,349 AMCI (WA) PTY LTD 71,086 — — (4,377 ) 6,228 72,937 Nickel Mining Company SAS 41,712 — — (4,250 ) 478 37,940 KOREA LNG LTD. 43,554 — (13,404 ) 13,501 2,906 46,557 NCR LLC 37,602 9,605 — (822 ) 6 46,391 ZHEJIANG HUAYOU-POSCO ESM CO., LTD — 22,423 — 61 (128 ) 22,356 PT. Batutua Tembaga Raya 20,479 — — (6,209 ) 447 14,717 PT. Wampu Electric Power 14,120 — — (1,247 ) 490 13,363 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 14,796 — — 10 322 15,128 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 6,478 — — 80 197 6,755 Roy Hill Holdings Pty Ltd 1,041,600 — — 158,562 35,520 1,235,682 POSCO-NPS 363,506 — (24,933 ) 24,543 13,294 376,410 KOBRASCO 133,449 — (74,716 ) 56,474 434 115,641 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 88,391 — (1,574 ) 665 1,453 88,935 DMSA/AMSA 26,709 23,682 — (40,415 ) 2,213 12,189 CSP - Compania Siderurgica do Pecem 24,832 35,352 — (57,647 ) (2,537 ) — Others (38 companies) 143,236 552 (19,430 ) 30,168 7,958 162,484 2,670,277 91,614 (186,325 ) 266,859 46,763 2,889,188 ￦ 3,650,003 178,960 (206,486 ) 273,741 31,537 3,927,755 (1) Other increase or decrease represents the changes in investments in associates and joint ventures due to disposals, change in capital adjustments effect from translations of financial statements of foreign investees and others.
Summarized Financial Information of Associates and Joint Ventures	(e) Summarized financial information of associates and joint ventures as of and for the years ended December 31, 2018 and 2019 are as follows: 1) December 31, 2018 (in millions of Won) Company Assets Liabilities Equity Sales Net income (loss) [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 552,760 783 551,977 — 10,249 POSPower Co., Ltd 425,632 35,761 389,871 — (4,536 ) SNNC 645,013 384,586 260,427 656,320 14,229 QSONE Co., Ltd. 249,384 78,285 171,099 16,597 2,101 Chun-cheon Energy Co., Ltd 667,454 525,308 142,146 320,950 (18,796 ) Nextrain Co., Ltd. 30 — 30 — — CHUNGJU ENTERPRISE CITY DEVELOPMENT Co., Ltd 63,554 35,003 28,551 16,237 439 BLUE OCEAN Private Equity Fund 305,876 174,640 131,236 459,491 (5,294 ) Daesung Steel 169,305 111,502 57,803 75,474 824 Incheon-Gimpo Expressway Co., Ltd. 1,049,629 931,937 117,692 45,566 (92,202 ) Keystone NO. 1. Private Equity Fund 177,024 144,186 32,838 15,507 (3,962 ) UITrans LRT Co., Ltd. 430,227 435,699 (5,472 ) 12,929 (85,344 ) KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 59,464 1,061 58,403 2,401 (12,313 ) KONES, Corp. 2,618 1,414 1,204 5,167 70 POSCO MITSUBISHI CARBON TECHNOLOGY 537,138 237,563 299,575 300,986 116,049 [Foreign] South-East Asia Gas Pipeline Company Ltd. 1,726,410 1,009,731 716,679 343,471 70,717 7623704 Canada Inc. 1,232,208 1 1,232,207 — 44,320 Nickel Mining Company SAS 465,463 329,084 136,379 207,956 (4,569 ) KOREA LNG LTD. 217,883 110 217,773 54,357 52,720 PT. Batutua Tembaga Raya 332,305 274,580 57,725 128,609 (8,451 ) PT. Wampu Electric Power 223,009 155,407 67,602 13,461 887 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 73,515 24,264 49,251 121,104 (2,231 ) POSCO SeAH Steel Wire (Nantong) Co., Ltd. 61,782 34,740 27,042 85,619 78 Roy Hill Holdings Pty Ltd 9,666,619 6,043,492 3,623,127 3,259,256 497,469 POSCO-NPS 726,810 — 726,810 — 41,812 KOBRASCO 317,842 50,945 266,897 229,340 150,550 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 710,518 384,572 325,946 1,341,849 2,159 DMSA/AMSA 5,562,877 4,171,896 1,390,981 731,127 (529,844 ) CSP - Compania Siderurgica do Pecem 4,194,242 4,192,867 1,375 1,860,198 (542,865 ) 2) December 31, 2019 (in millions of Won) Company Assets Liabilities Equity (deficit) Sales Net income (loss) [Domestic] EQP POSCO Global NO1 Natural Resources Private Equity Fund ￦ 516,659 786 515,873 — 7,479 POSPower Co., Ltd 707,051 199,846 507,205 — (5,294 ) SNNC 677,508 357,843 319,665 738,977 63,269 QSONE Co., Ltd. 250,364 78,589 171,775 17,591 2,576 Chun-cheon Energy Co., Ltd 610,089 492,620 117,469 313,438 (24,677 ) Nextrain Co., Ltd. 136,203 7,322 128,881 — (509 ) Keystone NO. 1. Private Equity Fund 187,156 138,219 48,937 18,342 (887 ) CHUNGJU ENTERPRISE CITY DEVELOPMENT Co., Ltd 53,019 22,971 30,048 17,824 1,497 Daesung Steel 164,708 108,441 56,267 85,537 (1,536 ) Incheon-Gimpo Expressway Co., Ltd. 1,014,410 951,321 63,089 50,575 (36,449 ) KoFC POSCO HANWHA KB Shared Growth NO. 2. Private Equity Fund 50,479 1,062 49,417 2,841 3,502 KONES, Corp. 1,950 1,648 302 4,416 (966 ) POSCO MITSUBISHI CARBON TECHNOLOGY 474,387 170,678 303,709 216,648 32,334 [Foreign] South-East Asia Gas Pipeline Company Ltd. 1,808,529 906,254 902,275 555,075 254,582 7623704 Canada Inc. 1,276,857 1 1,276,856 — 95,306 Nickel Mining Company SAS 471,377 331,194 140,183 245,509 2,432 ZHEJIANG HUAYOU-POSCO ESM CO., LTD 73,604 17,765 55,839 641 153 KOREA LNG LTD. 232,935 147 232,788 69,577 67,507 PT. Batutua Tembaga Raya 423,608 392,226 31,382 112,568 (28,360 ) PT. Wampu Electric Power 222,266 158,451 63,815 18,163 (6,233 ) Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 65,413 15,232 50,181 101,101 28 POSCO SeAH Steel Wire (Nantong) Co., Ltd. 61,847 33,989 27,858 77,371 327 Roy Hill Holdings Pty Ltd 11,143,705 5,718,152 5,425,553 5,037,471 1,660,577 POSCO-NPS 752,617 — 752,617 — 47,521 KOBRASCO 268,139 36,857 231,282 167,022 112,949 BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 969,280 637,478 331,802 1,145,794 1,704 DMSA/AMSA 5,703,501 4,202,704 1,500,797 638,797 (504,077 ) CSP - Compania Siderurgica do Pecem 3,959,365 4,249,083 (289,718 ) 1,623,843 (465,853 )

Joint Operations (Tables)

Joint Operations (Tables)	12 Months Ended
Joint Operations (Tables)	Dec. 31, 2019
Investments accounted for using equity method [abstract]
Details of Significant Joint Operations	Details of significant joint operations that the Company is participating in as a party to a joint arrangement as of December 31, 2019 are as follows: Joint operations Operation Ownership (%) Location Myanmar A-1/A-3 Mine development and gas production 51.00 Myanmar Offshore midstream Gas transportation facility 51.00 Myanmar Greenhills mine Mine development 20.00 Canada Arctos Anthracite coal project Mine development 50.00 Canada Mt. Thorley J/V Mine development 20.00 Australia POSMAC J/V Mine development 20.00 Australia RUM J/V Mine development 10.00 Australia Hanam-Gamil package public housing project Construction 7.70 Korea Hanam-Gamil district B6, C2, C3 Block public housing lot development project Construction 27.00 Korea Yangsan-Sasong district public housing project (private-participation) Construction 13.08 Korea Yangsan-Sasong district public housing project Construction 49.00 Korea Sejong 2-1 Construction 37.00 Korea Yongin-Giheung Station area city development project Construction 61.00 Korea Korean Wave World Complex land multi-purpose building development project Construction 33.30 Korea Sejong 4-1 Construction 60.00 Korea

Investment Property, Net (Table

Investment Property, Net (Tables)	12 Months Ended
Investment Property, Net (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Investment Property	Investment property as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Acquisition cost Accumulated depreciation impairment Book value Acquisition cost Accumulated depreciation impairment Book value Land ￦ 295,328 (16,743 ) 278,585 295,183 (16,718 ) 278,465 Buildings 681,518 (110,183 ) 571,335 778,816 (180,657 ) 598,159 Structures 3,327 (1,919 ) 1,408 3,455 (2,277 ) 1,178 Right of use assets — — — 434 (9 ) 425 Construction-in-progress 101,665 (24,378 ) 77,287 — — — ￦ 1,081,838 (153,223 ) 928,615 1,077,888 (199,661 ) 878,227
Changes in Carrying Amount of Investment Property	Changes in the carrying amount of investment property for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Acquisitions Disposals Depreciation(1) Others(2) Ending Land ￦ 360,402 1,327 (26,826 ) (16,743 ) (39,575 ) 278,585 Buildings 634,040 727 (32,807 ) (28,358 ) (2,267 ) 571,335 Structures 6,281 — — (603 ) (4,270 ) 1,408 Construction-in-progress 64,191 42,052 — (24,948 ) (4,008 ) 77,287 ￦ 1,064,914 44,106 (59,633 ) (70,652 ) (50,120 ) 928,615 (1) Includes impairment loss on investment property recognized by each of the consolidated subsidiaries, including the office lease of POSCO (Dalian) IT Center Development Co., Ltd. amounting to ￦ (2) Includes reclassification resulting from changing the purpose of use, adjustment of foreign currency translation difference and others. 2) For the year ended December 31, 2019 (in millions of Won) Beginning Acquisitions Disposals Depreciation(1) Others(2) Ending Land ￦ 278,585 — (5,921 ) — 5,801 278,465 Buildings 571,335 1,548 (5,343 ) (52,416 ) 83,035 598,159 Structures 1,408 — (50 ) (625 ) 445 1,178 Right of use assets — — — — 425 425 Construction-in-progress 77,287 18,644 — — (95,931 ) — ￦ 928,615 20,192 (11,314 ) (53,041 ) (6,225 ) 878,227 (1) Includes impairment loss on investment property recognized by POSCO (Dalian) IT Center Development Co., Ltd., a subsidiary, in relation to its office lease amounting to ￦ (2) Includes reclassification resulting from changing the purpose of use, adjustment of foreign currency translation difference and others.

Property, Plant and Equipment_2

Property, Plant and Equipment, Net (Tables)	12 Months Ended
Property, Plant and Equipment, Net (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Property, Plant and Equipment	Property, plant and equipment as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Acquisition Accumulated depreciation and impairment Government Book value Acquisition cost Accumulated depreciation and impairment Government Book value Land ￦ 2,553,957 (5,955 ) — 2,548,002 2,527,972 (1,913 ) — 2,526,059 Buildings 9,146,294 (4,743,449 ) (393 ) 4,402,452 9,227,064 (5,010,770 ) (840 ) 4,215,454 Structures 5,884,277 (2,966,304 ) (49 ) 2,917,924 6,066,000 (3,161,453 ) (41 ) 2,904,506 Machinery and equipment 47,610,225 (29,091,754 ) (342 ) 18,518,129 47,548,589 (30,326,324 ) (4,001 ) 17,218,264 Vehicles 302,767 (271,381 ) (45 ) 31,341 305,275 (272,977 ) (13 ) 32,285 Tools 399,638 (333,387 ) (87 ) 66,164 418,829 (348,032 ) (46 ) 70,751 Furniture and fixtures 638,553 (502,215 ) (51 ) 136,287 658,467 (528,066 ) (269 ) 130,132 Finance lease assets 213,873 (76,309 ) — 137,564 970,891 (196,309 ) — 774,582 Bearer plants 88,773 (8,002 ) — 80,771 138,818 (14,625 ) — 124,193 Construction-in- 1,964,267 (778,373 ) (6,255 ) 1,179,639 2,800,412 (856,548 ) (14,117 ) 1,929,747 ￦ 68,802,624 (38,777,129 ) (7,222 ) 30,018,273 70,662,317 (40,717,017 ) (19,327 ) 29,925,973
Changes in Carrying Amount of Property, Plant and Equipment	Changes in the carrying amount of property, plant and equipment for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Acquisitions Disposals Depreciation Impairment loss(1,2) Others(3) Ending Land ￦ 2,527,650 28,998 (26,157 ) — 6,399 11,112 2,548,002 Buildings 4,877,018 46,129 (21,501 ) (331,688 ) (73,523 ) (93,983 ) 4,402,452 Structures 2,765,852 18,749 (2,834 ) (220,218 ) (6,652 ) 363,027 2,917,924 Machinery and equipment 19,367,957 145,220 (62,135 ) (2,224,000 ) (143,293 ) 1,434,380 18,518,129 Vehicles 32,861 8,538 (1,149 ) (14,835 ) (56 ) 5,982 31,341 Tools 63,640 21,337 (1,867 ) (26,421 ) (206 ) 9,681 66,164 Furniture and fixtures 145,439 32,258 (577 ) (51,835 ) (1,494 ) 12,496 136,287 Finance lease assets 145,257 28,466 (420 ) (19,224 ) — (16,515 ) 137,564 Bearer plants 65,515 — — (3,636 ) — 18,892 80,771 Construction-in-progress 1,892,346 1,884,125 (23,814 ) — (778,373 ) (1,794,645 ) 1,179,639 ￦ 31,883,535 2,213,820 (140,454 ) (2,891,857 ) (997,198 ) (49,573 ) 30,018,273 (1) During 2018, the Controlling Company evaluated future economic performance of its Synthetic Natural Gas (SNG) facility that was still in trial run stage. Considering the continuous decline in LNG price, increase in coal prices and the need for additional capital investment in the SNG facility, the Controlling Company concluded that the profitability for the SNG facility is unlikely to be sustainable and decided to terminate the operation of SNG facility as of December 31, 2018. The property, plant and equipment in the SNG facility are primarily comprised of machinery and equipment, among which assets with a carrying value of ￦ re-used For the assets for which sale is probable, the recoverable amount is determined based on fair value less cost of disposal. Fair value was measured using cost approach, which is based on an estimation of the current cost to purchase or replace the asset less applicable depreciation and obsolescence. Specifically, the Controlling Company used indirect cost approach to estimate the replacement cost for a new asset by applying asset specific inflation factors to the asset’s historical cost. Then the Controlling Company estimated and deducted depreciation for physical deterioration. Depreciation factors are applied primarily based on estimated useful life of the asset and declining balance depreciation method. The fair value measurement of assets in SNG facility is considered to be level 3 because significant inputs used in the estimate, such as asset specific inflation factors and estimated useful lives, are unobservable. As a result of the impairment test, the Company recognized an impairment loss of ￦ The Controlling Company also has recognized an impairment loss amounting to ￦ (2) As of December 31, 2018, POSCO ENERGY CO., LTD., a subsidiary, performed an impairment test due to the continued operating losses of the fuel cell business, and recognized impairment losses amounting to ￦ (3) Represents assets transferred from construction-in-progress 2) For the year ended December 31, 2019 (in millions of Won) Beginning Acquisitions Business Combination Disposals Depreciation Impairment loss(1,2) Others(3) Ending Land ￦ 2,548,002 6,550 — (2,128 ) — — (26,365 ) 2,526,059 Buildings 4,402,452 39,551 22,836 (10,376 ) (314,107 ) (90,036 ) 165,134 4,215,454 Structures 2,917,924 49,931 2 (3,350 ) (228,616 ) (27,217 ) 195,832 2,904,506 Machinery and equipment 18,518,129 175,743 1,216 (78,236 ) (2,250,022 ) (309,604 ) 1,161,038 17,218,264 Vehicles 31,341 8,027 189 (742 ) (15,057 ) (559 ) 9,086 32,285 Tools 66,164 19,178 5,792 (1,340 ) (28,537 ) (2,106 ) 11,600 70,751 Furniture and fixtures 136,287 34,618 252 (1,630 ) (36,309 ) (1,808 ) (1,278 ) 130,132 Lease assets(4) 137,564 72,640 490 (8,401 ) (130,905 ) — 703,194 774,582 Bearer plants 80,771 — — — (5,916 ) — 49,338 124,193 Construction-in-progress 1,179,639 2,261,663 17,697 (24,840 ) — (10,150 ) (1,494,262 ) 1,929,747 ￦ 30,018,273 2,667,901 48,474 (131,043 ) (3,009,469 ) (441,480 ) 773,317 29,925,973 (1) During the year ended December 31, 2019, the Controlling Company estimated recoverable amount of individual assets in CEM and Fe-Si ￦ (2) As of December 31, 2019, POSCO SS VINA JOINT STOCK COMPANY (formerly, POSCO SS VINA Co., Ltd.), a subsidiary, performed impairment test due to the continued operating losses and recognized impairment losses amounting to ￦ value-in-use (3) Represents assets transferred from construction-in-progress (4) On the date of initial application of IFRS No.16 “Leases” (January 1, 2019), recognition of ￦ right-of-use
Borrowing Costs Capitalized and Capitalized Interest Rate	Borrowing costs capitalized and the capitalized interest rate for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Weighted average expenditure ￦ 628,595 587,628 Borrowing costs capitalized 22,619 22,775 Capitalization rate (%) 2.51 ~ 3.90 3.57 ~ 5.46
Property, Plant and Equipment and Investment Property Pledged as Collateral	Property, plant and equipment and investment property pledged as collateral as of December 31, 2018 and 2019 are as follows: (in millions of Won) Collateral right holder Book value 2018 2019 Land Korean Development Bank and others ￦ 769,843 765,307 Buildings and structures Korean Development Bank and others 1,522,129 1,363,709 Machinery and equipment Korean Development Bank and others 3,419,528 2,440,777 ￦ 5,711,500 4,569,793
Summary of changes in right of use assets property plant and equipment	Changes in the carrying amount of right of use assets presented as property, plant and equipment for the year ended December 31, 2019 were as follows: (in millions of Won) Beginning (Initial Right of use Acquisitions Depreciation Others Ending Land ￦ 340,107 22,850 (11,461 ) (10,154 ) 341,342 Buildings and structures 209,455 23,015 (38,853 ) (22,505 ) 171,112 Machinery and equipment 219,877 14,610 (33,751 ) 15,092 215,828 Vehicles 20,555 8,735 (10,050 ) (5,135 ) 14,105 others 52,028 3,430 (36,790 ) 13,527 32,195 ￦ 842,022 72,640 (130,905 ) (9,175 ) 774,582
Summary of lease expense recognised in the income statement	The amount recognized in profit or loss related to leases for the year ended December 31, 2019 are as follows: (in millions of Won) 2019 Interest on lease liabilities ￦ 35,483 Expenses related to short-term leases 41,974 Expenses related to leases of low-value 14,150 ￦ 91,607

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets, Net (Tables)	12 Months Ended
Goodwill and Other Intangible Assets, Net (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Goodwill and Other Intangible Assets	Goodwill and other intangible assets as of December 31, 2018 and 2019 are as follows: 2018 2019 (in millions of Won) Acquisition Accumulated Government Book value Acquisition Accumulated Government Book value Goodwill ￦ 1,603,308 (478,159 ) — 1,125,149 1,631,413 (533,604 ) — 1,097,809 Intellectual property rights 3,300,638 (901,113 ) — 2,399,525 3,449,796 (1,170,586 ) — 2,279,210 Premium in rental 158,338 (23,545 ) — 134,793 170,247 (22,169 ) — 148,078 Development expense 445,752 (346,589 ) — 99,163 483,539 (389,200 ) — 94,339 Port facilities usage rights 724,375 (419,294 ) — 305,081 686,525 (405,127 ) — 281,398 Exploration and evaluation assets 285,845 (93,715 ) — 192,130 294,874 (217,603 ) — 77,271 Customer relationships 860,951 (439,178 ) — 421,773 865,821 (490,946 ) — 374,875 Other intangible assets 1,115,742 (622,417 ) (114 ) 493,211 1,220,641 (665,026 ) (122 ) 555,493 ￦ 8,494,949 (3,324,010 ) (114 ) 5,170,825 8,802,856 (3,894,261 ) (122 ) 4,908,473
Changes in Carrying Amount of Goodwill and Other Intangible Assets	The changes in carrying amount of goodwill and other intangible assets for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Acquisitions Disposals Amortization Impairment loss Others(3) Ending Goodwill ￦ 1,349,838 — — — (223,709 ) (980 ) 1,125,149 Intellectual property rights 2,449,193 334,667 (18,619 ) (198,282 ) (96,475 ) (70,959 ) 2,399,525 Premium in rental(1) 118,310 36,196 (15,675 ) (330 ) (4,218 ) 510 134,793 Development expense 80,218 4,248 (32 ) (37,305 ) (411 ) 52,445 99,163 Port facilities usage rights 309,373 — — (22,975 ) — 18,683 305,081 Exploration and evaluation assets 205,944 2,654 — — (3,339 ) (13,129 ) 192,130 Customer relationships 466,945 — — (48,499 ) — 3,327 421,773 Power generation permit(2) 539,405 — — — — (539,405 ) — Other intangible assets 433,043 164,594 (1,644 ) (49,190 ) (8,844 ) (44,748 ) 493,211 ￦ 5,952,269 542,359 (35,970 ) (356,581 ) (336,996 ) (594,256 ) 5,170,825 (1) Premium in rental includes memberships with indefinite useful lives. (2) During the year ended December 31, 2018, the Company disposed of a portion of shares of its subsidiary, POSPower Co., Ltd, which resulted in the Company’s loss of control, and derecognition of corresponding intangible assets. (3) Represents assets transferred from construction-in-progress 2) For the year ended December 31, 2019 (in millions of Won) Beginning Acquisitions Business Combination Disposals Amortization Impairment loss(2) Others(3) Ending Goodwill ￦ 1,125,149 — 26,256 — — (55,445 ) 1,849 1,097,809 Intellectual property rights 2,399,525 127,479 — (6,566 ) (271,694 ) (2 ) 30,468 2,279,210 Premium in rental(1) 134,793 15,636 — (3,326 ) (181 ) 24 1,132 148,078 Development expense 99,163 4,484 — (35 ) (44,418 ) (666 ) 35,811 94,339 Port facilities usage rights 305,081 — — (4,674 ) (22,923 ) — 3,914 281,398 Exploration and evaluation assets 192,130 9,642 — — — (123,888 ) (613 ) 77,271 Customer relationships 421,773 — — — (51,768 ) — 4,870 374,875 Other intangible assets 493,211 141,578 74 (10,718 ) (40,263 ) (10,111 ) (18,278 ) 555,493 — — — — — — — — ￦ 5,170,825 298,819 26,330 (25,319 ) (431,247 ) (190,088 ) 59,153 4,908,473 (1) Premium in rental includes memberships with indefinite useful lives. (2) From exploration and evaluation of natural gas in the AD-7 ￦ (3) Represents assets transferred from construction-in-progress
Allocation of Goodwill to Individually Operating Entities Which are Determined to be CGUs	For the purpose of impairment testing, goodwill is allocated to individually operating entities which are determined to be CGUs. The goodwill amounts as of December 31, 2018 and 2019 are as follows: (in millions of Won) Reportable segments Total number of 2018 2019 CGUs 2018 2019 Steel 7 7 POSCO VST CO., LTD. ￦ 36,955 36,955 Others 12,484 13,721 Trading 2 3 POSCO INTERNATIONAL CORPORATION(1) 1,006,879 951,434 GRAIN TERMINAL HOLDING(2) — 26,256 PT. Bio Inti Agrindo 6,902 7,468 Others 16 — E&C 2 2 POSCO ENGINEERING & CONSTRUCTION CO., LTD. 24,868 24,868 POSCO Center Beijing 155 158 POSCO ENERGY CO., LTD. 26,471 26,471 Others 5 5 Others 10,419 10,478 16 17 ￦ 1,125,149 1,097,809 (1) Recoverable amounts of POSCO INTERNATIONAL Corporation are determined based on its value in use. As of December 31, 2019, value in use is estimated by applying a 6.84% discount rate and a 1.9% terminal growth rate after 5 years, based on management’s business plan. The terminal growth rate does not exceed long-term growth rate of its industry. Impairment loss on goodwill of ￦ Value in use of the CGU was affected by the assumptions such as discount rate, terminal growth rate and estimated sales used in discounted cash flow model. When the discount rate increases by 0.25%, value in use will be decreased by ￦￦ (2) In connection with the acquisition of Grain Terminal Holding, the Company recognized goodwill of ￦

Other Assets (Tables)

Other Assets (Tables)	12 Months Ended
Other Assets (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Other Current Assets and Other Non-Current Assets	Other current assets and other non-current (in millions of Won) 2018 2019 Current Advance payment ￦ 539,894 453,538 Prepaid expenses 123,770 145,834 Firm commitment asset 11,246 17,490 Others 9,553 14,315 684,463 631,177 Non-current Long-term advance payment 24,280 21,950 Long-term prepaid expenses 334,918 41,256 Others(1) 149,566 262,036 ￦ 508,764 325,242 (1) ) As of December 31, 2018 and 2019 the Company recognized tax assets amounting to ￦￦

Borrowings (Tables)

Borrowings (Tables)	12 Months Ended
Borrowings (Tables)	Dec. 31, 2019
Statement [LineItems]
Summary of Assets Pledges as Collateral	Assets pledged as collateral in regard to the borrowings as of December 31, 2019 are as follows: (in millions of Won) Bank Book value Pledged Cash and cash equivalents Sinhan Bank and others 26,923 26,923 Property, plant and equipment and Investment property Korea Development Bank and others 4,420,551 4,967,168 Trade accounts and notes receivable Korea Development Bank and others 7,498 7,498 Inventories Export-Import Bank of Korea and others 118,824 12,650 Financial instruments KB Kookmin Bank and others 46,217 45,017 ￦ 4,620,013 5,059,256
Short-term borrowings and current portion of long-term borrowings [member]
Statement [LineItems]
Summary of Borrowings	Short-term borrowings and current portion of long-term borrowings as of December 31, 2018 and 2019 are as follows: (in millions of Won) Bank Issuance date Maturity date Interest 2018 2019 Short-term borrowings Bank overdrafts JP Morgan and others January, 2019~ December, 2019 January, 2020~ December, 2020 0.5~8.9 ￦ 294,364 159,075 Short-term borrowings HSBC and others January, 2019~ December, 2019 January, 2020~ December, 2020 0.2~12.7 7,193,416 5,327,258 7,487,780 5,486,333 Current portion of long-term liabilities Current portion of long-term borrowings Export-Import Bank of Korea and others November, 2004~ October, 2019 January, 2020~ December, 2020 0.7~6.6 1,234,915 1,491,934 Current portion of debentures Korea Development Bank and others October, 2010~ September, 2018 April, 2020~ October, 2020 1.5~4.3 1,568,108 1,571,194 Less: Current portion of discount on debentures issued (1,184 ) (1,249 ) 2,801,839 3,061,879 ￦ 10,289,619 8,548,212
Long-term borrowings [member]
Statement [LineItems]
Summary of Borrowings	Long-term borrowings, excluding current portion as of December 31, 2018 and 2019 are as follows: (in millions of Won) Bank Issuance date Maturity date Interest 2018 2019 Long-term borrowings Export-Import Bank of Korea and others September, 2001~ December, 2019 February, 2021~ March, 2037 0.2~12.5 ￦ 4,499,199 3,827,152 Less: Present value discount (30,526 ) (24,374 ) Bonds KB Securities co.,Ltd. and others April, 2011~ November, 2019 February, 2021~ October, 2029 1.6~5.3 5,469,580 8,124,194 Less: Discount on debentures issued (18,602 ) (33,571 ) ￦ 9,919,651 11,893,401

Other Payables (Tables)

Other Payables (Tables)	12 Months Ended
Other Payables (Tables)	Dec. 31, 2019
Statement [LineItems]
Summary of Financial Liabilities	Other financial liabilities as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Derivatives liabilities ￦ 27,328 28,021 Financial guarantee liabilities 50,472 49,806 ￦ 77,800 77,827 Non-current Derivatives liabilities ￦ 46,429 17,033 Financial guarantee liabilities 17,733 14,461 ￦ 64,162 31,494
Other payables [member]
Statement [LineItems]
Summary of Financial Liabilities	Other payables as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Accounts payable ￦ 783,562 832,845 Accrued expenses 720,773 742,370 Dividend payable 8,673 3,106 Lease liabilities(1) 10,152 149,176 Withholdings 196,937 152,011 ￦ 1,720,097 1,879,508 Non-current Accounts payable ￦ 1,624 2,718 Accrued expenses 19,021 4,805 Lease liabilities(1) 84,602 526,294 Long-term withholdings 43,621 51,312 ￦ 148,868 585,129 (*1) As of December 31, 2019, the Company recognized additional lease liabilities of ￦

Provisions (Tables)

Provisions (Tables)	12 Months Ended
Provisions (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Provisions	(a) Provisions as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Non-current Current Non-current Provision for bonus payments ￦ 46,514 26,964 76,432 47,237 Provision for construction warranties 11,842 130,391 7,655 162,773 Provision for legal contingencies and claims(1) 16,981 94,169 6,996 77,488 Provision for the restoration(2) 9,379 79,789 6,783 80,520 Others(3,4) 213,737 99,723 262,471 90,136 ￦ 298,453 431,036 360,337 458,154 (1) The Company recognized probable outflow of resources amounting to ￦￦ (2) Due to contamination of lands near the Company’s magnesium smelting plant located in Gangneung province and others, the Company recognized present values of estimated costs for recovery of ￦ (3) As of December 31, 2018 and 2019, POSCO ENERGY CO., LTD., and Korea Fuel Cell, recognized ￦￦ (*4) The Company has recognized emission liabilities of ￦
Changes in Provisions	(c) Changes in provisions for the years ended December 31, 2018 and 2019 were as follows: 1) For the year ended December 31, 2018 (in millions of Won) Beginning Increase Utilization Reversal Others(1) Ending Provision for bonus payments ￦ 49,171 88,879 (60,723 ) (3,856 ) 7 73,478 Provision for construction warranties 118,036 56,560 (24,608 ) (7,660 ) (95 ) 142,233 Provision for legal contingencies and claims 36,764 84,242 (6,066 ) (3,399 ) (391 ) 111,150 Provision for the restoration 134,190 14,912 (9,212 ) (47,682 ) (3,040 ) 89,168 Others 249,957 328,879 (118,388 ) (216,668 ) 69,680 313,460 ￦ 573,472 (218,997) (279,265) 66,161 729,489 (1) Includes adjustments of foreign currency translation differences and others. 2) For the year ended December 31, 2019 (in millions of Won) Beginning Increase Utilization Reversal Others(1) Ending Provision for bonus payments ￦ 73,478 122,714 (86,084 ) (3,077 ) 16,638 123,669 Provision for construction warranties 142,233 53,203 (22,858 ) (3,444 ) 1,294 170,428 Provision for legal contingencies and claims 111,150 26,407 (37,087 ) (18,098 ) 2,112 84,484 Provision for the restoration 89,168 23,559 (13,411 ) (14,379 ) 2,366 87,303 Others 313,460 95,747 (38,260 ) (86,458 ) 68,118 352,607 ￦ 321,630 (197,700) (125,456) 90,528 818,491 (1) Includes adjustments of foreign currency translation differences and others.

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
Employee Benefits (Tables)	Dec. 31, 2019
Text block [abstract]
Expense Related to Post-employment Benefit Plans under Defined Contribution Plans	The expenses related to post-employment benefit plans under defined contribution plans for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Expense related to post-employment benefit plans under defined contribution plans ￦ 35,538 42,825 46,846
Amounts Recognized in Relation to Net Defined Benefit Liabilities in Statements of Financial Position	1) The amounts recognized in relation to net defined benefit liabilities in the statements of financial position as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Present value of funded obligations ￦ 2,117,829 2,416,203 Fair value of plan assets(1) (1,997,717 ) (2,255,149 ) Present value of non-funded 19,332 15,677 Net defined benefit liabilities ￦ 139,444 176,731 (1) As of December 31, 2018 and 2019, the Company recognized net defined benefit assets amounting to ￦￦
Changes in Present Value of Defined Benefit Obligations and Fair Value of Plan Assets	2) Changes in present value of defined benefit obligations for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Defined benefit obligations at the beginning of year ￦ 1,843,135 2,137,161 Current service costs 212,323 236,735 Interest costs 54,950 51,900 Remeasurements : 212,678 152,713 - Gain from change in financial assumptions 173,084 103,850 - Loss (gain) from change in demographic assumptions 526 (492 ) - Others 39,068 49,355 Benefits paid (189,165 ) (152,275 ) Others 3,240 5,646 Defined benefit obligations at the end of year ￦ 2,137,161 2,431,880 3) Changes in fair value of plan assets for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Fair value of plan assets at the beginning of year ￦ 1,714,166 1,997,717 Interest on plan assets 50,784 48,210 Remeasurement of plan assets (19,761 ) (8,692 ) Contributions to plan assets 408,326 342,915 Benefits paid (163,112 ) (124,962 ) Others 7,314 (39 ) Fair value of plan assets at the end of year ￦ 1,997,717 2,255,149
Fair Value of Plan Assets	4) The fair value of plan assets as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Equity instruments ￦ 3,151 10,386 Debt instruments 692,825 1,013,716 Deposits 1,244,802 1,159,455 Others 56,939 71,592 ￦ 1,997,717 2,255,149
Amounts Recognized in Consolidated Statements of Comprehensive Income	5) The amounts recognized in consolidated statements of comprehensive income for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Current service costs ￦ 209,612 212,323 236,735 Net interest costs(1) (9,686 ) 4,166 3,690 ￦ 199,926 216,489 240,425 (1) The actual return on plan assets amounted to ￦￦￦ The expenses by function were as follows: (in millions of Won) 2017 2018 2019 Cost of sales ￦ 131,724 150,822 169,206 Selling and administrative expenses 67,424 64,505 70,060 Others 778 1,162 1,159 ￦ 199,926 216,489 240,425
Accumulated Actuarial Gains (Losses), Net of Tax Recognized in Other Comprehensive Income	6) Accumulated actuarial gains (losses), net of tax recognized in other comprehensive income for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Beginning ￦ (251,612 ) (299,155 ) (472,644 ) Current actuarial gains (losses) (47,543 ) (173,489 ) (117,152 ) Ending ￦ (299,155 ) (472,644 ) (589,796 )
Principal Actuarial Assumptions	7) The principal actuarial assumptions as of December 31, 2018 and 2019 are as follows: (%) 2018 2019 Discount rate 2.24~10.03 1.72 ~ 13.00 Expected future increase in salaries(1) 2.54~10.00 2.00 ~ 11.00 (1) The expected future increase in salaries is based on the average salary increase rate for the past 3 years.
Changes to Defined Benefit Obligation Due to Reasonably Possible Changes to one of the Relevant Actuarial Assumptions	8) Reasonably possible changes at the reporting date to one of the relevant actuarial assumptions, holding the other assumptions constant, would have affected the defined benefit obligation by the amounts shown below: (in millions of Won) 1% Increase 1% Decrease Amount Percentage(%) Amount Percentage(%) Discount rate ￦ (167,767 ) (6.9 ) 194,809 8.0 Expected future increase in salaries 195,098 8.0 (170,997 ) (7.0 )
Maturity of Expected Benefit Payments	9) As of December 31, 2019, the maturity of the expected benefit payments are as follows: (in millions of Won) Within 1 year - 5 years 5 years - 10 years 10 years - 20 years After 20 years Total Benefits paid ￦ 279,554 928,288 513,133 771,500 409,976 2,902,451

Other Liabilities (Tables)

Other Liabilities (Tables)	12 Months Ended
Other Liabilities (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Other Liabilities	Other liabilities as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Current Due to customers for contract work ￦ 641,064 644,947 Advances received 1,130,910 746,169 Unearned revenue 49,805 61,795 Withholdings 233,981 388,486 Firm commitment liability 24,373 15,637 Others 10,174 8,604 ￦ 2,090,307 1,865,638 Non-current Advances received 123,071 116,178 Unearned revenue 42,992 27,161 Others 84,369 52,349 ￦ 250,432 195,688

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
Financial Instruments (Tables)	Dec. 31, 2019
Statement [LineItems]
Summary of Carrying Amount and Fair Values of Financial Assets and Financial Liabilities by Fair value	1) The carrying amount and the fair values of financial assets and financial liabilities by fair value hierarchy as of December 31, 2018 and 2019 are as follows: ① (in millions of Won) Fair value Book value Level 1 Level 2 Level 3 Total Financial assets Fair value through profit or loss Derivative assets ￦ 16,662 — 16,662 — 16,662 Short-term financial instruments 6,099,303 — 6,099,303 — 6,099,303 Debt securities 27,229 — — 27,229 27,229 Other securities 338,106 1,224 5,205 331,677 338,106 Other receivables 2,000 — — 2,000 2,000 Derivative hedging instruments(2) 32,421 — 32,421 — 32,421 Fair value through other comprehensive income Equity securities 1,238,630 891,514 — 347,116 1,238,630 Debt securities 1,638 — — 1,638 1,638 Financial assets measured at amortized cost(1) — Cash and cash Equivalents 2,643,865 — — — — Trade accounts and notes receivable 8,819,617 — — — — Other receivables 1,843,381 — — — — Debt securities 8,447 — — — — Deposit instruments 1,966,558 — — — — ￦ 23,037,857 892,738 6,153,591 709,660 7,755,989 Financial liabilities Fair value through profit or loss Derivative liabilities ￦ 60,047 — 60,047 — 60,047 Derivative hedging instruments(2) 13,710 — 13,710 — 13,710 Financial liabilities measured at amortized cost(1) Trade accounts and notes payable 4,035,960 — — — — Borrowings 20,209,270 — 20,377,105 — 20,377,105 Financial guarantee liabilities 68,205 — — — — Others 1,803,353 — — — — ￦ 26,190,545 — 20,450,862 — 20,450,862 (1) Fair value of financial assets and liabilities measured at amortized cost except borrowings approximates carrying amounts. ② (in millions of Won) Fair value Book value Level 1 Level 2 Level 3 Total Financial assets Fair value through profit or loss Derivative assets ￦ 106,104 — 106,104 — 106,104 Short-term financial instruments 6,861,242 — 6,861,242 — 6,861,242 Debt securities 28,087 — — 28,087 28,087 Other securities 340,008 1,222 3,330 335,456 340,008 Other receivables 2,000 — — 2,000 2,000 Derivative hedging instruments(2) 6,174 — 6,174 — 6,174 Fair value through other comprehensive income Equity securities 1,204,902 782,108 73 422,721 1,204,902 Debt securities 5,686 — — 5,686 5,686 Financial assets measured at amortized cost(1) Cash and cash Equivalents 3,514,872 — — — — Trade accounts and notes receivable 8,214,459 — — — — Other receivables 2,193,700 — — — — Debt securities 334,153 — — — — Deposit instruments 1,779,082 — — — — ￦ 24,590,469 783,330 6,976,923 793,950 8,554,203 Financial liabilities Fair value through profit or loss Derivative liabilities ￦ 32,193 — 32,193 — 32,193 Derivative hedging instruments(2) 12,861 — 12,861 — 12,861 Financial liabilities measured at amortized cost(1) Trade accounts and notes payable 3,442,989 — — — — Borrowings 20,441,613 — 20,666,476 — 20,666,476 Financial guarantee liabilities 64,267 — — — — Others 2,401,382 — — — — ￦ 26,395,305 — 20,711,530 — 20,711,530 (1) Fair value of financial assets and liabilities measured at amortized cost except borrowings approximates carrying amounts. (*2) The Company applies fair value hedge for certain forward contracts utilized in hedging the risk of changes in fair value of product prices regarding firm commitments or purchase commitments. Also, the Company applies cash flow hedge for certain currency swap utilized in hedging the risk of changes in foreign currency which influences cash flow from borrowings. 2) Financial assets and financial liabilities classified as fair value hierarchy Level 2 Fair values of derivatives are measured using valuation models such as discounted cash flow method and others. Inputs of the valuation model include forward rate, interest rate and others. It may change depending on the type of derivatives and the nature of the underlying assets. 3) Financial assets and financial liabilities classified as fair value hierarchy Level 3
Value Measurement Method and Significant but not Observable Inputs for the Financial Assets Classified as Fair Value Hierarchy Level 3	① Fair value measurement method and significant but not observable inputs for the financial assets classified as fair value hierarchy Level 3 as of December 31, 2019 are as follows: (in millions of Won) Fair value Valuation technique Inputs Range of inputs Effect on fair value with unobservable input Financial assets at fair value ￦ 417,683 Discounted cash flows Growth rate 0% ~ 0.5% As growth rate increases, fair value increases Discount rate 6.0% ~ 18.4% As discount rate increases, fair value decreases 17,931 Proxy firm valuation method Price multiples 0.621 ~ 2.645 As price multiples increases, fair value increases 358,336 Asset value approach — — —
Sensitivity Analysis of Financial Assets and Financial Liabilities Classified as Level 3 of Fair Value Hierarchy	② Sensitivity analysis of financial assets and financial liabilities classified as Level 3 of fair value hierarchy If other inputs remain constant as of December 31, 2019 and one of the significant but not observable input is changed, the effect on fair value measurement is as follows: (in millions of Won) Input variable Favorable Unfavorable changes Financial assets at fair value Fluctuation 0.5% of growth rate ￦ 1,325 1,224 Fluctuation 0.5% of discount rate 24,766 21,845
Finance Income and Costs by Category of Financial Instruments	4) Finance income and costs by category of financial instrument for the years ended December 31, 2017, 2018 and 2019 were as follows: ① For the year ended December 31, 2017 Finance income and costs Other (in millions of Won) Interest Gain and Gain and Gain and Impairment Others Total Financial assets held for trading ￦ — 16 — — — — 16 — Derivatives assets — (99,942 ) — 206,362 — — 106,420 (143 ) Available-for-sale 60 — — 418,789 (123,214 ) 92,961 388,596 (31,389 ) Held-to-maturity 236 — — — — 7 243 — Loans and receivables 212,155 — (607,837 ) (32,456 ) — (304 ) (428,442 ) — Derivatives liabilities — (61,809 ) — (231,908 ) — — (293,717 ) — Financial liabilities measured at amortized cost (653,115 ) — 777,935 — — (9,546 ) 115,274 — ￦ (440,664 ) (161,735 ) 170,098 360,787 (123,214 ) 83,118 (111,610 ) (31,532 ) ② For the year ended December 31, 2018 Finance income and costs Other comprehensive (in millions of Won) Interest Gain and Gain and Gain and Others Total Financial assets at fair value through profit or loss ￦ 140,116 (43,293 ) — 11,919 3,644 112,386 — Derivative assets — 47,720 — 233,187 — 280,907 — Financial assets at fair value through other comprehensive income — — — — 59,701 59,701 (149,188 ) Financial assets measured at amortized cost 197,142 — 234,606 (39,970 ) (370 ) 391,408 — Derivative liabilities — 8,592 — (194,446 ) — (185,854 ) (212 ) Financial liabilities measured at amortized cost (741,296 ) — (438,708 ) — (16,990 ) (1,196,994 ) — ￦ (404,038 ) 13,019 (204,102 ) 10,690 45,985 (538,446 ) (149,400 ) ③ For the year ended December 31, 2019 Finance income and costs Other comprehensive (in millions of Won) Interest Gain and Gain and Gain and Others Total Financial assets at fair value through profit or loss ￦ 142,873 (23,551 ) — 5,556 630 125,508 — Derivative assets — 123,538 — 184,861 — 308,399 — Financial assets at fair value through other comprehensive income — — — — 74,825 74,825 (10,541 ) Financial assets measured at amortized cost 209,511 — 295,319 (36,935 ) (8,042 ) 459,853 — Derivative liabilities — (7,494 ) — (217,072 ) — (224,566 ) (90 ) Financial liabilities measured at amortized cost (755,711 ) — (330,808 ) (2,432 ) (24,988 ) (1,113,939 ) — ￦ (403,327 ) 92,493 (35,489 ) (66,022 ) 42,425 (369,920 ) (10,631 )
Maximum Exposure to Credit Risk	(b) Credit risk 1) Credit risk exposure The carrying amount of financial assets represents the Company’s maximum exposure to credit risk. The maximum exposure to credit risk as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Cash and cash equivalents ￦ 2,643,865 3,514,872 Derivative assets 49,083 112,278 Short-term financial instrument 6,099,303 6,861,242 Debt securities 37,314 367,926 Other securities 338,106 340,008 Other receivables 1,845,381 2,195,700 Trade accounts and nores receivable 8,819,617 8,214,459 Deposit instruments 1,966,558 1,779,082 ￦ 21,799,227 23,385,567
Allowance for Doubtful Accounts	① Allowance for doubtful accounts as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Trade accounts and notes receivable ￦ 588,733 465,524 Other accounts receivable 160,729 210,313 Loans 147,980 195,339 Other assets 19,348 27,098 ￦ 916,790 898,274
Impairment Losses on Financial Assets	② Impairment losses on financial assets for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Bad debt expenses ￦ 74,781 (28,105 ) Other bad debt expenses(1) 81,353 88,787 Less: Recovery of allowance for other bad debt accounts (18,261 ) (8,464 ) ￦ 137,873 52,218 (1) Other bad debt expenses are mainly related to loans and other accounts receivable.
Aging and Impairment Losses of Trade Accounts and Notes Receivable and Other Receivables	③ The aging and allowance for doubtful accounts of trade accounts and notes receivable as of December 31, 2018 and 2019 are as follows: 2018 2019 (in millions of Won) Trade accounts and Impairment Trade accounts and Impairment Current (not past due) ￦ 8,021,110 70,418 7,528,607 75,324 Over due less than 1 month 632,082 14,434 876,753 9,395 1 month - 3 months 226,082 4,116 228,115 6,647 3 months - 12 months 118,094 11,774 134,888 7,954 Over 12 months 1,148,694 487,991 965,977 366,204 ￦ 10,146,062 588,733 9,734,340 465,524 ④ The aging and allowance for doubtful accounts of other receivables as of December 31, 2018 and 2019 are as follows: 2018 2019 (in millions of Won) Loans and other Impairment Loans and other account receivable Impairment Current (not past due) ￦ 1,754,293 140,072 1,220,756 56,354 Over due less than 1 month 100,102 4,307 432,220 1,546 1 month - 3 months 28,351 851 91,521 239 3 months - 12 months 59,946 12,411 271,814 10,846 over 12 months 230,746 170,416 612,139 363,765 ￦ 2,173,438 328,057 2,628,450 432,750
Changes in Allowance for Doubtful Accounts	⑤ Changes in the allowance for doubtful accounts for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Beginning ￦ 977,771 1,094,464 916,790 Initial application of IFRS No.9 — 107,454 — Bad debt expenses 173,694 74,781 (28,105 ) Other bad debt expenses 98,177 63,092 80,323 Others(1) (155,178 ) (423,001 ) (70,735 ) Ending ￦ 1,094,464 916,790 898,273 (1) Others for the years ended December 31, 2017, 2018 and 2019, included decreases mainly due to write-off ￦￦￦
Contractual Maturities for Non-derivative Financial Liabilities	1) Contractual maturities of non-derivative (in millions of Won) Book value Contractual cash flow Within 1 year 1 year - 5 years After 5 years Trade accounts and notes payable ￦ 3,442,989 3,444,596 3,422,957 21,639 — Borrowings 20,441,613 22,161,306 9,262,808 11,171,927 1,726,571 Financial guarantee liabilities(1) 64,267 3,406,609 3,406,609 — — Lease liabilities 675,470 858,662 166,854 502,674 189,134 Other financial liabilities 1,725,912 1,797,765 1,667,087 130,678 — ￦ 26,350,251 31,668,938 17,926,315 11,826,918 1,915,705 (1) For issued financial guarantee contracts, the maximum amount of the guarantee is allocated to the earliest period in which the guarantee could be called.
Contractual Maturities Analysis of Derivative Financial Liabilities	2) Contractual maturities of derivative financial liabilities are as follows: (in millions of Won) Within 1 year - 5 years After 5 years Total Currency forward ￦ 11,779 10,132 — 21,911 Currency swap 570 1,687 3,845 6,102 Interest rate swap 1,525 1,368 — 2,893 Others 14,148 — — 14,148 ￦ 28,022 13,187 3,845 45,054
Currency risk [member]
Statement [LineItems]
Market Risk Exposure	1) The Company has exposure to the risk that the fair value or future cash flows of a financial instrument will fluctuate because of the changes in foreign exchange rates. The exposure to currency risk as of December 31, 2018 and 2019 is as follows: (in millions of Won) 2018 2019 Assets Liabilities Assets Liabilities USD ￦ 4,346,481 6,389,276 4,423,107 6,166,765 EUR 657,690 509,437 592,381 180,816 JPY 97,722 389,625 79,664 253,542 Others 259,949 142,868 481,455 319,046
Sensitivity Analysis for Market Risk	2) As of December 31, 2018 and 2019, provided that functional currency against foreign currencies other than functional currency hypothetically strengthens or weakens by 10%, the changes in gain or loss for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 10% increase 10% decrease 10% increase 10% decrease USD ￦ (204,280 ) 204,280 (174,366 ) 174,366 EUR 14,825 (14,825 ) 41,156 (41,156 ) JPY (29,190 ) 29,190 (17,388 ) 17,388
Interest rate risk [member]
Statement [LineItems]
Market Risk Exposure	1) The carrying amount of interest-bearing financial instruments as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Fixed rate Financial assets ￦ 11,565,519 13,391,637 Financial liabilities (11,781,701 ) (13,264,607 ) (216,182 ) 127,030 Variable rate Financial liabilities ￦ (8,522,323 ) (7,852,476 )
Sensitivity Analysis for Market Risk	As of December 31, 2018 and 2019, provided that other factors remain the same and the interest rate of borrowings with floating rates increases or decreases by 1%, the changes in interest expense for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 1% increase 1% decrease 1% increase 1% decrease Variable rate financial instruments ￦ (85,223 ) 85,223 (78,525 ) 78,525
Level 3 [member]
Statement [LineItems]
Fair Values of Financial Assets and Financial Liabilities	③ Changes in fair value of financial assets and financial liabilities classified as Level 3 for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Beginning ￦ 880,012 709,660 Acquisition 134,325 68,461 Loss on valuation of financial assets (34,555 ) (9,412 ) Other comprehensive income 26,771 106,586 Disposal and others (296,893 ) (81,345 ) Ending ￦ 709,660 793,950

Share Capital and Capital Sur_2

Share Capital and Capital Surplus (Tables)	12 Months Ended
Share Capital and Capital Surplus (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Share Capital	(a) Share capital as of December 31, 2018 and 2019 are as follows: (Share, in Won) 2018 2019 Authorized shares 200,000,000 200,000,000 Par value ￦ 5,000 5,000 Issued shares(1) 87,186,835 87,186,835 Shared capital(2) ￦ 482,403,125,000 482,403,125,000 (1) As of December 31, 2019, total shares of ADRs of 34,827,912 outstanding in overseas stock market are equivalent to 8,706,978 of common stock. (2) As of December 31, 2019, the difference between the ending balance of common stock and the par value of issued common stock is ￦
Changes in Issued Common Stock	(b) The changes in issued common stock for the years ended December 31, 2018 and 2019 were as follows: (share) 2018 2019 Issued shares Treasury shares Number of Issued shares Treasury shares Number of Beginning 87,186,835 (7,187,231 ) 79,999,604 87,186,835 (7,185,703 ) 80,001,132 Disposal of treasury shares — 1,528 1,528 — 114,509 114,509 Ending 87,186,835 (7,185,703 ) 80,001,132 87,186,835 (7,071,194 ) 80,115,641
Summary of Capital Surplus	(c) Capital surplus as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Share premium ￦ 463,825 463,825 Gain on disposal of treasury shares 784,047 796,623 Other capital deficit 172,135 125,259 ￦ 1,420,007 1,385,707
Summary of Redeemable Convertible Preferred Shares	(d) POSCO Energy Co., Ltd., a subsidiary of the Company, issued redeemable convertible preferred shares which are classified as non-controlling (Share, in Won) Redeemable Convertible Preferred Shares Issue date February 25, 2017 Number of shares issued 8,643,193 shares Price per share ￦ Voting rights No voting rights for 3 years from issue date Dividend rights Cumulative, Non-participating · Minimum dividend rate for 1 year : 3.98% · Dividend rate for 2~3 years : 4.48% · Minimum dividend rate after 4 years : Comparative rate + Issuance spread + 2% Details about Redemption Issuer can demand redemption of all or part of redeemable convertible preferred shares every year after the issue date, for a period of 10 years from the issue date. Details about Conversion Stockholders of redeemable convertible preferred shares can convert them to common shares from 3 years after the issue date to the end of the redemption period (10 years). Conversion price is equal to issue price, which could be adjusted according to anti-dilution clause.

Hybrid Bonds (Tables)

Hybrid Bonds (Tables)	12 Months Ended
Hybrid Bonds (Tables)	Dec. 31, 2019
POSCO ENERGY CO., LTD. [member]
Statement [LineItems]
Summary of Hybrid Bonds	(a) Hybrid bonds classified as equity as of December 31, 2018 and 2019 are as follows: (in millions of Won) Date of issue Date of Interest 2018 2019 Hybrid bond 1-2(1) 2013-06-13 2043-06-13 4.60 ￦ 200,000 200,000 Issuance cost (616 ) (616 ) ￦ 199,384 199,384 (1) Details of issuance of hybrid bonds as of December 31, 2019 are as follows: Hybrid bond 1-2 Maturity date 30 years (POSCO has a right to extend the maturity date) Interest rate Issue date ~ 2023-06-12 Reset every 10 years as follows; · After 10 years : return on government bond (10 years) + 1.40% · After 10 years : additionally +0.25% according to Step-up · After 30 years : additionally +0.75% Interest payments condition Quarterly (Optional deferral of interest payment is available to POSCO) Others POSCO can call the hybrid bond at year 10 and interest payment date afterwards The hybrid bond holder’s preference in the event of liquidation is senior to the common shareholders, but subordinate to other creditors. The interest accumulated but not paid on the hybrid bonds as of December 31, 2019 amounts to ￦ (b) POSCO ENERGY CO., LTD., a subsidiary of the Company, issued hybrid bonds, which are classified as non-controlling (in millions of Won) Date of issue Date of maturity Interest rate (%) 2018 2019 Hybrid bond 1-4(*1) 2013-08-29 2043-08-29 5.21 140,000 140,000 Issuance cost (429 ) (429 ) ￦ 139,571 139,571

Reserves (Tables)

Reserves (Tables)	Jan. 01, 2019	Dec. 31, 2019
Statement [LineItems]
Summary of Reserves		(a) Reserves as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Accumulated comprehensive loss of investments in associates and joint ventures ￦ (670,435 ) (648,712 ) Changes in fair value of equity investments at fair value through other comprehensive income (295,300 ) (285,073 ) Foreign currency translation differences (417,817 ) (202,636 ) Gain or losses on valuation of derivatives (352 ) (438 ) Others (20,464 ) (21,121 ) ￦ (1,404,368 ) (1,157,980 )
Unrealized fair value of available-for-sale investments [member]
Statement [LineItems]
Summary of Reserves	(b) Changes in unrealized fair value of available-for-sale (in millions of Won) 2018 2019 Beginning balance ￦ 230,190 (295,300 ) Initial application of IFRS No. 9 (421,525 ) — Changes in unrealized fair value of equity investments (139,226 ) (9,422 ) Reclassification upon disposal 45,737 21,902 Others (10,476 ) (2,253 ) Ending balance ￦ (295,300 ) (285,073 )

Treasury Shares (Tables)

Treasury Shares (Tables)	12 Months Ended
Treasury Shares (Tables)	Dec. 31, 2019
Text block [abstract]
Changes in Treasury Shares	Based on the Board of Directors’ resolution, POSCO holds treasury shares for business purposes including its share price stabilization. The changes in treasury shares for the years ended December 31, 2018 and 2019 were as follows: (shares, in millions of Won) 2018 2019 Number of shares Amount Number of shares Amount Beginning 7,187,231 ￦ 1,533,054 7,185,703 ￦ 1,532,728 Disposal of treasury shares (1,528 ) (326 ) (114,509 ) (24,425 ) Ending 7,185,703 ￦ 1,532,728 7,071,194 ￦ 1,508,303

Revenue (Tables)

Revenue (Tables)	12 Months Ended
Revenue (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Revenue Disaggregated by Types of Revenue and Timing of Revenue Recognition	1) Details of revenue disaggregated by types of revenue and timing of revenue recognition for the years ended December 31, 2017, 2018 and 2019 were as follows: ① For the year ended December 31, 2017 (in millions of Won) Steel Trading Construction Others Total Types of revenue Revenue from sales of goods ￦ 30,064,680 20,655,267 20,368 617,394 51,357,709 Revenue from services 111,494 28,793 48,408 1,876,179 2,064,874 Revenue from construction contract — — 6,262,038 37,154 6,299,192 Others 54,194 118,147 87,559 205,192 465,092 ￦ 30,230,368 20,802,207 6,418,373 2,735,919 60,186,867 Timing of revenue recognition Revenue recognized at a point in time ￦ 30,118,874 20,773,414 334,345 832,369 52,059,002 Revenue recognized over time 111,494 28,793 6,084,028 1,903,550 8,127,865 ￦ 30,230,368 20,802,207 6,418,373 2,735,919 60,186,867 ② For the year ended December 31, 2018 (in millions of Won) Steel Trading Construction Others Total Types of revenue Revenue from sales of goods ￦ 31,733,609 21,632,183 3,568 605,206 53,974,566 Revenue from services 583,359 611,752 63,922 2,274,606 3,533,639 Revenue from construction contract — — 6,860,995 272,778 7,133,773 Others 41,041 163,782 17,784 290,051 512,658 ￦ 32,358,009 22,407,717 6,946,269 3,442,641 65,154,636 Timing of revenue recognition Revenue recognized at a point in time ￦ 31,774,650 21,795,965 743,448 906,120 55,220,183 Revenue recognized over time 583,359 611,752 6,202,821 2,536,521 9,934,453 ￦ 32,358,009 22,407,717 6,946,269 3,442,641 65,154,636 ③ For the year ended December 31, 2019 (in millions of Won) Steel Trading Construction Others Total Types of revenue Revenue from sales of goods ￦ 31,456,714 21,629,838 — 712,196 53,798,748 Revenue from services 573,463 369,730 49,696 2,217,862 3,210,751 Revenue from construction contract — — 7,308,401 30,998 7,339,399 Others 48,276 157,564 5,393 225,578 436,811 ￦ 32,078,453 22,157,132 7,363,490 3,186,634 64,785,709 Timing of revenue recognition Revenue recognized at a point in time ￦ 31,504,990 21,787,402 747,917 943,037 54,983,346 Revenue recognized over time 573,463 369,730 6,615,573 2,243,597 9,802,363 ￦ 32,078,453 22,157,132 7,363,490 3,186,634 64,785,709
Summary of Contract Assets and Liabilities From Contracts With Customers	(b) Details of contract assets and liabilities from contracts with customers as of December 31, 2018 and 2019, are as follows. (in millions of Won) 2018 2019 Receivables Account receivables ￦ 8,819,617 8,214,459 Contract assets Due from customers for contract work 737,712 1,054,357 Contract liabilities Advance received 1,278,731 864,480 Due to customers for contract work 641,064 644,947 Unearned revenue 91,872 88,733

Revenue - Contract Balances (Ta

Revenue - Contract Balances (Tables)	12 Months Ended
Revenue - Contract Balances (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of In-Progress Contracts	(a) Details of in-progress (in millions of Won) 2018 2019 Accumulated cost ￦ 26,153,452 27,281,031 Accumulated contract profit 1,848,718 2,462,008 Accumulated contract loss (804,538 ) (1,185,200 ) Accumulated contract revenue 27,197,632 28,557,839
Summary of Due From Customers for Contract Work and Due to Customers for Contract Work	(b) Details of due from customers for contract work and due to customers for contract work as of December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Unbilled due from customers for contract work ￦ 810,655 1,128,116 Due to customers for contract work (641,064 ) (644,947 ) ￦ 169,591 483,169
Summary of Changes in Estimated Total Contract Costs and Impact on Profit or Loss	(c) Due to the factors causing the variation of costs for the years ended December 31, 2018 and 2019, the estimated total contract costs have changed. Details of changes in estimated total contract costs and the impact on profit before income taxes for the years ended December 31, 2018, 2019 and future periods are as follows: (in millions of Won) 2018 2019 Changes in estimated total contract costs ￦ 427,812 533,639 Changes in profit before income taxes of construction contract : - Current period (38,720 ) (166,077 ) - Future periods 69,428 (43,584 )
Summary of Significant Assumptions Including Uncertainty of Estimate of Total Contract Costs	The significant assumptions including uncertainty of the estimate of total contract costs are as follows: Method of significant assumption Material cost Assumption based on recent purchasing price and quoted market price Labor cost Assumption based on standard monthly and daily labor cost Outsourcing cost Assumption based on the past experience rate of similar project and market price
Summary of Expected Revenue In Relation To Performance Obligations	(e) As of December 31, 2019, revenue expected to be recognized in the future in relation to performance obligations that have not been fulfilled (or partially fulfilled) is as follows: (in millions of Won) 2020 2021 2022 After 2023 Total Expected Revenue ￦ 6,387,124 4,279,557 2,105,577 1,965,478 14,737,736

Selling and Administrative Ex_2

Selling and Administrative Expenses (Tables)	12 Months Ended
Selling and Administrative Expenses (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Other Administrative Expenses	Other administrative expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Wages and salaries ￦ 774,900 813,467 840,599 Expenses related to post-employment benefits 78,654 73,290 88,880 Other employee benefits 159,920 176,240 177,908 Travel 39,790 40,929 42,692 Depreciation 97,261 101,274 131,337 Amortization 146,314 112,418 112,171 Communication 11,740 10,616 11,150 Electricity 7,050 8,309 8,799 Taxes and public dues 72,826 71,973 78,932 Rental 69,976 69,516 39,886 Repairs 9,859 15,291 13,454 Entertainment 11,582 11,816 11,123 Advertising 119,724 106,875 82,574 Research & development 125,795 108,352 110,315 Service fees 193,387 165,938 193,486 Vehicles maintenance 8,211 8,942 7,660 Industry association fee 10,140 9,571 9,609 Conference 14,494 14,510 15,104 Increase to provisions 10,990 14,433 18,071 Others 40,493 51,995 47,536 ￦ 2,003,106 1,985,755 2,041,286
Summary of Selling Expenses	Selling expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Freight and custody(1) ￦ 1,336,969 184,675 180,341 Operating expenses for distribution center 10,503 10,614 9,222 Sales commissions 115,925 79,080 73,941 Sales advertising 3,800 4,821 1,552 Sales promotion 12,414 13,792 9,989 Sample 1,989 2,716 2,287 Sales insurance premium 36,546 37,251 32,632 Contract cost 23,061 16,992 38,081 Others 16,070 19,304 20,273 ￦ 1,557,277 369,245 368,318 (1) From the year ended December 31, 2018, upon adoption of IFRS No. 15, the Company recognized the freight expenses included in selling expenses incurred for the delivery of transportation services identified as a separate performance obligations in cost of sales.

Research and Development Expe_2

Research and Development Expenditures Recognized as Expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Text block [abstract]
Summary of Research and Development Expenditures Recognized as Expenses	Research and development expenditures recognized as expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Administrative expenses ￦ 125,795 108,352 110,315 Cost of sales 361,093 418,250 389,460 ￦ 486,888 526,602 499,775

Other Operating Income and Ex_2

Other Operating Income and Expenses (Tables)	12 Months Ended
Other Operating Income and Expenses (Tables)	Dec. 31, 2019
Text block [abstract]
Details of Other Operating Income and Expenses	Details of other operating income and expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Other operating income Gain on disposals of assets held for sale ￦ 1,180 27,171 37,461 Gain on disposals of investment in subsidiaries, associates and joint ventures 81,794 45,241 27,836 Gain on disposals of property, plant and equipment 32,145 53,139 49,367 Gain on disposals of intangible assets 23,391 117,139 1,896 Gain on valuation of firm commitment 56,301 39,028 60,201 Gain on valuation of emission rights — — 25,440 Gain on disposals of emission rights — — 11,141 Reversal of other provisions — 3,557 36,522 Others(1,3) 253,670 238,311 201,027 ￦ 448,481 523,586 450,891 Other operating expenses Impairment loss on assets held for sale ￦ — (50,829 ) (38,328 ) Loss on disposals of investments in subsidiaries, associates and joint ventures (19,985 ) (5,226 ) (6,539 ) Loss on disposals of property, plant and equipment (151,343 ) (117,614 ) (120,227 ) Impairment loss on property, plant and equipment (117,231 ) (1,004,704 ) (442,700 ) Impairment loss on investment property — (51,461 ) (32,642 ) Impairment loss on intangible assets (167,995 ) (337,519 ) (191,021 ) Loss on valuation of firm commitment (43,164 ) (66,281 ) (37,685 ) Idle tangible asset expenses (10,490 ) (9,257 ) (34,152 ) Increase to provisions (33,964 ) (134,632 ) (23,074 ) Donations (51,424 ) (52,074 ) (51,567 ) Others(2) (95,780 ) (184,865 ) (112,029 ) ￦ (691,376 ) (2,014,462 ) (1,089,964 ) (1) During the year ended December 31, 2019, the Company recognized other operating income of ￦ (2) During the 2018, the Company recognized the other-operating expenses of ￦ (*3) During the year ended December 31, 2018, the Company recognized other operating income of ￦

Finance Income and Costs (Table

Finance Income and Costs (Tables)	12 Months Ended
Finance Income and Costs (Tables)	Dec. 31, 2019
Text block [abstract]
Details of Finance Income and Costs	Details of finance income and costs for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Finance income Interest income(1) ￦ 212,451 337,258 352,384 Dividend income 92,962 63,345 75,455 Gain on foreign currency transactions 785,616 716,060 824,565 Gain on foreign currency translations 564,016 212,443 206,019 Gain on derivatives transactions 210,727 247,513 195,933 Gain on valuations of derivatives 64,735 96,986 163,491 Gain on disposals of financial assets at fair value through profit of loss — 8,742 8,525 Gain on disposals of available-for-sale 425,684 — — Gain on valuations of financial assets at fair value through profit or loss — 16,149 42,297 Others 16,476 7,474 3,474 ￦ 2,372,667 1,705,970 1,872,143 Finance costs Interest expenses ￦ (653,115 ) (741,296 ) (755,711 ) Loss on foreign currency transactions (756,654 ) (810,857 ) (746,603 ) Loss on foreign currency translations (422,880 ) (321,748 ) (319,470 ) Loss on derivatives transactions (236,273 ) (208,772 ) (228,144 ) Loss on valuations of derivatives (226,487 ) (40,674 ) (47,447 ) Loss on disposals of trade accounts and notes receivable (32,456 ) (39,970 ) (36,935 ) Impairment loss on available-for-sale (123,214 ) — — Loss on disposals of financial assets at fair value through profit or loss — (1,474 ) (2,969 ) Loss on valuations of financial assets at fair value through profit or loss — (59,442 ) (65,848 ) Others (33,198 ) (20,183 ) (38,936 ) ￦ (2,484,277 ) (2,244,416 ) (2,242,063 ) (1) Interest income calculated using the effective interest method for the years ended December 31, 2017, 2018 and 2019 were ￦￦￦

Expenses by Nature (Tables)

Expenses by Nature (Tables)	12 Months Ended
Expenses by Nature (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Expenses by Nature	Expenses that are recorded by nature as cost of sales, selling and administrative expenses, impairment loss on other receivables and other operating expenses in the statements of comprehensive income for the years ended December 31, 2017, 2018 and 2019 were as follows (excluding finance costs and income tax expense): (in millions of Won) 2017 2018 2019 Raw material used, changes in inventories and others ￦ 35,584,184 38,884,690 39,279,866 Employee benefits(2) 3,357,861 3,639,192 3,623,611 Outsourced processing cost 7,074,948 7,462,656 8,250,372 Electricity 933,045 949,435 912,832 Depreciation(1) 2,887,646 2,911,048 3,029,868 Amortization 409,774 356,581 431,247 Freight and custody 1,336,969 1,414,940 1,446,628 Sales commissions 115,925 79,080 73,941 Loss on disposal of property, plant and equipment 151,343 117,614 120,227 Impairment loss on property, plant and equipment 117,231 1,004,704 442,700 Impairment loss on goodwill and intangible assets 167,995 337,519 191,021 Donations 51,424 52,074 51,567 Other 4,253,625 4,445,124 4,168,470 ￦ 56,441,970 61,654,657 62,022,350 (1) Includes depreciation of investment property. (2) The details of employee benefits expenses for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Wages and salaries ￦ 3,105,364 3,372,831 3,313,642 Expenses related to post-employment benefits 252,497 266,361 309,969 ￦ 3,357,861 3,639,192 3,623,611

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2019
Text block [abstract]
Summary of Income Tax Expense	(a) Income tax expense for the years ended December 31, 2017, 2018 and 2019 was as follows: (in millions of Won) 2017 2018 2019 Current income taxes(1) ￦ 864,143 1,577,581 913,286 Deferred income tax due to temporary differences 300,037 (38,851 ) 164,078 Items recorded directly in equity 21,560 144,900 11,005 Income tax expense ￦ 1,185,740 1,683,630 1,088,369 (1) Refund (additional payment) of income taxes when filing a final corporation tax return credited (charged) directly to current income taxes.
Income Tax Credit (Charged) Directly to Equity	(b) The income taxes credited (charged) directly to equity for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Net changes in the unrealized fair value of available-for-sale ￦ 1,271 47,423 (26,744 ) Gain on disposal of treasury shares (40 ) (50 ) — Others 20,329 97,527 37,749 ￦ 21,560 144,900 11,005
Reconciliation of Calculated Income Tax Expense Based on the Statutory Rate to Actual Amount of Taxes Recorded	(c) The following table reconciles the calculated income tax expense based on POSCO’s statutory rate (27.5%) to the actual amount of taxes recorded by the Company for the years ended December 31, 2017, 2018 and 2019. (in millions of Won) 2017 2018 2019 Profit before income tax expense ￦ 4,095,051 3,616,016 3,126,534 Income tax expense computed at statutory rate 990,540 982,287 847,017 Adjustments: Tax credits (40,757 ) (32,103 ) (39,709 ) Additional income tax expense for prior years (over provisions from prior years) (20,912 ) 44,336 (35,389 ) Tax effect from tax audit — 130,196 14,775 Investment in subsidiaries, associates and joint ventures (12,510 ) 114,856 317,977 Tax effects due to permanent differences 72,421 64,708 (5,588 ) Effect of tax rate change(1) 175,647 — — Others(2) 21,311 379,350 (10,714 ) 195,200 701,343 241,352 Income tax expense ￦ 1,185,740 1,683,630 1,088,369 Effective tax rate (%) 28.96 % 46.56 % 34.81 % (1) During the year ended 31, 2017, the statutory rate changed from 24.2% to 27.5% for taxable income in excess of ￦ (2) Includes the effect of undeductible impairment loss related to Synthetic Natural Gas (SNG) facility for the year ended December 31, 2018.
Movements in Deferred Tax Assets (Liabilities)	(d) The movements in deferred tax assets (liabilities) for the years ended December 31, 2018 and 2019 were as follows: (in millions of Won) 2018 2019 Beginning Inc. Ending Beginning Inc. Ending Deferred income tax due to temporary differences Allowance for doubtful accounts ￦ 273,994 (92,851 ) 181,143 181,143 (28,007 ) 153,136 Reserve for technology developments (37,987 ) 37,987 — — — — PP&E - Depreciation 14,641 (4,804 ) 9,837 9,837 12,374 22,211 Share of profit or loss of equity-accounted investees 196,042 31,552 227,594 227,594 (108,480 ) 119,114 Allowance for inventories valuation 10,780 (104 ) 10,676 10,676 (1,231 ) 9,445 PP&E - Revaluation (1,828,164 ) (33,548 ) (1,861,712 ) (1,861,712 ) 43,251 (1,818,461 ) Prepaid expenses 20,000 (2,741 ) 17,259 17,259 (2,047 ) 15,212 PP&E - Impairment loss 5,540 (927 ) 4,613 4,613 (208 ) 4,405 Gain or loss on foreign currency translation (48,472 ) 10,462 (38,010 ) (38,010 ) 45,046 7,036 Defined benefit liabilities (36,754 ) (36,835 ) (73,589 ) (73,589 ) (22,094 ) (95,683 ) Provision for construction losses 441 6,964 7,405 7,405 (102 ) 7,303 Provision for construction warranty 28,717 41,601 70,318 70,318 (8,517 ) 61,801 Accrued income (12,915 ) (179 ) (13,094 ) (13,094 ) (17,722 ) (30,816 ) Impairment loss on AFS 202,795 (126,876 ) 75,919 75,919 36,636 112,555 Difference in acquisition costs of treasury shares 70,547 (15 ) 70,532 70,532 (1,124 ) 69,408 Others 490,225 (65,906 ) 424,319 424,319 (30,535 ) 393,784 (650,570 ) (236,220 ) (886,790 ) (886,790 ) (82,760 ) (969,550 ) Deferred income taxes recognized directly to equity Net changes in fair value of equity investments at fair value through other comprehensive income(1) (49,236 ) 206,121 156,885 156,885 (26,744 ) 130,141 Others 72,161 58,111 130,272 130,272 37,749 168,021 22,925 264,232 287,157 287,157 11,005 298,162 Deferred tax from tax credit Tax credit carry-forward and others 118,032 (2,443 ) 115,589 115,589 (23,750 ) 91,839 Investments in subsidiaries, associates and joint ventures Investments in subsidiaries, associates and joint ventures 68,426 135,512 203,938 203,938 (68,574 ) 135,364 ￦ (441,187 ) 161,081 (280,106 ) (280,106 ) (164,079 ) (444,185 ) (1) These changes include the cumulative impact of initial application of IFRS No. 15 and IFRS No. 9 from the year ended December 31, 2018.
Summary of Deferred Tax Assets And Liabilities	(e) Deferred tax assets and liabilities for the years ended December 31, 2018 and 2019 are as follows: (in millions of Won) 2018 2019 Assets Liabilities Net Assets Liabilities Net Deferred income tax due to temporary differences Allowance for doubtful accounts ￦ 181,143 — 181,143 153,136 — 153,136 Reserve for technology developments — — — — — — PP&E - Depreciation 55,354 (45,517 ) 9,837 68,649 (46,438 ) 22,211 Share of profit or loss of equity-accounted investees 278,466 (50,872 ) 227,594 177,467 (58,353 ) 119,114 Allowance for inventories valuation 10,676 — 10,676 9,445 — 9,445 PP&E - Revaluation — (1,861,712 ) (1,861,712 ) — (1,818,461 ) (1,818,461 ) Prepaid expenses 17,259 — 17,259 15,212 — 15,212 PP&E - Impairment loss 5,240 (627 ) 4,613 4,405 — 4,405 Gain or loss on foreign currency translation 121,797 (159,807 ) (38,010 ) 136,360 (129,324 ) 7,036 Defined benefit liabilities 390,972 (464,561 ) (73,589 ) 426,930 (522,613 ) (95,683 ) Provision for construction losses 7,405 — 7,405 7,303 — 7,303 Provision for construction warranty 70,318 — 70,318 61,801 — 61,801 Accrued income — (13,094 ) (13,094 ) — (30,816 ) (30,816 ) Impairment loss on AFS 75,919 — 75,919 112,555 — 112,555 Difference in acquisition costs of treasury shares 70,532 — 70,532 69,408 — 69,408 Others 820,611 (396,292 ) 424,319 471,621 (77,836 ) 393,784 2,105,692 (2,992,482 ) (886,790 ) 1,714,292 (2,683,841 ) (969,550 ) Deferred income taxes recognized directly to equity Net changes in fair value of equity investments at fair value through other comprehensive income 247,921 (91,036 ) 156,885 220,276 (90,135 ) 130,141 Others 153,609 (23,337 ) 130,272 193,384 (25,363 ) 168,021 401,530 (114,373 ) 287,157 413,660 (115,498 ) 298,162 Deferred tax from tax credit Tax credit carry-forward and others 115,589 — 115,589 91,839 — 91,839 Investments in subsidiaries, associates and joint ventures Investments in subsidiaries, associates and joint ventures 547,662 (343,724 ) 203,938 441,172 (305,808 ) 135,364 ￦ 3,170,473 (3,450,579 ) (280,106 ) 2,660,963 (3,105,147 ) (444,185 )

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
Earnings per Share (Tables)	Dec. 31, 2019
Text block [abstract]
Basic And Diluted Earnings Per Share	Basic and diluted earnings per share for the years ended December 31, 2017, 2018 and 2019 were as follows: (in Won, except per share 2017 2018 2019 Profit attribute to controlling interest ￦ 2,756,230,487,872 1,711,901,875,666 1,864,405,092,477 Interests of hybrid bonds (33,048,799,997 ) (17,720,986,299 ) (6,669,999,999 ) Weighted-average number of common shares outstanding(1) 79,998,600 80,000,606 80,113,759 Basic and diluted earnings per share ￦ 34,040 21,177 23,189 (1) The weighted-average number of common shares used to calculate basic and diluted earnings per share are as follows: (shares) 2017 2018 2019 Total number of common shares issued 87,186,835 87,186,835 87,186,835 Weighted-average number of treasury shares (7,188,235 ) (7,186,229 ) (7,073,076 ) Weighted-average number of common shares outstanding 79,998,600 80,000,606 80,113,759

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
Related Party Transactions (Tables)	Dec. 31, 2019
Statement [LineItems]
Significant Financial Transactions Between the Company, Excluding the Controlling Company, and Related Parties	(e) Significant financial transactions between the Company, excluding the controlling company, and related companies for the years ended December 31, 2018 and 2019 were as follows: 1) December 31, 2018 (in millions of Won) Beginning Lend Collect Others(2) Ending Associates and joint ventures New Songdo International City Development, LLC ￦ 282,775 150 (252,759 ) (30,166 ) — GALE International Korea, LLC 2,000 8,500 (10,500 ) — — UITrans LRT Co., Ltd. — 5,695 — — 5,695 DMSA/AMSA(1) 69,713 9,965 (342 ) (15,039 ) 64,297 South-East Asia Gas Pipeline Company Ltd. 229,880 — (47,569 ) 8,796 191,107 PT. Batutua Tembaga Raya 29,048 4,678 — 1,374 35,100 PT. Tanggamus Electric Power 3,197 — — 1,226 4,423 PT. Wampu Electric Power 5,107 — — 223 5,330 PT. POSMI Steel Indonesia 4,286 — (2,200 ) 150 2,236 Nickel Mining Company SAS 59,668 — — (4 ) 59,664 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 5,357 — (5,357 ) — — KRAKATAU POS-CHEM DONG-SUH 6,428 — — 281 6,709 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 5,357 4,451 (6,454 ) — 3,354 POS-SeAH 6,428 — — 281 6,709 AMCI (WA) PTY LTD 92,061 3,795 — (5,376 ) 90,480 POS-AUSTEM 5,357 5,564 (5,357 ) 26 5,590 POS-AUSTEM 8,571 8,902 (8,571 ) 43 8,945 SAMHWAN VINA CO., LTD 1,071 — (1,071 ) — — ￦ 816,304 51,700 (340,180 ) (38,185 ) 489,639 (1) During the year ended December 31, 2018, loans amounting to ￦ (2) Includes adjustments of foreign currency translation differences and others. 2) December 31, 2019 (in millions of Won) Beginning Lend Collect Others(2) Ending Associates and joint ventures UITrans LRT Co., Ltd. ￦ 5,695 4,884 — — 10,579 DMSA/AMSA(1) 64,297 15,451 — (21,749 ) 57,999 South-East Asia Gas Pipeline Company Ltd. 191,107 — (48,027 ) 4,287 147,367 PT. Batutua Tembaga Raya 35,100 — — 1,191 36,291 PT. Tanggamus Electric Power 4,423 — — 157 4,580 PT. Wampu Electric Power 5,330 — — 189 5,519 PT. POSMI Steel Indonesia 2,236 — — 80 2,316 Nickel Mining Company SAS 59,664 — — 852 60,516 KRAKATAU POS-CHEM DONG-SUH 6,709 — — 238 6,947 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 3,354 — (3,354 ) — — POS-SeAH 6,709 — — 238 6,947 AMCI (WA) PTY LTD 90,480 4,669 — (16,596 ) 78,553 POS-AUSTEM 5,590 — — 199 5,789 POS-AUSTEM 8,945 — — 317 9,262 Hyo-chun — — — 2,382 2,382 Chuncheon Energy Co., Ltd. — 8,234 — — 8,234 POS-AUSTEM — 5,827 — (38 ) 5,789 ￦ 489,639 39,065 (51,381 ) (28,253 ) 449,070 (1) During the year ended December 31, 2019, loans amounting to ￦ (2) Includes adjustments of foreign currency translation differences and others. (*3) During the year ended December 31, 2019, it was newly classified to associates.
Details of Compensation to Key Management Officers	(f) For the years ended December 31, 2017, 2018 and 2019, details of compensation to key management officers were as follows: (in millions of Won) 2017 2018 2019 Short-term benefits ￦ 112,688 115,618 119,658 Long-term benefits 8,632 13,400 13,562 Retirement benefits 20,422 21,658 21,231 ￦ 141,742 150,676 154,451
Posco [member]
Statement [LineItems]
Significant Transactions With Related Parties	(a) Significant transactions between the controlling company and related companies for the years ended December 31, 2017, 2018 and 2019 were as follows: 1) For the year ended December 31, 2017 (in millions of Won) Sales and others(1) Purchase and others (2) Sales Others Purchase of Purchase of Outsourced Others Subsidiaries(3) POSCO ENGINEERING & CONSTRUCTION CO.,LTD. ￦ 3,328 71 — 151,639 32 18,352 POSCO Processing&Service 298,781 1 113,628 4,595 8,309 404 POSCO COATED & COLOR STEEL Co., Ltd. 417,369 3,533 — — 8,483 106 POSCO ICT(4) 1,697 5,097 — 315,748 29,773 183,226 eNtoB Corporation 1 30 330,921 8,215 139 26,023 POSCO CHEMICAL CO., LTD 359,862 33,076 479,896 23,043 296,296 6,860 POSCO ENERGY CO., LTD. 179,966 1,456 — — — 2 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 5,214,127 35,182 550,258 221 44,108 1,948 POSCO Thainox Public Company Limited 218,005 9,780 10,168 — — — POSCO America Corporation 345,225 — 90 — — 1,776 POSCO Canada Ltd. 439 690 278,915 — — — POSCO Asia Co., Ltd. 1,949,354 1,454 365,025 337 1,625 4,982 Qingdao Pohang Stainless Steel Co., Ltd. 161,803 — — — — 176 POSCO JAPAN Co., Ltd. 1,436,159 20 26,256 621 — 44,829 POSCO-VIETNAM Co., Ltd. 212,883 — — — — 7 POSCO MEXICO S.A. DE C.V. 276,387 — — — — 1,749 POSCO Maharashtra Steel Private Limited 467,206 — — — — 65 POSCO(Suzhou) Automotive Processing Center Co., Ltd. 192,467 — — — — — Others 932,048 10,073 262,828 25,270 240,687 118,665 12,667,107 100,463 2,417,985 529,689 629,452 409,170 Associates and joint ventures(3) POSCO PLANTEC Co., Ltd. 2,947 112 5,487 300,041 20,718 19,763 SNNC 6,734 712 554,151 — — 4 POSCO-SAMSUNG-Slovakia Processing Center 52,779 — — — — — Roy Hill Holdings Pty Ltd — — 697,096 — — — CSP - Compania Siderurgica do Pecem 7,384 — 159,501 — — — Others 14,943 52,583 79,103 — — 3 84,787 53,407 1,495,338 300,041 20,718 19,770 ￦ 12,751,894 153,870 3,913,323 829,730 650,170 428,940 (1) Sales and others mainly consist of sales of steel products to subsidiaries, associates and joint ventures. These are priced on an arm’s length basis. (2) Purchases and others mainly consist of subsidiaries’ purchases of construction services and purchases of raw materials to manufacture steel products. These are priced on an arm`s length basis. (3) As of December 31, 2017, the Company provided guarantees to related parties (Note 38). (4) Others (purchase) mainly consist of service fees related to maintenance and repair of ERP System. 2) For the year ended December 31, 2018 (in millions of Won) Sales and others(1) Purchase and others(2) Sales Others Purchase of Purchase of fixed assets Outsourced Others Subsidiaries(3) POSCO ENGINEERING & CONSTRUCTION CO., LTD. ￦ 7,827 97 — 322,924 47 36,428 POSCO COATED & COLOR STEEL Co., Ltd. 476,105 2,725 — — 9,211 1,434 POSCO ICT(4) 2,624 7,479 — 341,472 34,376 196,252 eNtoB Corporation 12 60 377,198 27,508 390 31,455 POSCO CHEMICAL CO., LTD 417,957 35,762 531,452 21,730 319,868 2,802 POSCO ENERGY CO., LTD. 206,638 1,445 — — — — POSCO INTERNATIONAL Corporation 5,835,226 42,888 690,345 — 57,624 4,318 POSCO Thainox Public Company Limited 299,450 5,335 10,115 — — 71 POSCO America Corporation 336,366 — — — — 2,486 POSCO Canada Ltd. — 2,155 300,982 — — — POSCO Asia Co., Ltd. 1,857,665 253 536,280 650 2,449 6,524 Qingdao Pohang Stainless Steel Co., Ltd. 188,252 7 — — — 34 POSCO JAPAN Co., Ltd. 1,353,313 6 25,773 4,204 — 5,411 POSCO-VIETNAM Co., Ltd. 273,573 156 — — — 8 POSCO MEXICO S.A. DE C.V. 299,276 17 — — — 35 POSCO Maharashtra Steel Private Limited 563,618 584 — — — 156 POSCO(Suzhou) Automotive Processing Center Co., Ltd. 196,095 — 2,616 — — 5 Others(5) 1,158,122 44,098 456,804 31,787 264,060 140,869 13,472,119 143,067 2,931,565 750,275 688,025 428,288 Associates and joint ventures(3) POSCO PLANTEC Co., Ltd. 10,904 240 3,166 215,023 24,192 10,257 SNNC 5,105 4,108 558,425 — — 80 POSCO-SAMSUNG-Slovakia Processing Center 61,981 — — — — — Roy Hill Holdings Pty Ltd — — 810,196 — — — Others 14,199 54,747 64,335 — — 6 92,189 59,095 1,436,122 215,023 24,192 10,343 ￦ 13,564,308 202,162 4,367,687 965,298 712,217 438,631 (1) Sales and others mainly consist of sales of steel products to subsidiaries, associates and joint ventures. (2) Purchases and others mainly consist of subsidiaries’ purchases of construction services and purchases of raw materials to manufacture steel products. (3) As of December 31, 2018, the Company provided guarantees to related parties (Note 38). (4) Others (purchase) mainly consist of service fees related to maintenance and repair of ERP System. (5) During the year ended December 31, 2018, the Company made loans of ￦ 3) For the year ended December 31, 2019 (in millions of Won) Sales and others(1) Purchase and others(2) Sales Others Purchase of Purchase of Outsourced Others Subsidiaries(3) POSCO ENGINEERING & CONSTRUCTION CO., LTD. ￦ 6,688 11,137 4,725 416,734 57 24,174 POSCO COATED & COLOR STEEL Co., Ltd. 468,070 2,014 95 — 20,298 724 POSCO ICT(4) 2,924 4,994 — 344,977 34,638 181,128 eNtoB Corporation 15 60 304,846 64,845 126 25,754 POSCO CHEMICAL CO., LTD (Formerly, POSCO CHEMTECH) 389,731 35,592 522,493 17,549 315,530 4,561 POSCO ENERGY CO., LTD. 148,205 2,211 5,123 94 — 7,561 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 6,025,938 46,661 541,002 — 49,506 7,149 POSCO Thainox Public Company Limited 265,374 13,795 10,037 — — 3 POSCO America Corporation 300,598 — — — — 2,994 POSCO Canada Ltd. 1,067 1,833 306,552 — — — POSCO Asia Co., Ltd. 1,781,841 1,352 390,056 1,338 1,574 7,561 Qingdao Pohang Stainless Steel Co., Ltd. 146,468 — — — — 110 POSCO JAPAN Co., Ltd. 1,509,631 36 38,631 6,269 — 5,835 POSCO-VIETNAM Co., Ltd. 265,849 368 — — — 66 POSCO MEXICO S.A. DE C.V. 303,924 159 — — — 809 POSCO Maharashtra Steel Private Limited 644,652 311 — — — 800 POSCO(Suzhou) Automotive Processing Center Co., Ltd. 121,633 27 2,189 — — — POSCO VST CO., LTD. 299,307 — — — — 114 POSCO INTERNATIONAL SINGAPORE PTE LTD. — 154 694,600 — — — Others 964,532 20,679 134,296 34,444 246,184 169,849 13,646,447 141,383 2,954,645 886,250 667,913 439,192 Associates and joint ventures(3) POSCO PLANTEC Co., Ltd. 1,364 86 2,882 306,927 15,089 30,317 SNNC 5,527 4,100 588,276 — — 9 POSCO-SAMSUNG-Slovakia Processing Center 65,688 — — — — — Roy Hill Holdings Pty Ltd — — 1,272,878 — — — Others 16,084 112,390 76,427 — — 85,167 88,663 116,576 1,940,463 306,927 15,089 115,493 ￦ 13,735,110 257,959 4,895,108 1,193,177 683,002 554,685 (1) Sales and others mainly consist of sales of steel products to subsidiaries, associates and joint ventures. (2) Purchases and others mainly consist of subsidiaries’ purchases of construction services and purchases of raw materials to manufacture steel products. (3) As of December 31, 2019, the company provided guarantees to related parties (Note 38) (*4) Others (purchase) mainly consist of service fees related to maintenance and repair of ERP System.
Related Account Balances With Related Parties	(b) The related account balances of receivables and payables resulting from significant transactions between the controlling company and related companies as of December 31, 2018 and 2019 are as follows: 1) December 31, 2018 (in millions of Won) Receivables Payables Trade accounts receivable Others Total Trade accounts Accounts Others Total Subsidiaries POSCO ENGINEERING & CONSTRUCTION CO., LTD. ￦ 57 5,181 5,238 — 52,775 438 53,213 POSCO COATED & COLOR STEEL Co., Ltd. 55,598 317 55,915 — 25 1,194 1,219 POSCO ICT — 229 229 1,572 112,960 8,717 123,249 eNtoB Corporation — — — 10,860 22,072 11 32,943 POSCO CHEMICAL CO., LTD (Formerly, POSCO CHEMTECH) 40,258 3,883 44,141 19,911 58,725 19,012 97,648 POSCO ENERGY CO., LTD. 22,163 1,700 23,863 — — 1,425 1,425 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 437,554 1,056 438,610 161 1,881 5,304 7,346 POSCO Thainox Public Company Limited 71,189 — 71,189 467 71 — 538 POSCO America Corporation 14,338 — 14,338 — 221 — 221 POSCO Asia Co., Ltd. 480,205 1,047 481,252 7,839 — — 7,839 Qingdao Pohang Stainless Steel Co., Ltd. 52,037 — 52,037 — — — — POSCO MEXICO S.A. DE C.V. 101,179 218 101,397 — — — — POSCO Maharashtra Steel Private Limited 390,413 1,428 391,841 — — — — Others 379,950 54,407 434,357 33,183 36,591 85,745 155,519 2,044,941 69,466 2,114,407 73,993 285,321 121,846 481,160 Associates and joint ventures POSCO PLANTEC Co., Ltd. 249 10 259 3,275 34,803 — 38,078 SNNC 541 61 602 22,188 — — 22,188 Roy Hill Holdings Pty Ltd — — — 22,997 — — 22,997 Others 918 910 1,828 217 76 — 293 1,708 981 2,689 48,677 34,879 — 83,556 ￦ 2,046,649 70,447 2,117,096 122,670 320,200 121,846 564,716 2) December 31, 2019 (in millions of Won) Receivables Payables Trade accounts Others Total Trade accounts Accounts Others Total Subsidiaries POSCO ENGINEERING & CONSTRUCTION CO.,LTD. ￦ 5,702 65 5,767 — 78,512 385 78,897 POSCO COATED & COLOR STEEL Co., Ltd. 57,792 — 57,792 — 11 3,828 3,839 POSCO ICT 225 1 226 1,147 129,424 42,844 173,415 eNtoB Corporation — — — 3,459 27,431 — 30,890 POSCO CHEMICAL CO., LTD (Formerly, POSCO CHEMTECH) 35,102 3,578 38,680 17,839 52,710 19,369 89,918 POSCO ENERGY CO., LTD. 1,876 4 1,880 — 3,229 14,912 18,141 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 633,073 — 633,073 345 2,218 3,839 6,402 POSCO Thainox Public Company Limited 52,826 2 52,828 916 — — 916 POSCO America Corporation 8,448 — 8,448 — — — — POSCO Asia Co., Ltd. 508,962 748 509,710 12,784 171 — 12,955 Qingdao Pohang Stainless Steel Co., Ltd. 29,842 — 29,842 — — — — POSCO MEXICO S.A. DE C.V. 90,351 702 91,053 — — — — POSCO Maharashtra Steel Private Limited 235,917 444 236,361 — — — — Others(1) 470,734 33,851 504,585 14,397 40,233 87,652 142,282 2,130,850 39,395 2,170,245 50,887 333,939 172,829 557,655 Associates and joint ventures POSCO PLANTEC Co., Ltd. 84 10 94 471 49,511 — 49,982 SNNC 297 65 362 19,769 — — 19,769 Roy Hill Holdings Pty Ltd — — — 93,383 — — 93,383 Others 942 706 1,648 3,447 586 — 4,033 1,323 781 2,104 117,070 50,097 — 167,167 ￦ 2,132,173 40,176 2,172,349 167,957 384,036 172,829 724,822 (1) During the year ended December 31, 2018, the Company made loans of ￦
Company, excluding the controlling company [member]
Statement [LineItems]
Significant Transactions With Related Parties	(c) Significant transactions between the Company, excluding the controlling company, and related companies for the years ended December 31, 2017, 2018 and 2019 were as follows: 1) For the year ended December 31, 2017 (in millions of Won) Sales and others Purchase and others Sales Others Purchase of Others Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 19,513 — 98 8,113 New Songdo International City Development, LLC 223,567 13,207 — 49 SNNC 26,288 — 3,578 17,985 Chuncheon Energy Co., Ltd. 42,147 — — — Noeul Green Energy Co., Ltd. 11,863 — — 2,178 VSC POSCO Steel Corporation 19,404 — 188 — USS-POSCO 26,899 107 2,222 — CSP - Compania Siderurgica do Pecem 241,299 — 101,018 21,154 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 38,484 — 47,241 — LLP POSUK Titanium — — 3,972 — BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 4 — 20,145 — POS-SEAHSTEELWIRE(TIANJIN)CO., 20,004 — — — PT. Batutua Tembaga Raya — — 21,024 — POSCO SeAH Steel Wire (Nantong) Co., Ltd. 34,088 — 192 — Zhangjiagang Pohang Refractories Co., Ltd. — — 87 1,632 Sebang Steel 441 — 23,778 — SHANGHAI WAIGAOQIAO FREE TRADE ZONE LANSHENG DAEWOO IN’L TRADING CO., LTD. 43,764 — — — DMSA/AMSA — 99 47,092 — South-East Asia Gas Pipeline Company Ltd. — 62,423 — — Others 272,107 43,126 19,520 19,483 ￦ 1,019,872 118,962 290,155 70,594 2) For the year ended December 31, 2018 (in millions of Won) Sales and others Purchase and others Sales Others Purchase of Others Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 19,394 — 83 24,103 New Songdo International City Development, LLC 30,997 53,316 — 97 SNNC 66,075 128 2,395 71,421 Chuncheon Energy Co., Ltd. 25,693 — — — Noeul Green Energy Co., Ltd. 6,444 — — 587 VSC POSCO Steel Corporation 12,504 — 2,314 — USS-POSCO — — 2,595 — CSP - Compania Siderurgica do Pecem 239,922 9,678 346,602 26,324 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 46,538 — 62,851 — BX STEEL POSCO Cold Rolled Sheet Co., Ltd. — — 10,572 — POS-SEAHSTEELWIRE(TIANJIN)CO., 12,244 — — — PT. Batutua Tembaga Raya — 168 15,663 — POSCO SeAH Steel Wire(Nantong) Co., Ltd. 30,417 — 249 — Sebang Steel — — 13,571 — DMSA/AMSA — — 46,293 — South-East Asia Gas Pipeline Company Ltd. — 50,789 — — Others 359,124 62,375 20,136 50,918 ￦ 849,352 176,454 523,324 173,450 3) For the year ended December 31, 2019 (in millions of Won) Sales and others Purchase and others Sales Others Purchase of Others Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 15,637 — 39 14,778 New Songdo International City Development, LLC 33,885 44,131 — 36 SNNC 74,034 — 35,910 65,503 Chuncheon Energy Co., Ltd. 1,156 — — — Noeul Green Energy Co., Ltd. 6,579 — — 1,217 USS-POSCO 4 — 1,835 — CSP - Compania Siderurgica do Pecem 98,330 12,718 416,541 23,398 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 34,895 — 39,733 — BX STEEL POSCO Cold Rolled Sheet Co., Ltd. 10 — 4,222 — POS-SEAHSTEELWIRE(TIANJIN)CO., 11,500 — — — PT. Batutua Tembaga Raya — 772 45,841 — POSCO SeAH Steel Wire(Nantong) Co., Ltd. 30,083 — 353 — Sebang Steel — — 4,862 — DMSA/AMSA — — 71,275 — South-East Asia Gas Pipeline Company Ltd. 64 42,010 — — POSCO MITSUBISHI CARBON TECHNOLOGY 88,506 16,424 4,769 2,144 POSPower Co., Ltd. 163,167 — — — TK CHEMICAL CORPORATION 172,133 — 63,836 — Others 252,125 53,596 31,460 28,039 ￦ 982,108 169,651 720,676 135,115
Related Account Balances With Related Parties	(d) The related account balances of receivables and payables resulting from significant transactions between the Company, excluding the controlling company, and related companies as of December 31, 2018 and December 31, 2019 are as follows: 1) December 31, 2018 (in millions of Won) Receivables(1) Payables Trade accounts Loan Others Total Trade accounts Others Total Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 3,593 — 6 3,599 6,160 217 6,377 New Songdo International City Development, LLC 233,157 — — 233,157 — — — Chuncheon Energy Co., Ltd — — — — — 1,758 1,758 POSPower Co.,Ltd 13,703 — — 13,703 — 66,856 66,856 Nickel Mining Company SAS — 59,664 118 59,782 — — — CSP - Compania Siderurgica do Pecem 364,190 — 9,669 373,859 62,578 — 62,578 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 10,836 — — 10,836 2,101 — 2,101 PT. Batutua Tembaga Raya — 35,100 171 35,271 — — — POSCO SeAH Steel Wire(Nantong) Co., Ltd. 6,274 3,354 27 9,655 66 — 66 DMSA/AMSA — 64,297 — 64,297 — — — South-East Asia Gas Pipeline Company Ltd. — 191,107 — 191,107 — — — Others 75,382 136,117 83,786 295,285 7,768 5,363 13,131 ￦ 707,135 489,639 93,777 1,290,551 78,673 74,194 152,867 (1) As of December 31, 2018, the Company recognizes bad debt allowance for receivables amounting to ￦ 2) December 31, 2019 (in millions of Won) Receivables(1) Payables Trade accounts Loan Others Total Trade accounts Others Total Associates and joint ventures POSCO PLANTEC Co., Ltd. ￦ 4,121 — 205 4,326 791 8 799 New Songdo International City Development, LLC 23,626 — 20,592 44,218 — 10 10 Chuncheon Energy Co., Ltd. — 8,234 — 8,234 657 — 657 POSPower Co., Ltd. 34,945 — — 34,945 — 67,543 67,543 Nickel Mining Company SAS — 60,516 120 60,636 — — — CSP - Compania Siderurgica do Pecem 244,700 — 14,264 258,964 — 33 33 Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd 10,273 — — 10,273 633 — 633 PT. Batutua Tembaga Raya — 36,291 19,993 56,284 56 — 56 POSCO SeAH Steel Wire(Nantong) Co., Ltd. 7,035 — — 7,035 101 — 101 DMSA/AMSA — 57,999 1,672 59,671 — — — South-East Asia Gas Pipeline Company Ltd. 14 147,367 — 147,381 — — — POSCO MITSUBISHI CARBON TECHNOLOGY 8,078 — — 8,078 916 — 916 TK CHEMICAL CORPORATION 37,373 — — 37,373 110 — 110 Others 94,914 138,663 97,804 331,381 7,128 13,379 20,507 ￦ 465,079 449,070 154,650 1,068,799 10,392 80,973 91,365 (1) As of December 31, 2019, the Company recognizes bad debt allowance for receivables amounting to ￦

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2019
Statement [LineItems]
Disclosure of major contingencies	Other major contingencies for the Company for the years ended December 31, 2019 are as follows: Company Description POSCO POSCO has provided 3 blank checks to Korea Energy Agency as collateral for long-term foreign currency borrowings. POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) As of December 31, 2019, POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) has provided 33 blank promissory notes and 20 blank checks to Korea Energy Agency and others as collateral for the guarantee on performance for contracts and others. POSCO ENGINEERING & CONSTRUCTION Co., LTD. As of December 31, 2019, POSCO ENGINEERING & CONSTRUCTION CO., LTD. has provided 26 blank checks and 4 blank promissory notes as collateral for agreements and outstanding loans, and has provided joint guarantee of ￦ POSCO ICT As of December 31, 2019, POSCO ICT has provided 2 blank promissory notes and 6 blank checks to financial institutions as collateral for the guarantee on performance for contracts and others.
Contingent liabilities on outstanding guarantees [member]
Statement [LineItems]
Summary of Contingent Liabilities	Contingent liabilities on outstanding guarantees and others provided by the Company as of December 31, 2019 are as follows. (in millions of Won) Guarantee limit Guarantee amount Guarantor Guarantee Financial Foreign currency Won Foreign Won [The Company] POSCO POSCO Asia Co., Ltd. BOC and others USD 100,000,000 115,780 100,000,000 115,780 POSCO ASSAN TST STEEL INDUSTRY SMBC and others USD 146,527,500 169,650 131,874,750 152,685 POSCO COATED STEEL (THAILAND) CO., LTD. The Great & CO Co., Ltd.(SPC) THB 5,501,000,000 212,669 5,501,000,000 212,669 POSCO Maharashtra Steel Private Limited Export-Import Bank of Korea and others USD 83,784,000 97,005 83,784,000 97,005 POSCO MEXICO S.A. DE C.V. BOA and others USD 120,000,000 138,936 120,000,000 138,936 POSCO SS VINA Co., Ltd. Export-Import Bank of Korea and others USD 298,000,000 345,024 298,000,000 345,024 POSCO-VIETNAM Co., Ltd. SMBC and others USD 156,000,000 180,617 156,000,000 180,617 PT. KRAKATAU POSCO Export-Import Bank of Korea and others USD 1,350,300,000 1,563,377 940,488,348 1,088,897 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) Daewoo Global Development. Pte., Ltd Export-Import Bank of Korea and others USD 199,884,500 231,426 183,992,000 213,026 Daewoo Power PNG Ltd. Export-Import Bank of Korea USD 53,517,404 61,962 41,167,234 47,663 POSCO ASSAN TST STEEL INDUSTRY ING and others USD 14,652,750 16,965 14,652,750 16,965 Songdo Posco family Housing SHINYOUNG SECURITIES CO., LTD. KRW 10,000 10,000 — — PT. Bio Inti Agrindo Export-Import Bank of Korea and others IDR 150,000,000,000 12,465 150,000,000,000 12,465 KEB Hana Bank USD 135,000,000 156,303 134,224,401 155,405 Golden Lace DAEWOO Company Limited Shinhan Bank USD 11,000,000 12,736 11,000,000 12,736 POSCO INTERNATIONAL AMERICA Corp. POSCO INTERNATIONAL SINGAPORE Pte. Ltd. POSCO INTERNATIONAL MEXICO S.A. de C.V. POSCO INTERNATIONAL Japan Corp. Bank Mendes Gans USD 50,000,000 57,890 5,602,997 6,487 POSCO INTERNATIONAL Malaysia SDN BHD POSCO INTERNATIONAL Deutschland GmbH POSCO INTERNATIONAL Italia S.R.L. Mykolaiv Milling Works PJSC. Black Sea Trade and Development Bank EUR 23,250,000 30,165 23,250,000 30,165 POSCO ENGINEERING & CONSTRUCTION CO., LTD. POSCO E&C Vietnam Co., Ltd. Export-Import Bank of Korea and others USD 47,000,000 54,417 47,000,000 54,417 HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd. Woori bank and others USD 160,000,000 185,248 149,740,000 173,369 POSCO Engineering and Construction India Private Limited KEB Hana Bank INR 221,000,000 3,587 171,200,000 2,779 PT. POSCO E&C INDONESIA POSCO Asia Co., Ltd. and others USD 10,900,000 12,620 10,900,000 12,620 JB CLARK HILLS Korea Investment & Securities Co., Ltd. KRW 60,000 60,000 55,000 55,000 Daewoo Global Development. Pte., Ltd SMBC and others USD 163,633,000 189,454 163,633,000 189,454 Songdo Posco family Housing SHINYOUNG SECURITIES CO., LTD. KRW 10,000 10,000 — — POSCO ICT PT.POSCO ICT INDONESIA POSCO Asia Co., Ltd. USD 1,500,000 1,737 1,500,000 1,737 POSCO CHEMCAL CO., LTD (Formerly, POSCO CHEMTECH) PT.Krakatau Posco Chemtech Calcination POSCO Asia Co., Ltd. USD 15,200,000 17,599 12,000,000 13,894 POSCO COATED & COLOR STEEL Co.,Ltd. Myanmar POSCO C&C Company, Limited. POSCO Asia Co., Ltd. USD 13,986,947 16,194 13,986,947 16,194 POSCO ENERGY CO., LTD. PT. KRAKATAU POSCO ENERGY Export-Import Bank of Korea and others USD 193,900,000 224,497 105,067,663 121,647 POSCO Asia Co., Ltd. POSCO America Corporation SMBC USD 70,000,000 81,046 70,000,000 81,046 [Associates and joint ventures] POSCO CSP - Compania Siderurgica do Pecem Export-Import Bank of Korea and others USD 420,000,000 486,276 373,565,631 432,514 BNDES BRL 464,060,000 133,672 464,060,000 133,672 LLP POSUK Titanium SMBC USD 15,000,000 17,367 15,000,000 17,367 Nickel Mining Company SAS SMBC EUR 46,000,000 59,682 46,000,000 59,682 POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) GLOBAL KOMSCO Daewoo LLC KEB Hana Bank USD 8,225,000 9,523 8,050,000 9,320 POSCO ENGINEERING & CONSTRUCTION CO., LTD. New Songdo International City Development, LLC Others KRW 386,000 386,000 386,000 386,000 RPSD Project Co., Ltd Others KRW 45,000 45,000 35,000 35,000 Chun-cheon Energy Co., Ltd Kookmin Bank and others KRW 12,430 12,430 8,234 8,234 Pohang E&E Co., Ltd Heungkuk Life Insurance Co., Ltd. KRW 71,930 71,930 64,592 64,592 Incheon-Gimpo Expressway Co, Ltd. Kookmin Bank and others KRW 28,940 28,940 — — PT. Wampu Electric Power KEB Hana Bank USD 2,365,099 2,738 2,365,099 2,738 PT.Tanggamus Electric Power KEB Hana Bank USD 1,936,699 2,242 1,936,699 2,242 Metropolitan Outer Ring Expressway co., ltd. Others KRW 276,521 276,521 14,486 14,486 UITrans LRT Co., Ltd. Kookmin Bank and others KRW 121,750 121,750 107,176 107,176 NEXTRAIN Co., Ltd Others KRW 634,752 634,752 — — Pureun Tongyeong Enviro Co., Ltd. KDB Bank and others KRW 22,714 22,714 16,017 16,017 Pure Gimpo Co., Ltd. KDB Bank and others KRW 44,740 44,740 32,847 32,847 Clean Iksan Co., Ltd. Samsung Fire & Marine Insurance Co., Ltd. KRW 44,054 44,054 31,062 31,062 POSCO ICT Incheon-Gimpo Expressway Co, Ltd. KDB Bank KRW 100,000 100,000 100,000 100,000 UITrans LRT Co., Ltd. Kookmin Bank KRW 76,000 76,000 76,000 76,000 Hyochun CO., LTD KYOBO SECURITIES CO., LTD. 39,575 39,575 39,575 39,575 Metropolitan Outer Ring Expressway co., ltd. Woori bank and others KRW 193,700 193,700 7,748 7,748 POSCO CHEMCAL CO., LTD (Formerly, POSCO CHEMTECH) KRAKATAU POS-CHEM DONG-SUH KEB Hana Bank USD 1,140,000 1,320 506,667 587 POSCO(Suzhou) Automotive Processing Center Co.,Ltd. POS-InfraAuto KDB Bank USD 769,500 891 769,500 891 [Others] POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) Ambatovy Project Investments Ltd. and others Export-Import Bank of Korea USD 21,818,182 25,261 3,451,287 3,996 POSCO ICT Soosungenc and others KEB Hana Bank KRW 1,198,724 1,198,724 1,198,724 1,198,724 POSCO ENGINEERING & CONSTRUCTION CO., LTD. Ecocity CO., LTD and others Others KRW 3,616,714 3,616,714 2,156,506 2,156,506 POSCO AUSTRALIA PTY LTD Department of Trade and Investment (NSW Government) and others Woori bank and others AUD 26,525,154 21,495 26,525,154 21,495 AUD 26,525,154 21,495 26,525,154 21,495 BRL 464,060,000 133,672 464,060,000 133,672 EUR 69,250,000 89,847 69,250,000 89,847 IDR 150,000,000,000 12,465 150,000,000,000 12,465 INR 221,000,000 3,587 171,200,000 2,779 KRW 6,993,544 6,993,544 4,329,507 4,329,507 THB 5,501,000,000 212,669 5,501,000,000 212,669 USD 3,866,040,581 4,476,101 3,200,258,973 3,705,259
Litigations in progress [member]
Statement [LineItems]
Summary of Contingent Liabilities	As of December 31, 2019, litigations in progress that POSCO and certain subsidiaries are defendants in legal actions arising from the normal course of business are as follows: (in millions of Won, in thousands of Company Legal Claim amount Won Descrioption POSCO 23 KRW 39,500 39,500 Lawsuit on claim for employee right and others(1) POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) 1 CAD 79,000 70,038 Lawsuit on claim for damages 5 INR 4,518,694 73,338 Lawsuit on claim for payment on guarantees and others(1) 8 KRW 18,786 18,786 Litigation for confirmation of deposit bond and others 4 USD 22,813 26,413 Lawsuit on claim for damages and others 1 PKR 124,775 931 Lawsuit on claim for damages POSCO ENGINEERING & CONSTRUCTION CO., LTD. 123 KRW 2,838,122 2,838,122 Lawsuit on claim for damages and others(1) POSCO ICT 1 BRL 10,244 2,951 Lawsuit on revocation of claim for damage(1) 11 KRW 8,500 8,500 Lawsuit on claim for damages and others(1) POSCO A&C 10 KRW 6,043 6,043 Lawsuit on claim for payment on construction and others POSCO ENERGY CO., LTD. 3 KRW 3,669 3,669 Lawsuit on claim for damages and others POSCO E&C CHINA CO., LTD. 5 CNY 66,655 11,047 Lawsuit over contract dispute and others POSCO COATED & COLOR STEEL Co., Ltd. 1 KRW 1,400 1,400 Lawsuit on claim for damages POSCO ENGINEERING (THAILAND) CO., LTD. 2 THB 160,929 6,222 Lawsuit on claim for payment on construction and others 1 USD 1,046 1,211 Lawsuit on claim for payment on construction PT. KRAKATAU POSCO 1 IDR 211,407,872 17,568 Lawsuit on claim for payment on construction POSCO E&C Vietnam Co., Ltd. 3 USD 5,131 5,941 Lawsuit on claim for payment on construction Pos-Sea 1 USD 12,700 14,704 Lawsuit over contract dispute POSCO TNPC Otomotiv Celik San. Ve Tic. A.S 7 TRY 102 20 Lawsuit over industrial accidents and others POSCO India Steel Distribution Center Private Ltd. 1 INR 223,795 3,632 Lawsuit on claim for tax restitution Brazil Sao Paulo Steel Processing Center 3 BRL 4,321 1,245 Lawsuit on claim for labor and others POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. 104 BRL 152,077 43,806 Lawsuit on claim for payment on construction and others(1) POSCO ASSAN TST STEEL INDUSTRY 1 TRY 1,965 383 Lawsuit on compensation POSCO Asia Co., Ltd. 1 USD 950 1,099 Lawsuit on claim for receivable ZHANGJIAGANG POHANG STAINLESS STEEL CO., LTD. 1 CNY 807 134 Lawsuit on claim for labor POSCO CHEMCAL CO., LTD (Formerly, POSCO CHEMTECH) 1 KRW 15,383 15,383 Calculation of stock purchase value POSCO M-TECH 2 KRW 425 425 Lawsuit on claim for damages POSCO Engineering and Construction India Private Limited 3 INR 27,995 454 Lawsuit on claim for payment POSCO INTERNATIONAL AMERICA Corp. 1 USD 150 174 Lawsuit over injury HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd. 1 KRW 3,305 3,305 Lawsuit on claim for payment (*1) The Company made a reliable estimate in 105 lawsuits by considering the possibility and estimated amount of outflow of resources and recognized ￦

Additional Information of Cas_2

Additional Information of Cash Flow Statements (Tables)	12 Months Ended
Additional Information of Cash Flow Statements (Tables)	Dec. 31, 2019
Text block [abstract]
Changes in Operating Assets and Liabilities	(a) Changes in operating assets and liabilities for the years ended December 31, 2017, 2018 and 2019 were as follows: (in millions of Won) 2017 2018 2019 Trade accounts and notes receivable ￦ 63,075 17,806 286,121 Other receivables 113,740 (20,786 ) (163,234 ) Inventories (1,435,170 ) (1,451,009 ) 1,136,819 Other current assets 110,688 1,118 42,337 Other non-current 12,455 5,974 (30,010 ) Trade accounts and notes payable (607,999 ) 379,742 (732,741 ) Other payables (26,922 ) (111,893 ) 2,762 Other current liabilities 338,273 (197,154 ) (173,762 ) Provisions (145,763 ) (119,617 ) (75,514 ) Payments of severance benefits (185,220 ) (189,165 ) (152,275 ) Plan assets 3,815 (245,214 ) (217,953 ) Other non-current (82,605 ) (175,528 ) (36,595 ) ￦ (1,841,633 ) (2,105,726 ) (114,045 )
Changes in Liabilities Arising from Financial Activities	(b) Changes in liabilities arising from financial activities for the years ended December 31, 2018 and 2019 were as follows: 1) December 31, 2018 (in millions of Won) Liabilities Derivatives that hedge Short-term borrowings long-term borrowings Dividend payable Finance lease liabilities Beginning ￦ 8,174,818 12,888,839 7,213 93,018 119,320 Changes from financing cash flows (854,554 ) (373,862 ) (770,099 ) (14,955 ) (17,237 ) Changes arising from obtaining or losing control of subsidiaries or other business (342 ) — — — — The effect of changes in foreign exchange rates 167,858 200,308 (5,573 ) (7,766 ) — Changes in fair values — — — — (58,666 ) Other changes: — Decrease in retained earnings — — 704,444 — — Decrease in non-controlling — — 72,688 — — Amortization of discount on debentures issued — 6,205 — — — Increase in finance lease assets — — — 24,457 — Ending ￦ 7,487,780 12,721,490 8,673 94,754 43,417 2) December 31, 2019 (in millions of Won) Liabilities Derivatives that hedge Short-term borrowings Long-term borrowings Dividend payable Lease liabilities Beginning ￦ 7,487,780 12,721,490 8,673 94,754 43,417 Changes from financing cash flows (2,194,727 ) 1,900,132 (962,712 ) (167,427 ) 7,657 Changes arising from obtaining or losing control of subsidiaries or other business (45,589 ) (88,966 ) 324 — — The effect of changes in foreign exchange rates 238,869 415,028 (649 ) (1,867 ) — Changes in fair values — — — — (117,023 ) Other changes: Decrease in retained earnings — — 889,900 — — Decrease in non-controlling — — 67,569 — — Amortization of discount on debentures issued — 7,596 — — — Initial application of IFRS No.16 — — — 677,370 — Increase in lease assets — — — 72,640 — Ending ￦ 5,486,333 14,955,280 3,105 675,470 (65,949 )

Operating Segments and Geogra_2

Operating Segments and Geographic Information (Tables)	12 Months Ended
Operating Segments and Geographic Information (Tables)	Dec. 31, 2019
Text block [abstract]
Information about Reportable Segments	(b) Information about reportable segments as of and for the years ended December 31, 2017, 2018 and 2019 were as follows: 1) As of and for the year ended December 31, 2017 (in millions of Won) Steel Trading Construction Others Total External revenues ￦ 30,230,368 20,802,207 6,886,606 2,735,919 60,655,100 Internal revenues 17,381,010 14,075,996 398,924 2,548,674 34,404,604 Including inter segment revenue 12,004,614 8,043,643 329,215 2,446,029 22,823,501 Total revenues 47,611,378 34,878,203 7,285,530 5,284,593 95,059,704 Interest income 128,827 32,799 100,922 17,940 280,488 Interest expenses (422,357 ) (121,967 ) (112,983 ) (100,656 ) (757,963 ) Depreciation and amortization (2,856,133 ) (206,490 ) (42,123 ) (255,620 ) (3,360,366 ) Impairment loss on property, plant and equipment and others (149,840 ) (140,839 ) (37,476 ) (8,564 ) (336,719 ) Impairment loss on available-for-sale (95,261 ) — (18,637 ) (13,421 ) (127,319 ) Share of profit or loss of investment in associates and JVs 8,352 — (8,555 ) (1,518 ) (1,721 ) Income tax expense (977,853 ) (109,710 ) (109,961 ) (77,172 ) (1,274,696 ) Segment profit (loss) 2,790,855 112,661 24,545 232,700 3,160,761 Segment assets 70,017,816 14,139,098 8,609,753 8,776,090 101,542,757 Investment in associates 16,116,654 1,134,798 668,392 1,193,895 19,113,739 Acquisition of non-current 2,033,184 286,185 99,190 251,665 2,670,224 Segment liabilities 19,057,249 10,386,294 5,744,693 4,620,902 39,809,138 2) As of and for the year ended December 31, 2018 (in millions of Won) Steel Trading Construction Others Total External revenues ￦ 32,358,009 22,407,717 6,769,410 3,442,641 64,977,777 Internal revenues 18,063,213 15,911,138 551,324 2,755,176 37,280,851 Including inter segment revenue 12,496,287 8,743,666 465,057 2,639,561 24,344,571 Total revenues 50,421,222 38,318,855 7,320,734 6,197,817 102,258,628 Interest income 199,016 36,437 115,019 23,454 373,926 Interest expenses (468,681 ) (189,165 ) (111,101 ) (94,613 ) (863,560 ) Depreciation and amortization (2,812,666 ) (210,493 ) (36,840 ) (265,416 ) (3,325,415 ) Impairment loss on property, plant and equipment and others (1,057,474 ) (86,085 ) (82,521 ) (117,280 ) (1,343,360 ) Impairment loss on investment in associates and JVs (733,879 ) (160,085 ) (155,371 ) — (1,049,335 ) Income tax expense (1,307,292 ) (52,914 ) (238,441 ) (65,611 ) (1,664,258 ) Segment profit (loss) 1,268,313 49,264 234 13,608 1,331,419 Segment assets 70,976,493 15,550,854 7,333,221 8,017,433 101,878,001 Investment in subsidiaries, associates and joint ventures 16,099,692 1,379,045 511,230 932,107 18,922,074 Acquisition of non-current 2,239,467 132,017 49,095 232,281 2,652,860 Segment liabilities 20,289,037 11,454,079 4,386,852 4,134,352 40,264,320 3) As of and for the year ended December 31, 2019 (in millions of Won) Steel Trading Construction Others Total External revenues ￦ 32,078,453 22,157,131 6,944,629 3,186,635 64,366,848 Internal revenues 17,729,990 15,467,687 743,376 2,796,306 36,737,359 Including inter segment revenue 12,184,743 8,130,503 686,881 2,638,449 23,640,576 Total revenues 49,808,443 37,624,818 7,688,005 5,982,941 101,104,207 Interest income 211,715 41,739 118,102 28,036 399,592 Interest expenses (529,743 ) (183,129 ) (77,005 ) (81,778 ) (871,655 ) Depreciation and amortization (2,892,901 ) (276,817 ) (29,266 ) (226,693 ) (3,425,677 ) Impairment loss on property, plant and equipment and others (497,583 ) (131,914 ) (1,490 ) (3,758 ) (634,745 ) Share of loss of equity-accounted investees, net (865,769 ) (76,038 ) (85,628 ) — (1,027,435 ) Income tax expense (725,448 ) (119,044 ) (86,106 ) (105,171 ) (1,035,769 ) Segment profit 585,948 165,348 27,789 544,961 1,324,046 Segment assets 71,153,809 14,482,538 7,653,637 9,212,225 102,502,209 Investment in subsidiaries, — — — — — associates and joint ventures 15,650,654 1,409,764 527,418 1,062,215 18,650,051 Acquisition of non-current 2,275,103 192,805 30,563 404,963 2,903,434 Segment liabilities 21,101,474 10,184,521 4,584,423 4,454,502 40,324,920
Reconciliation of Segment Revenues, Profit or Loss, Assets and Liabilities and Other Significant Items	(c) Reconciliations of total segment revenues, profit or loss, assets and liabilities, and other significant items to their respective consolidated financial statement line items are as follows: 1) Revenues (in millions of Won) 2017 2018 2019 Total revenue for reportable segments ￦ 95,059,704 102,258,628 101,104,207 Elimination of inter-segment revenue (34,404,604 ) (37,280,851 ) (36,737,359 ) Basis difference(2) (468,233 ) 176,859 418,861 ￦ 60,186,867 65,154,636 64,785,709 2) Profit (in millions of Won) 2017 2018 2019 Total profit (loss) for reportable segments ￦ 3,160,761 1,331,419 1,324,046 Goodwill and corporate FV adjustments (84,370 ) (77,756 ) (80,218 ) Elimination of inter-segment profits (102,922 ) 638,401 738,809 Income tax expense 1,206,223 1,670,757 1,070,641 Basis difference(2) (84,641 ) 53,195 73,256 Profit before income tax expense ￦ 4,095,051 3,616,016 3,126,534 3) Assets (in millions of Won) 2018 2019 Total assets for reportable segments(1) ￦ 101,878,001 102,502,209 Equity-accounted investees (15,272,243 ) (14,400,831 ) Goodwill and corporate FV adjustments 2,722,115 2,622,409 Elimination of inter-segment assets (11,079,608 ) (11,665,126 ) Basis difference(2) 528,726 312,147 ￦ 78,776,991 79,370,808 (1) As segment assets and liabilities are determined based on separate financial statements, for subsidiaries which are in a different segment from that of its immediate parent company, their carrying amount in separate financial statements is eliminated upon consolidation. In addition, adjustments are made to adjust the amount of investment in associates and joint ventures from the amount reflected in segment assets to that determined using equity method in consolidated financial statements. 4) Liabilities (in millions of Won) 2018 2019 Total liabilities for reportable segments ￦ 40,264,320 40,324,920 Corporate FV adjustments 321,320 292,124 Elimination of inter-segment liabilities (9,096,926 ) (9,353,090 ) Basis difference(2) 615,663 343,556 ￦ 32,104,377 31,607,510 5) Other significant items a) December 31, 2017 (in millions of Won) Total segment corporate FV Elimination of inter-segment Basis Consolidated Interest income ￦ 280,488 — (68,037 ) — 212,451 Interest expenses (757,963 ) 1,304 103,544 — (653,115 ) Depreciation and amortization (3,360,366 ) (106,195 ) 169,141 — (3,297,420 ) Share of profit or loss of investment in associates (1,721 ) — 12,261 — 10,540 Income tax expense (1,274,696 ) 21,270 47,203 20,483 (1,185,740 ) Impairment loss on property, plant and equipment and others (336,719 ) (867 ) 34,619 — (302,967 ) Impairment loss on available-for-sale (127,319 ) — 4,105 — (123,214 ) ￦ (5,578,296 ) (84,488 ) 302,836 20,483 (5,339,465 ) b) December 31, 2018 (in millions of Won) Total corporate FV Elimination of inter-segment Basis Consolidated Interest income ￦ 373,926 — (36,668 ) — 337,258 Interest expenses (863,560 ) 1,035 121,229 — (741,296 ) Depreciation and amortization (3,325,415 ) (103,932 ) 161,718 — (3,267,629 ) Share of profit or loss of investment in associates (1,049,335 ) — 1,161,970 — 112,635 Income tax expense (1,664,258 ) 25,921 (32,420 ) (12,873 ) (1,683,630 ) Impairment loss on property, plant and equipment and others (1,343,360 ) (779 ) (107,258 ) — (1,451,397 ) ￦ (7,872,002 ) (77,755 ) 1,268,571 (12,873 ) (6,694,059 ) c) December 31, 2019 (in millions of Won) Total segment Goodwill and Elimination of inter-segment Basis Consolidated Interest income ￦ 399,592 — (47,208 ) — 352,384 Interest expenses (871,655 ) 806 115,138 — (755,711 ) Depreciation and amortization (3,425,677 ) (109,941 ) 74,503 — (3,461,115 ) Share of profit of equity-accounted investees, net (1,027,435 ) — 1,301,176 — 273,741 Income tax expense (1,035,769 ) 28,917 (63,789 ) (17,728 ) (1,088,369 ) Impairment loss on property, plant and equipment and others (634,745 ) — (70,011 ) — (704,756 ) ￦ (6,595,689 ) (80,218 ) 1,309,809 (17,728 ) (5,383,826 ) (*2) Basis difference is related to the difference in recognizing revenue and expenses in connection with development and sale of certain residential real estate between the report reviewed by the CEO and the consolidated financial statements.
Revenue and Non-current Assets by Geographic Area	(d) Revenue by geographic area for the years ended December 31, 2017, 2018 and 2019 was as follows: (in millions of Won) 2017 2018 2019 Domestic ￦ 38,882,220 41,671,930 40,890,972 Japan 2,200,405 2,084,061 2,202,075 China 6,731,214 6,945,266 7,165,271 Asia-other 7,750,553 8,904,532 8,976,593 North America 1,725,120 1,834,534 1,711,859 Others 3,365,588 3,537,454 3,420,078 60,655,100 64,977,777 64,366,848 Basis difference (468,233 ) 176,859 418,861 ￦ 60,186,867 65,154,636 64,785,709 In presenting information on the basis of geography, segment revenue is based on the geographical location of customers. (e) Non-current (in millions of Won) 2018 2019 Domestic ￦ 28,298,293 27,742,370 Japan 146,490 175,719 China 1,185,828 1,307,847 Asia-other 5,067,936 4,916,775 North America 173,914 221,565 Others 1,245,252 1,348,397 ￦ 36,117,713 35,712,673 Non-current (f) There are no customers whose revenue is 10% or more of the consolidated revenue.

General Information - Additiona

General Information - Additional Information (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)EntitySteel_PlantOffice	Dec. 31, 2018KRW (₩)	Dec. 31, 2017KRW (₩)
Disclosure of general information [Line Items]
Number of associates and joint ventures \| Entity	131
Number of operational steel plants \| Steel_Plant	2
Increase in ownership interests in subsidiaries	₩ (177,125)	₩ (2,151)	₩ 163,707
Dividends paid by subsidiaries	100,862	100,582	₩ 70,087
POSCO CHEMICAL CO., LTD. and others [member]
Disclosure of general information [Line Items]
Increase in ownership interests in subsidiaries		₩ 48,538
POSCO Gulf SFC LLC and others [member]
Disclosure of general information [Line Items]
Increase in ownership interests in subsidiaries	₩ 1,497
Domestic [member]
Disclosure of general information [Line Items]
Number of subsidiaries \| Entity	32
Foreign [member]
Disclosure of general information [Line Items]
Number of subsidiaries \| Entity	131
Number of operational offices \| Office	6
Korea [member]
Disclosure of general information [Line Items]
Number of operational offices \| Office	1

General Information - POSCO's S

General Information - POSCO's Shareholders (Detail) - shares	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of details of shareholders [line items]
Number of shares	87,186,835	87,186,835	87,186,835
Ownership (%)	100.00%
National Pension Service [member]
Disclosure of details of shareholders [line items]
Number of shares	10,291,670
Ownership (%)	11.80%
BlackRock Fund Advisors [member]
Disclosure of details of shareholders [line items]
Number of shares	5,429,071
Ownership (%)	6.23%
Nippon Steel Corporation [Member]
Disclosure of details of shareholders [line items]
Number of shares	2,894,712
Ownership (%)	3.32%
Samsung Group and subsidiaries [member]
Disclosure of details of shareholders [line items]
Number of shares	2,401,789
Ownership (%)	2.75%
GIC private limited [member]
Disclosure of details of shareholders [line items]
Number of shares	1,777,316
Ownership (%)	2.04%
Others [member]
Disclosure of details of shareholders [line items]
Number of shares	64,392,277
Ownership (%)	73.86%

General Information - POSCO's_2

General Information - POSCO's Shareholders (Parenthetical) (Detail) - ₩ / shares	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Details of Shareholders [abstract]
Number of shares represented by ADRs	0.25
Common share par value	₩ 5,000	₩ 5,000

General Information - Details o

General Information - Details of Consolidated Subsidiaries (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of subsidiaries [line items]
Region	South Africa
POSCO INTERNATIONAL MALAYSIA SDN BHD [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Malaysia
Domestic [member] \| POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Engineering and construction
Ownership (%)	52.80%	52.80%
Region	Pohang
Domestic [member] \| POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	52.80%	52.80%
Domestic [member] \| POSCO COATED & COLOR STEEL Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Coated steel manufacturing
Ownership (%)	56.87%	56.87%
Region	Pohang
Domestic [member] \| POSCO COATED & COLOR STEEL Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	56.87%	56.87%
Domestic [member] \| POSCO ICT [member]
Disclosure of subsidiaries [line items]
Principal operations	Computer hardware and software distribution
Ownership (%)	65.38%	65.38%
Region	Pohang
Domestic [member] \| POSCO ICT [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	65.38%	65.38%
Domestic [member] \| POSCO Research Institute [member]
Disclosure of subsidiaries [line items]
Principal operations	Economic research and consulting
Ownership (%)	100.00%	100.00%
Region	Seoul
Domestic [member] \| POSCO Research Institute [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| POSCO O&M CO., Ltd. (formerly, POSMATE) [member]
Disclosure of subsidiaries [line items]
Principal operations	Business facility maintenance
Ownership (%)	100.00%	100.00%
Region	Seoul
Domestic [member] \| POSCO O&M CO., Ltd. (formerly, POSMATE) [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	47.17%	59.80%
Domestic [member] \| POSCO O&M CO., Ltd. (formerly, POSMATE) [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	52.83%	40.20%
Domestic [member] \| POSCO A&C [member]
Disclosure of subsidiaries [line items]
Principal operations	Architecture and consulting
Ownership (%)	100.00%	100.00%
Region	Seoul
Domestic [member] \| POSCO A&C [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	45.66%	100.00%
Domestic [member] \| POSCO A&C [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	54.34%
Domestic [member] \| POSCO Venture Capital Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in venture companies
Ownership (%)	95.00%	95.00%
Region	Pohang
Domestic [member] \| POSCO Venture Capital Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	95.00%	95.00%
Domestic [member] \| eNtoB Corporation [member]
Disclosure of subsidiaries [line items]
Principal operations	Electronic commerce
Ownership (%)	61.13%	61.13%
Region	Seoul
Domestic [member] \| eNtoB Corporation [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	7.50%	7.50%
Domestic [member] \| eNtoB Corporation [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	53.63%	53.63%
Domestic [member] \| POSCO CHEMICAL CO., LTD. (formerly, POSCO CHEMTECH) [member]
Disclosure of subsidiaries [line items]
Principal operations	Refractories manufacturing and sales
Ownership (%)	61.26%	60.00%
Region	Pohang
Domestic [member] \| POSCO CHEMICAL CO., LTD. (formerly, POSCO CHEMTECH) [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	61.26%	60.00%
Domestic [member] \| POSCO-Terminal Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Transporting and warehousing
Ownership (%)	51.00%	51.00%
Region	Gwangyang
Domestic [member] \| POSCO-Terminal Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	51.00%	51.00%
Domestic [member] \| POSCO M-TECH [member]
Disclosure of subsidiaries [line items]
Principal operations	Packing materials manufacturing and sales
Ownership (%)	48.85%	48.85%
Region	Pohang
Domestic [member] \| POSCO M-TECH [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	48.85%	48.85%
Domestic [member] \| POSCO ENERGY CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Generation of electricity
Ownership (%)	100.00%	89.02%
Region	Seoul
Domestic [member] \| POSCO ENERGY CO., LTD. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	89.02%
Domestic [member] \| POSCO NIPPON STEEL RHF JOINT VENTURE.CO., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel byproduct manufacturing and sales
Ownership (%)	70.00%	70.00%
Region	Pohang
Domestic [member] \| POSCO NIPPON STEEL RHF JOINT VENTURE.CO., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	70.00%
Domestic [member] \| Future Creation Fund Postech Early Stage account [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in venture companies
Ownership (%)	40.00%	40.00%
Region	Seoul
Domestic [member] \| Future Creation Fund Postech Early Stage account [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	40.00%	40.00%
Domestic [member] \| POSCO WOMAN'S FUND [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in venture companies
Ownership (%)	40.00%	40.00%
Region	Seoul
Domestic [member] \| POSCO WOMAN'S FUND [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	40.00%	40.00%
Domestic [member] \| SPH Co, ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	House manufacturing and management
Ownership (%)	100.00%	100.00%
Region	Incheon
Domestic [member] \| SPH Co, ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| Posco Group University [member]
Disclosure of subsidiaries [line items]
Principal operations	Education service and real estate business
Ownership (%)	100.00%	100.00%
Region	Incheon
Domestic [member] \| Posco Group University [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| 2015 POSCO New technology II Fund [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in venture companies
Ownership (%)	25.00%	25.00%
Region	Pohang
Domestic [member] \| 2015 POSCO New technology II Fund [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	25.00%	25.00%
Domestic [member] \| Growth Ladder POSCO K-Growth Global Fund [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in venture companies
Ownership (%)	50.00%	50.00%
Region	Pohang
Domestic [member] \| Growth Ladder POSCO K-Growth Global Fund [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	50.00%	50.00%
Domestic [member] \| POSCO Research & Technology [member]
Disclosure of subsidiaries [line items]
Principal operations	Intellectual Property Services and consulting
Ownership (%)	100.00%	100.00%
Region	Seoul
Domestic [member] \| POSCO Research & Technology [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| TANCHEON E&E (formerly, POSCO E&E) [member]
Disclosure of subsidiaries [line items]
Principal operations	Refuse derived fuel and power generation
Ownership (%)	100.00%	100.00%
Region	Seoul
Domestic [member] \| TANCHEON E&E (formerly, POSCO E&E) [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| POSCO Humans [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction
Ownership (%)	100.00%	90.30%
Region	Pohang
Domestic [member] \| POSCO Humans [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	75.49%	90.30%
Domestic [member] \| POSCO Humans [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	24.51%
Domestic [member] \| Mapo Hibroad Parking Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction
Ownership (%)	71.00%	71.00%
Region	Seoul
Domestic [member] \| Mapo Hibroad Parking Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	71.00%	71.00%
Domestic [member] \| Busan E&E Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Refuse derived fuel and power generation
Ownership (%)	70.00%	70.00%
Region	Busan
Domestic [member] \| Busan E&E Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	70.00%
Domestic [member] \| POSCO Family Strategy Fund [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in venture companies
Ownership (%)	100.00%	100.00%
Region	Pohang
Domestic [member] \| POSCO Family Strategy Fund [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	69.91%	69.91%
Domestic [member] \| POSCO Family Strategy Fund [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	30.09%	30.09%
Domestic [member] \| POSCO INTERNATIONAL Corporation (formerly, POSCO DAEWOO Corporation) [member]
Disclosure of subsidiaries [line items]
Principal operations	Trading, energy & resource development and others
Ownership (%)	62.94%	62.94%
Region	Seoul
Domestic [member] \| POSCO INTERNATIONAL Corporation (formerly, POSCO DAEWOO Corporation) [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	62.91%	62.90%
Domestic [member] \| POSCO INTERNATIONAL Corporation (formerly, POSCO DAEWOO Corporation) [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.03%	0.04%
Domestic [member] \| Pohang Scrap Recycling Distribution Center Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel processing and sales
Ownership (%)	51.00%	51.00%
Region	Pohang
Domestic [member] \| Pohang Scrap Recycling Distribution Center Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	51.00%	51.00%
Domestic [member] \| PSC Energy Global Co., Ltd. [Member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in energy industry
Ownership (%)	100.00%	100.00%
Region	Pohang
Domestic [member] \| PSC Energy Global Co., Ltd. [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| Suncheon Eco Trans Co., Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations	Train manufacturing and management
Ownership (%)	100.00%	100.00%
Region	Suncheon
Domestic [member] \| Suncheon Eco Trans Co., Ltd [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| Songdo Development PMC (Project Management Company) LLC. [member]
Disclosure of subsidiaries [line items]
Principal operations	Housing business agency
Ownership (%)	100.00%	100.00%
Region	Incheon
Domestic [member] \| Songdo Development PMC (Project Management Company) LLC. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Domestic [member] \| Korea Fuel Cell [Member]
Disclosure of subsidiaries [line items]
Principal operations	Fuel cell
Ownership (%)	100.00%
Region	Pohang
Domestic [member] \| Korea Fuel Cell [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%
Domestic [member] \| POSCO GEM 1th Fund [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in venture companies
Ownership (%)	100.00%
Region	Pohang
Domestic [member] \| POSCO GEM 1th Fund [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	98.81%
Domestic [member] \| POSCO GEM 1th Fund [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	1.19%
Domestic [member] \| POSCO Processing And Service [Member]
Disclosure of subsidiaries [line items]
Principal operations	Steel sales and trading
Ownership (%)		94.40%
Region	Seoul
Domestic [member] \| POSCO Processing And Service [Member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)		93.95%
Domestic [member] \| POSCO Processing And Service [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		0.45%
Domestic [member] \| Mega asset Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Real estate rental and sales
Ownership (%)		100.00%
Region	Gyeonggi
Domestic [member] \| Mega asset Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Domestic [member] \| HOTEL LAONZENA [member]
Disclosure of subsidiaries [line items]
Principal operations	Hotel business
Ownership (%)	0.00%	100.00%
Region	Daegu
Domestic [member] \| HOTEL LAONZENA [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.00%	100.00%
Domestic [member] \| Posco e&c Songdo International Building [member]
Disclosure of subsidiaries [line items]
Principal operations	Non-residental building rental	Non-residental building rental
Ownership (%)	0.00%	100.00%
Region	Seoul
Domestic [member] \| Posco e&c Songdo International Building [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.00%	100.00%
Domestic [member] \| POSCO ES MATERIALS CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Secondary and storage battery manufacturing
Ownership (%)	0.00%	90.00%
Region	Gumi
Domestic [member] \| POSCO ES MATERIALS CO., LTD. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.00%	90.00%
Domestic [member] \| BLUE O&M Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Engineering service
Ownership (%)		100.00%
Region	Pohang
Domestic [member] \| BLUE O&M Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| POSCO America Corporation [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel trading
Ownership (%)	100.00%	100.00%
Region	USA
Foreign [member] \| POSCO America Corporation [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	99.45%	99.45%
Foreign [member] \| POSCO America Corporation [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.55%	0.55%
Foreign [member] \| POSCO AUSTRALIA PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations	Raw material sales & mine development
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POSCO AUSTRALIA PTY LTD [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO Canada Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Coal sales
Ownership (%)	100.00%	100.00%
Region	Canada
Foreign [member] \| POSCO Canada Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%
Foreign [member] \| POSCO Canada Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| POSCAN Elkview [member]
Disclosure of subsidiaries [line items]
Principal operations	Coal sales
Ownership (%)	100.00%	100.00%
Region	Canada
Foreign [member] \| POSCAN Elkview [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO Asia Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel and raw material trading
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO Asia Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-CTPC Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO-CTPC Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	61.91%
Foreign [member] \| POSCO-CTPC Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		38.09%
Foreign [member] \| POSCO E&C Vietnam Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel structure manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	Vietnam
Foreign [member] \| POSCO E&C Vietnam Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| Zhangjiagang Pohang Stainless Steel Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Stainless steel manufacturing and sales
Ownership (%)	82.48%	82.48%
Region	China
Foreign [member] \| Zhangjiagang Pohang Stainless Steel Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	58.60%	58.60%
Foreign [member] \| Zhangjiagang Pohang Stainless Steel Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	23.88%	23.88%
Foreign [member] \| POSCO (Thailand) Company Limited [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	Thailand
Foreign [member] \| POSCO (Thailand) Company Limited [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	88.58%
Foreign [member] \| POSCO (Thailand) Company Limited [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.00%	11.42%
Foreign [member] \| Myanmar POSCO Steel Co., Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	70.00%	70.00%
Region	Myanmar
Foreign [member] \| POSCO-MKPC SDN BHD [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	70.00%	70.00%
Region	Malaysia
Foreign [member] \| POSCO-MKPC SDN BHD [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	44.69%
Foreign [member] \| POSCO-MKPC SDN BHD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.00%	25.31%
Foreign [member] \| Qingdao Pohang Stainless Steel Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Stainless steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| Qingdao Pohang Stainless Steel Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	70.00%
Foreign [member] \| Qingdao Pohang Stainless Steel Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	30.00%	30.00%
Foreign [member] \| POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	90.00%	90.00%
Foreign [member] \| POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| POSCO-China Qingdao Processing Center Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO-China Qingdao Processing Center Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%
Foreign [member] \| POSCO-China Qingdao Processing Center Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	0.00%	100.00%
Foreign [member] \| POS-ORE PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		Iron ore sales and sales
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POS-ORE PTY LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-China Holding Corp. [member]
Disclosure of subsidiaries [line items]
Principal operations		Holding company
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO-China Holding Corp. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO JAPAN Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel trading
Ownership (%)	100.00%	100.00%
Region	Japan
Foreign [member] \| POSCO JAPAN Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POS-CD PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		Coal sales
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POS-CD PTY LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POS-GC PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		Coal sales
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POS-GC PTY LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-India Private Limited [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	India
Foreign [member] \| POSCO-India Private Limited [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-India Pune Processing Center. Pvt. Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	65.00%	65.00%
Region	India
Foreign [member] \| POSCO-India Pune Processing Center. Pvt. Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	65.00%	65.00%
Foreign [member] \| POSCO Japan PC CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	86.12%	86.12%
Region	Japan
Foreign [member] \| POSCO Japan PC CO., LTD. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	86.12%	86.12%
Foreign [member] \| POSCO-CFPC Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO-CFPC Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	39.60%	39.60%
Foreign [member] \| POSCO-CFPC Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	60.40%	60.40%
Foreign [member] \| POSCO E&C CHINA Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Civil engineering and construction
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO E&C CHINA Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO MPPC S.A. de C.V. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	96.31%	96.31%
Region	Mexico
Foreign [member] \| POSCO MPPC S.A. de C.V. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	21.02%	21.02%
Foreign [member] \| POSCO MPPC S.A. de C.V. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	75.29%	75.29%
Foreign [member] \| Zhangjigang Pohang Port Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Loading and unloading service
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| Zhangjigang Pohang Port Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-VIETNAM Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	Vietnam
Foreign [member] \| POSCO-VIETNAM Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO MEXICO S.A. DE C.V. [member]
Disclosure of subsidiaries [line items]
Principal operations		Automotive steel sheet manufacturing and sales
Ownership (%)	98.16%	98.16%
Region	Mexico
Foreign [member] \| POSCO MEXICO S.A. DE C.V. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	83.28%	83.28%
Foreign [member] \| POSCO MEXICO S.A. DE C.V. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	14.88%	14.88%
Foreign [member] \| POSCO-Poland Wroclaw Processing Center Sp. z o. o. [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	60.00%	60.00%
Region	Poland
Foreign [member] \| POSCO-Poland Wroclaw Processing Center Sp. z o. o. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	60.00%	60.00%
Foreign [member] \| POS-NP PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		Coal sales
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POS-NP PTY LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO DAEWOO WAIGAIQIAO SHANGHAI CO., LTD [member]
Disclosure of subsidiaries [line items]
Principal operations	Intermediary trade & bonded warehouse operation
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO DAEWOO WAIGAIQIAO SHANGHAI CO., LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| PT. Bio Inti Agrindo [member]
Disclosure of subsidiaries [line items]
Principal operations		Forest resources development
Ownership (%)	85.00%	85.00%
Region	Indonesia
Foreign [member] \| PT. Bio Inti Agrindo [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	85.00%	85.00%
Foreign [member] \| POSCO ENGINEERING AND CONSTRUCTION AUSTRALIA (POSCO E&C AUSTRALIA) PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction and engineering service
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POSCO ENGINEERING AND CONSTRUCTION AUSTRALIA (POSCO E&C AUSTRALIA) PTY LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-TISCO (JILIN) PROCESSING CENTER Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	60.00%	60.00%
Region	China
Foreign [member] \| POSCO-TISCO (JILIN) PROCESSING CENTER Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	50.00%	50.00%
Foreign [member] \| POSCO-TISCO (JILIN) PROCESSING CENTER Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| POSCO Thainox Public Company Limited [member]
Disclosure of subsidiaries [line items]
Principal operations	STS cold-rolled steel manufacturing and sales
Ownership (%)	84.39%	84.66%
Region	Thailand
Foreign [member] \| POSCO Thainox Public Company Limited [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	84.39%	84.66%
Foreign [member] \| Hunchun Posco Hyundai Logistics [member]
Disclosure of subsidiaries [line items]
Principal operations	Logistics
Ownership (%)	80.00%	80.00%
Region	China
Foreign [member] \| Hunchun Posco Hyundai Logistics [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	80.00%	80.00%
Foreign [member] \| POSCO INTERNATIONAL VIETNAM COMPANY LIMITED [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Vietnam
Foreign [member] \| POSCO INTERNATIONAL VIETNAM COMPANY LIMITED [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO(Chongqing) Automotive Processing Center Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO(Chongqing) Automotive Processing Center Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	90.00%	90.00%
Foreign [member] \| POSCO(Chongqing) Automotive Processing Center Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| SUZHOU POSCO-CORE TECHNOLOGY CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Component manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| SUZHOU POSCO-CORE TECHNOLOGY CO., LTD. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	84.85%
Foreign [member] \| SUZHOU POSCO-CORE TECHNOLOGY CO., LTD. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	15.15%	100.00%
Foreign [member] \| PT.Krakatau Posco Chemtech Calcination [member]
Disclosure of subsidiaries [line items]
Principal operations	Quicklime manufacturing and sales
Ownership (%)	80.00%	80.00%
Region	Indonesia
Foreign [member] \| PT.Krakatau Posco Chemtech Calcination [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	80.00%	80.00%
Foreign [member] \| POSCO AFRICA (PROPRIETARY) LIMITED [member]
Disclosure of subsidiaries [line items]
Principal operations	Mine development
Ownership (%)	100.00%	100.00%
Region	South Africa
Foreign [member] \| POSCO AFRICA (PROPRIETARY) LIMITED [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO ICT BRASIL [member]
Disclosure of subsidiaries [line items]
Principal operations	IT service and engineering
Ownership (%)	100.00%	100.00%
Region	Brazil
Foreign [member] \| POSCO ICT BRASIL [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| LA-SRDC [member]
Disclosure of subsidiaries [line items]
Principal operations	Scrap manufacturing
Ownership (%)	100.00%	100.00%
Region	USA
Foreign [member] \| LA-SRDC [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO Center Beijing [member]
Disclosure of subsidiaries [line items]
Principal operations	Real estate development, rental and management
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO Center Beijing [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO AMERICA COMERCIALIZADORA S DE RL DE CV [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel sales
Ownership (%)	100.00%	100.00%
Region	Mexico
Foreign [member] \| POSCO AMERICA COMERCIALIZADORA S DE RL DE CV [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO(Guangdong) Automotive Steel Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	93.64%	93.64%
Region	China
Foreign [member] \| POSCO(Guangdong) Automotive Steel Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	83.64%	83.64%
Foreign [member] \| POSCO(Guangdong) Automotive Steel Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| POSCO-Malaysia SDN. BHD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	95.42%	95.42%
Region	Malaysia
Foreign [member] \| POSCO-Malaysia SDN. BHD. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	81.79%	81.79%
Foreign [member] \| POSCO-Malaysia SDN. BHD. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	13.63%	13.63%
Foreign [member] \| PT KRAKATAU BLUE WATER [member]
Disclosure of subsidiaries [line items]
Principal operations	Wastewater treamtment facilities operation and maintenance
Ownership (%)	67.00%	67.00%
Region	Indonesia
Foreign [member] \| PT KRAKATAU BLUE WATER [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	67.00%	67.00%
Foreign [member] \| POSCO DAEWOO MYANMAR CORPORATION LIMITED [member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Myanmar
Foreign [member] \| POSCO DAEWOO MYANMAR CORPORATION LIMITED [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-Italy Processing Center [member]
Disclosure of subsidiaries [line items]
Principal operations	Stainless steel sheetmanufacturing and sales
Ownership (%)	100.00%	90.00%
Region	Italy
Foreign [member] \| POSCO-Italy Processing Center [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	88.89%	80.00%
Foreign [member] \| POSCO-Italy Processing Center [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	11.11%	10.00%
Foreign [member] \| Myanmar POSCO C&C Company, Limited [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	70.00%
Foreign [member] \| POSCO ICT VIETNAM [member]
Disclosure of subsidiaries [line items]
Principal operations	IT service and electric control engineering
Ownership (%)	100.00%	100.00%
Region	Vietnam
Foreign [member] \| POSCO ICT VIETNAM [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| Daewoo Global Development. Pte., Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations	Real estate development
Ownership (%)	81.51%	81.51%
Region	Myanmar
Foreign [member] \| Daewoo Global Development. Pte., Ltd [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	81.51%	81.51%
Foreign [member] \| Myanmar POSCO Engineering & Construction Company, Limited [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction and engineering service
Ownership (%)	100.00%	100.00%
Region	Myanmar
Foreign [member] \| Myanmar POSCO Engineering & Construction Company, Limited [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POS-Minerals Corporation [member]
Disclosure of subsidiaries [line items]
Principal operations	Mine development management and sales
Ownership (%)	100.00%	100.00%
Region	USA
Foreign [member] \| POS-Minerals Corporation [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO(Wuhu) Automotive Processing Center Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO(Wuhu) Automotive Processing Center Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	68.57%	68.57%
Foreign [member] \| POSCO(Wuhu) Automotive Processing Center Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	31.43%	31.43%
Foreign [member] \| POSCO Engineering and Construction India Private Limited [member]
Disclosure of subsidiaries [line items]
Principal operations	Civil engineering and construction
Ownership (%)	100.00%	100.00%
Region	India
Foreign [member] \| POSCO Engineering and Construction India Private Limited [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO COATED STEEL (THAILAND) CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Automotive steel sheetmanufacturing and sales
Ownership (%)	100.00%	100.00%
Region	Thailand
Foreign [member] \| POSCO COATED STEEL (THAILAND) CO., LTD. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| Daewoo Amara Company Limited [member]
Disclosure of subsidiaries [line items]
Principal operations	Real estate development
Ownership (%)	85.00%	85.00%
Region	Myanmar
Foreign [member] \| Daewoo Amara Company Limited [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	85.00%	85.00%
Foreign [member] \| POSMATE-CHINA CO., LTD [member]
Disclosure of subsidiaries [line items]
Principal operations	Business facility maintenance
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSMATE-CHINA CO., LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-Mexico Villagran Wire-rod Processing Center [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	66.75%	66.75%
Region	Mexico
Foreign [member] \| POSCO-Mexico Villagran Wire-rod Processing Center [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	56.75%	56.75%
Foreign [member] \| POSCO-Mexico Villagran Wire-rod Processing Center [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| POSCO ChengDu Processing Center [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	43.00%	43.00%
Region	China
Foreign [member] \| POSCO ChengDu Processing Center [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	33.00%	33.00%
Foreign [member] \| POSCO ChengDu Processing Center [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| POSCO E&C SMART S DE RL DE CV [member]
Disclosure of subsidiaries [line items]
Principal operations	Civil engineering and construction
Ownership (%)	100.00%	100.00%
Region	Mexico
Foreign [member] \| POSCO E&C SMART S DE RL DE CV [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO Philippine Manila Processing Center, Inc. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	Philippines
Foreign [member] \| POSCO Philippine Manila Processing Center, Inc. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%
Foreign [member] \| POSCO Philippine Manila Processing Center, Inc. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| POSCO E&C HOLDINGS CO., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Holding company
Ownership (%)	100.00%	100.00%
Region	Thailand
Foreign [member] \| POSCO E&C HOLDINGS CO., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| Daewoo Power and Infra (PTY) Limited [member]
Disclosure of subsidiaries [line items]
Principal operations		Electricity
Ownership (%)		100.00%
Foreign [member] \| Daewoo Power and Infra (PTY) Limited [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| Daewoo Precious Resources Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Resources development
Ownership (%)		70.00%
Region	Myanmar
Foreign [member] \| Daewoo Precious Resources Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		70.00%
Foreign [member] \| PT.Krakatau Posco Social Enterprise [member]
Disclosure of subsidiaries [line items]
Principal operations	Social enterprise
Ownership (%)	100.00%	100.00%
Region	Indonesia
Foreign [member] \| PT.Krakatau Posco Social Enterprise [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| Ventanas Philippines Construction Inc [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction
Ownership (%)	100.00%	100.00%
Region	Philippines
Foreign [member] \| Ventanas Philippines Construction Inc [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO E&C Mongolia [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction and engineering service
Ownership (%)	100.00%	100.00%
Region	Mongolia
Foreign [member] \| POSCO E&C Mongolia [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| SANPU TRADING Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Raw material trading
Ownership (%)	70.04%	70.04%
Region	China
Foreign [member] \| SANPU TRADING Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.04%	70.04%
Foreign [member] \| Zhangjiagang BLZ Pohang International Trading [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel Intermediate trade
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| Zhangjiagang BLZ Pohang International Trading [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO RU Limited Liability Company [member]
Disclosure of subsidiaries [line items]
Principal operations	Trade and business development
Ownership (%)	100.00%	100.00%
Region	Russia
Foreign [member] \| POSCO RU Limited Liability Company [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO ICT-China [member]
Disclosure of subsidiaries [line items]
Principal operations	IT service and DVR business
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO ICT-China [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO Europe Steel Distribution Center [member]
Disclosure of subsidiaries [line items]
Principal operations	Logistics & Steel sales
Ownership (%)	70.00%	70.00%
Region	Slovenia
Foreign [member] \| POSCO Europe Steel Distribution Center [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	50.00%	50.00%
Foreign [member] \| POSCO Europe Steel Distribution Center [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	20.00%	20.00%
Foreign [member] \| POSCO ENGINEERING (THAILAND) CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction and engineering service
Ownership (%)	100.00%	100.00%
Region	Thailand
Foreign [member] \| POSCO ENGINEERING (THAILAND) CO., LTD. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| Zhangjiagang Pohang Refactories Co Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations	Refractory materials sales & furnace maintenance
Ownership (%)	51.00%	51.00%
Region	China
Foreign [member] \| Zhangjiagang Pohang Refactories Co Ltd [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	51.00%	51.00%
Foreign [member] \| POSCO Maharashtra Steel Private Limited [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	India
Foreign [member] \| POSCO Maharashtra Steel Private Limited [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO TNPC Otomotiv Celik San. Ve Tic. A.S [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	Turkey
Foreign [member] \| POSCO TNPC Otomotiv Celik San. Ve Tic. A.S [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO Gulf SFC LLC [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)		65.72%
Region	United Arab Emirates
Foreign [member] \| POSCO Gulf SFC LLC [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		65.72%
Foreign [member] \| Pos-Sea Pte Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel Intermediate trade
Ownership (%)	100.00%	100.00%
Region	Singapore
Foreign [member] \| Pos-Sea Pte Ltd [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO(Liaoning) Automotive [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO(Liaoning) Automotive [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	90.00%	90.00%
Foreign [member] \| POSCO(Liaoning) Automotive [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| POSCO-Indonesia Jakarta Processing Center [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	85.00%	85.00%
Region	Indonesia
Foreign [member] \| POSCO-Indonesia Jakarta Processing Center [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	65.00%	65.00%
Foreign [member] \| POSCO-Indonesia Jakarta Processing Center [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	20.00%	20.00%
Foreign [member] \| PT.MRI [member]
Disclosure of subsidiaries [line items]
Principal operations	Mine development
Ownership (%)	65.00%	65.00%
Region	Indonesia
Foreign [member] \| PT.MRI [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	65.00%	65.00%
Foreign [member] \| POSCO TMC INDIA PRIVATE LIMITED [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	India
Foreign [member] \| POSCO TMC INDIA PRIVATE LIMITED [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO-AAPC [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	97.80%	97.80%
Region	USA
Foreign [member] \| POSCO-AAPC [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	97.80%	97.80%
Foreign [member] \| POSCO(Yantai)Automotive Processing Center Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO(Yantai)Automotive Processing Center Co., Ltd. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	90.00%	90.00%
Foreign [member] \| POSCO(Yantai)Automotive Processing Center Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| POSCO India Steel Distribution Center Private Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel logistics
Ownership (%)	100.00%	100.00%
Region	India
Foreign [member] \| POSCO India Steel Distribution Center Private Ltd [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO China Dalian Plate Processing Center Co, Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations	Plate manufacturing and sales
Ownership (%)	91.22%	91.22%
Region	China
Foreign [member] \| POSCO China Dalian Plate Processing Center Co, Ltd [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	79.52%	79.52%
Foreign [member] \| POSCO China Dalian Plate Processing Center Co, Ltd [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	11.70%	11.70%
Foreign [member] \| POSCO SS-VINA Co., Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	Vietnam
Foreign [member] \| POSCO SS-VINA Co., Ltd [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| PT.POSCO ICT INDONESIA [member]
Disclosure of subsidiaries [line items]
Principal operations	IT service and electric control engineering
Ownership (%)	66.99%	66.99%
Region	Indonesia
Foreign [member] \| PT.POSCO ICT INDONESIA [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	66.99%	66.99%
Foreign [member] \| POSCO NCR Coal Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Coal sales
Ownership (%)	100.00%	100.00%
Region	Canada
Foreign [member] \| POSCO NCR Coal Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO WA PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations	Iron ore sales & mine development
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POSCO WA PTY LTD [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO AUSTRALIA GP PTY LIMITED [member]
Disclosure of subsidiaries [line items]
Principal operations	Resource development
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POSCO AUSTRALIA GP PTY LIMITED [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| PT. Krakatau Posco Energy [member]
Disclosure of subsidiaries [line items]
Principal operations	Electricity production construction and operation
Ownership (%)	90.00%	90.00%
Region	Indonesia
Foreign [member] \| PT. Krakatau Posco Energy [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	90.00%	90.00%
Foreign [member] \| POSCO DAEWOO SINGAPORE PTE LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Singapore
Foreign [member] \| POSCO DAEWOO SINGAPORE PTE LTD. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO MAURITIUS LIMITED [member]
Disclosure of subsidiaries [line items]
Principal operations	Coal development and sales
Ownership (%)	100.00%	100.00%
Region	Mauritius
Foreign [member] \| POSCO MAURITIUS LIMITED [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| PT. KRAKATAU POSCO [member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	70.00%	70.00%
Region	Indonesia
Foreign [member] \| PT. KRAKATAU POSCO [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	70.00%
Foreign [member] \| PT.POSCO-Indonesia Inti [member]
Disclosure of subsidiaries [line items]
Principal operations	Mine development
Ownership (%)	100.00%	100.00%
Region	Indonesia
Foreign [member] \| PT.POSCO-Indonesia Inti [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO DAEWOO SHANGHAI CO., LTD. [member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO DAEWOO SHANGHAI CO., LTD. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| PGSF, L.P. [member]
Disclosure of subsidiaries [line items]
Principal operations	Investment in bio tech Industry
Ownership (%)	100.00%	100.00%
Region	USA
Foreign [member] \| PGSF, L.P. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO(Dalian) IT Center Development Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations	Real estate development and investment
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO(Dalian) IT Center Development Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| PT. POSCO E&C INDONESIA [member]
Disclosure of subsidiaries [line items]
Principal operations		Civil engineering and construction
Ownership (%)	100.00%	100.00%
Region	Indonesia
Foreign [member] \| PT. POSCO E&C INDONESIA [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| HUME COAL PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		Raw material manufacturing
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| HUME COAL PTY LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| Brazil Sao Paulo Steel Processing Center [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	76.00%	76.00%
Region	Brazil
Foreign [member] \| Brazil Sao Paulo Steel Processing Center [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	76.00%	76.00%
Foreign [member] \| DAESAN (CAMBODIA) Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Principal operations		Real estate development and investment
Ownership (%)	100.00%	100.00%
Region	Cambodia
Foreign [member] \| DAESAN (CAMBODIA) Co., Ltd. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. [member]
Disclosure of subsidiaries [line items]
Principal operations	Construction
Ownership (%)	100.00%	100.00%
Region	Brazil
Foreign [member] \| POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO ASSAN TST STEEL INDUSTRY [member]
Disclosure of subsidiaries [line items]
Principal operations		Steel manufacturing and sales
Ownership (%)	70.00%	70.00%
Region	Turkey
Foreign [member] \| POSCO ASSAN TST STEEL INDUSTRY [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	60.00%	60.00%
Foreign [member] \| POSCO ASSAN TST STEEL INDUSTRY [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	10.00%	10.00%
Foreign [member] \| HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd [member]
Disclosure of subsidiaries [line items]
Principal operations		Real estate development and investment
Ownership (%)	100.00%	100.00%
Region	Hongkong
Foreign [member] \| HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POS-LT PTY LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		Lithium mining investment
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POS-LT PTY LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO SINGAPORE LNG TRADING PTE. LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		LNG trading
Ownership (%)		100.00%
Region	Singapore
Foreign [member] \| POSCO SINGAPORE LNG TRADING PTE. LTD [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)		50.00%
Foreign [member] \| POSCO SINGAPORE LNG TRADING PTE. LTD [member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		50.00%
Foreign [member] \| ZHEJIANG POSCO-HUAYOU ESM CO.,LTD [member]
Disclosure of subsidiaries [line items]
Principal operations		Anode material manufacturing
Ownership (%)	60.00%	100.00%
Region	China
Foreign [member] \| ZHEJIANG POSCO-HUAYOU ESM CO.,LTD [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	60.00%	100.00%
Foreign [member] \| POSCO Argentina S.A.U. [member]
Disclosure of subsidiaries [line items]
Principal operations		Mineral exploration/manufacturing/sales
Ownership (%)	100.00%	100.00%
Region	Argentina
Foreign [member] \| POSCO Argentina S.A.U. [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO SUZHOU PROCESSING CENTER CO., LTD. [Member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO SUZHOU PROCESSING CENTER CO., LTD. [Member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	30.00%	30.00%
Foreign [member] \| POSCO SUZHOU PROCESSING CENTER CO., LTD. [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	70.00%
Foreign [member] \| POSCO INTERNATIONAL POWER (PNGLAE) LTD. [Member]
Disclosure of subsidiaries [line items]
Principal operations	Electricity production
Ownership (%)	100.00%	100.00%
Region	Papua New Guinea
Foreign [member] \| POSCO INTERNATIONAL POWER (PNGLAE) LTD. [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| GOLDEN LACE POSCO INTERNATIONAL CO., LTD. [Member]
Disclosure of subsidiaries [line items]
Principal operations	Rice processing
Ownership (%)	60.00%	60.00%
Region	Myanmar
Foreign [member] \| GOLDEN LACE POSCO INTERNATIONAL CO., LTD. [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	60.00%	60.00%
Foreign [member] \| POSCO VST CO LTD [member]
Disclosure of subsidiaries [line items]
Principal operations	Stainless steel sheet manufacturing and sales
Ownership (%)	95.65%	95.65%
Region	Vietnam
Foreign [member] \| POSCO VST CO LTD [member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	95.65%	95.65%
Foreign [member] \| POSCO INDIA PROCESSING CENTER PRIVATE LIMITED [Member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	95.32%	95.32%
Region	India
Foreign [member] \| POSCO INDIA PROCESSING CENTER PRIVATE LIMITED [Member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	93.34%	93.34%
Foreign [member] \| POSCO INDIA PROCESSING CENTER PRIVATE LIMITED [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	1.98%	1.98%
Foreign [member] \| POSCO Vietnam Processing Center Co Ltd [Member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	88.83%	88.83%
Region	Vietnam
Foreign [member] \| POSCO Vietnam Processing Center Co Ltd [Member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)	83.54%	83.54%
Foreign [member] \| POSCO Vietnam Processing Center Co Ltd [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	5.29%	5.29%
Foreign [member] \| POSCO INTERNATIONAL POWER PNGPOM LTD [Member]
Disclosure of subsidiaries [line items]
Principal operations	Electricity production
Ownership (%)	100.00%	100.00%
Region	Papua New Guinea
Foreign [member] \| POSCO INTERNATIONAL POWER PNGPOM LTD [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL AMERICA CORP [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	USA
Foreign [member] \| POSCO INTERNATIONAL AMERICA CORP [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL Deutschland GMBH [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Germany
Foreign [member] \| POSCO INTERNATIONAL Deutschland GMBH [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL JAPAN CORP [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Japan
Foreign [member] \| POSCO INTERNATIONAL JAPAN CORP [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL ITALIA SRL [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Italy
Foreign [member] \| POSCO INTERNATIONAL ITALIA SRL [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL CHINA CO LTD [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	China
Foreign [member] \| POSCO INTERNATIONAL CHINA CO LTD [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL TEXTILE LLC [Member]
Disclosure of subsidiaries [line items]
Principal operations	Textile manufacturing
Ownership (%)	100.00%	100.00%
Region	Uzbekistan
Foreign [member] \| POSCO INTERNATIONAL TEXTILE LLC [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO DAEWOO AUSTRALIA HOLDINGS PTY LTD [Member]
Disclosure of subsidiaries [line items]
Principal operations	Resource development
Ownership (%)	100.00%	100.00%
Region	Australia
Foreign [member] \| POSCO DAEWOO AUSTRALIA HOLDINGS PTY LTD [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL MEXICO SA DE CV [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	Mexico
Foreign [member] \| POSCO INTERNATIONAL MEXICO SA DE CV [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| POSCO INTERNATIONAL INDIA PVT LTD [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)	100.00%	100.00%
Region	India
Foreign [member] \| POSCO INTERNATIONAL INDIA PVT LTD [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%
Foreign [member] \| JB CLARK HILLS1 [Member]
Disclosure of subsidiaries [line items]
Principal operations	Apartment construction
Ownership (%)	70.00%	25.00%
Region	Philippines
Foreign [member] \| JB CLARK HILLS1 [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	25.00%
Foreign [member] \| GRAIN TERMINAL HOLDING PTE LTD [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trade
Ownership (%)	75.00%
Region	Singapore
Foreign [member] \| GRAIN TERMINAL HOLDING PTE LTD [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	75.00%
Foreign [member] \| Mykolaiv Milling Works PJSC [Member]
Disclosure of subsidiaries [line items]
Principal operations	Grain trading
Ownership (%)	100.00%
Region	Ukraine
Foreign [member] \| Mykolaiv Milling Works PJSC [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%
Foreign [member] \| Yuzhnaya Stevedoring Company Limited LLC [Member]
Disclosure of subsidiaries [line items]
Principal operations	Cargo handling
Ownership (%)	100.00%
Region	Ukraine
Foreign [member] \| Yuzhnaya Stevedoring Company Limited LLC [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%
Foreign [member] \| Myanmar POSCO Steel Co Ltd [Member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)	70.00%	70.00%
Region	Myanmar
Foreign [member] \| Myanmar POSCO Steel Co Ltd [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	70.00%	70.00%
Foreign [member] \| POSCO DAEWOO EP CANADA CORPORATION [Member]
Disclosure of subsidiaries [line items]
Principal operations	Crude oil and natural gas mining
Ownership (%)		100.00%
Region	Canada
Foreign [member] \| POSCO DAEWOO EP CANADA CORPORATION [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| POSCO EC THAILAND COLtd [Member]
Disclosure of subsidiaries [line items]
Principal operations	Construction and engineering
Ownership (%)		100.00%
Region	Thailand
Foreign [member] \| POSCO EC THAILAND COLtd [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| POSCO South Asia Company Limited [Member]
Disclosure of subsidiaries [line items]
Principal operations	Steel sales
Ownership (%)		100.00%
Region	Thailand
Foreign [member] \| POSCO South Asia Company Limited [Member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| POSCO Guangdong Coated Steel Co Ltd [Member]
Disclosure of subsidiaries [line items]
Principal operations	Steel manufacturing and sales
Ownership (%)		97.08%
Region	China
Foreign [member] \| POSCO Guangdong Coated Steel Co Ltd [Member] \| Posco [member]
Disclosure of subsidiaries [line items]
Ownership (%)		87.04%
Foreign [member] \| POSCO Guangdong Coated Steel Co Ltd [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		10.04%
Foreign [member] \| DAEWOO INTERNATIONAL GUANGZHOU CORP [Member]
Disclosure of subsidiaries [line items]
Principal operations	Trading business
Ownership (%)		100.00%
Region	China
Foreign [member] \| DAEWOO INTERNATIONAL GUANGZHOU CORP [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)		100.00%
Foreign [member] \| POSCO INTERNATIONAL UKRAINE LLC [Member]
Disclosure of subsidiaries [line items]
Principal operations	Grain sales
Ownership (%)	100.00%	100.00%
Region	Ukraine
Foreign [member] \| POSCO INTERNATIONAL UKRAINE LLC [Member] \| Subsidiaries [member]
Disclosure of subsidiaries [line items]
Ownership (%)	100.00%	100.00%

General Information - Details_2

General Information - Details of Non-controlling Interest (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of subsidiaries [line items]
Current assets	₩ 35,144,493	₩ 34,151,972
Non-current assets	44,226,315	44,625,019
Current liabilities	(16,551,068)	(19,430,577)
Non-current liabilities	(15,056,442)	(12,673,800)
Equity	47,763,298	46,672,614	₩ 47,326,725	₩ 45,765,269
Non-controlling interests	3,308,010	3,347,256
Sales	64,785,709	65,154,636	60,186,867
Profit (loss) for the period	2,038,165	1,932,386	2,909,311
Profit (loss) attributable to non-controlling interests	173,760	220,484	153,081
Cash flows from operating activities	6,004,655	5,869,725	5,607,310
Cash flows from investing activities	(3,682,859)	(2,647,970)	(3,817,874)
Effect of exchange rate fluctuation on cash held	61,764	4,628	(58,997)
Net increase (decrease) in cash and cash equivalents	871,381	31,335	164,911
POSCO DAEWOO Corporation [member]
Disclosure of subsidiaries [line items]
Current assets	4,396,683	5,311,596	4,483,544
Non-current assets	4,186,197	4,363,490	4,590,394
Current liabilities	(3,013,269)	(4,724,056)	(4,221,443)
Non-current liabilities	(2,087,769)	(1,563,107)	(1,549,013)
Equity	3,481,842	3,387,923	3,303,482
Non-controlling interests	1,290,600	1,255,728	1,224,303
Sales	22,745,239	23,314,595	20,891,526
Profit (loss) for the period	199,721	113,196	115,321
Profit (loss) attributable to non-controlling interests	74,030	41,956	42,739
Cash flows from operating activities	580,372	(61,173)	128,875
Cash flows from investing activities	(40,264)	(12,780)	(86,365)
Cash flows from financing activities (before dividends to non-controlling interest)	(502,801)	99,496	(19,295)
Dividend to non-controlling interest	(27,432)	(22,862)	(22,597)
Effect of exchange rate fluctuation on cash held	1,736	807	(459)
Net increase (decrease) in cash and cash equivalents	11,611	3,488	159
PT. KRAKATAU POSCO [member]
Disclosure of subsidiaries [line items]
Current assets	520,057	615,491	557,041
Non-current assets	2,723,254	2,730,865	2,771,504
Current liabilities	(1,570,204)	(1,368,498)	(1,237,255)
Non-current liabilities	(1,590,810)	(1,754,797)	(1,933,247)
Equity	82,297	223,061	158,043
Non-controlling interests	24,689	66,918	47,413
Sales	1,906,302	1,871,634	1,635,837
Profit (loss) for the period	(146,975)	54,257	(117,729)
Profit (loss) attributable to non-controlling interests	(44,093)	16,277	(35,318)
Cash flows from operating activities	61,398	89,131	(27,817)
Cash flows from investing activities	(7,173)	(6,432)	(5,502)
Cash flows from financing activities (before dividends to non-controlling interest)	(53,890)	(82,295)	31,782
Effect of exchange rate fluctuation on cash held	25	21	(147)
Net increase (decrease) in cash and cash equivalents	360	425	(1,684)
POSCO CHEMTECH [member]
Disclosure of subsidiaries [line items]
Current assets	624,017	416,284	441,325
Non-current assets	1,050,406	460,905	316,724
Current liabilities	(236,968)	(140,268)	(145,649)
Non-current liabilities	(462,361)	(10,767)	(970)
Equity	975,094	726,154	611,430
Non-controlling interests	377,770	290,461	244,572
Sales	1,434,507	1,340,984	1,163,918
Profit (loss) for the period	94,481	142,918	101,019
Profit (loss) attributable to non-controlling interests	36,604	57,167	40,408
Cash flows from operating activities	22,794	29,865	20,042
Cash flows from investing activities	(111,996)	(15,801)	(18,699)
Cash flows from financing activities (before dividends to non-controlling interest)	134,609		8
Dividend to non-controlling interest	(9,451)	(8,270)	(7,088)
Effect of exchange rate fluctuation on cash held	(7)	(17)	(6)
Net increase (decrease) in cash and cash equivalents	35,949	5,777	(5,743)
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of subsidiaries [line items]
Current assets	4,242,954	4,100,967	4,878,251
Non-current assets	1,808,919	1,911,844	2,444,616
Current liabilities	(2,734,305)	(3,007,029)	(3,896,680)
Non-current liabilities	(786,191)	(608,089)	(833,403)
Equity	2,531,377	2,397,693	2,592,784
Non-controlling interests	1,194,833	1,131,733	1,223,816
Sales	7,625,389	6,799,292	5,794,532
Profit (loss) for the period	330,298	290,131	169,011
Profit (loss) attributable to non-controlling interests	155,904	136,944	79,775
Cash flows from operating activities	24,636	207,729	(84,840)
Cash flows from investing activities	(6,620)	272,230	(171,924)
Cash flows from financing activities (before dividends to non-controlling interest)	(25,448)	(400,499)	150,801
Dividend to non-controlling interest	(9,867)
Effect of exchange rate fluctuation on cash held	1,401	1,257	(3,541)
Net increase (decrease) in cash and cash equivalents	(15,898)	80,717	(109,504)
POSCO ENERGY CO., LTD. [member]
Disclosure of subsidiaries [line items]
Current assets	441,208	825,241	1,054,538
Non-current assets	210,037	2,767,203	2,859,824
Current liabilities	(262,265)	(1,197,845)	(785,462)
Non-current liabilities	(38,836)	(1,445,288)	(2,200,065)
Equity	350,144	949,311	928,835
Non-controlling interests	121,213	335,203	762,390
Sales	925,551	1,841,187	1,578,026
Profit (loss) for the period	32,954	(73,948)	70,795
Profit (loss) attributable to non-controlling interests	11,408	(8,116)	7,770
Cash flows from operating activities	21,571	16,211	30,295
Cash flows from investing activities	(2,129)	35,460	(2,792)
Cash flows from financing activities (before dividends to non-controlling interest)	(336)	(71,378)	220,317
Dividend to non-controlling interest	(2,628)	(19,813)	(24,183)
Effect of exchange rate fluctuation on cash held	(47)
Net increase (decrease) in cash and cash equivalents	16,431	(39,520)	223,637
Others [member]
Disclosure of subsidiaries [line items]
Current assets	8,062,428	9,137,798	8,579,813
Non-current assets	4,740,887	5,493,324	6,676,559
Current liabilities	(7,672,691)	(8,026,474)	(8,313,902)
Non-current liabilities	(2,095,797)	(1,925,084)	(2,048,454)
Equity	3,034,827	4,679,564	4,894,016
Non-controlling interests	1,124,381	929,506	974,941
Sales	22,975,605	24,721,939	23,547,072
Profit (loss) for the period	(587,146)	(56,151)	258,053
Profit (loss) attributable to non-controlling interests	(89,676)	(101,156)	39,605
Cash flows from operating activities	(16,324)	14,869	140,418
Cash flows from investing activities	31,057	(13,199)	(63,621)
Cash flows from financing activities (before dividends to non-controlling interest)	(4,295)	(16,094)	(38,090)
Dividend to non-controlling interest	(11,079)	(6,906)	(12,777)
Effect of exchange rate fluctuation on cash held	3,931	1,682	(15,532)
Net increase (decrease) in cash and cash equivalents	3,290	(19,648)	10,398
Non-controlling Interest [member]
Disclosure of subsidiaries [line items]
Current assets	18,287,347	20,407,377	19,994,512
Non-current assets	14,719,700	17,727,631	19,659,621
Current liabilities	(15,489,702)	(18,464,170)	(18,600,391)
Non-current liabilities	(7,061,764)	(7,307,132)	(8,565,152)
Equity	10,455,581	12,363,706	12,488,590
Non-controlling interests	4,133,486	4,009,549	4,477,435
Sales	57,612,593	59,889,631	54,610,911
Profit (loss) for the period	(76,667)	470,403	596,470
Profit (loss) attributable to non-controlling interests	144,177	143,072	174,979
Cash flows from operating activities	694,447	296,632	206,973
Cash flows from investing activities	(137,125)	259,478	(348,903)
Cash flows from financing activities (before dividends to non-controlling interest)	(452,161)	(470,770)	345,523
Dividend to non-controlling interest	(60,457)	(57,851)	(66,645)
Effect of exchange rate fluctuation on cash held	7,039	3,750	(19,685)
Net increase (decrease) in cash and cash equivalents	₩ 51,743	₩ 31,239	₩ 117,263

General Information - Details_3

General Information - Details of Associates (Detail)	12 Months Ended
General Information - Details of Associates (Detail)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Domestic [member] \| New Songdo International City Development, LLC [member]
Disclosure of associates [line items]
Category of business	Real estate rental
Ownership (%)	29.90%	29.90%
Region	Seoul
Domestic [member] \| Gale International Korea, LLC [member]
Disclosure of associates [line items]
Category of business	Real estate rental
Ownership (%)	29.90%	29.90%
Region	Seoul
Domestic [member] \| SNNC [member]
Disclosure of associates [line items]
Category of business	Raw material manufacturing and sales
Ownership (%)	49.00%	49.00%
Region	Gwangyang
Domestic [member] \| KONES, Corp. [member]
Disclosure of associates [line items]
Category of business	Technical service
Ownership (%)	41.67%	41.67%
Region	Gyeongju
Domestic [member] \| Chungju Enterprise City Development Co., Ltd [member]
Disclosure of associates [line items]
Category of business	Real estate development
Ownership (%)	29.53%	29.53%
Region	Chungju
Domestic [member] \| DAEHO GLOBAL MANAGEMENT CO., LTD. [member]
Disclosure of associates [line items]
Category of business	Investment advisory service
Ownership (%)	35.82%	35.82%
Region	Pohang
Domestic [member] \| Mokpo Deayang Industrial Corporation [member]
Disclosure of associates [line items]
Category of business	Real estate development and rental
Ownership (%)	27.40%	27.40%
Region	Mokpo
Domestic [member] \| Gunggi Green Energy [member]
Disclosure of associates [line items]
Category of business	Electricity generation
Ownership (%)	19.00%	19.00%
Region	Hwaseong
Domestic [member] \| Pohang Special Welding Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Welding material and tools manufacturing and sales
Ownership (%)	50.00%	50.00%
Region	Pohang
Domestic [member] \| KoFC POSCO HANWHA KB Shared Growth No. 2. Private Equity Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	12.50%	12.50%
Region	Seoul
Domestic [member] \| EQP POSCO Global No1 Natural Resources Private Equity Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	33.41%	31.27%
Region	Seoul
Domestic [member] \| KC Chemicals CORP [member]
Disclosure of associates [line items]
Category of business	Machinery manufacturing
Ownership (%)	19.00%	19.00%
Region	Hwaseong
Domestic [member] \| Garolim Tidal Power Plant Co., Ltd [member]
Disclosure of associates [line items]
Category of business	Tidal power plant construction and management
Ownership (%)	32.13%	32.13%
Region	Seosan
Domestic [member] \| POSTECH Social Enterprise Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	9.17%	9.17%
Region	Seoul
Domestic [member] \| QSONE Co.,Ltd. [member]
Disclosure of associates [line items]
Category of business	Real estate rental and facility management
Ownership (%)	50.00%	50.00%
Region	Seoul
Domestic [member] \| Chun-cheon Energy Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Electricity generation
Ownership (%)	49.10%	45.67%
Region	Chuncheon
Domestic [member] \| Keystone NO. 1. Private Equity Fund [member]
Disclosure of associates [line items]
Category of business	Private equity financial
Ownership (%)	52.58%	40.45%
Region	Seoul
Domestic [member] \| Noeul Green Energy Co., Ltd [member]
Disclosure of associates [line items]
Category of business	Electricity generation
Ownership (%)	10.00%	10.00%
Region	Seoul
Domestic [member] \| Posco-IDV Growth Ladder IP Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	17.86%	17.86%
Region	Seoul
Domestic [member] \| Daesung Steel [member]
Disclosure of associates [line items]
Category of business	Steel sales
Ownership (%)	17.54%	17.54%
Region	Busan
Domestic [member] \| Pohang E&E Co,. Ltd. [member]
Disclosure of associates [line items]
Category of business	Investment in waste energy
Ownership (%)	30.00%	30.00%
Region	Pohang
Domestic [member] \| POSCO Energy Valley Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	20.00%	20.00%
Region	Pohang
Domestic [member] \| Hyundai Invest Guggenheim CLO Private Special Asset Investment Trust II [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	35.44%	38.47%
Region	Seoul
Domestic [member] \| PoscoPlutus Bio Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	11.97%	11.97%
Region	Seoul
Domestic [member] \| PoscoPlutus Project Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	11.91%	11.91%
Region	Seoul
Domestic [member] \| Posco Agri-Food Export Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	30.00%	30.00%
Region	Seoul
Domestic [member] \| PoscoPlutus Project Second Project Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	0.61%	0.61%
Region	Seoul
Domestic [member] \| Posco Culture Contents Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	31.67%	31.67%
Region	Seoul
Domestic [member] \| PCC Centroid New 1st Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	24.10%	24.10%
Region	Seoul
Domestic [member] \| PCC Amberstone Private Equity Fund I [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	8.80%	8.80%
Region	Seoul
Domestic [member] \| UITrans LRT Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Transporting
Ownership (%)	38.19%	38.19%
Region	Seoul
Domestic [member] \| POSCO Advanced Technical Staff Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	15.87%	15.87%
Region	Seoul
Domestic [member] \| POSCO 4th Industrial Revolution Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	19.05%	19.05%
Region	Seoul
Domestic [member] \| Incheon-Gimpo Expressway Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Construction
Ownership (%)	18.26%	18.26%
Region	Anyang
Domestic [member] \| Pureun Tongyeong Enviro Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Sewerage treatment
Ownership (%)	20.40%	20.40%
Region	Tongyeong
Domestic [member] \| Pure Gimpo Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Construction
Ownership (%)	28.79%	28.79%
Region	Seoul
Domestic [member] \| POSCO PLANTEC Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Construction of industrial plant
Ownership (%)	73.94%	73.94%
Region	Ulsan
Domestic [member] \| Posgreen Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Lime and plaster manufacturing
Ownership (%)	19.00%	19.00%
Region	Gwangyang
Domestic [member] \| Clean Iksan Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Construction
Ownership (%)	23.50%	23.50%
Region	Iksan
Domestic [member] \| Innovalley Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Real estate development
Ownership (%)	28.77%	28.77%
Region	Yongin
Domestic [member] \| Pohang Techno Valley PFV Corporation [member]
Disclosure of associates [line items]
Category of business	Real estate development, supply and rental
Ownership (%)	57.39%	57.39%
Region	Pohang
Domestic [member] \| Blue Ocean private equity fund [member]
Disclosure of associates [line items]
Category of business	Private equity financial
Ownership (%)	27.52%	27.52%
Region	Seoul
Domestic [member] \| Western Inland Highway Co Ltd [member]
Disclosure of associates [line items]
Category of business	Construction
Ownership (%)	30.00%	27.50%
Region	Incheon
Domestic [member] \| Metropolitan Outer Ring Expressway Co Ltd [member]
Disclosure of associates [line items]
Category of business	Investment in Expressway
Ownership (%)	21.27%	47.58%
Region	Incheon
Domestic [member] \| IT Engineering CO. Ltd [member]
Disclosure of associates [line items]
Category of business	Vehicle engineering
Ownership (%)	4.99%	10.84%
Region	Seoul
Domestic [member] \| PCC Bio 1ST Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	13.46%	13.46%
Region	Seoul
Domestic [member] \| INNOPOLIS Job Creation Fund II [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	6.21%	6.43%
Region	Seoul
Domestic [member] \| Pospower Co Ltd [member]
Disclosure of associates [line items]
Category of business	Generation of electricity
Ownership (%)	34.00%	34.00%
Region	Samcheok
Domestic [member] \| INKOTECH INC [Member]
Disclosure of associates [line items]
Category of business	Electricity generation and sales
Ownership (%)	10.00%	10.00%
Region	Seoul
Domestic [member] \| PCC Social Enterprise Fund II [member]
Disclosure of associates [line items]
Category of business	Investment in venture companies
Ownership (%)	16.67%	16.67%
Region	Seoul
Domestic [member] \| PCC Amberstone Private Equity Fund II [member]
Disclosure of associates [line items]
Category of business	Private equity trust
Ownership (%)	19.91%	19.70%
Region	Seoul
Domestic [member] \| Synapse Fund [member]
Disclosure of associates [line items]
Category of business	Investment in new technologies
Ownership (%)	16.26%	16.26%
Region	Seoul
Domestic [member] \| NEXTRAIN Co., Ltd [member]
Disclosure of associates [line items]
Category of business	Service maintenance and management
Ownership (%)	32.00%	32.00%
Region	Incheon
Domestic [member] \| TK CHEMICAL CORPORATION [member]
Disclosure of associates [line items]
Category of business	Chemical
Ownership (%)	5.01%	8.80%
Region	Daegu
Domestic [member] \| Hanil-Daewoo Cement Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Cement
Ownership (%)	15.00%	15.00%
Region	Incheon
Domestic [member] \| PCC S/W 2nd Fund [Member]
Disclosure of associates [line items]
Category of business	Investment in new technologies business
Ownership (%)	12.81%
Region	Pohang
Domestic [member] \| PCCConar No 1 Fund l [Member]
Disclosure of associates [line items]
Category of business	Investment in venture
Ownership (%)	13.64%
Region	Pohang
Domestic [member] \| Hyochun CO., LTD [member]
Disclosure of associates [line items]
Category of business	Screen door operation and other
Ownership (%)	18.00%
Region	Seoul
Domestic [member] \| PCC EV Fund [Member]
Disclosure of associates [line items]
Category of business	Investment in new technologies business
Ownership (%)	18.18%
Region	Pohang
Domestic [member] \| IBKCPCC 1st Fund [Member]
Disclosure of associates [line items]
Category of business	Investment in new technologies business
Ownership (%)	18.18%
Region	Pohang
Domestic [member] \| 2019 PCC Materials and Parts Fund [Member]
Disclosure of associates [line items]
Category of business	Investment in new technologies business
Ownership (%)	8.70%
Region	Pohang
Domestic [member] \| Shinahn wind Power generation [Member]
Disclosure of associates [line items]
Category of business	Electric, gas, steam
Ownership (%)	19.00%
Region	Suwon
Domestic [member] \| 2019 PCC New technology Fund [Member]
Disclosure of associates [line items]
Category of business	Investment in new technologies business
Ownership (%)	4.76%
Region	Pohang
Domestic [member] \| PCCWoori LP secondary Fund [Member]
Disclosure of associates [line items]
Category of business	Investment in new technologies business
Ownership (%)	18.85%
Region	Pohang
Domestic [member] \| 2016 Posco Plutus New technology Fund [Member]
Disclosure of associates [line items]
Category of business	New technology business investment
Ownership (%)		25.17%
Region	Seoul
Domestic [member] \| Clean Gimpo Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Waste treatment and others
Ownership (%)	0.00%	29.58%
Region		Gimpo
Domestic [member] \| Postech Early Stage Fund [member]
Disclosure of associates [line items]
Category of business	investment in New technology
Ownership (%)	0.00%	10.00%
Region		Pohang
Domestic [member] \| Applied Science Corp. [member]
Disclosure of associates [line items]
Category of business	Machine manufacturing for semiconductor manufacturing
Domestic [member] \| RPSD Project Co Ltd [Member]
Disclosure of associates [line items]
Category of business	Real estate development
Ownership (%)	29.00%
Region	Incheon
Domestic [member] \| Appliedscience Co Ltd [Member]
Disclosure of associates [line items]
Category of business	Machine manufacturing for semiconductor manufacturing
Ownership (%)		22.89%
Region	Paju
Foreign [member] \| VSC POSCO Steel Corporation [member]
Disclosure of associates [line items]
Category of business	Steel processing and sales	Steel processing and sales
Ownership (%)	50.00%	50.00%	50.00%
Region	Vietnam
Foreign [member] \| JB CLARK HILLS [member]
Disclosure of associates [line items]
Category of business	Apartment Construction
Ownership (%)	70.00%	25.00%
Region	Philippines
Foreign [member] \| POSCHROME (PROPRIETARY) LIMITED [member]
Disclosure of associates [line items]
Category of business	Raw material manufacturing and sales	Raw material manufacturing and sales
Ownership (%)	50.00%	50.00%	50.00%
Region	South Africa
Foreign [member] \| CAML RESOURCES PTY LTD. [member]
Disclosure of associates [line items]
Category of business	Raw material manufacturing and sales	Raw material manufacturing and sales
Ownership (%)	33.34%	33.34%	33.34%
Region	Australia
Foreign [member] \| Nickel mining company SAS [member]
Disclosure of associates [line items]
Category of business	Raw material manufacturing and sales	Raw material manufacturing and sales
Ownership (%)	49.00%	49.00%	49.00%
Region	New Caledonia
Foreign [member] \| PT. wampu electric power [member]
Disclosure of associates [line items]
Category of business	Construction and civil engineering	Construction and civil engineering
Ownership (%)	20.00%	20.00%	20.00%
Region	Indonesia
Foreign [member] \| POSK(Pinghu) Steel Processing Center Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Steel processing and sales	Steel processing and sales
Ownership (%)	20.00%	20.00%	20.00%
Region	China
Foreign [member] \| PT.INDONESIA POS CHEMTECH CHOSUN Ref [member]
Disclosure of associates [line items]
Category of business	Refractory manufacturing and sales
Ownership (%)	30.19%	30.19%
Region		Indonesia
Foreign [member] \| NS-Thainox Auto Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Steel manufacturing and sales	Steel manufacturing and sales
Ownership (%)	49.00%	49.00%	49.00%
Region	Vietnam
Foreign [member] \| Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of associates [line items]
Category of business	Tinplate manufacturing and sales	Tinplate manufacturing and sales
Ownership (%)	34.00%	34.00%	34.00%
Region	China
Foreign [member] \| PT. Tanggamus Electric Power [member]
Disclosure of associates [line items]
Category of business	Construction and civil engineering	Construction and civil engineering
Ownership (%)	17.50%	17.50%	17.50%
Region	Indonesia
Foreign [member] \| LLP POSUK Titanium [member]
Disclosure of associates [line items]
Category of business	Titanium manufacturing and sales	Titanium manufacturing and sales
Ownership (%)	35.30%	36.83%	36.83%
Region	Kazakhstan
Foreign [member] \| LI3 ENERGY INC [member]
Disclosure of associates [line items]
Category of business	Resource development	Resource development
Ownership (%)	26.06%	26.06%	26.06%
Region	Peru
Foreign [member] \| IMFA ALLOYS FINLEASE LTD. [member]
Disclosure of associates [line items]
Category of business	Raw material manufacturing and sales	Raw material manufacturing and sales
Ownership (%)	24.00%	24.00%	24.00%
Region	India
Foreign [member] \| KRAKATAU POS-CHEM DONG-SUH CHEMICAL [member]
Disclosure of associates [line items]
Category of business	Chemical by-product manufacturing and sales
Ownership (%)	19.00%	19.00%	19.00%
Region	Indonesia
Foreign [member] \| 7623704 Canada Inc. [member]
Disclosure of associates [line items]
Category of business	Investments management	Investments management
Ownership (%)	10.40%	10.40%	10.40%
Region	Canada
Foreign [member] \| Hamparan Mulya [member]
Disclosure of associates [line items]
Category of business	Resource development	Resource development
Ownership (%)	45.00%	45.00%	45.00%
Region	Indonesia
Foreign [member] \| POS-SEAHSTEELWIRE (TIANJIN) CO., Ltd [member]
Disclosure of associates [line items]
Category of business	Steel manufacturing and sales
Ownership (%)	25.00%	25.00%
Region		China
Foreign [member] \| Eureka Moly LLC [member]
Disclosure of associates [line items]
Category of business	Raw material manufacturing and sales	Raw material manufacturing and sales
Ownership (%)	20.00%	20.00%	20.00%
Region	USA
Foreign [member] \| PT. batutua tembaga raya [member]
Disclosure of associates [line items]
Category of business	Raw material manufacturing and sales	Raw material manufacturing and sales
Ownership (%)	22.00%	22.00%	22.00%
Region	Indonesia
Foreign [member] \| KIRIN VIETNAM CO., LTD [member]
Disclosure of associates [line items]
Category of business	Panel manufacturing	Panel manufacturing
Ownership (%)	19.00%	19.00%	19.00%
Region	Vietnam
Foreign [member] \| POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Steel processing and sales	Steel processing and sales
Ownership (%)	25.00%	25.00%	25.00%
Region	China
Foreign [member] \| POS-SeAH Steel Wire (Thailand) Co., Ltd. [member]
Disclosure of associates [line items]
Category of business	Steel manufacturing and sales	Steel manufacturing and sales
Ownership (%)	25.00%	25.00%	25.00%
Region	Thailand
Foreign [member] \| Jupiter Mines Limited [member]
Disclosure of associates [line items]
Category of business	Resource development	Resource development
Ownership (%)	6.93%	6.93%	6.93%
Region	Australia
Foreign [member] \| SAMHWAN VINA CO., LTD [member]
Disclosure of associates [line items]
Category of business	Steel manufacturing and sales	Steel manufacturing and sales
Ownership (%)	19.00%	19.00%	19.00%
Region	Vietnam
Foreign [member] \| Saudi-Korean Company for Maintenance Properties Management LLC [member]
Disclosure of associates [line items]
Category of business	Building management	Building management
Ownership (%)	19.00%	19.00%	19.00%
Region	Saudi Arabia
Foreign [member] \| AMCI (WA) PTY LTD [member]
Disclosure of associates [line items]
Category of business	Iron ore sales & mine development
Ownership (%)	49.00%	49.00%
Region	Australia
Foreign [member] \| NCR LLC [member]
Disclosure of associates [line items]
Category of business	Coal sales
Ownership (%)	29.40%	29.41%
Region	Canada
Foreign [member] \| SHANGHAI LANSHENG DAEWOO CORP. [member]
Disclosure of associates [line items]
Category of business	Trading
Ownership (%)	49.00%	49.00%
Region	China
Foreign [member] \| SHANGHAI WAIGAOQIAO FREE TRADE ZONE LANSHENG DAEWOO IN'L TRADING CO., LTD. [member]
Disclosure of associates [line items]
Category of business	Trading
Ownership (%)	49.00%	49.00%
Region	China
Foreign [member] \| General Medicines Company Ltd. [member]
Disclosure of associates [line items]
Category of business	Medicine manufacturing and sales
Ownership (%)	33.00%	33.00%
Region	Sudan
Foreign [member] \| KOREA LNG LTD. [member]
Disclosure of associates [line items]
Category of business	Gas production and sales
Ownership (%)	20.00%	20.00%
Region	England
Foreign [member] \| AES-VCM Mong Duong Power Company Limited [member]
Disclosure of associates [line items]
Category of business	Electricity generation
Ownership (%)	30.00%	30.00%
Region	Vietnam
Foreign [member] \| KG Power(M) SDN. BHD [member]
Disclosure of associates [line items]
Category of business	Resource development
Ownership (%)	20.00%	20.00%
Region	Malaysia
Foreign [member] \| South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of associates [line items]
Category of business	Pipeline construction and management
Ownership (%)	25.04%	25.04%
Region	Myanmar
Foreign [member] \| GLOBAL KOMSCO Daewoo LLC [member]
Disclosure of associates [line items]
Category of business	Cotton celluloid manufacturing and sales
Ownership (%)	35.00%	35.00%
Region	Uzbekistan
Foreign [member] \| POSCO-Poggenamp Electrical Steel Pvt. Ltd. [member]
Disclosure of associates [line items]
Category of business	Steel processing and sales
Ownership (%)	26.00%	26.00%
Region	India
Foreign [member] \| Qingdao Pohang DGENX Stainless Steel Pipe Co Ltd [member]
Disclosure of associates [line items]
Category of business	Exhaust meter manufacturing
Ownership (%)	40.00%	40.00%
Region	China
Foreign [member] \| SHINPOONG DAEWOO PHARMA VIETNAM CO.,LTD [member]
Disclosure of associates [line items]
Category of business	Medicine production
Ownership (%)	3.42%	3.42%
Region	Vietnam
Foreign [member] \| ZHEJIANG HUAYOUPOSCO ESM [Member]
Disclosure of associates [line items]
Category of business	Produce
Ownership (%)	40.00%
Region	China
Foreign [member] \| Sebang Steel [member]
Disclosure of associates [line items]
Category of business	Scrap sale
Ownership (%)		49.00%
Region		Japan
Foreign [member] \| ERAE Automotive Systems Mexico, S. DE R.L. DE C.V [member]
Disclosure of associates [line items]
Category of business	Automobile parts manufacturing
Ownership (%)	0.00%	7.65%
Region	Mexico

General Information - Details_4

General Information - Details of Joint Ventures (Detail)	12 Months Ended
General Information - Details of Joint Ventures (Detail)	Dec. 31, 2019	Dec. 31, 2018
Domestic [member] \| POSCO MITSUBISHI CARBON TECHNOLOGY [member]
Disclosure of joint ventures [line items]
Category of business	Steel processing and sales
Ownership (%)	60.00%	60.00%
Region	Gwangyang
Domestic [member] \| POSCO-SGI Falcon Pharma Biological Secondary Fund [member]
Disclosure of joint ventures [line items]
Category of business	Investment in new technologies
Ownership (%)	24.55%	24.55%
Region	Seoul
Domestic [member] \| POSCO-KB Shipbuilding Restructuring Fund [member]
Disclosure of joint ventures [line items]
Category of business	Investment in new technologies
Ownership (%)	18.75%	18.75%
Region	Seoul
Domestic [member] \| POSCO-NSC Venture Fund [member]
Disclosure of joint ventures [line items]
Category of business	Investment in new technologies
Ownership (%)	16.67%	16.67%
Region	Seoul
Domestic [member] \| Posto Plutus Project 3rd Project Fund [member]
Disclosure of joint ventures [line items]
Category of business	Investment in new technologies
Ownership (%)	5.96%	5.96%
Region	Seoul
Domestic [member] \| PCC Bio 2nd Fund [member]
Disclosure of joint ventures [line items]
Category of business	Investment in new technologies
Ownership (%)	19.72%	19.72%
Region	Seoul
Domestic [member] \| PCC Material 3rd Fund [member]
Disclosure of joint ventures [line items]
Category of business	Investment in new technologies
Ownership (%)	2.38%	2.38%
Region	Seoul
Domestic [member] \| Union PCC Portfolio Fund [member]
Disclosure of joint ventures [line items]
Category of business	Investment in venture
Ownership (%)	14.12%
Region	Seoul
Domestic [member] \| PCC S/W FUND [member]
Disclosure of joint ventures [line items]
Category of business	Investment in new technologies
Ownership (%)	0.46%
Region	Seoul
Foreign [member] \| KOBRASCO [member]
Disclosure of joint ventures [line items]
Category of business	Steel materials manufacturing and sales
Ownership (%)	50.00%	50.00%
Region	Brazil
Foreign [member] \| USS-POSCO Industries [member]
Disclosure of joint ventures [line items]
Category of business	Cold-rolled steel manufacturing and sales
Ownership (%)	50.00%	50.00%
Region	USA
Foreign [member] \| PT. POSMI Steel Indonesia [member]
Disclosure of joint ventures [line items]
Category of business	Steel processing and sales
Ownership (%)	36.69%	36.69%
Region	Indonesia
Foreign [member] \| United Spiral Pipe, LLC [member]
Disclosure of joint ventures [line items]
Category of business	Material manufacturing and sales
Ownership (%)	35.00%	35.00%
Region	USA
Foreign [member] \| CSP — Compania Siderurgica do Pecem [member]
Disclosure of joint ventures [line items]
Category of business	Steel manufacturing and sales
Ownership (%)	20.00%	20.00%
Region	Brazil
Foreign [member] \| BX STEEL POSCO Cold Rolled Sheet Co., Ltd. [member]
Disclosure of joint ventures [line items]
Category of business	Steel processing and sales
Ownership (%)	25.00%	25.00%
Region	China
Foreign [member] \| POSCO-SAMSUNG-Slovakia Processing Center [member]
Disclosure of joint ventures [line items]
Category of business	Steel processing and sales
Ownership (%)	30.00%	30.00%
Region	Slovakia
Foreign [member] \| YULCHON MEXICO S.A. DE C.V. [member]
Disclosure of joint ventures [line items]
Category of business	Tube for automobile manufacturing
Ownership (%)	19.00%	19.00%
Region	Mexico
Foreign [member] \| Hyunson Engineering & Construction HYENCO [member]
Disclosure of joint ventures [line items]
Category of business	Construction
Ownership (%)	4.89%	4.89%
Region	Algeria
Foreign [member] \| POSCO E&C Saudi Arabia [member]
Disclosure of joint ventures [line items]
Category of business	Civil engineering and construction
Ownership (%)	40.00%	40.00%
Region	Saudi Arabia
Foreign [member] \| POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member]
Disclosure of joint ventures [line items]
Category of business	Automotive parts manufacturing
Ownership (%)	19.90%	19.90%
Region	China
Foreign [member] \| POS-InfraAuto (Suzhou) Co., Ltd [member]
Disclosure of joint ventures [line items]
Category of business	Automotive parts manufacturing
Ownership (%)	16.20%	16.20%
Region	China
Foreign [member] \| POSCO(Yantai)Automotive Processing Center Co., Ltd. [member]
Disclosure of joint ventures [line items]
Category of business	Automotive parts manufacturing
Ownership (%)	11.10%	11.10%
Region	China
Foreign [member] \| POS-AUSTEM WUHAN AUTOMOTIVE CO., LTD [member]
Disclosure of joint ventures [line items]
Category of business	Automotive parts manufacturing
Ownership (%)	13.00%	13.00%
Region	China
Foreign [member] \| Kwanika Copper Corporation [member]
Disclosure of joint ventures [line items]
Category of business	Energy & resource development
Ownership (%)	35.00%	35.00%
Region	Canada
Foreign [member] \| DMSA/AMSA [member]
Disclosure of joint ventures [line items]
Category of business	Energy & resource development
Ownership (%)	4.00%	4.00%
Region	Madagascar
Foreign [member] \| Roy Hill Holdings Pty Ltd. [member]
Disclosure of joint ventures [line items]
Category of business	Energy & resource development
Ownership (%)	12.50%	12.50%
Region	Australia
Foreign [member] \| POSCO-NPS Niobium LLC [member]
Disclosure of joint ventures [line items]
Category of business	Mine development
Ownership (%)	50.00%	50.00%
Region	USA
Foreign [member] \| VNS-DAEWOO Co., Ltd. [member]
Disclosure of joint ventures [line items]
Category of business	Fabricate and sell iron scraps
Ownership (%)		50.00%
Region	Vietnam

General Information - Consolida

General Information - Consolidated Subsidiaries Acquired or Newly Established (Detail)	12 Months Ended
	Dec. 31, 2019
GRAIN TERMINAL HOLDING PTE LTD [member]
Disclosure of subsidiaries [line items]
Date of addition	2019-06
Ownership (%)	75.00%
Reason	Acquisition of control
Mykolaiv Milling Works PJSC [member]
Disclosure of subsidiaries [line items]
Date of addition	2019-06
Ownership (%)	100.00%
Reason	Acquisition of control
Yuzhnaya Stevedoring Company Limited LLC [member]
Disclosure of subsidiaries [line items]
Date of addition	2019-06
Ownership (%)	100.00%
Reason	Acquisition of control
Chargev Co., Ltd [member]
Disclosure of subsidiaries [line items]
Date of addition	2019-09
Ownership (%)	100.00%
Reason	New establishment
Korea Fuel Cell [member]
Disclosure of subsidiaries [line items]
Date of addition	2019-11
Ownership (%)	100.00%
Reason	New establishment
JB CLARK HILLS [member]
Disclosure of subsidiaries [line items]
Date of addition	2019-12
Ownership (%)	70.00%
Reason	Reclassified to subsidiary from associate
POSCO GEM 1st Fund [member]
Disclosure of subsidiaries [line items]
Date of addition	2019-12
Ownership (%)	100.00%
Reason	New establishment

General Information - Subsidiar

General Information - Subsidiaries That Were Excluded From Consolidation (Detail)	12 Months Ended
	Dec. 31, 2019
POSCO Processing Service Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-01
Reason	Merged into POSCO Co.,Ltd
Daewoo Precious Resources Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-01
Reason	Liquidation
BLUE O&M Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-02
Reason	Merged into POSCO O&M CO.,Ltd.
Mega asset Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-02
Reason	Merged into POSCO O&M CO.,Ltd.
POSCO ESM Co., Ltd.[member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-04
Reason	Merged into POSCO Chemical CO.,Ltd.
Daewoo International Guangzhou Corp. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-04
Reason	Merged into POSCO INTERNATIONAL(CHINA) CO.,Ltd.
POSCO(Guangdong) Coated Steel Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-06
Reason	Disposal
POSCO EC THAILAND CO., Ltd.[member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-06
Reason	Liquidation
POSCO Gulf SFC LLC [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-06
Reason	Liquidation
HOTEL LAONZENA [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-07
Reason	Disposal
Daewoo Power and Infra (PTY) Limited [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-07
Reason	Liquidation
POSCO SINGAPORE LNG TRADING PTE. LTD [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-09
Reason	Liquidation
POSCO-South Asia Co., Ltd. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-09
Reason	Liquidation
PSIB CO.,Ltd. [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-10
Reason	Liquidation
Chargev Co., Ltd [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-12
Reason	Disposal
POSCO DAEWOO E&P CANADA CORPORATION [member]
Disclosure of subsidiaries [line items]
Date of exclusion	2019-12
Reason	Liquidation

Statement of Compliance - Addit

Statement of Compliance - Additional Information (Detail) - IFRS 16 [member] ₩ in Millions	Jan. 01, 2019KRW (₩)
Disclosure of initial application of standards or interpretations [line items]
Finance lease receivables	₩ 264,809
Bottom of range [member]
Disclosure of initial application of standards or interpretations [line items]
Weighted average incremental borrowing rates for leases	1.80%
Top of range [member]
Disclosure of initial application of standards or interpretations [line items]
Weighted average incremental borrowing rates for leases	18.50%

Statement of Compliance - Summa

Statement of Compliance - Summary of Additional Right-of-use Assets and Liabilities Recognized (Detail) - KRW (₩) ₩ in Millions	Jan. 01, 2019	Dec. 31, 2019
Disclosure detail of additional right-of-use assets and liabilities recognized [line items]
Right-of-use assets presented as property, plant and equipment		₩ 774,582
IFRS 16 [member]
Disclosure detail of additional right-of-use assets and liabilities recognized [line items]
Right-of-use assets presented as property, plant and equipment	₩ 704,458
Lease receivable	264,809
Lease liabilities	₩ 677,370

Statement of Compliance - Sum_2

Statement of Compliance - Summary of Additional Right-of-use Assets and Liabilities Recognized (Parenthetical) (Detail) ₩ in Millions	Jan. 01, 2019KRW (₩)
Right of use assets [member] \| IFRS 16 [member]
Disclosure detail of additional right-of-use assets and liabilities recognized [line items]
Reclassification of prepayment lease fees	₩ 271,825

Statement of Compliance - Sum_3

Statement of Compliance - Summary of Carrying Amount of Lease Liabilities (Detail) - IFRS 16 [member] ₩ in Millions	Jan. 01, 2019KRW (₩)
Disclosure detail of carrying amount of lease liabilities [line items]
Operating lease commitments as of December 31, 2018	₩ 913,630
Operating lease commitments not recognized as lease liabilities:
- Leases of low-value assets	(50,364)
- Leases with less than 12 months of lease term at transition	(17,635)
Operating lease commitments recognized as lease liabilities	845,631
Amount discounted using the ,incremental borrowing rate as of January 1, 2019	677,370
Finance lease liabilities recognized as of December 31, 2018	94,754
Lease liabilities as of January 1, 2019, the date of initial application	₩ 772,124

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Estimated Useful Lives of Property, Plant and Equipment (Detail)	12 Months Ended
	Dec. 31, 2019
Bearer plants [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	20 years
Bottom of range [member] \| Buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	5 years
Bottom of range [member] \| Structures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	4 years
Bottom of range [member] \| Machinery and equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	4 years
Bottom of range [member] \| Vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	3 years
Bottom of range [member] \| Tools [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	3 years
Bottom of range [member] \| Furniture and fixtures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	3 years
Bottom of range [member] \| Finance lease assets [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	2 years
Top of range [member] \| Buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	50 years
Top of range [member] \| Structures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	50 years
Top of range [member] \| Machinery and equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	25 years
Top of range [member] \| Vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	20 years
Top of range [member] \| Tools [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	10 years
Top of range [member] \| Furniture and fixtures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	20 years
Top of range [member] \| Finance lease assets [member]
Disclosure of detailed information about property, plant and equipment [line items]
Estimated useful lives	30 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Estimated Useful Lives of Intangible Assets (Detail)	12 Months Ended
	Dec. 31, 2019
Intellectual property rights [member] \| Bottom of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	4 years
Intellectual property rights [member] \| Top of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	25 years
Development costs [member] \| Bottom of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	3 years
Development costs [member] \| Top of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	5 years
Port facilities usage rights [member] \| Bottom of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	4 years
Port facilities usage rights [member] \| Top of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	75 years
Other intangible assets [member] \| Bottom of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	2 years
Other intangible assets [member] \| Top of range [member]
Disclosure of detailed information about intangible assets [line items]
Estimated useful lives of intangible assets	15 years

Financial Risk Management - Net

Financial Risk Management - Net Borrowing-to-Equity Ratio (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of nature and extent of risks arising from financial instruments [abstract]
Total borrowings	₩ 20,441,613	₩ 20,209,270
Less: Cash and cash equivalents	3,514,872	2,643,865
Net borrowings	16,926,741	17,565,405
Total equity	₩ 47,763,298	₩ 46,672,614	₩ 47,326,725	₩ 45,765,269
Net borrowings-to-equity ratio	35.42%	37.57%

Cash and Cash Equivalents - Sum

Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Cash and cash equivalents [abstract]
Cash	₩ 2,081	₩ 1,668
Demand deposits and checking accounts	1,581,428	1,471,891
Time deposits	701,865	538,130
Other cash equivalents	1,229,498	632,176
Cash and cash equivalents	₩ 3,514,872	₩ 2,643,865

Cash and Cash Equivalents - S_2

Cash and Cash Equivalents - Summary of Cash and Cash Equivalents - Additional Information (Detail) ₩ in Millions	Dec. 31, 2019KRW (₩)
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of Cash and Cash Equivalents [Line Items]
Cash equivalents, restricted	₩ 1,699

Trade Accounts and Notes Rece_3

Trade Accounts and Notes Receivable - Summary of Trade Accounts and Notes Receivables (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current
Current trade accounts and notes receivable	₩ 9,070,031	₩ 9,130,204
Non-current
Non-current trade accounts and notes receivable	198,785	427,125
Gross amount [member]
Current
Trade accounts and notes receivable	8,352,968	8,648,250
Finance lease receivables	221	57,487
Unbilled due from customers for contract work	128,116	810,655
Non-current
Trade accounts and notes receivable	209,310	583,797
Finance lease receivables	43,725	45,873
Allowance for credit losses [member]
Current
Less: Allowance for doubtful accounts	(411,274)	(386,188)
Non-current
Less: Allowance for doubtful accounts	₩ (54,250)	₩ (202,545)

Trade Accounts and Notes Rece_4

Trade Accounts and Notes Receivable - Additional Information (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Trade accounts and notes receivables, net [member]
Disclosure of financial assets [line items]
Trade accounts and notes receivable sold to financial institutions, for which the derecognition conditions were not met	₩ 244,305	₩ 468,706

Trade Accounts and Notes Rece_5

Trade Accounts and Notes Receivable - Finance Lease Receivables (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of finance lease and operating lease by lessor [line items]
Finance lease receivables	₩ 43,946	₩ 103,360
Officers and employees [member]
Disclosure of finance lease and operating lease by lessor [line items]
Finance lease receivables	43,445	₩ 103,360
ZHAOHUUI PROSPERITY INT'L LTD [member]
Disclosure of finance lease and operating lease by lessor [line items]
Finance lease receivables	₩ 501

Trade Accounts and Notes Rece_6

Trade Accounts and Notes Receivable - Summary of lease investment and net lease investment (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of finance lease and operating lease by lessor [line items]
Present value of minimum lease payment	₩ 43,946	₩ 103,360
Trade accounts and notes receivables, net [member]
Disclosure of finance lease and operating lease by lessor [line items]
Undiscounted lease payments	46,398	107,498
Unrealized interest income	(2,452)	(4,138)
Present value of minimum lease payment	43,946	103,360
Less than 1 year [member] \| Trade accounts and notes receivables, net [member]
Disclosure of finance lease and operating lease by lessor [line items]
Gross amount of lease payment	237	57,820
1 year - 3 years [member] \| Trade accounts and notes receivables, net [member]
Disclosure of finance lease and operating lease by lessor [line items]
Gross amount of lease payment	₩ 46,161	₩ 49,678

Other Receivables - Summary of

Other Receivables - Summary of Other Receivables (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current
Other current receivables	₩ 1,581,517	₩ 1,385,629
Non-current
Lease receivables	1,140,879	863,240
Other non-current receivables	1,140,879	863,240
Gross amount [member]
Current
Loans	367,580	236,782
Other accounts receivable	971,845	954,030
Accrued income	272,528	220,066
Deposits	86,519	108,640
Lease receivables	48,744
Others	14,510	16,201
Non-current
Loans	701,529	731,344
Other accounts receivable	209,039	155,936
Accrued income	65,275	1,855
Deposits	238,261	152,072
Lease receivables	179,315
Allowance for credit losses [member]
Current
Other current receivables	(180,209)	(150,090)
Non-current
Other non-current receivables	₩ (252,540)	₩ (177,967)

Other Receivables - Finance Lea

Other Receivables - Finance Lease Receivables (Detail) - Lease receivables [member] ₩ in Millions	Dec. 31, 2019KRW (₩)
Disclosure of finance lease and operating lease by lessor [line items]
Undiscounted finance lease payments to be received	₩ 228,059
HEUNG-A SHIPPING CO., LTD., MSC [member]
Disclosure of finance lease and operating lease by lessor [line items]
Undiscounted finance lease payments to be received	212,933
GAIL(India) Limited, Myanma Oil and Gas Enterprise [member]
Disclosure of finance lease and operating lease by lessor [line items]
Undiscounted finance lease payments to be received	₩ 15,126

Other Receivables - Summary o_2

Other Receivables - Summary of lease investment and net lease investment (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure Of Leases By Lessor [Line Items]
Present value of minimum lease payment	₩ 43,946	₩ 103,360
Other receivables [member]
Disclosure Of Leases By Lessor [Line Items]
Undiscounted lease payments	251,582
Unrealized interest income	(23,523)
Present value of minimum lease payment	228,059
Less than 1 year [member] \| Other receivables [member]
Disclosure Of Leases By Lessor [Line Items]
Gross amount of lease payment	56,796
1 year - 3 years [member] \| Other receivables [member]
Disclosure Of Leases By Lessor [Line Items]
Gross amount of lease payment	107,955
3 year – 5 years [member] \| Other receivables [member]
Disclosure Of Leases By Lessor [Line Items]
Gross amount of lease payment	70,742
Over 5 years [members] \| Other receivables [member]
Disclosure Of Leases By Lessor [Line Items]
Gross amount of lease payment	₩ 16,089

Other Financial Assets - Summar

Other Financial Assets - Summary of Other Financial Assets (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current
Derivatives assets	₩ 47,541	₩ 47,288
Debt securities	342,371	2,987
Deposit instruments	1,744,895	1,931,518
Short-term financial instruments	6,861,242	6,099,303
Other current financial assets	8,996,049	8,081,096
Non-current
Derivatives assets	64,737	1,795
Equity securities	1,204,902	1,238,630
Debt securities	22,380	34,327
Other Securities	343,183	338,106
Deposit instruments	34,187	35,040
Other non current financial assets	₩ 1,669,389	₩ 1,647,898

Other Financial Assets - Summ_2

Other Financial Assets - Summary of Other Financial Assets (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Government [member]
Disclosure of financial assets [line items]
Financial instruments restricted for use	₩ 4,524	₩ 5,715
Financial arrangements, pledge and others [member]
Disclosure of financial assets [line items]
Financial instruments restricted for use	73,525	73,935
Available-for-sale financial assets [member]
Disclosure of financial assets [line items]
Available-for-sale securities, respectively, have been provided as collateral for borrowings, construction projects and others	₩ 109,395	₩ 115,431

Inventories - Summary of Invent

Inventories - Summary of Inventories (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of inventories [Line Items]
Inventories	₩ 11,230,759	₩ 12,153,303
Gross amount [member]
Disclosure of inventories [Line Items]
Finished goods	1,655,228	1,886,040
Merchandise	1,058,874	1,131,416
Semi-finished goods	2,097,289	1,945,567
Raw materials	2,656,341	2,821,972
Fuel and materials	1,026,133	888,941
Construction inventories	1,045,088	1,372,259
Materials-in-transit	1,824,044	2,245,740
Others	83,905	68,150
Inventories	11,446,902	12,360,085
Allowance for inventories valuation [member]
Disclosure of inventories [Line Items]
Inventories	₩ (216,143)	₩ (206,782)

Inventories - Changes of Allowa

Inventories - Changes of Allowance for Inventories Valuation (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Classes of current inventories [abstract]
Allowance for inventories valuation, beginning balance	₩ 206,782	₩ 135,631	₩ 203,164
Loss on valuation of inventories	96,201	141,799	78,560
Realization on disposal of inventories	(79,419)	(69,426)	(138,967)
Others	(7,421)	(1,222)	(7,126)
Allowance for inventories valuation, ending balance	₩ 216,143	₩ 206,782	₩ 135,631

Assets Held for Sale - Details

Assets Held for Sale - Details of Assets Held For Sale and Related Liabilities (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Assets
Property, plant and equipment	₩ 29,925,973	₩ 30,018,273	₩ 31,883,535
Assets held for sale	74,158	21,854
Liabilities
Others	8
Assets held for sale and related liabilities [member]
Assets
Cash and cash equivalents	374
Other financial assets	185
Property, plant and equipment	69,293
Others	4,306
Posco [member]
Assets
Assets held for sale	36,321
Posco [member] \| Assets held for sale and related liabilities [member]
Assets
Property, plant and equipment	36,321
Subsidiaries [member]
Assets
Assets held for sale	37,837	21,854
Liabilities
Others	8
Subsidiaries [member] \| Assets held for sale and related liabilities [member]
Assets
Cash and cash equivalents	374
Other financial assets		778
Property, plant and equipment	32,972	₩ 21,076
Others	₩ 4,306

Assets Held for Sale - Detail_2

Assets Held for Sale - Details of Assets Held For Sale and Related Liabilities (Parenthetical) (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)
Land [member] \| Daesan Combodia Company Co Limited [member]
Assets and liabilities held for sale [Line Items]
Gain loss on disposal of investment	₩ 22,683
Assets held for sale and related liabilities [member] \| Parent [member]
Assets and liabilities held for sale [Line Items]
Impairment loss on assets held for sale	₩ 659

Investments in Associates and_3

Investments in Associates and Joint Ventures - Summary of Investments in Associates and Joint Ventures (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments in subsidiaries, joint ventures and associates [abstract]
Investments in associates	₩ 1,864,509	₩ 1,738,692
Investments in joint ventures	2,063,246	1,911,311
Investments in associates and joint ventures	₩ 3,927,755	₩ 3,650,003	₩ 3,557,932

Investments in Associates and_4

Investments in Associates and Joint Ventures - Details of Investments in Associates (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)Companiesshares	Dec. 31, 2018KRW (₩)	Dec. 31, 2017
Disclosure of associates [line items]
Investments in associates	₩ 1,864,509	₩ 1,738,692
Bottom of range [member]
Disclosure of associates [line items]
Ownership (%)	20.00%
Domestic [member]
Disclosure of associates [line items]
Investments in associates	₩ 845,614	₩ 790,410
Domestic [member] \| EQP POSCO Global No1 Natural Resources Private Equity Fund [member]
Disclosure of associates [line items]
Number of shares \| shares	178,787,468,209
Ownership (%)	33.41%	31.27%
Investments in associates	₩ 175,907	₩ 174,123
Domestic [member] \| Pospower Co Ltd [member]
Disclosure of associates [line items]
Number of shares \| shares	4,507,138
Ownership (%)	34.00%	34.00%
Investments in associates	₩ 161,280	₩ 161,477
Domestic [member] \| SNNC [member]
Disclosure of associates [line items]
Number of shares \| shares	18,130,000
Ownership (%)	49.00%	49.00%
Investments in associates	₩ 142,602	₩ 116,922
Domestic [member] \| QSONE Co.,Ltd. [member]
Disclosure of associates [line items]
Number of shares \| shares	200,000
Ownership (%)	50.00%	50.00%
Investments in associates	₩ 85,887	₩ 85,550
Domestic [member] \| Chun-cheon Energy Co., Ltd. [member]
Disclosure of associates [line items]
Number of shares \| shares	17,308,143
Ownership (%)	49.10%	45.67%
Investments in associates	₩ 56,679	₩ 62,478
Domestic [member] \| Chungju Enterprise City Development Co., Ltd [member]
Disclosure of associates [line items]
Number of shares \| shares	2,008,000
Ownership (%)	29.53%	29.53%
Investments in associates	₩ 17,824	₩ 17,382
Domestic [member] \| Daesung Steel [member]
Disclosure of associates [line items]
Number of shares \| shares	108,038
Ownership (%)	17.54%	17.54%
Investments in associates	₩ 15,375	₩ 15,644
Domestic [member] \| Incheon-Gimpo Expressway Co., Ltd. [member]
Disclosure of associates [line items]
Number of shares \| shares	9,032,539
Ownership (%)	18.26%	18.26%
Investments in associates	₩ 7,904	₩ 13,329
Domestic [member] \| Keystone-HYUNDAI SECURITIES NO. 1. Private Equity Fund [member]
Disclosure of associates [line items]
Number of shares \| shares	22,523,123
Ownership (%)	52.58%
Investments in associates	₩ 19,438	₩ 11,183
Domestic [member] \| KoFC POSCO HANWHA KB Shared Growth No. 2. Private Equity Fund [member]
Disclosure of associates [line items]
Number of shares \| shares	6,485
Ownership (%)	12.50%	12.50%
Investments in associates	₩ 6,177	₩ 5,739
Domestic [member] \| KONES, Corp. [member]
Disclosure of associates [line items]
Number of shares \| shares	3,250,000
Ownership (%)	41.67%	41.67%
Investments in associates	₩ 2,473	₩ 2,849
Domestic [member] \| Other associates [member]
Disclosure of associates [line items]
Number of companies in other associates \| Companies	53
Investments in associates	₩ 112,621	₩ 123,724
Domestic [member] \| NEXTRAIN Co Ltd [Member]
Disclosure of associates [line items]
Number of shares \| shares	8,321,920
Ownership (%)	32.00%	32.00%
Investments in associates	₩ 41,447	₩ 10
Domestic [member] \| Acquisition cost [member] \| EQP POSCO Global No1 Natural Resources Private Equity Fund [member]
Disclosure of associates [line items]
Investments in associates	178,787
Domestic [member] \| Acquisition cost [member] \| Pospower Co Ltd [member]
Disclosure of associates [line items]
Investments in associates	179,410
Domestic [member] \| Acquisition cost [member] \| SNNC [member]
Disclosure of associates [line items]
Investments in associates	90,650
Domestic [member] \| Acquisition cost [member] \| QSONE Co.,Ltd. [member]
Disclosure of associates [line items]
Investments in associates	84,395
Domestic [member] \| Acquisition cost [member] \| Chun-cheon Energy Co., Ltd. [member]
Disclosure of associates [line items]
Investments in associates	86,541
Domestic [member] \| Acquisition cost [member] \| Chungju Enterprise City Development Co., Ltd [member]
Disclosure of associates [line items]
Investments in associates	10,040
Domestic [member] \| Acquisition cost [member] \| Daesung Steel [member]
Disclosure of associates [line items]
Investments in associates	14,000
Domestic [member] \| Acquisition cost [member] \| Incheon-Gimpo Expressway Co., Ltd. [member]
Disclosure of associates [line items]
Investments in associates	45,163
Domestic [member] \| Acquisition cost [member] \| Keystone-HYUNDAI SECURITIES NO. 1. Private Equity Fund [member]
Disclosure of associates [line items]
Investments in associates	22,523
Domestic [member] \| Acquisition cost [member] \| KoFC POSCO HANWHA KB Shared Growth No. 2. Private Equity Fund [member]
Disclosure of associates [line items]
Investments in associates	6,485
Domestic [member] \| Acquisition cost [member] \| KONES, Corp. [member]
Disclosure of associates [line items]
Investments in associates	6,893
Domestic [member] \| Acquisition cost [member] \| NEXTRAIN Co Ltd [Member]
Disclosure of associates [line items]
Investments in associates	41,610
Foreign [member]
Disclosure of associates [line items]
Investments in associates	₩ 1,018,895	948,282
Foreign [member] \| Other associates [member]
Disclosure of associates [line items]
Number of companies in other associates \| Companies	26
Investments in associates	₩ 121,048	₩ 99,728
Foreign [member] \| AES-VCM Mong Duong Power Company Limited [member]
Disclosure of associates [line items]
Ownership (%)	30.00%	30.00%
Investments in associates	₩ 178,892	₩ 209,936
Foreign [member] \| South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of associates [line items]
Number of shares \| shares	135,219,000
Ownership (%)	25.04%	25.04%
Investments in associates	₩ 225,933	₩ 179,459
Foreign [member] \| 7623704 Canada Inc. [member]
Disclosure of associates [line items]
Number of shares \| shares	114,452,000
Ownership (%)	10.40%	10.40%	10.40%
Investments in associates	₩ 131,529	₩ 126,885
Foreign [member] \| Eureka Moly LLC [member]
Disclosure of associates [line items]
Ownership (%)	20.00%	20.00%	20.00%
Investments in associates	₩ 85,349	₩ 82,447
Foreign [member] \| AMCI (WA) PTY LTD [member]
Disclosure of associates [line items]
Number of shares \| shares	49
Ownership (%)	49.00%	49.00%
Investments in associates	₩ 72,937	₩ 71,086
Foreign [member] \| KOREA LNG LTD. [member]
Disclosure of associates [line items]
Number of shares \| shares	2,400
Ownership (%)	20.00%	20.00%
Investments in associates	₩ 46,557	₩ 43,554
Foreign [member] \| Nickel mining company SAS [member]
Disclosure of associates [line items]
Number of shares \| shares	3,234,698
Ownership (%)	49.00%	49.00%	49.00%
Investments in associates	₩ 37,940	₩ 41,712
Foreign [member] \| NCR LLC [member]
Disclosure of associates [line items]
Ownership (%)	29.40%	29.41%
Investments in associates	₩ 46,391	₩ 37,602
Foreign [member] \| PT. batutua tembaga raya [member]
Disclosure of associates [line items]
Number of shares \| shares	128,285
Ownership (%)	22.00%	22.00%	22.00%
Investments in associates	₩ 14,717	₩ 20,479
Foreign [member] \| Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of associates [line items]
Number of shares \| shares	10,200,000
Ownership (%)	34.00%	34.00%	34.00%
Investments in associates	₩ 15,128	₩ 14,796
Foreign [member] \| PT. wampu electric power [member]
Disclosure of associates [line items]
Number of shares \| shares	8,708,400
Ownership (%)	20.00%	20.00%	20.00%
Investments in associates	₩ 13,363	₩ 14,120
Foreign [member] \| POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of associates [line items]
Number of shares \| shares	50
Ownership (%)	25.00%	25.00%	25.00%
Investments in associates	₩ 6,755	₩ 6,478
Foreign [member] \| Zhejiang Huayou Posco Esm Co Ltd [Member]
Disclosure of associates [line items]
Number of shares \| shares	134,400,000
Ownership (%)	40.00%
Investments in associates	₩ 22,356
Foreign [member] \| Acquisition cost [member] \| AES-VCM Mong Duong Power Company Limited [member]
Disclosure of associates [line items]
Investments in associates	164,303
Foreign [member] \| Acquisition cost [member] \| South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of associates [line items]
Investments in associates	135,899
Foreign [member] \| Acquisition cost [member] \| 7623704 Canada Inc. [member]
Disclosure of associates [line items]
Investments in associates	124,341
Foreign [member] \| Acquisition cost [member] \| Eureka Moly LLC [member]
Disclosure of associates [line items]
Investments in associates	240,123
Foreign [member] \| Acquisition cost [member] \| AMCI (WA) PTY LTD [member]
Disclosure of associates [line items]
Investments in associates	209,664
Foreign [member] \| Acquisition cost [member] \| KOREA LNG LTD. [member]
Disclosure of associates [line items]
Investments in associates	135,205
Foreign [member] \| Acquisition cost [member] \| Nickel mining company SAS [member]
Disclosure of associates [line items]
Investments in associates	157,585
Foreign [member] \| Acquisition cost [member] \| NCR LLC [member]
Disclosure of associates [line items]
Investments in associates	49,744
Foreign [member] \| Acquisition cost [member] \| PT. batutua tembaga raya [member]
Disclosure of associates [line items]
Investments in associates	21,824
Foreign [member] \| Acquisition cost [member] \| Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of associates [line items]
Investments in associates	9,517
Foreign [member] \| Acquisition cost [member] \| PT. wampu electric power [member]
Disclosure of associates [line items]
Investments in associates	10,054
Foreign [member] \| Acquisition cost [member] \| POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of associates [line items]
Investments in associates	4,723
Foreign [member] \| Acquisition cost [member] \| Zhejiang Huayou Posco Esm Co Ltd [Member]
Disclosure of associates [line items]
Investments in associates	₩ 22,423

Investments in Associates and_5

Investments in Associates and Joint Ventures - Details of Investments in Associates (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of associates [line items]
Investment in associates provided as collateral for borrowings	₩ 258,754	₩ 285,066
Top of range [member] \| Keystone NO. 1. Private Equity Fund [member]
Disclosure of associates [line items]
Percentage of stake in associate	50.00%

Investments in Associates and_6

Investments in Associates and Joint Ventures - Details of Investments in Joint Ventures (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)Companiesshares	Dec. 31, 2018KRW (₩)
Disclosure of joint ventures [line items]
Investments in joint ventures	₩ 2,063,246	₩ 1,911,311
Foreign [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	₩ 1,870,293	1,721,995
Foreign [member] \| Other joint ventures [member]
Disclosure of joint ventures [line items]
Number of companies in other joint ventures \| Companies	12
Investments in joint ventures	₩ 41,436	₩ 43,508
Foreign [member] \| Roy Hill Holdings Pty Ltd. [member]
Disclosure of joint ventures [line items]
Number of shares \| shares	13,117,972
Ownership (%)	12.50%	12.50%
Investments in joint ventures	₩ 1,235,682	₩ 1,041,600
Foreign [member] \| POSCO-NPS Niobium LLC [member]
Disclosure of joint ventures [line items]
Number of shares \| shares	325,050,000
Ownership (%)	50.00%	50.00%
Investments in joint ventures	₩ 376,410	₩ 363,506
Foreign [member] \| CSP - Compania Siderurgica do Pecem [member]
Disclosure of joint ventures [line items]
Number of shares \| shares	1,221,586,532
Ownership (%)	20.00%	20.00%
Investments in joint ventures		₩ 24,832
Foreign [member] \| KOBRASCO [member]
Disclosure of joint ventures [line items]
Number of shares \| shares	2,010,719,185
Ownership (%)	50.00%	50.00%
Investments in joint ventures	₩ 115,641	₩ 133,449
Foreign [member] \| BX STEEL POSCO Cold Rolled Sheet Co., Ltd. [member]
Disclosure of joint ventures [line items]
Ownership (%)	25.00%	25.00%
Investments in joint ventures	₩ 88,935	₩ 88,391
Foreign [member] \| DMSA/AMSA [member]
Disclosure of joint ventures [line items]
Ownership (%)	4.00%	4.00%
Investments in joint ventures	₩ 12,189	₩ 26,709
Foreign [member] \| Acquisition cost [member] \| Roy Hill Holdings Pty Ltd. [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	1,528,672
Foreign [member] \| Acquisition cost [member] \| POSCO-NPS Niobium LLC [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	364,609
Foreign [member] \| Acquisition cost [member] \| CSP - Compania Siderurgica do Pecem [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	594,173
Foreign [member] \| Acquisition cost [member] \| KOBRASCO [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	32,950
Foreign [member] \| Acquisition cost [member] \| BX STEEL POSCO Cold Rolled Sheet Co., Ltd. [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	61,961
Foreign [member] \| Acquisition cost [member] \| DMSA/AMSA [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	346,278
Domestic [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	₩ 192,953	₩ 189,316
Domestic [member] \| POSCO MITSUBISHI CARBON TECHNOLOGY [member]
Disclosure of joint ventures [line items]
Number of shares \| shares	11,568,000
Ownership (%)	60.00%	60.00%
Investments in joint ventures	₩ 182,648	₩ 180,192
Domestic [member] \| Other joint ventures [member]
Disclosure of joint ventures [line items]
Number of companies in other joint ventures \| Companies	8
Investments in joint ventures	₩ 10,305	₩ 9,124
Domestic [member] \| Acquisition cost [member] \| POSCO MITSUBISHI CARBON TECHNOLOGY [member]
Disclosure of joint ventures [line items]
Investments in joint ventures	₩ 115,680

Investments in Associates and_7

Investments in Associates and Joint Ventures - Changes in Investments in Associates and Joint Ventures (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)Companies	Dec. 31, 2018KRW (₩)Companies	Dec. 31, 2017KRW (₩)
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	₩ 3,650,003	₩ 3,557,932
Acquisition	178,960	244,609
Dividends	(206,486)	(154,348)
Share of profits (losses)	273,741	112,635	₩ 10,540
Other increase (decrease)	31,537	(110,825)
Book value, ending balance	3,927,755	3,650,003	3,557,932
Domestic [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	979,726	751,490
Acquisition	87,346	221,360
Dividends	(20,161)	(1,334)
Share of profits (losses)	6,882	25,500
Other increase (decrease)	(15,226)	(17,290)
Book value, ending balance	1,038,567	979,726	751,490
Domestic [member] \| POSCO MITSUBISHI CARBON TECHNOLOGY [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	180,192	110,760
Dividends	(16,369)
Share of profits (losses)	19,377	69,594
Other increase (decrease)	(552)	(162)
Book value, ending balance	182,648	180,192	110,760
Domestic [member] \| EQP POSCO Global No1 Natural Resources Private Equity Fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	174,123	175,553
Share of profits (losses)	(976)	(1,430)
Other increase (decrease)	2,760
Book value, ending balance	175,907	174,123	175,553
Domestic [member] \| Pospower Co Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	161,477
Acquisition		176,731
Share of profits (losses)	(4,744)	(3,198)
Other increase (decrease)	4,547	(12,056)
Book value, ending balance	161,280	161,477
Domestic [member] \| SNNC [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	116,922	110,424
Dividends	(1,450)
Share of profits (losses)	27,655	6,624
Other increase (decrease)	(525)	(126)
Book value, ending balance	142,602	116,922	110,424
Domestic [member] \| QSONE Co.,Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	85,550	85,049
Dividends	(950)	(550)
Share of profits (losses)	1,287	1,051
Book value, ending balance	85,887	85,550	85,049
Domestic [member] \| Chun-cheon Energy Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	62,478	74,378
Acquisition	6,050
Share of profits (losses)	(11,849)	(11,900)
Book value, ending balance	56,679	62,478	74,378
Domestic [member] \| Chungju Enterprise City Development Co., Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	17,382	17,252
Share of profits (losses)	442	130
Book value, ending balance	17,824	17,382	17,252
Domestic [member] \| Blue Ocean private equity fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance		19,620
Share of profits (losses)		(17,930)
Other increase (decrease)		(1,690)
Book value, ending balance			19,620
Domestic [member] \| Daesung Steel [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	15,644	15,500
Share of profits (losses)	(269)	144
Book value, ending balance	15,375	15,644	15,500
Domestic [member] \| Incheon-Gimpo Expressway Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	13,329	31,660
Share of profits (losses)	(5,425)	(18,331)
Book value, ending balance	7,904	13,329	31,660
Domestic [member] \| Keystone NO. 1. Private Equity Fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	11,183	12,379
Acquisition	8,723
Share of profits (losses)	(342)	(1,295)
Other increase (decrease)	(126)	99
Book value, ending balance	19,438	11,183	12,379
Domestic [member] \| UITrans LRT Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance		15,841
Share of profits (losses)		(15,841)
Book value, ending balance			15,841
Domestic [member] \| KoFC POSCO HANWHA KB Shared Growth No. 2. Private Equity Fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	5,739	6,828
Share of profits (losses)	438	(1,089)
Book value, ending balance	6,177	5,739	6,828
Domestic [member] \| KONES, Corp. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	2,849	2,827
Share of profits (losses)	(403)	29
Other increase (decrease)	27	(7)
Book value, ending balance	₩ 2,473	₩ 2,849	2,827
Domestic [member] \| Other associates and joint ventures [member]
Disclosure of investments in associates and joint ventures [Line Items]
Number of companies in other associates and joint ventures \| Companies	61	52
Domestic [member] \| Other 61 companies associates and joint ventures [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	₩ 132,848
Acquisition	30,973
Dividends	(1,392)
Share of profits (losses)	(18,146)
Other increase (decrease)	(21,357)
Book value, ending balance	122,926	₩ 132,848
Domestic [member] \| Other 51 companies associates and joint ventures [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	132,858	73,419
Acquisition		44,629
Dividends		(784)
Share of profits (losses)		18,942
Other increase (decrease)		(3,348)
Book value, ending balance		132,858	73,419
Domestic [member] \| NEXTRAIN Co., Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	10
Acquisition	41,600
Share of profits (losses)	(163)
Book value, ending balance	41,447	10
Foreign [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	2,670,277	2,806,442
Acquisition	91,614	23,249
Dividends	(186,325)	(153,014)
Share of profits (losses)	266,859	87,135
Other increase (decrease)	46,763	(93,535)
Book value, ending balance	2,889,188	2,670,277	2,806,442
Foreign [member] \| Roy Hill Holdings Pty Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	1,041,600	1,125,133
Share of profits (losses)	158,562	59,095
Other increase (decrease)	35,520	(142,628)
Book value, ending balance	1,235,682	1,041,600	1,125,133
Foreign [member] \| POSCO-NPS Niobium LLC [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	363,506	348,836
Dividends	(24,933)	(22,254)
Share of profits (losses)	24,543	21,536
Other increase (decrease)	13,294	15,388
Book value, ending balance	376,410	363,506	348,836
Foreign [member] \| KOBRASCO [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	133,449	108,485
Dividends	(74,716)	(37,710)
Share of profits (losses)	56,474	75,170
Other increase (decrease)	434	(12,496)
Book value, ending balance	115,641	133,449	108,485
Foreign [member] \| BX STEEL POSCO Cold Rolled Sheet Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	88,391	88,305
Dividends	(1,574)	0
Share of profits (losses)	665	540
Other increase (decrease)	1,453	(454)
Book value, ending balance	88,935	88,391	88,305
Foreign [member] \| DMSA/AMSA [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	26,709	56,735
Acquisition	23,682	17,973
Share of profits (losses)	(40,415)	(48,802)
Other increase (decrease)	2,213	803
Book value, ending balance	12,189	26,709	56,735
Foreign [member] \| CSP - Compania Siderurgica do Pecem [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	24,832	146,427
Acquisition	35,352
Share of profits (losses)	(57,647)	(109,714)
Other increase (decrease)	₩ (2,537)	(11,881)
Book value, ending balance		₩ 24,832	146,427
Foreign [member] \| Other associates and joint ventures [member]
Disclosure of investments in associates and joint ventures [Line Items]
Number of companies in other associates and joint ventures \| Companies	38	42
Book value, beginning balance	₩ 143,236	₩ 158,213
Acquisition	552	2,771
Dividends	(19,430)	(22,588)
Share of profits (losses)	30,168	42,937
Other increase (decrease)	7,958	(38,097)
Book value, ending balance	162,484	143,236	158,213
Foreign [member] \| AES-VCM Mong Duong Power Company Limited [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	209,936	142,348
Dividends	(18,099)	(26,108)
Share of profits (losses)	24,126	30,096
Other increase (decrease)	(37,071)	63,600
Book value, ending balance	178,892	209,936	142,348
Foreign [member] \| South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	179,459	197,069
Dividends	(24,267)	(29,301)
Share of profits (losses)	63,749	17,709
Other increase (decrease)	6,992	(6,018)
Book value, ending balance	225,933	179,459	197,069
Foreign [member] \| 7623704 Canada Inc. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	126,885	121,702
Dividends	(9,902)	(4,509)
Share of profits (losses)	9,912	4,373
Other increase (decrease)	4,634	5,319
Book value, ending balance	131,529	126,885	121,702
Foreign [member] \| Eureka Moly LLC [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	82,447	79,398
Share of profits (losses)	(25)	(406)
Other increase (decrease)	2,927	3,455
Book value, ending balance	85,349	82,447	79,398
Foreign [member] \| AMCI (WA) PTY LTD [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	71,086	63,378
Share of profits (losses)	(4,377)	(3,412)
Other increase (decrease)	6,228	11,120
Book value, ending balance	72,937	71,086	63,378
Foreign [member] \| Nickel mining company SAS [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	41,712	45,905
Share of profits (losses)	(4,250)	(4,268)
Other increase (decrease)	478	75
Book value, ending balance	37,940	41,712	45,905
Foreign [member] \| KOREA LNG LTD. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	43,554	33,422
Dividends	(13,404)	(10,544)
Share of profits (losses)	13,501	10,542
Other increase (decrease)	2,906	10,134
Book value, ending balance	46,557	43,554	33,422
Foreign [member] \| NCR LLC [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	37,602	33,738
Acquisition	9,605	2,505
Share of profits (losses)	(822)	(5,909)
Other increase (decrease)	6	7,268
Book value, ending balance	46,391	37,602	33,738
Foreign [member] \| PT. batutua tembaga raya [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	20,479	21,823
Share of profits (losses)	(6,209)	(1,817)
Other increase (decrease)	447	473
Book value, ending balance	14,717	20,479	21,823
Foreign [member] \| PT. wampu electric power [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	14,120	13,391
Share of profits (losses)	(1,247)	177
Other increase (decrease)	490	552
Book value, ending balance	13,363	14,120	13,391
Foreign [member] \| Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	14,796	15,617
Share of profits (losses)	10	(735)
Other increase (decrease)	322	(86)
Book value, ending balance	15,128	14,796	15,617
Foreign [member] \| POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Book value, beginning balance	6,478	6,517
Share of profits (losses)	80	23
Other increase (decrease)	197	(62)
Book value, ending balance	6,755	₩ 6,478	₩ 6,517
Foreign [member] \| Zhejiang Huayou Posco Esm Co Ltd [Member]
Disclosure of investments in associates and joint ventures [Line Items]
Acquisition	22,423
Share of profits (losses)	61
Other increase (decrease)	(128)
Book value, ending balance	₩ 22,356

Investments in Associates and_8

Investments in Associates and Joint Ventures - Summarized Financial Information of Associates and Joint Ventures (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of investments in associates and joint ventures [Line Items]
Assets	₩ 79,370,808	₩ 78,776,991
Liabilities	31,607,510	32,104,377
Equity	47,763,298	46,672,614	₩ 47,326,725	₩ 45,765,269
Sales	64,785,709	65,154,636	60,186,867
Net income (loss)	2,038,165	1,932,386	₩ 2,909,311
Domestic [member] \| POSCO MITSUBISHI CARBON TECHNOLOGY [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	474,387	537,138
Liabilities	170,678	237,563
Equity	303,709	299,575
Sales	216,648	300,986
Net income (loss)	32,334	116,049
Domestic [member] \| EQP POSCO Global No1 Natural Resources Private Equity Fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	516,659	552,760
Liabilities	786	783
Equity	515,873	551,977
Net income (loss)	7,479	10,249
Domestic [member] \| SNNC [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	677,508	645,013
Liabilities	357,843	384,586
Equity	319,665	260,427
Sales	738,977	656,320
Net income (loss)	63,269	14,229
Domestic [member] \| QSONE Co.,Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	250,364	249,384
Liabilities	78,589	78,285
Equity	171,775	171,099
Sales	17,591	16,597
Net income (loss)	2,576	2,101
Domestic [member] \| Chun-cheon Energy Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	610,089	667,454
Liabilities	492,620	525,308
Equity	117,469	142,146
Sales	313,438	320,950
Net income (loss)	(24,677)	(18,796)
Domestic [member] \| Daesung Steel [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	164,708	169,305
Liabilities	108,441	111,502
Equity	56,267	57,803
Sales	85,537	75,474
Net income (loss)	(1,536)	824
Domestic [member] \| Incheon-Gimpo Expressway Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	1,014,410	1,049,629
Liabilities	951,321	931,937
Equity	63,089	117,692
Sales	50,575	45,566
Net income (loss)	(36,449)	(92,202)
Domestic [member] \| Chungju Enterprise City Development Co., Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	53,019	63,554
Liabilities	22,971	35,003
Equity	30,048	28,551
Sales	17,824	16,237
Net income (loss)	1,497	439
Domestic [member] \| Blue Ocean private equity fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets		305,876
Liabilities		174,640
Equity		131,236
Sales		459,491
Net income (loss)		(5,294)
Domestic [member] \| Keystone NO. 1. Private Equity Fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	187,156	177,024
Liabilities	138,219	144,186
Equity	48,937	32,838
Sales	18,342	15,507
Net income (loss)	(887)	(3,962)
Domestic [member] \| UITrans LRT Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets		430,227
Liabilities		435,699
Equity		(5,472)
Sales		12,929
Net income (loss)		(85,344)
Domestic [member] \| KoFC POSCO HANWHA KB Shared Growth No. 2. Private Equity Fund [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	50,479	59,464
Liabilities	1,062	1,061
Equity	49,417	58,403
Sales	2,841	2,401
Net income (loss)	3,502	(12,313)
Domestic [member] \| KONES, Corp. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	1,950	2,618
Liabilities	1,648	1,414
Equity	302	1,204
Sales	4,416	5,167
Net income (loss)	(966)	70
Domestic [member] \| Pospower Co Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	707,051	425,632
Liabilities	199,846	35,761
Equity	507,205	389,871
Net income (loss)	(5,294)	(4,536)
Domestic [member] \| NEXTRAIN Co., Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	136,203	30
Liabilities	7,322
Equity	128,881	30
Net income (loss)	(509)
Foreign [member] \| Roy Hill Holdings Pty Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	11,143,705	9,666,619
Liabilities	5,718,152	6,043,492
Equity	5,425,553	3,623,127
Sales	5,037,471	3,259,256
Net income (loss)	1,660,577	497,469
Foreign [member] \| POSCO-NPS Niobium LLC [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	752,617	726,810
Equity	752,617	726,810
Net income (loss)	47,521	41,812
Foreign [member] \| KOBRASCO [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	268,139	317,842
Liabilities	36,857	50,945
Equity	231,282	266,897
Sales	167,022	229,340
Net income (loss)	112,949	150,550
Foreign [member] \| BX STEEL POSCO Cold Rolled Sheet Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	969,280	710,518
Liabilities	637,478	384,572
Equity	331,802	325,946
Sales	1,145,794	1,341,849
Net income (loss)	1,704	2,159
Foreign [member] \| DMSA/AMSA [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	5,703,501	5,562,877
Liabilities	4,202,704	4,171,896
Equity	1,500,797	1,390,981
Sales	638,797	731,127
Net income (loss)	(504,077)	(529,844)
Foreign [member] \| CSP - Compania Siderurgica do Pecem [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	3,959,365	4,194,242
Liabilities	4,249,083	4,192,867
Equity	(289,718)	1,375
Sales	1,623,843	1,860,198
Net income (loss)	(465,853)	(542,865)
Foreign [member] \| South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	1,808,529	1,726,410
Liabilities	906,254	1,009,731
Equity	902,275	716,679
Sales	555,075	343,471
Net income (loss)	254,582	70,717
Foreign [member] \| 7623704 Canada Inc. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	1,276,857	1,232,208
Liabilities	1	1
Equity	1,276,856	1,232,207
Net income (loss)	95,306	44,320
Foreign [member] \| Nickel mining company SAS [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	471,377	465,463
Liabilities	331,194	329,084
Equity	140,183	136,379
Sales	245,509	207,956
Net income (loss)	2,432	(4,569)
Foreign [member] \| KOREA LNG LTD. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	232,935	217,883
Liabilities	147	110
Equity	232,788	217,773
Sales	69,577	54,357
Net income (loss)	67,507	52,720
Foreign [member] \| PT. batutua tembaga raya [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	423,608	332,305
Liabilities	392,226	274,580
Equity	31,382	57,725
Sales	112,568	128,609
Net income (loss)	(28,360)	(8,451)
Foreign [member] \| PT. wampu electric power [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	222,266	223,009
Liabilities	158,451	155,407
Equity	63,815	67,602
Sales	18,163	13,461
Net income (loss)	(6,233)	887
Foreign [member] \| Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	65,413	73,515
Liabilities	15,232	24,264
Equity	50,181	49,251
Sales	101,101	121,104
Net income (loss)	28	(2,231)
Foreign [member] \| POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	61,847	61,782
Liabilities	33,989	34,740
Equity	27,858	27,042
Sales	77,371	85,619
Net income (loss)	327	₩ 78
Foreign [member] \| Zhejiang Huayou Posco Esm Co Ltd [Member]
Disclosure of investments in associates and joint ventures [Line Items]
Assets	73,604
Liabilities	17,765
Equity	55,839
Sales	641
Net income (loss)	₩ 153

Joint Operations - Details of S

Joint Operations - Details of Significant Joint Operations (Detail)	12 Months Ended
	Dec. 31, 2019
Myanmar A-1/A-3 mine [member]
Disclosure of joint operations [line items]
Category of business	Mine development and gas production
Ownership (%)	51.00%
Location	Myanmar
Offshore midstream [member]
Disclosure of joint operations [line items]
Category of business	Gas transportation facility
Ownership (%)	51.00%
Location	Myanmar
Greenhills mine [member]
Disclosure of joint operations [line items]
Category of business	Mine development
Ownership (%)	20.00%
Location	Canada
Arctos Anthracite coal project [member]
Disclosure of joint operations [line items]
Category of business	Mine development
Ownership (%)	50.00%
Location	Canada
Mt. Thorley J/V [member]
Disclosure of joint operations [line items]
Category of business	Mine development
Ownership (%)	20.00%
Location	Australia
POSMAC J/V [member]
Disclosure of joint operations [line items]
Category of business	Mine development
Ownership (%)	20.00%
Location	Australia
RUM J/V [member]
Disclosure of joint operations [line items]
Category of business	Mine development
Ownership (%)	10.00%
Location	Australia
Hanam Gamil package public housing project [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	7.70%
Location	Korea
Hanam-Gamil district B6, C2, C3 Block public housing lot development project [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	27.00%
Location	Korea
Yangsan-Sasong district public housing project (private-participation) [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	13.08%
Location	Korea
Yangsan-Sasong district public housing project [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	49.00%
Location	Korea
Sejong 2-1 P3 Block public housing project [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	37.00%
Location	Korea
Yongin-Giheung Station area city development project [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	61.00%
Location	Korea
Korean Wave World Complex land multi-purpose building development project [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	33.30%
Location	Korea
Sejong 4-1 P3 Block public housing project [member]
Disclosure of joint operations [line items]
Category of business	Construction
Ownership (%)	60.00%
Location	Korea

Investment Property, Net - Summ

Investment Property, Net - Summary of Investment Property (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about investment property [line items]
Investment property	₩ 878,227	₩ 928,615	₩ 1,064,914
Land [member]
Disclosure of detailed information about investment property [line items]
Investment property	278,465	278,585	360,402
Buildings [member]
Disclosure of detailed information about investment property [line items]
Investment property	598,159	571,335	634,040
Structures [member]
Disclosure of detailed information about investment property [line items]
Investment property	1,178	1,408	6,281
Right of use assets [member]
Disclosure of detailed information about investment property [line items]
Investment property	425
Construction-in-progress [member]
Disclosure of detailed information about investment property [line items]
Investment property		77,287	₩ 64,191
Gross amount [member]
Disclosure of detailed information about investment property [line items]
Investment property	1,077,888	1,081,838
Gross amount [member] \| Land [member]
Disclosure of detailed information about investment property [line items]
Investment property	295,183	295,328
Gross amount [member] \| Buildings [member]
Disclosure of detailed information about investment property [line items]
Investment property	778,816	681,518
Gross amount [member] \| Structures [member]
Disclosure of detailed information about investment property [line items]
Investment property	3,455	3,327
Gross amount [member] \| Right of use assets [member]
Disclosure of detailed information about investment property [line items]
Investment property	434
Gross amount [member] \| Construction-in-progress [member]
Disclosure of detailed information about investment property [line items]
Investment property		101,665
Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about investment property [line items]
Investment property	(199,661)	(153,223)
Accumulated depreciation, amortization and impairment [member] \| Land [member]
Disclosure of detailed information about investment property [line items]
Investment property	(16,718)	(16,743)
Accumulated depreciation, amortization and impairment [member] \| Buildings [member]
Disclosure of detailed information about investment property [line items]
Investment property	(180,657)	(110,183)
Accumulated depreciation, amortization and impairment [member] \| Structures [member]
Disclosure of detailed information about investment property [line items]
Investment property	(2,277)	(1,919)
Accumulated depreciation, amortization and impairment [member] \| Right of use assets [member]
Disclosure of detailed information about investment property [line items]
Investment property	₩ (9)
Accumulated depreciation, amortization and impairment [member] \| Construction-in-progress [member]
Disclosure of detailed information about investment property [line items]
Investment property		₩ (24,378)

Investment Property, Net - Addi

Investment Property, Net - Additional Information (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about investment property [line items]
Investment property	₩ 878,227	₩ 928,615	₩ 1,064,914
Fair value [member] \| 6 Subsidiaries, including POSCO(Dalian) IT Center Development Co.,Ltd [member]
Disclosure of detailed information about investment property [line items]
Investment property	₩ 1,545,310

Investment Property, Net - Chan

Investment Property, Net - Changes in Carrying Amount of Investment Property (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about investment property [line items]
Beginning	₩ 928,615	₩ 1,064,914
Acquisitions	20,192	44,106
Disposals	(11,314)	(59,633)
Depreciation	(53,041)	(70,652)
Others	(6,225)	(50,120)
Ending	878,227	928,615
Land [member]
Disclosure of detailed information about investment property [line items]
Beginning	278,585	360,402
Acquisitions		1,327
Disposals	(5,921)	(26,826)
Depreciation		(16,743)
Others	5,801	(39,575)
Ending	278,465	278,585
Buildings [member]
Disclosure of detailed information about investment property [line items]
Beginning	571,335	634,040
Acquisitions	1,548	727
Disposals	(5,343)	(32,807)
Depreciation	(52,416)	(28,358)
Others	83,035	(2,267)
Ending	598,159	571,335
Structures [member]
Disclosure of detailed information about investment property [line items]
Beginning	1,408	6,281
Disposals	(50)
Depreciation	(625)	(603)
Others	445	(4,270)
Ending	1,178	1,408
Right of use assets [member]
Disclosure of detailed information about investment property [line items]
Others	425
Ending	425
Construction-in-progress [member]
Disclosure of detailed information about investment property [line items]
Beginning	77,287	64,191
Acquisitions	18,644	42,052
Depreciation		(24,948)
Others	₩ (95,931)	(4,008)
Ending		₩ 77,287

Investment Property, Net - Ch_2

Investment Property, Net - Changes in Carrying Amount of Investment Property (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about investment property [line items]
Impairment loss on investment property	₩ 32,642	₩ 51,461
POSCO(Dalian) IT Center Development Co., Ltd. [member]
Disclosure of detailed information about investment property [line items]
Impairment loss on investment property	₩ 32,642	₩ 51,461

Property, Plant and Equipment_3

Property, Plant and Equipment, Net - Summary of Property, Plant and Equipment (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	₩ 29,925,973	₩ 30,018,273	₩ 31,883,535
Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	70,662,317	68,802,624
Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(40,717,017)	(38,777,129)
Government grants	(19,327)	(7,222)
Land [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	2,526,059	2,548,002	2,527,650
Land [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	2,527,972	2,553,957
Land [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(1,913)	(5,955)
Buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	4,215,454	4,402,452	4,877,018
Buildings [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	9,227,064	9,146,294
Buildings [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(5,010,770)	(4,743,449)
Government grants	(840)	(393)
Structures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	2,904,506	2,917,924	2,765,852
Structures [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	6,066,000	5,884,277
Structures [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(3,161,453)	(2,966,304)
Government grants	(41)	(49)
Machinery and equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	17,218,264	18,518,129	19,367,957
Machinery and equipment [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	47,548,589	47,610,225
Machinery and equipment [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(30,326,324)	(29,091,754)
Government grants	(4,001)	(342)
Vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	32,285	31,341	32,861
Vehicles [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	305,275	302,767
Vehicles [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(272,977)	(271,381)
Government grants	(13)	(45)
Tools [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	70,751	66,164	63,640
Tools [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	418,829	399,638
Tools [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(348,032)	(333,387)
Government grants	(46)	(87)
Furniture and fixtures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	130,132	136,287	145,439
Furniture and fixtures [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	658,467	638,553
Furniture and fixtures [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(528,066)	(502,215)
Government grants	(269)	(51)
Finance lease assets [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	774,582	137,564	145,257
Finance lease assets [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	970,891	213,873
Finance lease assets [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(196,309)	(76,309)
Bearer plants [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	124,193	80,771	65,515
Bearer plants [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	138,818	88,773
Bearer plants [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(14,625)	(8,002)
Construction-in-progress [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	1,929,747	1,179,639	₩ 1,892,346
Construction-in-progress [member] \| Gross amount [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	2,800,412	1,964,267
Construction-in-progress [member] \| Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment	(856,548)	(778,373)
Government grants	₩ (14,117)	₩ (6,255)

Property, Plant and Equipment_4

Property, Plant and Equipment, Net - Changes in Carrying Amount of Property, Plant and Equipment (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	₩ 30,018,273	₩ 31,883,535
Acquisitions	2,667,901	2,213,820
Business Combination	48,474
Disposals	(131,043)	(140,454)
Depreciation	(3,009,469)	(2,891,857)
Impairment loss	(441,480)	(997,198)
Others	773,317	(49,573)
Ending	29,925,973	30,018,273
Land [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	2,548,002	2,527,650
Acquisitions	6,550	28,998
Disposals	(2,128)	(26,157)
Impairment loss		6,399
Others	(26,365)	11,112
Ending	2,526,059	2,548,002
Buildings [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	4,402,452	4,877,018
Acquisitions	39,551	46,129
Business Combination	22,836
Disposals	(10,376)	(21,501)
Depreciation	(314,107)	(331,688)
Impairment loss	(90,036)	(73,523)
Others	165,134	(93,983)
Ending	4,215,454	4,402,452
Structures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	2,917,924	2,765,852
Acquisitions	49,931	18,749
Business Combination	2
Disposals	(3,350)	(2,834)
Depreciation	(228,616)	(220,218)
Impairment loss	(27,217)	(6,652)
Others	195,832	363,027
Ending	2,904,506	2,917,924
Machinery and equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	18,518,129	19,367,957
Acquisitions	175,743	145,220
Business Combination	1,216
Disposals	(78,236)	(62,135)
Depreciation	(2,250,022)	(2,224,000)
Impairment loss	(309,604)	(143,293)
Others	1,161,038	1,434,380
Ending	17,218,264	18,518,129
Vehicles [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	31,341	32,861
Acquisitions	8,027	8,538
Business Combination	189
Disposals	(742)	(1,149)
Depreciation	(15,057)	(14,835)
Impairment loss	(559)	(56)
Others	9,086	5,982
Ending	32,285	31,341
Tools [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	66,164	63,640
Acquisitions	19,178	21,337
Business Combination	5,792
Disposals	(1,340)	(1,867)
Depreciation	(28,537)	(26,421)
Impairment loss	(2,106)	(206)
Others	11,600	9,681
Ending	70,751	66,164
Furniture and fixtures [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	136,287	145,439
Acquisitions	34,618	32,258
Business Combination	252
Disposals	(1,630)	(577)
Depreciation	(36,309)	(51,835)
Impairment loss	(1,808)	(1,494)
Others	(1,278)	12,496
Ending	130,132	136,287
Finance lease assets [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	137,564	145,257
Acquisitions	72,640	28,466
Business Combination	490
Disposals	(8,401)	(420)
Depreciation	(130,905)	(19,224)
Others	703,194	(16,515)
Ending	774,582	137,564
Construction-in-progress [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	1,179,639	1,892,346
Acquisitions	2,261,663	1,884,125
Business Combination	17,697
Disposals	(24,840)	(23,814)
Impairment loss	(10,150)	(778,373)
Others	(1,494,262)	(1,794,645)
Ending	1,929,747	1,179,639
Bearer plants [member]
Disclosure of detailed information about property, plant and equipment [line items]
Beginning	80,771	65,515
Depreciation	(5,916)	(3,636)
Others	49,338	18,892
Ending	₩ 124,193	₩ 80,771

Property, Plant and Equipment_5

Property, Plant and Equipment, Net - Changes in Carrying Amount of Property, Plant and Equipment (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss on property, plant and equipment	₩ 442,700	₩ 1,004,704	₩ 117,231
Property plant and equipment	29,925,973	30,018,273	31,883,535
Machinery and equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property plant and equipment	17,218,264	18,518,129	19,367,957
Finance lease assets [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property plant and equipment	774,582	137,564	₩ 145,257
Finance lease assets [member] \| IFRS 16 [member]
Disclosure of detailed information about property, plant and equipment [line items]
Right-of-use assets presented as property, plant and equipment	704,458
POSCO SS-VINA Co., Ltd [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss on property, plant and equipment	204,546
Synthetic Natural Gas [Member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss on property, plant and equipment		809,737
Synthetic Natural Gas [Member] \| Machinery and equipment [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property plant and equipment		167,054
CEM And Fe-Si factories [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss on property, plant and equipment	₩ 205,396
Fuel cell business [member] \| POSCO ENERGY CO., LTD. [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss on property, plant and equipment		54,250
Strip casting facilities [member]
Disclosure of detailed information about property, plant and equipment [line items]
Impairment loss on property, plant and equipment		₩ 61,787

Property, Plant and Equipment_6

Property, Plant and Equipment, Net - Borrowing Costs Capitalized and Capitalized Interest Rate (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about property, plant and equipment [line items]
Expenditure	₩ 2,519,219	₩ 2,135,550	₩ 2,287,580
Borrowing costs capitalized	22,775	22,619
Weighted average [member]
Disclosure of detailed information about property, plant and equipment [line items]
Expenditure	₩ 587,628	₩ 628,595
Bottom of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Capitalization rate (%)	3.57%	2.51%
Top of range [member]
Disclosure of detailed information about property, plant and equipment [line items]
Capitalization rate (%)	5.46%	3.90%

Property, Plant and Equipment_7

Property, Plant and Equipment, Net - Property, Plant and Equipment and Investment Property Pledged as Collateral (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment and investment property pledged as collateral	₩ 4,569,793	₩ 5,711,500
Land [member] \| Korean Development Bank and others [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment and investment property pledged as collateral	765,307	769,843
Buildings and structures [member] \| Korean Development Bank and others [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment and investment property pledged as collateral	1,363,709	1,522,129
Machinery and equipment [member] \| Korean Development Bank and others [member]
Disclosure of detailed information about property, plant and equipment [line items]
Property, plant and equipment and investment property pledged as collateral	₩ 2,440,777	₩ 3,419,528

Property, Plant and Equipment_8

Property, Plant and Equipment, Net - Property, Plant and Equipment and Investment Property Pledged as Collateral (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about property, plant and equipment [line items]
Assets pledged as collateral	₩ 4,569,793	₩ 5,711,500
Investment Property And Other Assets [member]
Disclosure of detailed information about property, plant and equipment [line items]
Assets pledged as collateral	₩ 5,016,568

Property, Plant and Equipment_9

Property, Plant and Equipment, Net - Summary of Changes in Right-of-use Assets Property Plant and Equipment (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Right of use assets Acquisitions	₩ 72,640
Depreciation	(130,905)
Others	(9,175)
Ending balance	774,582
Land [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Right of use assets Acquisitions	22,850
Depreciation	(11,461)
Others	(10,154)
Ending balance	341,342
Buildings and structures [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Right of use assets Acquisitions	23,015
Depreciation	(38,853)
Others	(22,505)
Ending balance	171,112
Machinery and equipment [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Right of use assets Acquisitions	14,610
Depreciation	(33,751)
Others	15,092
Ending balance	215,828
Vehicles [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Right of use assets Acquisitions	8,735
Depreciation	(10,050)
Others	(5,135)
Ending balance	14,105
Other assets [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Right of use assets Acquisitions	3,430
Depreciation	(36,790)
Others	13,527
Ending balance	32,195
Date of initial application IFRS-16 [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Beginning Balance	842,022
Date of initial application IFRS-16 [member] \| Land [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Beginning Balance	340,107
Date of initial application IFRS-16 [member] \| Buildings and structures [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Beginning Balance	209,455
Date of initial application IFRS-16 [member] \| Machinery and equipment [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Beginning Balance	219,877
Date of initial application IFRS-16 [member] \| Vehicles [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Beginning Balance	20,555
Date of initial application IFRS-16 [member] \| Other assets [member]
Disclosure details of changes in right-of-use assets property plant and equipment [line items]
Beginning Balance	₩ 52,028

Property, Plant and Equipmen_10

Property, Plant and Equipment, Net - Summary of Lease Expense Recognised in the Income Statement (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)
Text block [abstract]
Interest on lease liabilities	₩ 35,483
Expenses related to short-term leases	41,974
Expenses related to leases of low-value assets	14,150
Total	₩ 91,607

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets, Net - Summary of Goodwill and Other Intangible Assets (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	₩ 4,908,473	₩ 5,170,825	₩ 5,952,269
Goodwill [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	1,097,809	1,125,149	1,349,838
Intellectual property rights [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	2,279,210	2,399,525	2,449,193
Premium in rental [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	148,078	134,793	118,310
Development costs [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	94,339	99,163	80,218
Port facilities usage rights [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	281,398	305,081	309,373
Exploration and evaluation assets [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	77,271	192,130	205,944
Customer relationships [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	374,875	421,773	466,945
Other intangible assets [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	555,493	493,211	₩ 433,043
Gross amount [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	8,802,856	8,494,949
Gross amount [member] \| Goodwill [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	1,631,413	1,603,308
Gross amount [member] \| Intellectual property rights [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	3,449,796	3,300,638
Gross amount [member] \| Premium in rental [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	170,247	158,338
Gross amount [member] \| Development costs [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	483,539	445,752
Gross amount [member] \| Port facilities usage rights [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	686,525	724,375
Gross amount [member] \| Exploration and evaluation assets [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	294,874	285,845
Gross amount [member] \| Customer relationships [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	865,821	860,951
Gross amount [member] \| Other intangible assets [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	1,220,641	1,115,742
Accumulated depreciation, amortization and impairment [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(3,894,261)	(3,324,010)
Government grants	(122)	(114)
Accumulated depreciation, amortization and impairment [member] \| Goodwill [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(533,604)	(478,159)
Accumulated depreciation, amortization and impairment [member] \| Intellectual property rights [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(1,170,586)	(901,113)
Accumulated depreciation, amortization and impairment [member] \| Premium in rental [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(22,169)	(23,545)
Accumulated depreciation, amortization and impairment [member] \| Development costs [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(389,200)	(346,589)
Accumulated depreciation, amortization and impairment [member] \| Port facilities usage rights [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(405,127)	(419,294)
Accumulated depreciation, amortization and impairment [member] \| Exploration and evaluation assets [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(217,603)	(93,715)
Accumulated depreciation, amortization and impairment [member] \| Customer relationships [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(490,946)	(439,178)
Accumulated depreciation, amortization and impairment [member] \| Other intangible assets [member]
Disclosure of detailed information about intangible assets [line items]
Goodwill and other intangible assets	(665,026)	(622,417)
Government grants	₩ (122)	₩ (114)

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets, Net - Changes in Carrying Amount of Goodwill and Other Intangible Assets (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	₩ 5,170,825	₩ 5,952,269
Acquisitions	298,819	542,359
Business combination	26,330
Disposals	(25,319)	(35,970)
Amortization	(431,247)	(356,581)
Impairment loss	(190,088)	(336,996)
Others	59,153	(594,256)
Ending	4,908,473	5,170,825	₩ 5,952,269
Impairment loss on property, plant and equipment	442,700	1,004,704	117,231
POSCO INTERNATIONAL CORPORATION [Member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Impairment loss on property, plant and equipment	118,140
Goodwill [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	1,125,149	1,349,838
Business combination	26,256
Impairment loss	(55,445)	(223,709)
Others	1,849	(980)
Ending	1,097,809	1,125,149	1,349,838
Intellectual property rights [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	2,399,525	2,449,193
Acquisitions	127,479	334,667
Disposals	(6,566)	(18,619)
Amortization	(271,694)	(198,282)
Impairment loss	(2)	(96,475)
Others	30,468	(70,959)
Ending	2,279,210	2,399,525	2,449,193
Premium in rental [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	134,793	118,310
Acquisitions	15,636	36,196
Disposals	(3,326)	(15,675)
Amortization	(181)	(330)
Impairment loss	24	(4,218)
Others	1,132	510
Ending	148,078	134,793	118,310
Development costs [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	99,163	80,218
Acquisitions	4,484	4,248
Disposals	(35)	(32)
Amortization	(44,418)	(37,305)
Impairment loss	(666)	(411)
Others	35,811	52,445
Ending	94,339	99,163	80,218
Port facilities usage rights [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	305,081	309,373
Disposals	(4,674)
Amortization	(22,923)	(22,975)
Others	3,914	18,683
Ending	281,398	305,081	309,373
Exploration and evaluation assets [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	192,130	205,944
Acquisitions	9,642	2,654
Impairment loss	(123,888)	(3,339)
Others	(613)	(13,129)
Ending	77,271	192,130	205,944
Customer relationships [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	421,773	466,945
Amortization	(51,768)	(48,499)
Others	4,870	3,327
Ending	374,875	421,773	466,945
Power generation permit [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning		539,405
Others		(539,405)
Ending			539,405
Other intangible assets [member]
Disclosure of reconciliation of changes in intangible assets and goodwill [line items]
Beginning	493,211	433,043
Acquisitions	141,578	164,594
Business combination	74
Disposals	(10,718)	(1,644)
Amortization	(40,263)	(49,190)
Impairment loss	(10,111)	(8,844)
Others	(18,278)	(44,748)
Ending	₩ 555,493	₩ 493,211	₩ 433,043

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets, Net - Allocation of Goodwill to Individually Operating Entities Which are Determined to be CGUs (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)Cash_Generating_Units	Dec. 31, 2018KRW (₩)Cash_Generating_Units
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Goodwill	₩ 1,097,809	₩ 1,125,149
Steel [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Total number of CGUs \| Cash_Generating_Units	7	7
Trading [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Total number of CGUs \| Cash_Generating_Units	3	2
Construction [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Total number of CGUs \| Cash_Generating_Units	2	2
Other reportable segment [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Total number of CGUs \| Cash_Generating_Units	5	5
Others [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Total number of CGUs \| Cash_Generating_Units	17	16
POSCO VST Co., Ltd. [member] \| Steel [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	POSCO VST CO., LTD.
Goodwill	₩ 36,955	₩ 36,955
Others [member] \| Steel [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	Others
Goodwill	₩ 13,721	12,484
Others [member] \| Trading [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Goodwill		16
Others [member] \| Other reportable segment [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	Others
Goodwill	₩ 10,478	10,419
POSCO INTERNATIONAL CORPORATION [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Discount rate	6.84%
Terminal growth rate	1.90%
Period for the estimated future cash flows	5 years
Impairment loss on goodwill	₩ 55,445
Discount rate increase	0.25%
Value in use decrease due to increase in discount rate	4.65%
Terminal growth rate decrease	0.25%
Value in use decrease due to decrease in terminal growth rate	2.05%
Value in use decrease due to increase in discount rate, amount	₩ 157,501
Value in use decrease due to decrease in terminal growth rate, amount	₩ 69,413
POSCO INTERNATIONAL CORPORATION [Member] \| Trading [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	POSCO INTERNATIONAL CORPORATION
Goodwill	₩ 951,434	1,006,879
GRAIN TERMINAL HOLDING [Member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Goodwill	₩ 26,256
GRAIN TERMINAL HOLDING [Member] \| Trading [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	GRAIN TERMINAL HOLDING
Goodwill	₩ 26,256
PT. Bio Inti Agrindo [member] \| Trading [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	PT. Bio Inti Agrindo
Goodwill	₩ 7,468	6,902
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Construction [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	POSCO ENGINEERING & CONSTRUCTION CO., LTD.
Goodwill	₩ 24,868	24,868
POSCO Center Beijing [member] \| Construction [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	POSCO Center Beijing
Goodwill	₩ 158	155
POSCO ENERGY CO., LTD. [member] \| Construction [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
Goodwill	₩ 26,471	₩ 26,471
POSCO ENERGY CO., LTD. [member] \| Other reportable segment [member]
Disclosure of information for impairment loss recognised or reversed for individual asset or cash-generating unit [line items]
CGUs	POSCO ENERGY CO., LTD.

Other Assets - Summary of Other

Other Assets - Summary of Other Current Assets and Other Non-Current Assets (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current
Advance payment	₩ 453,538	₩ 539,894
Prepaid expenses	145,834	123,770
Firm commitment asset	17,490	11,246
Others	14,315	9,553
Other current assets	631,177	684,463
Non-current
Long-term advance payment	21,950	24,280
Long-term prepaid expenses	41,256	334,918
Others	262,036	149,566
Other non-current assets	₩ 325,242	₩ 508,764

Other Assets - Summary of Oth_2

Other Assets - Summary of Other Current Assets and Other Non-Current Assets (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Subclassifications of assets, liabilities and equities [abstract]
Tax assets	₩ 213,071	₩ 116,693

Borrowings - Short-term Borrowi

Borrowings - Short-term Borrowings and Current Portion of Long-term Borrowings (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about borrowings [line items]
Short-term borrowings	₩ 5,486,333	₩ 7,487,780
Current portion of debentures	3,061,879	2,801,839
Current borrowings and current portion of non-current borrowings	8,548,212	10,289,619
JP Morgan and others [member]
Disclosure of detailed information about borrowings [line items]
Short-term borrowings	159,075	294,364
HSBC and others [member]
Disclosure of detailed information about borrowings [line items]
Short-term borrowings	₩ 5,327,258	7,193,416
Bottom of range [member] \| Short-term borrowings [member] \| JP Morgan and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	January, 2019
Maturity date	January, 2020
Interest rate (%)	0.50%
Bottom of range [member] \| Short-term borrowings [member] \| HSBC and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	January, 2019
Maturity date	January, 2020
Interest rate (%)	0.20%
Bottom of range [member] \| Current portion of long-term liabilities [member] \| Export-Import Bank of Korea and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	November, 2004
Maturity date	January, 2020
Interest rate (%)	0.70%
Bottom of range [member] \| Current portion of long-term liabilities [member] \| Korean Development Bank and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	October, 2010
Maturity date	April, 2020
Interest rate (%)	1.50%
Top of range [member] \| Short-term borrowings [member] \| JP Morgan and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	December, 2019
Maturity date	December, 2020
Interest rate (%)	8.90%
Top of range [member] \| Short-term borrowings [member] \| HSBC and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	December, 2019
Maturity date	December, 2020
Interest rate (%)	12.70%
Top of range [member] \| Current portion of long-term liabilities [member] \| Export-Import Bank of Korea and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	October, 2019
Maturity date	December, 2020
Interest rate (%)	6.60%
Top of range [member] \| Current portion of long-term liabilities [member] \| Korean Development Bank and others [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	September, 2018
Maturity date	October, 2020
Interest rate (%)	4.30%
Gross amount [member] \| Export-Import Bank of Korea and others [member]
Disclosure of detailed information about borrowings [line items]
Current portion of debentures	₩ 1,491,934	1,234,915
Gross amount [member] \| Korean Development Bank and others [member]
Disclosure of detailed information about borrowings [line items]
Current portion of debentures	1,571,194	1,568,108
Discount on debentures [member]
Disclosure of detailed information about borrowings [line items]
Current portion of debentures	₩ (1,249)	₩ (1,184)

Borrowings - Long-term Borrowin

Borrowings - Long-term Borrowings, Excluding Current Portion (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about borrowings [line items]
Long-term borrowings, excluding current portion	₩ 11,893,401	₩ 9,919,651
Export-Import Bank of Korea and others [member] \| Long-term borrowings [member] \| Bottom of range [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	September, 2001
Maturity date	February, 2021
Interest rate (%)	0.20%
Export-Import Bank of Korea and others [member] \| Long-term borrowings [member] \| Top of range [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	December, 2019
Maturity date	March, 2037
Interest rate (%)	12.50%
KB Securities and others [member] \| Long-term borrowings [member] \| Bottom of range [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	April, 2011
Maturity date	February, 2021
Interest rate (%)	1.60%
KB Securities and others [member] \| Long-term borrowings [member] \| Top of range [member]
Disclosure of detailed information about borrowings [line items]
Issuance date	November, 2019
Maturity date	October, 2029
Interest rate (%)	5.30%
Gross amount [member] \| Export-Import Bank of Korea and others [member]
Disclosure of detailed information about borrowings [line items]
Long-term borrowings, excluding current portion	₩ 3,827,152	4,499,199
Gross amount [member] \| KB Securities and others [member]
Disclosure of detailed information about borrowings [line items]
Long-term borrowings, excluding current portion	8,124,194	5,469,580
Present value discount [member]
Disclosure of detailed information about borrowings [line items]
Long-term borrowings, excluding current portion	(24,374)	(30,526)
Discount on debentures [member]
Disclosure of detailed information about borrowings [line items]
Long-term borrowings, excluding current portion	₩ (33,571)	₩ (18,602)

Borrowings - Summary of Assets

Borrowings - Summary of Assets Pledges as Collateral (Detail) ₩ in Millions	Dec. 31, 2019KRW (₩)
Disclosure Of Assets Pledged As Collateral [line items]
Pledged amount	₩ 5,059,256
Book value [member]
Disclosure Of Assets Pledged As Collateral [line items]
Assets	4,620,013
Property, plant and equipment including investment property [member] \| Korean Development Bank and others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Pledged amount	4,967,168
Property, plant and equipment including investment property [member] \| Book value [member] \| Korean Development Bank and others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Assets	4,420,551
Trade accounts and notes receivables, net [member] \| Korean Development Bank and others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Pledged amount	7,498
Trade accounts and notes receivables, net [member] \| Book value [member] \| Korean Development Bank and others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Assets	7,498
Inventories [member] \| Export-Import Bank of Korea and others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Pledged amount	12,650
Inventories [member] \| Book value [member] \| Export-Import Bank of Korea and others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Assets	118,824
Cash and cash equivalents [member] \| Shinhan Bank [member]
Disclosure Of Assets Pledged As Collateral [line items]
Pledged amount	26,923
Cash and cash equivalents [member] \| Book value [member] \| Shinhan Bank [member]
Disclosure Of Assets Pledged As Collateral [line items]
Assets	26,923
Financial Instruments [Member] \| Kookmin Bank and Others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Pledged amount	45,017
Financial Instruments [Member] \| Book value [member] \| Kookmin Bank and Others [member]
Disclosure Of Assets Pledged As Collateral [line items]
Assets	₩ 46,217

Other Payables - Summary of Oth

Other Payables - Summary of Other Payables (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current
Accounts payable	₩ 832,845	₩ 783,562
Accrued expenses	742,370	720,773
Dividend payable	3,106	8,673
Lease liabilities	149,176	10,152
Withholdings	152,011	196,937
Other payables, current	1,879,508	1,720,097
Non-current
Accounts payable	2,718	1,624
Accrued expenses	4,805	19,021
Finance lease liabilities	526,294	84,602
Long-term withholdings	51,312	43,621
Other payables, non-current	₩ 585,129	₩ 148,868

Other Payables - Summary of O_2

Other Payables - Summary of Other Payables (Parenthetical) (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)
Trade and other payables [abstract]
Additional lease liability recognized	₩ 590,225

Other Financial Liabilities - S

Other Financial Liabilities - Summary of Other Financial Liabilities (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current
Derivatives liabilities	₩ 28,021	₩ 27,328
Financial guarantee liabilities	49,806	50,472
Other financial liabilities, current	77,827	77,800
Non-current
Derivatives liabilities	17,033	46,429
Financial guarantee liabilities	14,461	17,733
Other financial liabilities, non-current	₩ 31,494	₩ 64,162

Provisions - Summary of Provisi

Provisions - Summary of Provisions (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of other provisions [line items]
Current	₩ 360,337	₩ 298,453
Non-current	458,154	431,036
Provision for bonus payments [member]
Disclosure of other provisions [line items]
Current	76,432	46,514
Non-current	47,237	26,964
Provision for construction warranties [member]
Disclosure of other provisions [line items]
Current	7,655	11,842
Non-current	162,773	130,391
Provision for legal contingencies and claims [member]
Disclosure of other provisions [line items]
Current	6,996	16,981
Non-current	77,488	94,169
Provisions for the restoration [member]
Disclosure of other provisions [line items]
Current	6,783	9,379
Non-current	80,520	79,789
Others [member]
Disclosure of other provisions [line items]
Current	262,471	213,737
Non-current	₩ 90,136	₩ 99,723

Provisions - Summary of Provi_2

Provisions - Summary of Provisions (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of other provisions [line items]
Other provisions	₩ 818,491	₩ 729,489	₩ 588,118
Other provisions current	360,337	298,453
Others [member]
Disclosure of other provisions [line items]
Other provisions	352,607	313,460	₩ 249,957
Other provisions current	262,471	213,737
Others [member] \| POSCO ENERGY and Korea Fuel Cell [member]
Disclosure of other provisions [line items]
Other provisions	178,959	200,407
Lawsuits provision [member]
Disclosure of other provisions [line items]
Other provisions	54,228	₩ 50,888
Emission of greenhouse gases [member]
Disclosure of other provisions [line items]
Other provisions current	50,965
Land [member] \| Gangneung province [member]
Disclosure of other provisions [line items]
Other provisions	₩ 22,725
Land [member] \| Gangneung province [member] \| Bottom of range [member]
Disclosure of other provisions [line items]
Discount rates	1.74%
Land [member] \| Gangneung province [member] \| Top of range [member]
Disclosure of other provisions [line items]
Discount rates	1.84%
Land [member] \| Pohang work [member] \| Bottom of range [member]
Disclosure of other provisions [line items]
Discount rates	1.74%
Land [member] \| Pohang work [member] \| Top of range [member]
Disclosure of other provisions [line items]
Discount rates	1.84%

Provisions - Changes in Provisi

Provisions - Changes in Provisions (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of other provisions [line items]
Beginning	₩ 729,489	₩ 588,118
Increase	321,630	573,472
Utilization	(197,700)	(218,997)
Reversal	(125,456)	(279,265)
Others	90,528	66,161
Ending	818,491	729,489
Provision for bonus payments [member]
Disclosure of other provisions [line items]
Beginning	73,478	49,171
Increase	122,714	88,879
Utilization	(86,084)	(60,723)
Reversal	(3,077)	(3,856)
Others	16,638	7
Ending	123,669	73,478
Provision for construction warranties [member]
Disclosure of other provisions [line items]
Beginning	142,233	118,036
Increase	53,203	56,560
Utilization	(22,858)	(24,608)
Reversal	(3,444)	(7,660)
Others	1,294	(95)
Ending	170,428	142,233
Provision for legal contingencies and claims [member]
Disclosure of other provisions [line items]
Beginning	111,150	36,764
Increase	26,407	84,242
Utilization	(37,087)	(6,066)
Reversal	(18,098)	(3,399)
Others	2,112	(391)
Ending	84,484	111,150
Provisions for the restoration [member]
Disclosure of other provisions [line items]
Beginning	89,168	134,190
Increase	23,559	14,912
Utilization	(13,411)	(9,212)
Reversal	(14,379)	(47,682)
Others	2,366	(3,040)
Ending	87,303	89,168
Others [member]
Disclosure of other provisions [line items]
Beginning	313,460	249,957
Increase	95,747	328,879
Utilization	(38,260)	(118,388)
Reversal	(86,458)	(216,668)
Others	68,118	69,680
Ending	₩ 352,607	₩ 313,460

Employee Benefits - Expense Rel

Employee Benefits - Expense Related to Post-employment Benefit Plans under Defined Contribution Plans (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of defined benefit plans [abstract]
Expense related to post-employment benefit plans under defined contribution plans	₩ 46,846	₩ 42,825	₩ 35,538

Employee Benefits - Amounts Rec

Employee Benefits - Amounts Recognized in Relation to Net Defined Benefit Liabilities in Statements of Financial Position (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [abstract]
Present value of funded obligations	₩ 2,416,203	₩ 2,117,829
Fair value of plan assets	(2,255,149)	(1,997,717)
Present value of non-funded obligations	15,677	19,332
Net defined benefit liabilities	₩ 176,731	₩ 139,444

Employee Benefits - Amounts R_2

Employee Benefits - Amounts Recognized in Relation to Net Defined Benefit Liabilities in Statements of Financial Position (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of defined benefit plans [abstract]
Net defined benefit assets	₩ 4,280	₩ 1,489

Employee Benefits - Changes in

Employee Benefits - Changes in Present Value of Defined Benefit Obligations (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of net defined benefit liability (asset) [line items]
Current service costs	₩ 236,735	₩ 212,323	₩ 209,612
Interest	3,690	4,166	(9,686)
Defined benefit obligations [member]
Disclosure of net defined benefit liability (asset) [line items]
Beginning of year	2,137,161	1,843,135
Current service costs	236,735	212,323
Interest	51,900	54,950
Remeasurements :	152,713	212,678
- Gain from change in financial assumptions	103,850	173,084
- Loss (gain) from change in demographic assumptions	(492)	526
- Others	49,355	39,068
Benefits paid	(152,275)	(189,165)
Others	5,646	3,240
End of year	₩ 2,431,880	₩ 2,137,161	₩ 1,843,135

Employee Benefits - Changes i_2

Employee Benefits - Changes in Fair Value of Plan Assets (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of net defined benefit liability (asset) [line items]
Interest	₩ 3,690	₩ 4,166	₩ (9,686)
Plan assets [member]
Disclosure of net defined benefit liability (asset) [line items]
Beginning of year	1,997,717	1,714,166
Interest	48,210	50,784
Remeasurements	(8,692)	(19,761)
Contributions to plan assets	342,915	408,326
Benefits paid	(124,962)	(163,112)
Others	(39)	7,314
End of year	₩ 2,255,149	₩ 1,997,717	₩ 1,714,166

Employee Benefits - Additional

Employee Benefits - Additional Information (Detail) ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)
Disclosure of net defined benefit liability (asset) [abstract]
Estimated contribution to the defined benefit plan assets	₩ 331,415

Employee Benefits - Fair Value

Employee Benefits - Fair Value of Plan Assets (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of fair value of plan assets [abstract]
Equity instruments	₩ 10,386	₩ 3,151
Debt instruments	1,013,716	692,825
Deposits	1,159,455	1,244,802
Others	71,592	56,939
Fair value of plan assets	₩ 2,255,149	₩ 1,997,717

Employee Benefits - Amounts R_3

Employee Benefits - Amounts Recognized in Consolidated Statements of Comprehensive Income (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of defined benefit plans [line items]
Current service costs	₩ 236,735	₩ 212,323	₩ 209,612
Net interest costs	3,690	4,166	(9,686)
Amounts recognized in consolidated statements of comprehensive income	240,425	216,489	199,926
Cost of sales [member]
Disclosure of defined benefit plans [line items]
Amounts recognized in consolidated statements of comprehensive income	169,206	150,822	131,724
Selling and administrative expenses [member]
Disclosure of defined benefit plans [line items]
Amounts recognized in consolidated statements of comprehensive income	70,060	64,505	67,424
Others [member]
Disclosure of defined benefit plans [line items]
Amounts recognized in consolidated statements of comprehensive income	₩ 1,159	₩ 1,162	₩ 778

Employee Benefits - Amounts R_4

Employee Benefits - Amounts Recognized in Consolidated Statements of Comprehensive Income (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of defined benefit plans [abstract]
Actual return on plan assets	₩ 39,518	₩ 31,023	₩ 30,422

Employee Benefits - Accumulated

Employee Benefits - Accumulated Actuarial Gains (Losses), Net of Tax Recognized in Other Comprehensive Income (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of defined benefit plans [abstract]
Beginning	₩ (472,644)	₩ (299,155)	₩ (251,612)
Current actuarial gains (losses)	(117,152)	(173,489)	(47,543)
Ending	₩ (589,796)	₩ (472,644)	₩ (299,155)

Employee Benefits - Principal A

Employee Benefits - Principal Actuarial Assumptions (Detail)	Dec. 31, 2019	Dec. 31, 2018
Bottom of range [member]
Disclosure of defined benefit plans [line items]
Discount rate	1.72%	2.24%
Expected future increase in salaries	2.00%	2.54%
Top of range [member]
Disclosure of defined benefit plans [line items]
Discount rate	13.00%	10.03%
Expected future increase in salaries	11.00%	10.00%

Employee Benefits - Changes to

Employee Benefits - Changes to Defined Benefit Obligation Due to Reasonably Possible Changes to one of the Relevant Actuarial Assumptions (Detail) ₩ in Millions	Dec. 31, 2019KRW (₩)
Discount rate [member]
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Affect on defined benefit obligation due to reasonably possible 1% increase in actuarial assumption	₩ (167,767)
Affect on defined benefit obligation due to reasonably possible 1% decrease in actuarial assumption	₩ 194,809
Percentage of reasonably possible 1% decrease in actuarial assumption	8.00%
Percentage of reasonably possible 1% decrease in actuarial assumption	(6.90%)
Expected future increase in salaries [member]
Disclosure of sensitivity analysis for actuarial assumptions [line items]
Affect on defined benefit obligation due to reasonably possible 1% increase in actuarial assumption	₩ 195,098
Percentage of reasonably possible 1% increase in actuarial assumption	8.00%
Affect on defined benefit obligation due to reasonably possible 1% decrease in actuarial assumption	₩ (170,997)
Percentage of reasonably possible 1% decrease in actuarial assumption	(7.00%)

Employee Benefits - Maturity of

Employee Benefits - Maturity of Expected Benefit Payments (Detail) ₩ in Millions	Dec. 31, 2019KRW (₩)
Disclosure of defined benefit plans [line items]
Benefits paid	₩ 2,902,451
Less than 1 year [member]
Disclosure of defined benefit plans [line items]
Benefits paid	279,554
1 year - 5 years [member]
Disclosure of defined benefit plans [line items]
Benefits paid	928,288
5 years - 10 years [member]
Disclosure of defined benefit plans [line items]
Benefits paid	513,133
10 years - 20 years [member]
Disclosure of defined benefit plans [line items]
Benefits paid	771,500
After 20 years [member]
Disclosure of defined benefit plans [line items]
Benefits paid	₩ 409,976

Other Liabilities - Summary of

Other Liabilities - Summary of Other Liabilities (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current
Due to customers for contract work	₩ 644,947	₩ 641,064
Advances received	746,169	1,130,910
Unearned revenue	61,795	49,805
Withholdings	388,486	233,981
Firm commitment liability	15,637	24,373
Others	8,604	10,174
Other current liabilities	1,865,638	2,090,307
Non-current
Advances received	116,178	123,071
Unearned revenue	27,161	42,992
Others	52,349	84,369
Other non-current liabilities	₩ 195,688	₩ 250,432

Financial Instruments - Summary

Financial Instruments - Summary of Carrying Amount and Fair Values of Financial Assets and Financial Liabilities by Fair value (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Cash and cash Equivalents	₩ 3,514,872	₩ 2,643,865
Borrowings	5,486,333	7,487,780
Financial guarantee liabilities	64,267
Others	1,725,912
Short-term financial instruments	6,861,242	6,099,303
Other receivables	1,581,517	1,385,629
Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial assets	24,590,469	23,037,857
Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial liabilities	26,395,305	26,190,545
Financial assets at fair value through profit or loss [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Derivatives assets held for trading	106,104	16,662
Short-term financial instruments	6,861,242	6,099,303
Debt securities	28,087	27,229
Other securities	340,008	338,106
Other receivables	2,000	2,000
Derivative hedging instruments(*2)	6,174	32,421
Fair value through other comprehensive income [Member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Equity securities	1,204,902	1,238,630
Debt securities	5,686	1,638
Amortized cost [Member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Cash and cash Equivalents	3,514,872	2,643,865
Trade accounts and notes receivable	8,214,459	8,819,617
Debt securities	334,153	8,447
Other receivables	2,193,700	1,843,381
Deposit instruments	1,779,082	1,966,558
Financial liabilities at fair value through profit or loss [Member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Fair value through profit or loss Derivative liabilities	32,193	60,047
Derivative hedging instruments(*2)	12,861	13,710
Financial liabilities measured at amortized cost [member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Trade accounts and notes payable	3,442,989	4,035,960
Borrowings	20,441,613	20,209,270
Financial guarantee liabilities	64,267	68,205
Others	2,401,382	1,803,353
Fair value [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial assets	8,554,203	7,755,989
Fair value [member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial liabilities	20,711,530	20,450,862
Fair value [member] \| Financial assets at fair value through profit or loss [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Derivatives assets held for trading	106,104	16,662
Short-term financial instruments	6,861,242	6,099,303
Debt securities	28,087	27,229
Other securities	340,008	338,106
Other receivables	2,000	2,000
Derivative hedging instruments(*2)	6,174	32,421
Fair value [member] \| Fair value through other comprehensive income [Member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Equity securities	422,721	347,116
Debt securities	5,686	1,638
Fair value [member] \| Financial liabilities at fair value through profit or loss [Member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Fair value through profit or loss Derivative liabilities	32,193	60,047
Derivative hedging instruments(*2)	12,861	13,710
Fair value [member] \| Financial liabilities measured at amortized cost [member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Borrowings	20,666,476	20,377,105
Level 1 [member] \| Fair value [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial assets	783,330	892,738
Level 1 [member] \| Fair value [member] \| Financial assets at fair value through profit or loss [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Other securities	1,222	1,224
Level 1 [member] \| Fair value [member] \| Fair value through other comprehensive income [Member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Equity securities	782,108	891,514
Level 2 [member] \| Fair value [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial assets	6,976,923	6,153,591
Level 2 [member] \| Fair value [member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial liabilities	20,711,530	20,450,862
Level 2 [member] \| Fair value [member] \| Financial assets at fair value through profit or loss [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Derivatives assets held for trading	106,104	16,662
Short-term financial instruments	6,861,242	6,099,303
Other securities	3,330	5,205
Derivative hedging instruments(*2)	6,174	32,421
Level 2 [member] \| Fair value [member] \| Financial liabilities at fair value through profit or loss [Member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Fair value through profit or loss Derivative liabilities	32,193	60,047
Derivative hedging instruments(*2)	12,861	13,710
Level 2 [member] \| Fair value [member] \| Financial liabilities measured at amortized cost [member] \| Liabilities measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Borrowings	20,666,476	20,377,105
Level 3 [member] \| Fair value [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Financial assets	793,950	709,660
Level 3 [member] \| Fair value [member] \| Financial assets at fair value through profit or loss [member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Debt securities	28,087	27,229
Other securities	335,456	331,677
Other receivables	2,000	2,000
Level 3 [member] \| Fair value [member] \| Fair value through other comprehensive income [Member] \| Assets measured at fair value [member]
Disclosures Of Fair Value Hierarchy Of Financial Assets And Financial Liabilities [Line items]
Equity securities	1,204,902	1,238,630
Debt securities	₩ 5,686	₩ 1,638

Financial Instruments - Value M

Financial Instruments - Value Measurement Method and Significant but not Observable Inputs for the Financial Assets Classified as Fair Value Hierarchy Level 3 (Detail) - Fair value [member] - Level 3 [member] ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)
Discounted cash flow [member]
Disclosure of significant unobservable inputs used in fair value measurement of assets [line items]
Available-for-sale financial assets	₩ 417,683
PeerGroupUsage [member]
Disclosure of significant unobservable inputs used in fair value measurement of assets [line items]
Available-for-sale financial assets	17,931
Asset value approach [member]
Disclosure of significant unobservable inputs used in fair value measurement of assets [line items]
Available-for-sale financial assets	₩ 358,336
Available-for-sale financial assets [member] \| Bottom of range [member]
Disclosure of significant unobservable inputs used in fair value measurement of assets [line items]
Growth rate	0.00%
Discount rate	6.00%
Price multiple	0.621
Available-for-sale financial assets [member] \| Top of range [member]
Disclosure of significant unobservable inputs used in fair value measurement of assets [line items]
Growth rate	0.50%
Discount rate	18.40%
Price multiple	2.645

Financial Instruments - Sensiti

Financial Instruments - Sensitivity Analysis of Financial Assets and Financial Liabilities Classified as Level 3 of Fair Value Hierarchy (Detail) - Available-for-sale financial assets [member] ₩ in Millions	12 Months Ended
	Dec. 31, 2019KRW (₩)
Fluctuation 0.5% of growth rate [member]
Disclosure of significant unobservable inputs used in fair value measurement of assets [line items]
Favorable changes	₩ 1,325
Unfavorable changes	1,224
Fluctuation 0.5% of discount rate [member]
Disclosure of significant unobservable inputs used in fair value measurement of assets [line items]
Favorable changes	24,766
Unfavorable changes	₩ 21,845

Financial Instruments - Changes

Financial Instruments - Changes in Fair Value of Financial Assets and Financial Liabilities Classified as Level 3 (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of fair value measurement of assets [line items]
Beginning	₩ 78,776,991
Ending	79,370,808	₩ 78,776,991
Fair value [member] \| Level 3 [member]
Disclosure of fair value measurement of assets [line items]
Beginning	709,660	880,012
Acquisition and others	68,461	134,325
Loss on valuation of financial assets	(9,412)	(34,555)
Other comprehensive income	106,586	26,771
Disposal and others	(81,345)	(296,893)
Ending	₩ 793,950	₩ 709,660

Financial Instruments - Finance

Financial Instruments - Finance Income and Costs by Category of Financial Instruments (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of detailed information about financial instruments [line items]
Interest income (expense)	₩ (403,327)	₩ (404,038)	₩ (440,664)
Gain and loss on valuation	92,493	13,019	(161,735)
Gain and loss on foreign currency	(35,489)	(204,102)	170,098
Gain and loss on disposal	(66,022)	10,690	360,787
Impairment loss			(123,214)
Others	42,425	45,985	83,118
Total	(369,920)	(538,446)	(111,610)
Other comprehensive income (loss)	(10,631)	(149,400)	(31,532)
Derivative financial liabilities [member]
Disclosure of detailed information about financial instruments [line items]
Gain and loss on valuation	(7,494)	8,592	(61,809)
Gain and loss on disposal	(217,072)	(194,446)	(231,908)
Total	(224,566)	(185,854)	(293,717)
Other comprehensive income (loss)	(90)	(212)
Financial liabilities measured at amortized cost [member]
Disclosure of detailed information about financial instruments [line items]
Interest income (expense)	(755,711)	(741,296)	(653,115)
Gain and loss on foreign currency	(330,808)	(438,708)	777,935
Gain and loss on disposal	(2,432)
Others	(24,988)	(16,990)	(9,546)
Total	(1,113,939)	(1,196,994)	115,274
Derivative financial assets [member]
Disclosure of detailed information about financial instruments [line items]
Gain and loss on valuation	123,538	47,720	(99,942)
Gain and loss on disposal	184,861	233,187	206,362
Total	308,399	280,907	106,420
Other comprehensive income (loss)			(143)
Available-for-sale financial assets [member]
Disclosure of detailed information about financial instruments [line items]
Interest income (expense)			60
Gain and loss on disposal			418,789
Impairment loss			(123,214)
Others			92,961
Total			388,596
Other comprehensive income (loss)			(31,389)
Held-to-maturity financial assets [member]
Disclosure of detailed information about financial instruments [line items]
Interest income (expense)			236
Others			7
Total			243
Loans and receivables [member]
Disclosure of detailed information about financial instruments [line items]
Interest income (expense)			212,155
Gain and loss on foreign currency			(607,837)
Gain and loss on disposal			(32,456)
Others			(304)
Total			(428,442)
Financial assets held for trading [member]
Disclosure of detailed information about financial instruments [line items]
Gain and loss on valuation			16
Total			₩ 16
Financial assets at fair value through profit or loss [member]
Disclosure of detailed information about financial instruments [line items]
Interest income (expense)	142,873	140,116
Gain and loss on valuation	(23,551)	(43,293)
Gain and loss on disposal	5,556	11,919
Others	630	3,644
Total	125,508	112,386
Fair value through other comprehensive income [Member]
Disclosure of detailed information about financial instruments [line items]
Others	74,825	59,701
Total	74,825	59,701
Other comprehensive income (loss)	(10,541)	(149,188)
Amortized cost [Member]
Disclosure of detailed information about financial instruments [line items]
Interest income (expense)	209,511	197,142
Gain and loss on foreign currency	295,319	234,606
Gain and loss on disposal	(36,935)	(39,970)
Others	(8,042)	(370)
Total	₩ 459,853	₩ 391,408

Financial Instruments - Maximum

Financial Instruments - Maximum Exposure to Credit Risk (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	₩ 23,385,567	₩ 21,799,227
Cash and cash equivalents [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	3,514,872	2,643,865
Derivative financial assets [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	112,278	49,083
Short-term financial instrument [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	6,861,242	6,099,303
Debt securities [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	367,926	37,314
Other securities [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	340,008	338,106
Other receivables [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	2,195,700	1,845,381
Trade accounts and nores receivable [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	8,214,459	8,819,617
Deposit instruments [member]
Disclosure of credit risk exposure [line items]
Maximum exposure to credit risk	₩ 1,779,082	₩ 1,966,558

Financial Instruments - Additio

Financial Instruments - Additional Information (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about financial instruments [line items]
Maximum exposure to credit risk related financial guarantees	₩ 23,385,567	₩ 21,799,227
Financial guarantees [member]
Disclosure of detailed information about financial instruments [line items]
Maximum exposure to credit risk related financial guarantees	₩ 4,959,011	₩ 3,147,280

Financial Instruments - Allowan

Financial Instruments - Allowance for Doubtful Accounts (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of financial assets [line items]
Allowance for doubtful accounts	₩ 898,274	₩ 916,790	₩ 1,094,464	₩ 977,771
Trade accounts and notes receivable [member]
Disclosure of financial assets [line items]
Allowance for doubtful accounts	465,524	588,733
Other accounts receivable [member]
Disclosure of financial assets [line items]
Allowance for doubtful accounts	210,313	160,729
Loans [member]
Disclosure of financial assets [line items]
Allowance for doubtful accounts	195,339	147,980
Other assets [member]
Disclosure of financial assets [line items]
Allowance for doubtful accounts	₩ 27,098	₩ 19,348

Financial Instruments - Impairm

Financial Instruments - Impairment Losses on Financial Assets (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of financial assets [line items]
Impairment loss on financial assets			₩ 123,214
Impairment loss on financial assets, net	₩ 52,218	₩ 137,873
Bad debt expenses [member]
Disclosure of financial assets [line items]
Impairment loss on financial assets	(28,105)	74,781
Others [member]
Disclosure of financial assets [line items]
Impairment loss on financial assets	88,787	81,353
Less: Recovery of impairment loss on financial assets	₩ (8,464)	₩ (18,261)

Financial Instruments - Aging a

Financial Instruments - Aging and Impairment Losses of Trade Accounts and Notes Receivable and Other Receivables (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of financial assets that are either past due or impaired [line items]
Allowance for doubtful accounts	₩ 898,274	₩ 916,790	₩ 1,094,464	₩ 977,771
Trade accounts and notes receivables, net [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	9,734,340	10,146,062
Allowance for doubtful accounts	465,524	588,733
Trade accounts and notes receivables, net [member] \| Current (not past due) [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	7,528,607	8,021,110
Allowance for doubtful accounts	75,324	70,418
Trade accounts and notes receivables, net [member] \| Overdue less than 1 month [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	876,753	632,082
Allowance for doubtful accounts	9,395	14,434
Trade accounts and notes receivables, net [member] \| 1 month-3 months [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	228,115	226,082
Allowance for doubtful accounts	6,647	4,116
Trade accounts and notes receivables, net [member] \| 3 months-12 months [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	134,888	118,094
Allowance for doubtful accounts	7,954	11,774
Trade accounts and notes receivables, net [member] \| Over 12 months [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	965,977	1,148,694
Allowance for doubtful accounts	366,204	487,991
Other receivables [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	2,628,450	2,173,438
Allowance for doubtful accounts	432,750	328,057
Other receivables [member] \| Current (not past due) [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	1,220,756	1,754,293
Allowance for doubtful accounts	56,354	140,072
Other receivables [member] \| Overdue less than 1 month [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	432,220	100,102
Allowance for doubtful accounts	1,546	4,307
Other receivables [member] \| 1 month-3 months [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	91,521	28,351
Allowance for doubtful accounts	239	851
Other receivables [member] \| 3 months-12 months [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	271,814	59,946
Allowance for doubtful accounts	10,846	12,411
Other receivables [member] \| Over 12 months [member]
Disclosure of financial assets that are either past due or impaired [line items]
Financial assets	612,139	230,746
Allowance for doubtful accounts	₩ 363,765	₩ 170,416

Financial Instruments - Chang_2

Financial Instruments - Changes in Allowance for Doubtful Accounts (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of changes in allowance account for credit losses of financial assets [abstract]
Beginning	₩ 916,790	₩ 1,094,464	₩ 977,771
Initial application of IFRS No.9		107,454
Bad debt expenses	(28,105)	74,781	173,694
Other bad debt expenses	80,323	63,092	98,177
Others	(70,735)	(423,001)	(155,178)
Ending	₩ 898,274	₩ 916,790	₩ 1,094,464

Financial Instruments - Contrac

Financial Instruments - Contractual Maturities for Non-derivative Financial Liabilities (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Trade accounts and notes payable, book value	₩ 3,442,989
Borrowings, book value	20,441,613	₩ 20,209,270
Financial guarantee liabilities, book value	64,267
Lease liabilities book value	675,470
Other financial liabilities, book value	1,725,912
Non-derivative financial liabilities, book value	26,350,251
Trade accounts and notes payable, contractual cash flow	3,444,596
Borrowings, contractual cash flow	22,161,306
Financial guarantee liabilities, contractual cash flow	3,406,609
Lease liabilities contractual cash flows	858,662
Other financial liabilities, contractual cash flow	1,797,765
Non-derivative financial liabilities, contractual cash flow	31,668,938
Less than 1 year [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Trade accounts and notes payable, contractual cash flow	3,422,957
Borrowings, contractual cash flow	9,262,808
Financial guarantee liabilities, contractual cash flow	3,406,609
Lease liabilities contractual cash flows	166,854
Other financial liabilities, contractual cash flow	1,667,087
Non-derivative financial liabilities, contractual cash flow	17,926,315
1 year - 5 years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Trade accounts and notes payable, contractual cash flow	21,639
Borrowings, contractual cash flow	11,171,927
Financial guarantee liabilities, contractual cash flow	0
Lease liabilities contractual cash flows	502,674
Other financial liabilities, contractual cash flow	130,678
Non-derivative financial liabilities, contractual cash flow	11,826,918
After 5 years [member]
Disclosure of maturity analysis for non-derivative financial liabilities [line items]
Borrowings, contractual cash flow	1,726,571
Lease liabilities contractual cash flows	189,134
Non-derivative financial liabilities, contractual cash flow	₩ 1,915,705

Financial Instruments - Chang_3

Financial Instruments - Changes in Allowance for Doubtful Accounts (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of changes in allowance account for credit losses of financial assets [abstract]
Write-off of receivables	₩ 78,505	₩ 383,714	₩ 119,964

Financial Instruments - Maturit

Financial Instruments - Maturity Analysis of Derivative Financial Liabilities (Detail) ₩ in Millions	Dec. 31, 2019KRW (₩)
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	₩ 45,054
Currency forward [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	21,911
Currency swap [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	6,102
Interest swap [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	2,893
Others [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	14,148
Less than 1 year [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	28,022
Less than 1 year [member] \| Currency forward [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	11,779
Less than 1 year [member] \| Currency swap [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	570
Less than 1 year [member] \| Interest swap [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	1,525
Less than 1 year [member] \| Others [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	14,148
1 year - 5 years [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	13,187
1 year - 5 years [member] \| Currency forward [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	10,132
1 year - 5 years [member] \| Currency swap [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	1,687
1 year - 5 years [member] \| Interest swap [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	1,368
After 5 years [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	3,845
After 5 years [member] \| Currency swap [member]
Disclosure of maturity analysis for derivative financial liabilities [line items]
Derivative financial liabilities	₩ 3,845

Financial Instruments - Exposur

Financial Instruments - Exposure to Currency Risk (Detail) - Currency risk [member] - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
USD [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Assets	₩ 4,423,107	₩ 4,346,481
Liabilities	6,166,765	6,389,276
EUR [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Assets	592,381	657,690
Liabilities	180,816	509,437
JPY [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Assets	79,664	97,722
Liabilities	253,542	389,625
Others [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Assets	481,455	259,949
Liabilities	₩ 319,046	₩ 142,868

Financial Instruments - Chang_4

Financial Instruments - Changes in Gain or Loss Due to a Hypothetically Strengthening or Weakening in Foreign Currencies (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
10% increase [member] \| USD [member]
Disclosure of detailed information about hedging instruments [line items]
Changes in gain or loss due to hypothetically strengthens or weakens of functional currency against foreign currencies other than functional currency	₩ (174,366)	₩ (204,280)
Hypothetical percentage change in functional currency against foreign currencies other than functional currency	10.00%	10.00%
10% increase [member] \| EUR [member]
Disclosure of detailed information about hedging instruments [line items]
Changes in gain or loss due to hypothetically strengthens or weakens of functional currency against foreign currencies other than functional currency	₩ 41,156	₩ 14,825
Hypothetical percentage change in functional currency against foreign currencies other than functional currency	10.00%	10.00%
10% increase [member] \| JPY [member]
Disclosure of detailed information about hedging instruments [line items]
Changes in gain or loss due to hypothetically strengthens or weakens of functional currency against foreign currencies other than functional currency	₩ (17,388)	₩ (29,190)
Hypothetical percentage change in functional currency against foreign currencies other than functional currency	10.00%	10.00%
10% decrease [member] \| USD [member]
Disclosure of detailed information about hedging instruments [line items]
Changes in gain or loss due to hypothetically strengthens or weakens of functional currency against foreign currencies other than functional currency	₩ 174,366	₩ 204,280
Hypothetical percentage change in functional currency against foreign currencies other than functional currency	10.00%	10.00%
10% decrease [member] \| EUR [member]
Disclosure of detailed information about hedging instruments [line items]
Changes in gain or loss due to hypothetically strengthens or weakens of functional currency against foreign currencies other than functional currency	₩ (41,156)	₩ (14,825)
Hypothetical percentage change in functional currency against foreign currencies other than functional currency	10.00%	10.00%
10% decrease [member] \| JPY [member]
Disclosure of detailed information about hedging instruments [line items]
Changes in gain or loss due to hypothetically strengthens or weakens of functional currency against foreign currencies other than functional currency	₩ 17,388	₩ 29,190
Hypothetical percentage change in functional currency against foreign currencies other than functional currency	10.00%	10.00%

Financial Instruments - Carryin

Financial Instruments - Carrying Amount of Interest-Bearing Financial Instruments (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Fixed rate [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Financial assets	₩ 13,391,637	₩ 11,565,519
Financial liabilities	(13,264,607)	(11,781,701)
Financial asset and liabilities	127,030	(216,182)
Variable rate [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Financial liabilities	₩ (7,852,476)	₩ (8,522,323)

Financial Instruments - Chang_5

Financial Instruments - Changes in Interest Expense Due to an Increases or Decreases in Interest Rate (Detail) - Variable rate [member] - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
1% increase in floating rates [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Hypothetical percentage change in the floating rate	1.00%	1.00%
Change in interest expense due to hypothetical increase or decrease in the floating rate	₩ (78,525)	₩ (85,223)
1% decrease in floating rates [member]
Disclosure of nature and extent of risks arising from financial instruments [line items]
Hypothetical percentage change in the floating rate	1.00%	(1.00%)
Change in interest expense due to hypothetical increase or decrease in the floating rate	₩ 78,525	₩ 85,223

Share Capital and Capital Sur_3

Share Capital and Capital Surplus - Summary of Share Capital (Detail) - KRW (₩) ₩ / shares in Units, ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of classes of share capital [abstract]
Authorized shares	200,000,000	200,000,000
Par value	₩ 5,000	₩ 5,000
Issued shares(*1)	87,186,835	87,186,835	87,186,835
Shared capital(*2)	₩ 482,403	₩ 482,403

Share Capital and Capital Sur_4

Share Capital and Capital Surplus - Summary of Share Capital (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of classes of share capital [line items]
Total shares of ADRs outstanding	80,115,641	80,001,132	79,999,604
Total shares of ADRs outstanding, equivalent common stock shares	8,706,978
Difference between the ending balance of common stock and the par value of issued common stock due to retirement of treasury stocks	₩ 46,469
Retirement of treasury stock	9,293,790
ADRs [member]
Disclosure of classes of share capital [line items]
Total shares of ADRs outstanding	34,827,912

Share Capital and Capital Sur_5

Share Capital and Capital Surplus - Changes in Issued Common Stock (Detail) - shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of classes of share capital [abstract]
Shares issued beginning balance	87,186,835	87,186,835
Disposal of treasury shares	0	0
Shares issued ending balance	87,186,835	87,186,835
Treasury shares beginning balance	(7,185,703)	(7,187,231)
Disposal of treasury shares	114,509	1,528
Treasury shares ending balance	(7,071,194)	(7,185,703)
Number of outstanding shares beginning balance	80,001,132	79,999,604
Disposal of treasury shares	114,509	1,528
Number of outstanding shares ending balance	80,115,641	80,001,132

Share Capital and Capital Sur_6

Share Capital and Capital Surplus - Summary of Capital Surplus (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Statement of changes in equity [abstract]
Share premium	₩ 463,825	₩ 463,825
Gain on disposal of treasury shares	796,623	784,047
Other capital deficit	125,259	172,135
Capital surplus	₩ 1,385,707	₩ 1,420,007

Share Capital and Capital Sur_7

Share Capital and Capital Surplus - Summary of Redeemable Convertible Preferred Shares (Detail) - Redeemable convertible preferred stock [member]	12 Months Ended
	Dec. 31, 2019₩ / sharesshares
Disclosure Of Redeemable Convertible Preferred Shares [line items]
Issue date	Feb. 25, 2017
Number of shares issued \| shares	8,643,193
Price per share \| ₩ / shares	₩ 28,346
Voting rights	No voting rights for 3 years from issue date
Dividend rights	Cumulative, Non-participating
Dividend rate issuance spread on comparative rate	Minimum dividend rate after 4 years : Comparative rate + Issuance spread + 2%
Details about redemption	Issuer can demand redemption of all or part of redeemable convertible preferred shares every year after the issue date, for a period of 10 years from the issue date.
Details about Conversion	Stockholders of redeemable convertible preferred shares can convert them to common shares from 3 years after the issue date to the end of the redemption period (10 years). Conversion price is equal to issue price, which could be adjusted according to anti-dilution clause.
Not later than one year [member]
Disclosure Of Redeemable Convertible Preferred Shares [line items]
Dividend rate description	Minimum dividend rate for 1 year : 3.98%
Dividend rate	3.98%
Later than one year [member]
Disclosure Of Redeemable Convertible Preferred Shares [line items]
Dividend rate description	Dividend rate for 2~3 years : 4.48%
Dividend rate	4.48%

Hybrid Bonds - Summary of Hybri

Hybrid Bonds - Summary of Hybrid Bonds (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about borrowings [line items]
Hybrid bonds classified as equity	₩ 199,384	₩ 199,384
Hybrid bond 1-2 [member]
Disclosure of detailed information about borrowings [line items]
Date of issue	Jun. 13, 2013
Date of maturity	Jun. 13, 2043
Interest rate (%)	4.60%
Gross amount [member] \| Hybrid bond 1-2 [member]
Disclosure of detailed information about borrowings [line items]
Hybrid bonds classified as equity	₩ 200,000	200,000
Issuance cost [member]
Disclosure of detailed information about borrowings [line items]
Hybrid bonds classified as equity	₩ (616)	₩ (616)

Hybrid Bonds - Summary of Hyb_2

Hybrid Bonds - Summary of Hybrid Bonds (Parenthetical) (Detail) - Hybrid bond 1-2 [member]	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about borrowings [line items]
Maturity date	30 years (POSCO has a right to extend the maturity date)
Interest rate adjustment	4.60%
Interest payments condition	Quarterly (Optional deferral of interest payment is available to POSCO)
Others	POSCO can call the hybrid bond at year 10 and interest payment date afterwards
After 10 years [member]
Disclosure of detailed information about borrowings [line items]
Interest rate adjustment	1.40%
After 10 years : Return on Government Bond [member]
Disclosure of detailed information about borrowings [line items]
Interest rate adjustment	0.25%
After 30 years [member]
Disclosure of detailed information about borrowings [line items]
Interest rate adjustment	0.75%

Hybrid Bonds - Additional Infor

Hybrid Bonds - Additional Information (Detail) - Hybrid bonds [member] ₩ in Millions	Dec. 31, 2019KRW (₩)
Disclosure of detailed information about borrowings [line items]
Interest accumulated but not paid on hybrid bonds	₩ 479
POSCO ENERGY CO., LTD. [member]
Disclosure of detailed information about borrowings [line items]
Interest accumulated but not paid on hybrid bonds	₩ 639

Hybrid Bonds - Hybrid Bonds Iss

Hybrid Bonds - Hybrid Bonds Issued by POSCO ENERGY Co., Ltd. (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of detailed information about borrowings [line items]
Hybrid bond	₩ 199,384	₩ 199,384
Hybrid bond 1-4 [member]
Disclosure of detailed information about borrowings [line items]
Interest rate (%)	5.21%
Issuance cost [member]
Disclosure of detailed information about borrowings [line items]
Hybrid bond	₩ (616)	(616)
POSCO ENERGY CO., LTD. [member]
Disclosure of detailed information about borrowings [line items]
Hybrid bond	₩ 139,571	139,571
POSCO ENERGY CO., LTD. [member] \| Hybrid bond 1-4 [member]
Disclosure of detailed information about borrowings [line items]
Date of issue	Aug. 29, 2013
Date of maturity	Aug. 29, 2043
Interest rate (%)	5.21%
POSCO ENERGY CO., LTD. [member] \| Gross amount [member] \| Hybrid bond 1-4 [member]
Disclosure of detailed information about borrowings [line items]
Hybrid bond	₩ 140,000	140,000
POSCO ENERGY CO., LTD. [member] \| Issuance cost [member]
Disclosure of detailed information about borrowings [line items]
Hybrid bond	₩ (429)	₩ (429)

Hybrid Bonds - Hybrid Bonds I_2

Hybrid Bonds - Hybrid Bonds Issued by POSCO ENERGY Co., Ltd. (Parenthetical) (Detail) - Hybrid bond 1-4 [member]	12 Months Ended
	Dec. 31, 2019
Disclosure of detailed information about borrowings [line items]
Interest rate (%)	5.21%
POSCO ENERGY CO., LTD. [member]
Disclosure of detailed information about borrowings [line items]
Maturity date	30 years (The Company has a right to extend the maturity date)
Interest rate (%)	5.21%
Interest rate adjustment	0.75%
Interest payments condition	Quarterly (Optional deferral of interest payment is available to the issuer)
Others	The issuer can call the hybrid bond at year 10 and interest payment date afterwards
After 10 years : Return on Government Bond [member]
Disclosure of detailed information about borrowings [line items]
Interest rate adjustment	1.55%
After 10 years [member]
Disclosure of detailed information about borrowings [line items]
Interest rate adjustment	0.25%

Reserves - Summary of Reserves

Reserves - Summary of Reserves (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of reserves within equity [abstract]
Accumulated comprehensive loss of investments in associates and joint ventures	₩ (648,712)	₩ (670,435)
Changes in fair value of equity investments at fair value through other comprehensive income	(285,073)	(295,300)
Foreign currency translation differences	(202,636)	(417,817)
Gain or losses on valuation of derivatives	(438)	(352)
Others	(21,121)	(20,464)
Reserves	₩ (1,157,980)	₩ (1,404,368)

Reserves - Changes in the Unrea

Reserves - Changes in the Unrealized Fair Value of Available-for-sale Investments (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of reserves within equity [abstract]
Changes in unrealized fair value of available-for-sale investments, beginning balance	₩ (295,300)	₩ 230,190
Initial application of IFRS No. 9		(421,525)
Changes in unrealized fair value of equity investments	(9,422)	(139,226)
Reclassification upon disposal	21,902	45,737
Others	(2,253)	(10,476)
Changes in unrealized fair value of available-for-sale investments, ending balance	₩ (285,073)	₩ (295,300)

Treasury Shares - Changes in Tr

Treasury Shares - Changes in Treasury Shares (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Number of shares, Beginning	7,185,703	7,187,231
Number of shares, Disposal of treasury shares	(114,509)	(1,528)
Number of shares, Ending	7,071,194	7,185,703	7,187,231
Amount, Beginning	₩ 1,532,728
Amount, Disposal of treasury shares	(37,001)	₩ (459)	₩ (540)
Amount, Ending	₩ 1,508,303	₩ 1,532,728
Treasury shares [member]
Number of shares, Beginning	7,185,703	7,187,231
Number of shares, Disposal of treasury shares	(114,509)	(1,528)
Number of shares, Ending	7,071,194	7,185,703	7,187,231
Amount, Beginning	₩ 1,532,728	₩ 1,533,054
Amount, Disposal of treasury shares	(24,425)	(326)	₩ (414)
Amount, Ending	₩ 1,508,303	₩ 1,532,728	₩ 1,533,054

Revenue - Summary of Revenue Di

Revenue - Summary of Revenue Disaggregated by Types of Revenue and Timing of Revenue Recognition (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	₩ 64,785,709	₩ 65,154,636	₩ 60,186,867
Revenue from sales of goods [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	53,798,748	53,974,566	51,357,709
Revenue from services [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	3,210,751	3,533,639	2,064,874
Revenue from construction contract [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	7,339,399	7,133,773	6,299,192
Others [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	436,811	512,658	465,092
Revenue recognized at a point in time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	54,983,346	55,220,183	52,059,002
Revenue recognized over time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	9,802,363	9,934,453	8,127,865
Steel [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	32,078,453	32,358,009	30,230,368
Steel [member] \| Revenue from sales of goods [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	31,456,714	31,733,609	30,064,680
Steel [member] \| Revenue from services [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	573,463	583,359	111,494
Steel [member] \| Others [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	48,276	41,041	54,194
Steel [member] \| Revenue recognized at a point in time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	31,504,990	31,774,650	30,118,874
Steel [member] \| Revenue recognized over time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	573,463	583,359	111,494
Trading [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	22,157,132	22,407,717	20,802,207
Trading [member] \| Revenue from sales of goods [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	21,629,838	21,632,183	20,655,267
Trading [member] \| Revenue from services [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	369,730	611,752	28,793
Trading [member] \| Others [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	157,564	163,782	118,147
Trading [member] \| Revenue recognized at a point in time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	21,787,402	21,795,965	20,773,414
Trading [member] \| Revenue recognized over time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	369,730	611,752	28,793
Construction [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	7,363,490	6,946,269	6,418,373
Construction [member] \| Revenue from sales of goods [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue		3,568	20,368
Construction [member] \| Revenue from services [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	49,696	63,922	48,408
Construction [member] \| Revenue from construction contract [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	7,308,401	6,860,995	6,262,038
Construction [member] \| Others [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	5,393	17,784	87,559
Construction [member] \| Revenue recognized at a point in time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	747,917	743,448	334,345
Construction [member] \| Revenue recognized over time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	6,615,573	6,202,821	6,084,028
Other [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	3,186,634	3,442,641	2,735,919
Other [member] \| Revenue from sales of goods [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	712,196	605,206	617,394
Other [member] \| Revenue from services [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	2,217,862	2,274,606	1,876,179
Other [member] \| Revenue from construction contract [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	30,998	272,778	37,154
Other [member] \| Others [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	225,578	290,051	205,192
Other [member] \| Revenue recognized at a point in time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	943,037	906,120	832,369
Other [member] \| Revenue recognized over time [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Revenue	₩ 2,243,597	₩ 2,536,521	₩ 1,903,550

Revenue - Summary of Contract A

Revenue - Summary of Contract Assets and Liabilities From Contracts With Customers (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Receivables, customer finance, contract assets and contract liabilities [abstract]
Account receivables	₩ 8,214,459	₩ 8,819,617
Due from customers for contract work	1,054,357	737,712
Advance received	864,480	1,278,731
Due to customers for contract work	644,947	641,064
Unearned revenue	₩ 88,733	₩ 91,872

Revenue - Contract Balances - S

Revenue - Contract Balances - Summary of In-Progress Contracts (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of disaggregation of revenue from contracts with customers [line items]
Accumulated cost	₩ 27,281,031	₩ 26,153,452
Accumulated contract profit	2,462,008	1,848,718
Accumulated contract loss	(1,185,200)	(804,538)
Accumulated contract revenue	₩ 28,557,839	₩ 27,197,632

Revenue - Contract Details - Su

Revenue - Contract Details - Summary of Due From Customers for Contract Work and Due to Customers for Contract Work (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of disaggregation of revenue from contracts with customers [line items]
Unbilled due from customers for contract work	₩ 1,128,116	₩ 810,655
Due to customers for contract work	(644,947)	(641,064)
Construction contract in progress	₩ 483,169	₩ 169,591

Revenue - Summary of Changes in

Revenue - Summary of Changes in Estimated Total Contract Costs and Impact on Profit or Loss (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of disaggregation of revenue from contracts with customers [line items]
Changes in estimated total contract costs	₩ 533,639	₩ 427,812
Changes in profit before income taxes of construction contract
- Current period	(166,077)	(38,720)
- Future periods	₩ (43,584)	₩ 69,428

Revenue - Summary of Significan

Revenue - Summary of Significant Assumptions Including Uncertainty of Estimate of Total Contract Costs (Detail)	12 Months Ended
	Dec. 31, 2018
Material cost [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Method of significant assumption	Assumption based on recent purchasing price and quoted market price
Labor cost [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Method of significant assumption	Assumption based on standard monthly and daily labor cost
Outsourcing cost [member]
Disclosure of disaggregation of revenue from contracts with customers [line items]
Method of significant assumption	Assumption based on the past experience rate of similar project and market price

Revenue - Contract Balances -_2

Revenue - Contract Balances - Summary of Expected Revenue In Relation To Performance Obligations (Detail) ₩ in Millions	Dec. 31, 2019KRW (₩)
Disclosure Of Expected Revenue In Relation To Performance Obligations [Line Items]
Expected Performance Obligations	₩ 14,737,736
2020
Disclosure Of Expected Revenue In Relation To Performance Obligations [Line Items]
Expected Performance Obligations	6,387,124
2021
Disclosure Of Expected Revenue In Relation To Performance Obligations [Line Items]
Expected Performance Obligations	4,279,557
2022
Disclosure Of Expected Revenue In Relation To Performance Obligations [Line Items]
Expected Performance Obligations	2,105,577
After 2023
Disclosure Of Expected Revenue In Relation To Performance Obligations [Line Items]
Expected Performance Obligations	₩ 1,965,478

Selling and Administrative Ex_3

Selling and Administrative Expenses - Summary of Other Administrative Expenses (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of comprehensive income [Line Items]
Wages and salaries	₩ 3,313,642	₩ 3,372,831	₩ 3,105,364
Expenses related to post-employment benefits	240,425	216,489	199,926
Depreciation	3,029,868	2,911,048	2,887,646
Amortization	431,247	356,581	409,774
Electricity	912,832	949,435	933,045
Research & development	499,775	526,602	486,888
Vehicles maintenance	1,446,628	1,414,940	1,336,969
Total administrative expenses	2,041,286	1,985,755	2,003,106
Administrative expenses [member]
Statement of comprehensive income [Line Items]
Wages and salaries	840,599	813,467	774,900
Expenses related to post-employment benefits	88,880	73,290	78,654
Other employee benefits	177,908	176,240	159,920
Travel	42,692	40,929	39,790
Depreciation	131,337	101,274	97,261
Amortization	112,171	112,418	146,314
Communication	11,150	10,616	11,740
Electricity	8,799	8,309	7,050
Taxes and public dues	78,932	71,973	72,826
Rental	39,886	69,516	69,976
Repairs	13,454	15,291	9,859
Entertainment	11,123	11,816	11,582
Advertising	82,574	106,875	119,724
Research & development	110,315	108,352	125,795
Service fees	193,486	165,938	193,387
Vehicles maintenance	7,660	8,942	8,211
Industry association fee	9,609	9,571	10,140
Conference	15,104	14,510	14,494
Increase to provisions	18,071	14,433	10,990
Others	₩ 47,536	₩ 51,995	₩ 40,493

Selling and Administrative Ex_4

Selling and Administrative Expenses - Summary of Selling Expenses (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of comprehensive income [Line Items]
Freight and custody	₩ 1,446,628	₩ 1,414,940	₩ 1,336,969
Sales commissions	73,941	79,080	115,925
Total Selling expenses	368,318	369,245	1,557,277
Selling expenses [member]
Statement of comprehensive income [Line Items]
Freight and custody	180,341	184,675	1,336,969
Operating expenses for distribution center	9,222	10,614	10,503
Sales commissions	73,941	79,080	115,925
Sales advertising	1,552	4,821	3,800
Sales promotion	9,989	13,792	12,414
Sample	2,287	2,716	1,989
Sales insurance premium	32,632	37,251	36,546
Contract cost	38,081	16,992	23,061
Others	₩ 20,273	₩ 19,304	₩ 16,070

Research and Development Expe_3

Research and Development Expenditures Recognized as Expenses - Summary of Research and Development Expenditures Recognized as Expenses (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of comprehensive income [Line Items]
Research and development expenditures recognized as expenses	₩ 499,775	₩ 526,602	₩ 486,888
Administrative expenses [member]
Statement of comprehensive income [Line Items]
Research and development expenditures recognized as expenses	110,315	108,352	125,795
Cost of sales [member]
Statement of comprehensive income [Line Items]
Research and development expenditures recognized as expenses	₩ 389,460	₩ 418,250	₩ 361,093

Other Operating Income and Ex_3

Other Operating Income and Expenses - Details of Other Operating Income and Expenses (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other operating income
Gain on disposals of assets held for sale	₩ 37,461	₩ 27,171	₩ 1,180
Gain on disposals of investment in subsidiaries, associates and joint ventures	27,836	45,241	81,794
Gain on disposals of property, plant and equipment	49,367	53,139	32,145
Gain on disposals of intangible assets	1,896	117,139	23,391
Gain on valuation of firm commitment	60,201	39,028	56,301
Gain on valuation of emission rights	25,440
Gain on disposals of emission rights	11,141
Reversal of other provisions	36,522	3,557
Others	201,027	238,311	253,670
Other operating income	450,891	523,586	448,481
Other operating expenses
Impairment loss on assets held for sale	(38,328)	(50,829)
Loss on disposals of investments in subsidiaries, associates and joint ventures	(6,539)	(5,226)	(19,985)
Loss on disposal of property, plant and equipment	(120,227)	(117,614)	(151,343)
Impairment loss on property, plant and equipment	(442,700)	(1,004,704)	(117,231)
Impairment loss on investment property	(32,642)	(51,461)
Impairment loss on intangible assets	(191,021)	(337,519)	(167,995)
Loss on valuation of firm commitment	(37,685)	(66,281)	(43,164)
Idle tangible asset expenses	(34,152)	(9,257)	(10,490)
Increase to provisions	(23,074)	(134,632)	(33,964)
Donations	(51,567)	(52,074)	(51,424)
Others	(112,029)	(184,865)	(95,780)
Other operating expenses	₩ (1,089,965)	₩ (2,014,462)	₩ (691,376)

Other Operating Income and Ex_4

Other Operating Income and Expenses - Details of Other Operating Income and Expenses (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Analysis of income and expense [abstract]
Non operating income rebates	₩ 74,044	₩ 55,306
Fines imposed on value added tax		₩ 52,997

Finance Income and Costs - Deta

Finance Income and Costs - Details of Finance Income and Costs (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Finance income
Interest income	₩ 352,384	₩ 337,258	₩ 212,451
Dividend income	75,455	63,345	92,962
Gain on foreign currency transactions	824,565	716,060	785,616
Gain on foreign currency translations	206,019	212,443	564,016
Gain on derivatives transactions	195,933	247,513	210,727
Gain on valuations of derivatives	163,491	96,986	64,735
Gain on disposals of available-for-sale financial assets			425,684
Gain on disposals of financial assets at fair value through profit of loss	8,525	8,742
Gain on valuations of financial assets at fair value through profit or loss	42,297	16,149
Others	3,474	7,474	16,476
Finance income	1,872,143	1,705,970	2,372,667
Finance costs
Interest expenses	(755,711)	(741,296)	(653,115)
Loss on foreign currency transactions	(746,603)	(810,857)	(756,654)
Loss on foreign currency translations	(319,470)	(321,748)	(422,880)
Loss on derivatives transactions	(228,144)	(208,772)	(236,273)
Loss on valuation of derivatives	(47,447)	(40,674)	(226,487)
Loss on disposals of trade accounts and notes receivable	(36,935)	(39,970)	(32,456)
Loss on disposals of financial assets at fair value through profit or loss	(2,969)	(1,474)
Impairment loss on available-for-sale financial assets			(123,214)
Loss on valuations of financial assets at fair value through profit or loss	(65,848)	(59,442)
Others	(38,936)	(20,183)	(33,198)
Finance costs	₩ (2,242,063)	₩ (2,244,416)	₩ (2,484,277)

Finance Income and Costs - De_2

Finance Income and Costs - Details of Finance Income and Costs (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Analysis of income and expense [abstract]
Interest income	₩ 209,511	₩ 197,142	₩ 130,710

Expenses by Nature - Summary of

Expenses by Nature - Summary of Expenses by Nature (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Analysis of income and expense [abstract]
Raw material used, changes in inventories and others	₩ 39,279,866	₩ 38,884,690	₩ 35,584,184
Employee benefits	3,623,611	3,639,192	3,357,861
Outsourced processing cost	8,250,372	7,462,656	7,074,948
Electricity	912,832	949,435	933,045
Depreciation	3,029,868	2,911,048	2,887,646
Amortization	431,247	356,581	409,774
Freight and custody	1,446,628	1,414,940	1,336,969
Sales commissions	73,941	79,080	115,925
Loss on disposal of property, plant and equipment	120,227	117,614	151,343
Impairment loss on property, plant and equipment	442,700	1,004,704	117,231
Impairment loss on goodwill and intangible assets	191,021	337,519	167,995
Donations	51,567	52,074	51,424
Other	4,168,470	4,445,124	4,253,625
Expenses by nature	62,022,350	61,654,657	56,441,970
Wages and salaries	3,313,642	3,372,831	3,105,364
Expenses related to post-employment benefits	309,969	266,361	252,497
Employee benefits expenses	₩ 3,623,611	₩ 3,639,192	₩ 3,357,861

Income Taxes - Summary of Incom

Income Taxes - Summary of Income Tax Expense (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Major components of tax expense (income) [abstract]
Current income taxes	₩ 913,286	₩ 1,577,581	₩ 864,143
Deferred income tax due to temporary differences	164,078	(38,851)	300,037
Items recorded directly in equity	11,005	144,900	21,560
Income tax expense	₩ 1,088,369	₩ 1,683,630	₩ 1,185,740

Income Taxes - Income Tax Credi

Income Taxes - Income Tax Credit (Charged) Directly to Equity (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Current and deferred tax relating to items charged or credited directly to equity [abstract]
Net changes in the unrealized fair value of available-for-sale investments	₩ (26,744)	₩ 47,423	₩ 1,271
Gain on disposal of treasury shares		(50)	(40)
Others	37,749	97,527	20,329
Income taxes credited (charged) directly to equity	₩ 11,005	₩ 144,900	₩ 21,560

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
POSCO's statutory rate	27.50%	27.50%	27.50%
Deductible temporary differences	₩ 7,217,365
Taxable temporary differences, not recognized	6,195,282
Deferred tax liabilities	₩ 1,691,498	₩ 1,688,893

Income Taxes - Reconciliation O

Income Taxes - Reconciliation Of Calculated Income Tax Expense Based on the Statutory Rate to Actual Amount of Taxes Recorded (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of accounting profit multiplied by applicable tax rates [abstract]
Profit before income tax expense	₩ 3,126,534	₩ 3,616,016	₩ 4,095,051
Income tax expense computed at statutory rate	847,017	982,287	990,540
Adjustments:
Tax credits	(39,709)	(32,103)	(40,757)
Additional income tax expense for prior years (over provisions from prior years)	(35,389)	44,336	(20,912)
Tax effect from tax audit	14,775	130,196
Investment in subsidiaries, associates and joint ventures	317,977	114,856	(12,510)
Tax effects due to permanent differences	(5,588)	64,708	72,421
Effect of tax rate change			175,647
Others	(10,714)	379,350	21,311
Adjustments	241,352	701,343	195,200
Income tax expense	₩ 1,088,369	₩ 1,683,630	₩ 1,185,740
Effective tax rate	34.81%	46.56%	28.96%

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation Of Calculated Income Tax Expense Based on the Statutory Rate to Actual Amount of Taxes Recorded (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of Income Taxes [Line Items]
Statutory rate	27.50%	27.50%	27.50%
Changes in tax rates or tax laws enacted or announced [member]
Disclosure of Income Taxes [Line Items]
Statutory rate	27.50%
Excess of taxable income enacted	₩ 300,000

Income Taxes - Movements in Def

Income Taxes - Movements in Deferred Tax Assets (Liabilities) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	₩ (280,106)	₩ (441,187)
Inc. (Dec.)	(164,079)	161,081
Ending	(444,185)	(280,106)
Allowance for credit losses [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	181,143	273,994
Inc. (Dec.)	(28,007)	(92,851)
Ending	153,136	181,143
Reserve for technology developments [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning		(37,987)
Inc. (Dec.)		37,987
Property, plant and equipment depreciation [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	9,837	14,641
Inc. (Dec.)	12,374	(4,804)
Ending	22,211	9,837
Share of profit or loss of equity-accounted investees [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	227,594	196,042
Inc. (Dec.)	(108,480)	31,552
Ending	119,114	227,594
Allowance for inventories valuation [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	10,676	10,780
Inc. (Dec.)	(1,231)	(104)
Ending	9,445	10,676
Property, plant and equipment revaluation [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	(1,861,712)	(1,828,164)
Inc. (Dec.)	43,251	(33,548)
Ending	(1,818,461)	(1,861,712)
Prepaid expenses [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	17,259	20,000
Inc. (Dec.)	(2,047)	(2,741)
Ending	15,212	17,259
Property, plant and equipment impairment loss [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	4,613	5,540
Inc. (Dec.)	(208)	(927)
Ending	4,405	4,613
Gain or loss on foreign currency [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	(38,010)	(48,472)
Inc. (Dec.)	45,046	10,462
Ending	7,036	(38,010)
Defined benefit liabilities [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	(73,589)	(36,754)
Inc. (Dec.)	(22,094)	(36,835)
Ending	(95,683)	(73,589)
Provision for construction losses [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	7,405	441
Inc. (Dec.)	(102)	6,964
Ending	7,303	7,405
Provision for construction warranty [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	70,318	28,717
Inc. (Dec.)	(8,517)	41,601
Ending	61,801	70,318
Accrued income [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	(13,094)	(12,915)
Inc. (Dec.)	(17,722)	(179)
Ending	(30,816)	(13,094)
Impairment loss on AFS [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	75,919	202,795
Inc. (Dec.)	36,636	(126,876)
Ending	112,555	75,919
Difference in acquisition costs of treasury shares [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	70,532	70,547
Inc. (Dec.)	(1,124)	(15)
Ending	69,408	70,532
Other [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	424,319	490,225
Inc. (Dec.)	(30,535)	(65,906)
Ending	393,784	424,319
Temporary differences [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	(886,790)	(650,570)
Inc. (Dec.)	(82,760)	(236,220)
Ending	(969,550)	(886,790)
Changes in fair value of investments in equity instruments measured at fair value through other comprehensive income [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	156,885	(49,236)
Inc. (Dec.)	(26,744)	206,121
Ending	130,141	156,885
Other deferred income taxes recognized directly to equity [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	130,272	72,161
Inc. (Dec.)	37,749	58,111
Ending	168,021	130,272
Deferred income taxes recognized directly to equity [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	287,157	22,925
Inc. (Dec.)	11,005	264,232
Ending	298,162	287,157
Tax credit carryforward and others [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	115,589	118,032
Inc. (Dec.)	(23,750)	(2,443)
Ending	91,839	115,589
Investments in subsidiaries, associates and joint ventures [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Beginning	203,938	68,426
Inc. (Dec.)	(68,574)	135,512
Ending	₩ 135,364	₩ 203,938

Income Taxes - Summary of Defer

Income Taxes - Summary of Deferred Tax Assets And Liabilities (Detail) - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	₩ 2,660,963	₩ 3,170,473
Liabilities	(3,105,147)	(3,450,579)
Net	(444,185)	(280,106)	₩ (441,187)
Allowance for credit losses [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	153,136	181,143
Net	153,136	181,143	273,994
Property, plant and equipment depreciation [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	68,649	55,354
Liabilities	(46,438)	(45,517)
Net	22,211	9,837	14,641
Share of profit or loss of equity-accounted investees [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	177,467	278,466
Liabilities	(58,353)	(50,872)
Net	119,114	227,594	196,042
Allowance for inventories valuation [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	9,445	10,676
Net	9,445	10,676	10,780
Property, plant and equipment revaluation [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Liabilities	(1,818,461)	(1,861,712)
Net	(1,818,461)	(1,861,712)	(1,828,164)
Prepaid expenses [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	15,212	17,259
Net	15,212	17,259	20,000
Property, plant and equipment impairment loss [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	4,405	5,240
Liabilities		(627)
Net	4,405	4,613	5,540
Gain or loss on foreign currency [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	136,360	121,797
Liabilities	(129,324)	(159,807)
Net	7,036	(38,010)	(48,472)
Defined benefit liabilities [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	426,930	390,972
Liabilities	(522,613)	(464,561)
Net	(95,683)	(73,589)	(36,754)
Provision for construction losses [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	7,303	7,405
Net	7,303	7,405	441
Provision for construction warranty [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	61,801	70,318
Net	61,801	70,318	28,717
Accrued income [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Liabilities	(30,816)	(13,094)
Net	(30,816)	(13,094)	(12,915)
Impairment loss on AFS [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	112,555	75,919
Net	112,555	75,919	202,795
Difference in acquisition costs of treasury shares [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	69,408	70,532
Net	69,408	70,532	70,547
Other [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	471,621	820,611
Liabilities	(77,836)	(396,292)
Net	393,784	424,319	490,225
Temporary differences [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	1,714,292	2,105,692
Liabilities	(2,683,841)	(2,992,482)
Net	(969,550)	(886,790)	(650,570)
Changes in fair value of investments in equity instruments measured at fair value through other comprehensive income [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	220,276	247,921
Liabilities	(90,135)	(91,036)
Net	130,141	156,885	(49,236)
Other deferred income taxes recognized directly to equity [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	193,384	153,609
Liabilities	(25,363)	(23,337)
Net	168,021	130,272	72,161
Deferred income taxes recognized directly to equity [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	413,660	401,530
Liabilities	(115,498)	(114,373)
Net	298,162	287,157	22,925
Tax credit carryforward and others [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	91,839	115,589
Net	91,839	115,589	118,032
Investments in subsidiaries, associates and joint ventures [member]
Disclosure of temporary difference, unused tax losses and unused tax credits [line items]
Assets	441,172	547,662
Liabilities	(305,808)	(343,724)
Net	₩ 135,364	₩ 203,938	₩ 68,426

Earnings Per Share - Basic And

Earnings Per Share - Basic And Diluted Earnings Per Share (Detail) - KRW (₩)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings per share [abstract]
Profit attribute to controlling interest	₩ 1,864,405,000,000	₩ 1,711,902,000,000	₩ 2,756,230,000,000
Interests of hybrid bonds	₩ (6,669,999,999)	₩ (17,720,986,299)	₩ (33,048,799,997)
Weighted-average number of common shares outstanding	80,113,759	80,000,606	79,998,600
Basic and diluted earnings per share	₩ 23,189	₩ 21,177	₩ 34,040
Total number of common shares issued	87,186,835	87,186,835	87,186,835
Weighted-average number of treasury shares	(7,073,076)	(7,186,229)	(7,188,235)
Weighted-average number of common shares outstanding	80,113,759	80,000,606	79,998,600

Related Party Transactions - Si

Related Party Transactions - Significant Transactions Between the Controlling Company and Related Parties (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Other sales	₩ 27
Subsidiaries [member]
Disclosure of transactions between related parties [line items]
Other sales		₩ 143,067
Purchase of material		2,931,565
Purchase of fixed assets		750,275
Outsourced processing cost		688,025
Posco [member]
Disclosure of transactions between related parties [line items]
Sales	13,735,110	13,564,308	₩ 12,751,894
Other sales	257,959	202,162	153,870
Purchase of material	4,895,108	4,367,687	3,913,323
Purchase of fixed assets	1,193,177	965,298	829,730
Outsourced processing cost	683,002	712,217	650,170
Others	554,685	438,631	428,940
Posco [member] \| POSCO PLANTEC Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	1,364	10,904	2,947
Other sales	86	240	112
Purchase of material	2,882	3,166	5,487
Purchase of fixed assets	306,927	215,023	300,041
Outsourced processing cost	15,089	24,192	20,718
Others	30,317	10,257	19,763
Posco [member] \| SNNC [member]
Disclosure of transactions between related parties [line items]
Sales	5,527	5,105	6,734
Other sales	4,100	4,108	712
Purchase of material	588,276	558,425	554,151
Others	9	80	4
Posco [member] \| POSCO-SAMSUNG-Slovakia Processing Center [member]
Disclosure of transactions between related parties [line items]
Sales	65,688	61,981	52,779
Posco [member] \| Roy Hill Holdings Pty Ltd. [member]
Disclosure of transactions between related parties [line items]
Purchase of material	1,272,878	810,196	697,096
Posco [member] \| CSP - Compania Siderurgica do Pecem [member]
Disclosure of transactions between related parties [line items]
Sales			7,384
Purchase of material			159,501
Posco [member] \| Other associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Sales	16,084	14,199	14,943
Other sales	112,390	54,747	52,583
Purchase of material	76,427	64,335	79,103
Others	85,167	6	3
Posco [member] \| Associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Sales	88,663	92,189	84,787
Other sales	116,576	59,095	53,407
Purchase of material	1,940,463	1,436,122	1,495,338
Purchase of fixed assets	306,927	215,023	300,041
Outsourced processing cost	15,089	24,192	20,718
Others	115,493	10,343	19,770
Posco [member] \| POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of transactions between related parties [line items]
Sales	6,688	7,827	3,328
Other sales	11,137	97	71
Purchase of material	4,725
Purchase of fixed assets	416,734	322,924	151,639
Outsourced processing cost	57	47	32
Others	24,174	36,428	18,352
Posco [member] \| POSCO Processing & Service [member]
Disclosure of transactions between related parties [line items]
Sales			298,781
Other sales			1
Purchase of material			113,628
Purchase of fixed assets			4,595
Outsourced processing cost			8,309
Others			404
Posco [member] \| POSCO COATED & COLOR STEEL Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	468,070	476,105	417,369
Other sales	2,014	2,725	3,533
Purchase of material	95
Outsourced processing cost	20,298	9,211	8,483
Others	724	1,434	106
Posco [member] \| POSCO ICT [member]
Disclosure of transactions between related parties [line items]
Sales	2,924	2,624	1,697
Other sales	4,994	7,479	5,097
Purchase of fixed assets	344,977	341,472	315,748
Outsourced processing cost	34,638	34,376	29,773
Others	181,128	196,252	183,226
Posco [member] \| eNtoB Corporation [member]
Disclosure of transactions between related parties [line items]
Sales	15	12	1
Other sales	60	60	30
Purchase of material	304,846	377,198	330,921
Purchase of fixed assets	64,845	27,508	8,215
Outsourced processing cost	126	390	139
Others	25,754	31,455	26,023
Posco [member] \| POSCO CHEMTECH [member]
Disclosure of transactions between related parties [line items]
Sales	389,731	417,957	359,862
Other sales	35,592	35,762	33,076
Purchase of material	522,493	531,452	479,896
Purchase of fixed assets	17,549	21,730	23,043
Outsourced processing cost	315,530	319,868	296,296
Others	4,561	2,802	6,860
Posco [member] \| POSCO ENERGY CO., LTD. [member]
Disclosure of transactions between related parties [line items]
Sales	148,205	206,638	179,966
Other sales	2,211	1,445	1,456
Purchase of material	5,123
Purchase of fixed assets	94
Others	7,561		2
Posco [member] \| POSCO DAEWOO Corporation [member]
Disclosure of transactions between related parties [line items]
Sales	6,025,938	5,835,226	5,214,127
Other sales	46,661	42,888	35,182
Purchase of material	541,002	690,345	550,258
Purchase of fixed assets			221
Outsourced processing cost	49,506	57,624	44,108
Others	7,149	4,318	1,948
Posco [member] \| POSCO Thainox Public Company Limited [member]
Disclosure of transactions between related parties [line items]
Sales	265,374	299,450	218,005
Other sales	13,795	5,335	9,780
Purchase of material	10,037	10,115	10,168
Others	3	71
Posco [member] \| POSCO America Corporation [member]
Disclosure of transactions between related parties [line items]
Sales	300,598	336,366	345,225
Purchase of material			90
Others	2,994	2,486	1,776
Posco [member] \| POSCO Canada Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	1,067		439
Other sales	1,833	2,155	690
Purchase of material	306,552	300,982	278,915
Posco [member] \| POSCO Asia Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	1,781,841	1,857,665	1,949,354
Other sales	1,352	253	1,454
Purchase of material	390,056	536,280	365,025
Purchase of fixed assets	1,338	650	337
Outsourced processing cost	1,574	2,449	1,625
Others	7,561	6,524	4,982
Posco [member] \| Qingdao Pohang Stainless Steel Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	146,468	188,252	161,803
Other sales	0	7
Others	110	34	176
Posco [member] \| POSCO JAPAN Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	1,509,631	1,353,313	1,436,159
Other sales	36	6	20
Purchase of material	38,631	25,773	26,256
Purchase of fixed assets	6,269	4,204	621
Others	5,835	5,411	44,829
Posco [member] \| POSCO-VIETNAM Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	265,849	273,573	212,883
Other sales	368	156
Others	66	8	7
Posco [member] \| POSCO MEXICO S.A. DE C.V. [member]
Disclosure of transactions between related parties [line items]
Sales	303,924	299,276	276,387
Other sales	159	17
Others	809	35	1,749
Posco [member] \| POSCO Maharashtra Steel Private Limited [member]
Disclosure of transactions between related parties [line items]
Sales	644,652	563,618	467,206
Other sales	311	584
Others	800	156	65
Posco [member] \| POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	121,633	196,095	192,467
Purchase of material	2,189	2,616
Others		5
Posco [member] \| POSCO VST CO LTD [member]
Disclosure of transactions between related parties [line items]
Sales	299,307
Others	114
Posco [member] \| POSCO INTERNATIONAL SINGAPORE PTE LTD [member]
Disclosure of transactions between related parties [line items]
Other sales	154
Purchase of material	694,600
Posco [member] \| Others [member]
Disclosure of transactions between related parties [line items]
Sales	964,532	1,158,122	932,048
Other sales	20,679	44,098	10,073
Purchase of material	134,296	456,804	262,828
Purchase of fixed assets	34,444	31,787	25,270
Outsourced processing cost	246,184	264,060	240,687
Others	169,849	140,869	118,665
Posco [member] \| Subsidiaries [member]
Disclosure of transactions between related parties [line items]
Sales	13,646,447	13,472,119	12,667,107
Other sales	141,383		100,463
Purchase of material	2,954,645		2,417,985
Purchase of fixed assets	886,250		529,689
Outsourced processing cost	667,913		629,452
Others	₩ 439,192	₩ 428,288	₩ 409,170

Related Party Transactions - _2

Related Party Transactions - Significant Transactions Between the Controlling Company and Related Parties (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of transactions between related parties [line items]
Loans to related parties during the year	₩ 450,638	₩ 627,783	₩ 1,055,895
Loans recorded as allowance for doubtful accounts	898,274	916,790	₩ 1,094,464	₩ 977,771
Posco [member] \| Suncheon Eco Trans Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Loans to related parties during the year		2,950
Loans [member]
Disclosure of transactions between related parties [line items]
Loans recorded as allowance for doubtful accounts	195,339	147,980
Loans [member] \| Suncheon Eco Trans Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Loans recorded as allowance for doubtful accounts	₩ 2,950
Loans [member] \| Posco [member] \| Suncheon Eco Trans Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Loans recorded as allowance for doubtful accounts		₩ 2,950

Related Party Transactions - Re

Related Party Transactions - Related Account Balances of Significant Transactions Between the Controlling Company and Related Parties (Detail) - Posco [member] - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	₩ 2,132,173	₩ 2,046,649
Other receivables	40,176	70,447
Total receivables	2,172,349	2,117,096
Trade accounts and notes payable	167,957	122,670
Accounts payable	384,036	320,200
Other payables	172,829	121,846
Total payables	724,822	564,716
POSCO PLANTEC Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	84	249
Other receivables	10	10
Total receivables	94	259
Trade accounts and notes payable	471	3,275
Accounts payable	49,511	34,803
Total payables	49,982	38,078
SNNC [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	297	541
Other receivables	65	61
Total receivables	362	602
Trade accounts and notes payable	19,769	22,188
Total payables	19,769	22,188
Roy Hill Holdings Pty Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable		22,997
Trade accounts and notes payable	93,383
Total payables	93,383	22,997
Other associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	942	918
Other receivables	706	910
Total receivables	1,648	1,828
Trade accounts and notes payable	3,447	217
Accounts payable	586	76
Total payables	4,033	293
Associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	1,323	1,708
Other receivables	781	981
Total receivables	2,104	2,689
Trade accounts and notes payable	117,070	48,677
Accounts payable	50,097	34,879
Total payables	167,167	83,556
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	5,702	57
Other receivables	65	5,181
Total receivables	5,767	5,238
Accounts payable	78,512	52,775
Other payables	385	438
Total payables	78,897	53,213
POSCO COATED & COLOR STEEL Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	57,792	55,598
Other receivables		317
Total receivables	57,792	55,915
Accounts payable	11	25
Other payables	3,828	1,194
Total payables	3,839	1,219
POSCO ICT [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	225
Other receivables	1	229
Total receivables	226	229
Trade accounts and notes payable	1,147	1,572
Accounts payable	129,424	112,960
Other payables	42,844	8,717
Total payables	173,415	123,249
eNtoB Corporation [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes payable	3,459	10,860
Accounts payable	27,431	22,072
Other payables		11
Total payables	30,890	32,943
POSCO CHEMICAL CO., LTD [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	35,102	40,258
Other receivables	3,578	3,883
Total receivables	38,680	44,141
Trade accounts and notes payable	17,839	19,911
Accounts payable	52,710	58,725
Other payables	19,369	19,012
Total payables	89,918	97,648
POSCO ENERGY CO., LTD. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	1,876	22,163
Other receivables	4	1,700
Total receivables	1,880	23,863
Accounts payable	3,229
Other payables	14,912	1,425
Total payables	18,141	1,425
POSCO DAEWOO Corporation [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	633,073	437,554
Other receivables		1,056
Total receivables	633,073	438,610
Trade accounts and notes payable	345	161
Accounts payable	2,218	1,881
Other payables	3,839	5,304
Total payables	6,402	7,346
POSCO Thainox Public Company Limited [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	52,826	71,189
Other receivables	2
Total receivables	52,828	71,189
Trade accounts and notes payable	916	467
Accounts payable		71
Total payables	916	538
POSCO America Corporation [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	8,448	14,338
Total receivables	8,448	14,338
Accounts payable		221
Total payables		221
POSCO Asia Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	508,962	480,205
Other receivables	748	1,047
Total receivables	509,710	481,252
Trade accounts and notes payable	12,784	7,839
Accounts payable	171
Total payables	12,955	7,839
Qingdao Pohang Stainless Steel Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	29,842	52,037
Total receivables	29,842	52,037
POSCO MEXICO S.A. DE C.V. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	90,351	101,179
Other receivables	702	218
Total receivables	91,053	101,397
POSCO Maharashtra Steel Private Limited [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	235,917	390,413
Other receivables	444	1,428
Total receivables	236,361	391,841
Others [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	470,734	379,950
Other receivables	33,851	54,407
Total receivables	504,585	434,357
Trade accounts and notes payable	14,397	33,183
Accounts payable	40,233	36,591
Other payables	87,652	85,745
Total payables	142,282	155,519
Subsidiaries [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	2,130,850	2,044,941
Other receivables	39,395	69,466
Total receivables	2,170,245	2,114,407
Trade accounts and notes payable	50,887	73,993
Accounts payable	333,939	285,321
Other payables	172,829	121,846
Total payables	₩ 557,655	₩ 481,160

Related Party Transactions - _3

Related Party Transactions - Related Account Balances of Significant Transactions Between the Controlling Company and Related Parties (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disclosure of transactions between related parties [line items]
Loans to related parties during the year	₩ 450,638	₩ 627,783	₩ 1,055,895
Loans recorded as allowance for doubtful accounts	898,274	916,790	₩ 1,094,464	₩ 977,771
Loans [member]
Disclosure of transactions between related parties [line items]
Loans recorded as allowance for doubtful accounts	195,339	147,980
Loans [member] \| Suncheon Eco Trans Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Loans recorded as allowance for doubtful accounts	₩ 2,950
Posco [member] \| Suncheon Eco Trans Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Loans to related parties during the year		2,950
Posco [member] \| Loans [member] \| Suncheon Eco Trans Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Loans recorded as allowance for doubtful accounts		₩ 2,950

Related Party Transactions - _4

Related Party Transactions - Significant Transactions Between the Company, Excluding the Controlling Company, and Related Companies (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
POSCO MITSUBISHI CARBON TECHNOLOGY [member]
Disclosure of transactions between related parties [line items]
Sales	₩ 88,506
Other sales	16,424
Purchase of material	4,769
Other purchases	2,144
Pospower Co Ltd [member]
Disclosure of transactions between related parties [line items]
Sales	163,167
TK CHEMICAL CORPORATION [member]
Disclosure of transactions between related parties [line items]
Sales	172,133
Purchase of material	63,836
Company, excluding the controlling company [member] \| POSCO PLANTEC Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	15,637	₩ 19,394	₩ 19,513
Purchase of material	39	83	98
Other purchases	14,778	24,103	8,113
Company, excluding the controlling company [member] \| New Songdo International City Development, LLC [member]
Disclosure of transactions between related parties [line items]
Sales	33,885	30,997	223,567
Other sales	44,131	53,316	13,207
Other purchases	36	97	49
Company, excluding the controlling company [member] \| SNNC [member]
Disclosure of transactions between related parties [line items]
Sales	74,034	66,075	26,288
Other sales		128
Purchase of material	35,910	2,395	3,578
Other purchases	65,503	71,421	17,985
Company, excluding the controlling company [member] \| Chuncheon Energy Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	1,156	25,693	42,147
Company, excluding the controlling company [member] \| Noeul Green Energy Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Sales	6,579	6,444	11,863
Other purchases	1,217	587	2,178
Company, excluding the controlling company [member] \| VSC POSCO Steel Corporation [member]
Disclosure of transactions between related parties [line items]
Sales		12,504	19,404
Purchase of material		2,314	188
Company, excluding the controlling company [member] \| USS-POSCO Industries [member]
Disclosure of transactions between related parties [line items]
Sales	4		26,899
Other sales			107
Purchase of material	1,835	2,595	2,222
Company, excluding the controlling company [member] \| CSP - Compania Siderurgica do Pecem [member]
Disclosure of transactions between related parties [line items]
Sales	98,330	239,922	241,299
Other sales	12,718	9,678
Purchase of material	416,541	346,602	101,018
Other purchases	23,398	26,324	21,154
Company, excluding the controlling company [member] \| Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Sales	34,895	46,538	38,484
Purchase of material	39,733	62,851	47,241
Company, excluding the controlling company [member] \| LLP POSUK Titanium [member]
Disclosure of transactions between related parties [line items]
Purchase of material		944	3,972
Company, excluding the controlling company [member] \| BX STEEL POSCO Cold Rolled Sheet Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	10		4
Purchase of material	4,222	10,572	20,145
Company, excluding the controlling company [member] \| POS-SEAHSTEELWIRE (TIANJIN) CO., Ltd [member]
Disclosure of transactions between related parties [line items]
Sales	11,500	12,244	20,004
Company, excluding the controlling company [member] \| PT. batutua tembaga raya [member]
Disclosure of transactions between related parties [line items]
Other sales	772	168
Purchase of material	45,841	15,663	21,024
Company, excluding the controlling company [member] \| POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	30,083	30,417	34,088
Purchase of material	353	249	192
Company, excluding the controlling company [member] \| Zhangjiagang Pohang Refractories Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Purchase of material			87
Other purchases			1,632
Company, excluding the controlling company [member] \| Sebang Steel [member]
Disclosure of transactions between related parties [line items]
Sales			441
Purchase of material	4,862	13,571	23,778
Company, excluding the controlling company [member] \| SHANGHAI WAIGAOQIAO FREE TRADE ZONE LANSHENG DAEWOO IN'L TRADING CO., LTD. [member]
Disclosure of transactions between related parties [line items]
Sales			43,764
Company, excluding the controlling company [member] \| DMSA/AMSA [member]
Disclosure of transactions between related parties [line items]
Other sales			99
Purchase of material	71,275	46,293	47,092
Company, excluding the controlling company [member] \| South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of transactions between related parties [line items]
Sales	64
Other sales	42,010	50,789	62,423
Company, excluding the controlling company [member] \| Other associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Sales	252,125	359,124	272,107
Other sales	53,596	62,375	43,126
Purchase of material	31,460	20,136	19,520
Other purchases	28,039	50,918	19,483
Company, excluding the controlling company [member] \| Associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Sales	982,108	849,352	1,019,872
Other sales	169,651	176,454	118,962
Purchase of material	720,676	523,324	290,155
Other purchases	₩ 135,115	₩ 173,450	₩ 70,594

Related Party Transactions - _5

Related Party Transactions - Related Account Balances of Significant Transactions Between the Company, Excluding the Controlling Company, and Related Parties (Detail) - Company, excluding the controlling company [member] - KRW (₩) ₩ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of transactions between related parties [line items]
Other payables	₩ 80,973
Total payables	91,365
POSCO PLANTEC Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	4,121	₩ 3,593
Other receivables	205	6
Total receivables	4,326	3,599
Trade accounts and notes payable	791	6,160
Other payables	8	217
Total payables	799	6,377
New Songdo International City Development, LLC [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	23,626	233,157
Loan	0		₩ 282,775
Other receivables	20,592
Total receivables	44,218	233,157
Other payables	10
Total payables	10
Chuncheon Energy Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Loan	8,234
Other receivables	0
Total receivables	8,234
Trade accounts and notes payable	657
Other payables		1,758
Total payables	657	1,758
Nickel mining company SAS [member]
Disclosure of transactions between related parties [line items]
Loan	60,516	59,664	59,668
Other receivables	120	118
Total receivables	60,636	59,782
CSP — Compania Siderurgica do Pecem [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	244,700	364,190
Other receivables	14,264	9,669
Total receivables	258,964	373,859
Trade accounts and notes payable		62,578
Other payables	33
Total payables	33	62,578
Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	10,273	10,836
Loan	0		5,357
Other receivables	0
Total receivables	10,273	10,836
Trade accounts and notes payable	633	2,101
Total payables	633	2,101
PT. batutua tembaga raya [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	0
Loan	36,291	35,100	29,048
Other receivables	19,993	171
Total receivables	56,284	35,271
Trade accounts and notes payable	56
Total payables	56
POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	7,035	6,274
Loan	0	3,354	5,357
Other receivables	0	27
Total receivables	7,035	9,655
Trade accounts and notes payable	101	66
Total payables	101	66
DMSA/AMSA [member]
Disclosure of transactions between related parties [line items]
Loan	57,999	64,297	69,713
Other receivables	1,672
Total receivables	59,671	64,297
South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	14
Loan	147,367	191,107	229,880
Total receivables	147,381	191,107
Other associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	94,914	75,382
Loan	138,663	136,117
Other receivables	97,804	83,786
Total receivables	331,381	295,285
Trade accounts and notes payable	7,128	7,768
Other payables	13,379	5,363
Total payables	20,507	13,131
Associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	465,079	707,135
Loan	449,070	489,639	₩ 816,304
Other receivables	154,650	93,777
Total receivables	1,068,799	1,290,551
Trade accounts and notes payable	10,392	78,673
Other payables	80,973	74,194
Total payables	91,365	152,867
POSPower Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	34,945	13,703
Total receivables	34,945	13,703
Other payables	67,543	66,856
Total payables	67,543	₩ 66,856
POSCO MITSUBISHI CARBON TECHNOLOGY [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	8,078
Total receivables	8,078
Trade accounts and notes payable	916
Total payables	916
TK CHEMICAL CORPORATION [member]
Disclosure of transactions between related parties [line items]
Trade accounts and notes receivable	37,373
Total receivables	37,373
Trade accounts and notes payable	110
Total payables	₩ 110

Related Party Transactions - _6

Related Party Transactions - Related Account Balances of Significant Transactions Between the Company, Excluding the Controlling Company, and Related Parties (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	Jan. 01, 2019	Dec. 31, 2018
Company, excluding the controlling company [member]
Disclosure of transactions between related parties [line items]
Bad-debt allowance for receivables	₩ 132,554	₩ 102,694

Related Party Transactions - _7

Related Party Transactions - Significant Financial Transactions Between the Company, Excluding the Controlling Company, and Related Parties (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of transactions between related parties [line items]
Lend	₩ 450,638	₩ 627,783	₩ 1,055,895
Collect	(398,838)	(941,962)	(667,045)
Company, excluding the controlling company [member] \| New Songdo International City Development, LLC [member]
Disclosure of transactions between related parties [line items]
Beginning		282,775
Lend		150
Collect		(252,759)
Others		(30,166)
Ending	0		282,775
Company, excluding the controlling company [member] \| Gale International Korea, LLC [member]
Disclosure of transactions between related parties [line items]
Beginning		2,000
Lend		8,500
Collect		(10,500)
Ending			2,000
Company, excluding the controlling company [member] \| DMSA/AMSA [member]
Disclosure of transactions between related parties [line items]
Beginning	64,297	69,713
Lend	15,451	9,965
Collect		(342)
Others	(21,749)	(15,039)
Ending	57,999	64,297	69,713
Company, excluding the controlling company [member] \| South-East Asia Gas Pipeline Company Ltd. [member]
Disclosure of transactions between related parties [line items]
Beginning	191,107	229,880
Collect	(48,027)	(47,569)
Others	4,287	8,796
Ending	147,367	191,107	229,880
Company, excluding the controlling company [member] \| PT. batutua tembaga raya [member]
Disclosure of transactions between related parties [line items]
Beginning	35,100	29,048
Lend		4,678
Others	1,191	1,374
Ending	36,291	35,100	29,048
Company, excluding the controlling company [member] \| PT. Tanggamus Electric Power [member]
Disclosure of transactions between related parties [line items]
Beginning	4,423	3,197
Others	157	1,226
Ending	4,580	4,423	3,197
Company, excluding the controlling company [member] \| PT. wampu electric power [member]
Disclosure of transactions between related parties [line items]
Beginning	5,330	5,107
Others	189	223
Ending	5,519	5,330	5,107
Company, excluding the controlling company [member] \| PT. POSMI Steel Indonesia [member]
Disclosure of transactions between related parties [line items]
Beginning	2,236	4,286
Collect		(2,200)
Others	80	150
Ending	2,316	2,236	4,286
Company, excluding the controlling company [member] \| Nickel mining company SAS [member]
Disclosure of transactions between related parties [line items]
Beginning	59,664	59,668
Others	852	(4)
Ending	60,516	59,664	59,668
Company, excluding the controlling company [member] \| Zhongyue POSCO (Qinhuangdao) Tinplate Industrial Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Beginning		5,357
Collect		(5,357)
Ending	0		5,357
Company, excluding the controlling company [member] \| KRAKATAU POS-CHEM DONG-SUH CHEMICAL [member]
Disclosure of transactions between related parties [line items]
Beginning	6,709	6,428
Others	238	281
Ending	6,947	6,709	6,428
Company, excluding the controlling company [member] \| POSCO SeAH Steel Wire(Nantong) Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Beginning	3,354	5,357
Lend		4,451
Collect	(3,354)	(6,454)
Ending	0	3,354	5,357
Company, excluding the controlling company [member] \| POS-SeAH Steel Wire (Thailand) Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Beginning	6,709	6,428
Others	238	281
Ending	6,947	6,709	6,428
Company, excluding the controlling company [member] \| AMCI (WA) PTY LTD [member]
Disclosure of transactions between related parties [line items]
Beginning	90,480	92,061
Lend	4,669	3,795
Others	(16,596)	(5,376)
Ending	78,553	90,480	92,061
Company, excluding the controlling company [member] \| POS-AUSTEM WUHAN AUTOMOTIVE CO.,LTD [member]
Disclosure of transactions between related parties [line items]
Beginning	8,945	8,571
Lend		8,902
Collect		(8,571)
Others	317	43
Ending	9,262	8,945	8,571
Company, excluding the controlling company [member] \| SAMHWAN VINA CO., LTD [member]
Disclosure of transactions between related parties [line items]
Beginning		1,071
Collect		(1,071)
Ending			1,071
Company, excluding the controlling company [member] \| Associates and joint ventures [member]
Disclosure of transactions between related parties [line items]
Beginning	489,639	816,304
Lend	39,065	51,700
Collect	(51,381)	(340,180)
Others	(28,253)	(38,185)
Ending	449,070	489,639	816,304
Company, excluding the controlling company [member] \| UITrans LRT Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Beginning	5,695
Lend	4,884	5,695
Ending	10,579	5,695
Company, excluding the controlling company [member] \| POS-AUSTEM YANTAI AUTOMOTIVE COLTD [member]
Disclosure of transactions between related parties [line items]
Beginning	5,590	5,357
Lend		5,564
Collect		(5,357)
Others	199	26
Ending	5,789	₩ 5,590	₩ 5,357
Company, excluding the controlling company [member] \| Hyo-chun Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Others	2,382
Ending	2,382
Company, excluding the controlling company [member] \| Chun-cheon Energy Co., Ltd. [member]
Disclosure of transactions between related parties [line items]
Lend	8,234
Ending	8,234
Company, excluding the controlling company [member] \| POS-AUSTEM Suzhou Automotive Co., Ltd [member]
Disclosure of transactions between related parties [line items]
Lend	5,827
Others	(38)
Ending	₩ 5,789

Related Party Transactions - _8

Related Party Transactions - Significant Financial Transactions Between the Company, Excluding the Controlling Company, and Related Parties (Parenthetical) (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Company, excluding the controlling company [member] \| DMSA/AMSA [member]
Disclosure of transactions between related parties [line items]
Loans converted to shares of DMSA/AMSA	₩ 23,682	₩ 17,559

Related Party Transactions - De

Related Party Transactions - Details of Compensation to Key Management Officers (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related party transactions [abstract]
Short-term benefits	₩ 119,658	₩ 115,618	₩ 112,688
Long-term benefits	13,562	13,400	8,632
Retirement benefits	21,231	21,658	20,422
Compensation to key management	₩ 154,451	₩ 150,676	₩ 141,742

Commitments and Contingencies -

Commitments and Contingencies - Contingent Liabilities on Outstanding Guarantees (Detail) - Dec. 31, 2019 - Contingent liabilities on outstanding guarantees [member] ₩ in Millions	KRW (₩)	USD ($)	INR (₨)	BRL (R$)	IDR (Rp)	THB (฿)	EUR (€)	AUD ($)
USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	₩ 3,705,259	$ 3,200,258,973
KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	4,329,507
Indonesia, Rupiahs
Disclosure of contingent liabilities [line items]
Guarantee amount	12,465				Rp 150,000,000,000
India, Rupees
Disclosure of contingent liabilities [line items]
Guarantee amount	2,779		₨ 171,200,000
THB [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	212,669					฿ 5,501,000,000
EUR [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	89,847						€ 69,250,000
AUD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	21,495							$ 26,525,154
BRL [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	133,672			R$ 464060000
Top of range [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	4,476,101	3,866,040,581
Top of range [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	6,993,544
Top of range [member] \| Indonesia, Rupiahs
Disclosure of contingent liabilities [line items]
Guarantee amount	12,465				150,000,000,000
Top of range [member] \| India, Rupees
Disclosure of contingent liabilities [line items]
Guarantee amount	3,587		221,000,000
Top of range [member] \| THB [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	212,669					5,501,000,000
Top of range [member] \| EUR [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	89,847						69,250,000
Top of range [member] \| AUD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	21,495							26,525,154
Top of range [member] \| BRL [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	133,672			464,060,000
Posco [member] \| BNDES [member] \| BRL [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	133,672			464,060,000
Posco [member] \| POSCO Asia Co., Ltd. [member] \| BOC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	115,780	100,000,000
Posco [member] \| POSCO ASSAN TST STEEL INDUSTRY [member] \| SMBC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	152,685	131,874,750
Posco [member] \| POSCO COATED STEEL (THAILAND) CO., LTD. [member] \| The Great & CO Co., Ltd. (SPC) [member] \| THB [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	212,669					5,501,000,000
Posco [member] \| POSCO Maharashtra Steel Private Limited [member] \| Export-Import Bank of Korea [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	97,005	83,784,000
Posco [member] \| POSCO MEXICO S.A. DE C.V. [member] \| BOA and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	138,936	120,000,000
Posco [member] \| POSCO SS-VINA Co., Ltd [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	345,024	298,000,000
Posco [member] \| POSCO-VIETNAM Co., Ltd. [member] \| SMBC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	180,617	156,000,000
Posco [member] \| PT. KRAKATAU POSCO [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	1,088,897	940,488,348
Posco [member] \| CSP - Compania Siderurgica do Pecem [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	432,514	373,565,631
Posco [member] \| LLP POSUK Titanium [member] \| SMBC [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	17,367	15,000,000
Posco [member] \| Top of range [member] \| BNDES [member] \| BRL [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	133,672			R$ 464060000
Posco [member] \| Top of range [member] \| POSCO Asia Co., Ltd. [member] \| BOC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	115,780	100,000,000
Posco [member] \| Top of range [member] \| POSCO ASSAN TST STEEL INDUSTRY [member] \| SMBC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	169,650	146,527,500
Posco [member] \| Top of range [member] \| POSCO COATED STEEL (THAILAND) CO., LTD. [member] \| The Great & CO Co., Ltd. (SPC) [member] \| THB [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	212,669					฿ 5,501,000,000
Posco [member] \| Top of range [member] \| POSCO Maharashtra Steel Private Limited [member] \| Export-Import Bank of Korea [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	97,005	83,784,000
Posco [member] \| Top of range [member] \| POSCO MEXICO S.A. DE C.V. [member] \| BOA and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	138,936	120,000,000
Posco [member] \| Top of range [member] \| POSCO SS-VINA Co., Ltd [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	345,024	298,000,000
Posco [member] \| Top of range [member] \| POSCO-VIETNAM Co., Ltd. [member] \| SMBC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	180,617	156,000,000
Posco [member] \| Top of range [member] \| PT. KRAKATAU POSCO [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	1,563,377	1,350,300,000
Posco [member] \| Top of range [member] \| CSP - Compania Siderurgica do Pecem [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	486,276	420,000,000
Posco [member] \| Top of range [member] \| LLP POSUK Titanium [member] \| SMBC [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	17,367	15,000,000
POSCO DAEWOO Corporation [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	155,405	134,224,401
POSCO DAEWOO Corporation [member] \| POSCO ASSAN TST STEEL INDUSTRY [member] \| ING and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	16,965	14,652,750
POSCO DAEWOO Corporation [member] \| Daewoo Global Development. Pte., Ltd [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	213,026	183,992,000
POSCO DAEWOO Corporation [member] \| DAEWOO POWER PNG Ltd. [member] \| Export-Import Bank of Korea [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	47,663	41,167,234
POSCO DAEWOO Corporation [member] \| PT. Bio Inti Agrindo [member] \| Export-Import Bank of Korea and others [member] \| Indonesia, Rupiahs
Disclosure of contingent liabilities [line items]
Guarantee amount	12,465				150,000,000,000
POSCO DAEWOO Corporation [member] \| Golden Lace DAEWOO Company Limited [member] \| Shinhan Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	12,736	11,000,000
POSCO DAEWOO Corporation [member] \| Nickel mining company SAS [member] \| SMBC [member] \| EUR [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	59,682						46,000,000
POSCO DAEWOO Corporation [member] \| GLOBAL KOMSCO Daewoo LLC [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	9,320	8,050,000
POSCO DAEWOO Corporation [member] \| Ambatovy Project Investments Limited and others [member] \| Export-Import Bank of Korea [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	3,996	3,451,287
POSCO DAEWOO Corporation [member] \| Mykolaiv Milling Works PJSC [member] \| Black Sea Trade and Development Bank [member] \| EUR [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	30,165						23,250,000
POSCO DAEWOO Corporation [member] \| POSCO INTERNATIONAL [Member] \| Bank Mendes Gans [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	6,487	5,602,997
POSCO DAEWOO Corporation [member] \| Top of range [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	156,303	135,000,000
POSCO DAEWOO Corporation [member] \| Top of range [member] \| POSCO ASSAN TST STEEL INDUSTRY [member] \| ING and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	16,965	14,652,750
POSCO DAEWOO Corporation [member] \| Top of range [member] \| Daewoo Global Development. Pte., Ltd [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	231,426	199,884,500
POSCO DAEWOO Corporation [member] \| Top of range [member] \| DAEWOO POWER PNG Ltd. [member] \| Export-Import Bank of Korea [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	61,962	53,517,404
POSCO DAEWOO Corporation [member] \| Top of range [member] \| PT. Bio Inti Agrindo [member] \| Export-Import Bank of Korea and others [member] \| Indonesia, Rupiahs
Disclosure of contingent liabilities [line items]
Guarantee amount	12,465				Rp 150,000,000,000
POSCO DAEWOO Corporation [member] \| Top of range [member] \| Golden Lace DAEWOO Company Limited [member] \| Shinhan Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	12,736	11,000,000
POSCO DAEWOO Corporation [member] \| Top of range [member] \| Songdo Posco Family housing [member] \| SHINYOUNG SECURITIES CO., LTD [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	10,000
POSCO DAEWOO Corporation [member] \| Top of range [member] \| Nickel mining company SAS [member] \| SMBC [member] \| EUR [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	59,682						46,000,000
POSCO DAEWOO Corporation [member] \| Top of range [member] \| GLOBAL KOMSCO Daewoo LLC [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	9,523	8,225,000
POSCO DAEWOO Corporation [member] \| Top of range [member] \| Ambatovy Project Investments Limited and others [member] \| Export-Import Bank of Korea [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	25,261	21,818,182
POSCO DAEWOO Corporation [member] \| Top of range [member] \| Mykolaiv Milling Works PJSC [member] \| Black Sea Trade and Development Bank [member] \| EUR [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	30,165						€ 23,250,000
POSCO DAEWOO Corporation [member] \| Top of range [member] \| POSCO INTERNATIONAL [Member] \| Bank Mendes Gans [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	57,890	50,000,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Daewoo Global Development. Pte., Ltd [member] \| SMBC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	189,454	163,633,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Songdo Posco Family housing [member] \| SHINYOUNG SECURITIES CO., LTD [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	0
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| POSCO E&C Vietnam Co., Ltd. [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	54,417	47,000,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd [member] \| Woori Bank and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	173,369	149,740,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. [member] \| KEB Hana Bank [member] \| India, Rupees
Disclosure of contingent liabilities [line items]
Guarantee amount	2,779		171,200,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| PT. POSCO E&C INDONESIA [member] \| POSCO Asia Co., Ltd. And others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	12,620	10,900,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| New Songdo International City Development, LLC [member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	386,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| UITrans LRT Co., Ltd. [member] \| Kookmin Bank and Other [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	107,176
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Chun-cheon Energy Co., Ltd. [member] \| Kookmin Bank and Other [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	8,234
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Pohang E&E Co,. Ltd. [member] \| Heungkuk Life Insurance Co. LTD [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	64,592
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| JB CLARK HILLS [member] \| Korea Investment and securities co. ltd [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	55,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Ecocity Company Limited and Others [member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	2,156,506
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| PT. wampu electric power [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	2,738	2,365,099
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| PT. Tanggamus Electric Power [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	2,242	1,936,699
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| RPSD Project Co Ltd [Member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	35,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Metropolitan Outer Ring Expressway Co Ltd [Member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	14,486
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Pureun Tongyeong Enviro Co Ltd [member] \| KDB Bank and others [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	16,017
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Pure Gimpo Co Ltd [member] \| KDB Bank and others [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	32,847
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Clean Iksan Co Ltd [member] \| Samsung Fire Marine Insurance Co Ltd [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	31,062
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Daewoo Global Development. Pte., Ltd [member] \| SMBC and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	189,454	163,633,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Songdo Posco Family housing [member] \| SHINYOUNG SECURITIES CO., LTD [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	10,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| POSCO E&C Vietnam Co., Ltd. [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	54,417	47,000,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd [member] \| Woori Bank and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	185,248	160,000,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. [member] \| KEB Hana Bank [member] \| India, Rupees
Disclosure of contingent liabilities [line items]
Guarantee amount	3,587		₨ 221,000,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| PT. POSCO E&C INDONESIA [member] \| POSCO Asia Co., Ltd. And others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	12,620	10,900,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| New Songdo International City Development, LLC [member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	386,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| UITrans LRT Co., Ltd. [member] \| Kookmin Bank and Other [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	121,750
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Chun-cheon Energy Co., Ltd. [member] \| Kookmin Bank and Other [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	12,430
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Pohang E&E Co,. Ltd. [member] \| Heungkuk Life Insurance Co. LTD [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	71,930
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| JB CLARK HILLS [member] \| Korea Investment and securities co. ltd [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	60,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Incheon-Gimpo Expressway Co., Ltd. [member] \| Kookmin Bank and Other [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	28,940
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Ecocity Company Limited and Others [member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	3,616,714
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| PT. wampu electric power [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	2,738	2,365,099
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| PT. Tanggamus Electric Power [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	2,242	1,936,699
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| RPSD Project Co Ltd [Member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	45,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Metropolitan Outer Ring Expressway Co Ltd [Member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	276,521
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| NEXTRAIN Co Ltd [Member] \| Others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	634,752
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Pureun Tongyeong Enviro Co Ltd [member] \| KDB Bank and others [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	22,714
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Pure Gimpo Co Ltd [member] \| KDB Bank and others [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	44,740
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member] \| Clean Iksan Co Ltd [member] \| Samsung Fire Marine Insurance Co Ltd [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	44,054
POSCO ICT [member] \| PT.POSCO ICT INDONESIA [member] \| POSCO Asia Co., Ltd. [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	1,737	1,500,000
POSCO ICT [member] \| Incheon-Gimpo Expressway Co., Ltd. [member] \| KDB Bank [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	100,000
POSCO ICT [member] \| UITrans LRT Co., Ltd. [member] \| Kookmin Bank [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	76,000
POSCO ICT [member] \| Hyochun CO., LTD [member] \| Kyobo Securities Co, Ltd. [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	39,575
POSCO ICT [member] \| Soosungenc and others [Member] \| KEB Hana Bank [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	1,198,724
POSCO ICT [member] \| Metropolitan Outer Ring Expressway Co Ltd [Member] \| Woori Bank and others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	7,748
POSCO ICT [member] \| Top of range [member] \| PT.POSCO ICT INDONESIA [member] \| POSCO Asia Co., Ltd. [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	1,737	1,500,000
POSCO ICT [member] \| Top of range [member] \| Incheon-Gimpo Expressway Co., Ltd. [member] \| KDB Bank [Member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	100,000
POSCO ICT [member] \| Top of range [member] \| UITrans LRT Co., Ltd. [member] \| Kookmin Bank [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	76,000
POSCO ICT [member] \| Top of range [member] \| Hyochun CO., LTD [member] \| Kyobo Securities Co, Ltd. [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	39,575
POSCO ICT [member] \| Top of range [member] \| Soosungenc and others [Member] \| KEB Hana Bank [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	1,198,724
POSCO ICT [member] \| Top of range [member] \| Metropolitan Outer Ring Expressway Co Ltd [Member] \| Woori Bank and others [member] \| KRW [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	193,700
POSCO COATED & COLOR STEEL Co., Ltd. [member] \| Myanmar POSCO C&C Company, Limited [member] \| POSCO Asia Co., Ltd. [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	16,194	13,986,947
POSCO COATED & COLOR STEEL Co., Ltd. [member] \| Top of range [member] \| Myanmar POSCO C&C Company, Limited [member] \| POSCO Asia Co., Ltd. [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	16,194	13,986,947
POSCO Asia Co., Ltd. [member] \| POSCO America Corporation [member] \| SMBC [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	81,046	70,000,000
POSCO Asia Co., Ltd. [member] \| Top of range [member] \| POSCO America Corporation [member] \| SMBC [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	81,046	70,000,000
POSCO AUSTRALIA PTY LTD [member] \| Department of Trade and Investment (NSW Government) [member] \| Woori Bank and others [member] \| AUD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	21,495							26,525,154
POSCO AUSTRALIA PTY LTD [member] \| Top of range [member] \| Department of Trade and Investment (NSW Government) [member] \| Woori Bank and others [member] \| AUD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	21,495							$ 26,525,154
POSCO CHEMCAL CO LTD [Member] \| PT.Krakatau Posco Chemtech Calcination [member] \| POSCO Asia Co., Ltd. [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	13,894	12,000,000
POSCO CHEMCAL CO LTD [Member] \| KRAKATAU POS-CHEM DONG-SUH CHEMICAL [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	587	506,667
POSCO CHEMCAL CO LTD [Member] \| Top of range [member] \| PT.Krakatau Posco Chemtech Calcination [member] \| POSCO Asia Co., Ltd. [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	17,599	15,200,000
POSCO CHEMCAL CO LTD [Member] \| Top of range [member] \| KRAKATAU POS-CHEM DONG-SUH CHEMICAL [member] \| KEB Hana Bank [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	1,320	1,140,000
POSCO ENERGY CO., LTD. [member] \| PT. Krakatau Posco Energy [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	121,647	105,067,663
POSCO ENERGY CO., LTD. [member] \| Top of range [member] \| PT. Krakatau Posco Energy [member] \| Export-Import Bank of Korea and others [member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	224,497	193,900,000
POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member] \| POS INFRA AUTO [member] \| KDB Bank [Member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	891	769,500
POSCO(Suzhou) Automotive Processing Center Co., Ltd. [member] \| Top of range [member] \| POS INFRA AUTO [member] \| KDB Bank [Member] \| USD [member]
Disclosure of contingent liabilities [line items]
Guarantee amount	₩ 891	$ 769,500

Commitments and Contingencies_2

Commitments and Contingencies - Additional Information (Detail) T in Thousands, $ in Thousands, ₩ in Millions	12 Months Ended
	Dec. 31, 2019USD ($)Cash_Generating_UnitsT	Dec. 31, 2019KRW (₩)	Dec. 31, 2019USD ($)	Dec. 31, 2018KRW (₩)
Disclosure of contingent liabilities [line items]
Borrowings		₩ 20,441,613		₩ 20,209,270
Posco [member]
Disclosure of contingent liabilities [line items]
Remaining iron ore to be purchased \| T	102,000
Remaining coal to be purchased \| T	11,000
Liquefied natural gas to be purchased \| T	550
Liquefied natural gas terms	20 years
Number of vessels for transportation of raw materials \| Cash_Generating_Units	39
Average remaining contract period	10 years
Posco [member] \| Korea National Oil Corporation [member]
Disclosure of contingent liabilities [line items]
Borrowings \| $			$ 1,020
Posco [member] \| Bottom of range [member]
Disclosure of contingent liabilities [line items]
Iron ore and coal contracts terms	3 years
Nickel contracts terms	1 year
Posco [member] \| Top of range [member] \| Korea National Oil Corporation [member]
Disclosure of contingent liabilities [line items]
Borrowings \| $			4,120
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of contingent liabilities [line items]
Outstanding borrowings		2,613,700
Litigation Mediation Price \| $			$ 2,000,000
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Top of range [member]
Disclosure of contingent liabilities [line items]
Foreign currency guarantee \| $	$ 2,425,000
Busan E&E Co. [member]
Disclosure of contingent liabilities [line items]
Supplementary fund		9,800
Woori Bank and others [member]
Disclosure of contingent liabilities [line items]
Foreign currency guarantee \| $	$ 710,000
POSCO ICT [member]
Disclosure of contingent liabilities [line items]
Outstanding borrowings		882,000
POSCO ICT [member] \| Seoul Guarantee Insurance [member]
Disclosure of contingent liabilities [line items]
Contingent liabilities guarantee amount		3,482
POSCO ICT [member] \| Engineering Guarantee Insurance [member]
Disclosure of contingent liabilities [line items]
Contingent liabilities guarantee amount		305
POSCO ICT [member] \| Software Credit Union [Member]
Disclosure of contingent liabilities [line items]
Contingent liabilities guarantee amount		₩ 85,182

Commitments and Contingencies_3

Commitments and Contingencies - Litigations in Progress (Detail) - 12 months ended Dec. 31, 2019 ₺ in Thousands, ₨ in Thousands, ₨ in Thousands, ฿ in Thousands, ¥ in Thousands, Rp in Thousands, R$ in Thousands, $ in Thousands, $ in Thousands, ₩ in Millions	KRW (₩)LegalMatterCash_Generating_Units	USD ($)	INR (₨)	CNY (¥)	TRY (₺)	BRL (R$)	IDR (Rp)	THB (฿)	PKR (₨)	CAD ($)
Disclosure of contingent liabilities [line items]
Estimated lawsuits \| LegalMatter	105
Lawsuits provision [member]
Disclosure of contingent liabilities [line items]
Provision for legal contingencies and claims \| ₩	₩ 54,228
Posco [member]
Disclosure of contingent liabilities [line items]
Description	POSCO has provided 3 blank checks to Korea Energy Agency as collateral for long-term foreign currency borrowings.
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of contingent liabilities [line items]
Description	As of December 31, 2019, POSCO ENGINEERING & CONSTRUCTION CO., LTD. has provided 26 blank checks and 4 blank promissory notes as collateral for agreements and outstanding loans, and has provided joint guarantee of ￦9,887,559 million for guarantee that partners had issued from Korea Housing & Urban Guarantee Corporation and others.
POSCO ICT [member]
Disclosure of contingent liabilities [line items]
Description	As of December 31, 2019, POSCO ICT has provided 2 blank promissory notes and 6 blank checks to financial institutions as collateral for the guarantee on performance for contracts and others.
Litigations in progress [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	123
Litigations in progress [member] \| Posco [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	23
Claim amount \| ₩	₩ 39,500
Description	Lawsuit on claim for employee right and others
Litigations in progress [member] \| POSCO DAEWOO Corporation [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	8
Claim amount \| ₩	₩ 18,786
Description	Litigation for confirmation of deposit bond and others
Litigations in progress [member] \| POSCO DAEWOO Corporation [member] \| CAD [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 70,038									$ 79,000
Description	Lawsuit on claim for damages
Litigations in progress [member] \| POSCO DAEWOO Corporation [member] \| India [member]
Disclosure of contingent liabilities [line items]
Description	Lawsuit on claim for payment on guarantees and others
Litigations in progress [member] \| POSCO DAEWOO Corporation [member] \| US [member]
Disclosure of contingent liabilities [line items]
Legal actions	4
Claim amount	₩ 26,413	$ 22,813
Description	Lawsuit on claim for damages and others
Litigations in progress [member] \| POSCO DAEWOO Corporation [member] \| Pakistan [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 931								₨ 124,775
Description	Lawsuit on claim for damages
Litigations in progress [member] \| POSCO DAEWOO Corporation [member] \| India, Rupees
Disclosure of contingent liabilities [line items]
Legal actions	5
Claim amount	₩ 73,338		₨ 4,518,694
Litigations in progress [member] \| POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Claim amount \| ₩	₩ 2,838,122
Description	Lawsuit on claim for damages and others
Litigations in progress [member] \| POSCO ICT [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	11
Claim amount \| ₩	₩ 8,500
Description	Lawsuit on claim for damages and others
Litigations in progress [member] \| POSCO ICT [member] \| Brazil [Member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 2,951					R$ 10244
Description	Lawsuit on revocation of claim for damage
Litigations in progress [member] \| POSCO A&C [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	10
Claim amount \| ₩	₩ 6,043
Description	Lawsuit on claim for payment on construction and others
Litigations in progress [member] \| POSCO ENERGY CO., LTD. [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	3
Claim amount \| ₩	₩ 3,669
Description	Lawsuit on claim for damages and others
Litigations in progress [member] \| POSCO E&C CHINA Co., Ltd. [member] \| China [member]
Disclosure of contingent liabilities [line items]
Legal actions	5
Claim amount	₩ 11,047			¥ 66,655
Description	Lawsuit over contract dispute and others
Litigations in progress [member] \| POSCO COATED & COLOR STEEL Co., Ltd. [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount \| ₩	₩ 1,400
Description	Lawsuit on claim for damages
Litigations in progress [member] \| POSCO ENGINEERING (THAILAND) CO., LTD. [member] \| US [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 1,211	1,046
Description	Lawsuit on claim for payment on construction
Litigations in progress [member] \| POSCO ENGINEERING (THAILAND) CO., LTD. [member] \| Thailand [Member]
Disclosure of contingent liabilities [line items]
Legal actions	2
Claim amount	₩ 6,222							฿ 160,929
Description	Lawsuit on claim for payment on construction and others
Litigations in progress [member] \| PT. KRAKATAU POSCO [member] \| Indonesia [Member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 17,568						Rp 211,407,872
Description	Lawsuit on claim for payment on construction
Litigations in progress [member] \| POSCO E&C Vietnam Co., Ltd. [member] \| US [member]
Disclosure of contingent liabilities [line items]
Legal actions	3
Claim amount	₩ 5,941	5,131
Description	Lawsuit on claim for payment on construction
Litigations in progress [member] \| Pos-Sea Pte Ltd [member] \| US [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 14,704	12,700
Description	Lawsuit over contract dispute
Litigations in progress [member] \| POSCO TNPC Otomotiv Celik San. Ve Tic. A.S [member] \| Turkey [Member]
Disclosure of contingent liabilities [line items]
Legal actions	7
Claim amount	₩ 20				₺ 102
Description	Lawsuit over industrial accidents and others
Litigations in progress [member] \| POSCO India Steel Distribution Center Private Ltd [member] \| India, Rupees
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 3,632		223,795
Description	Lawsuit on claim for tax restitution
Litigations in progress [member] \| Brazil Sao Paulo Steel Processing Center [member] \| Brazil [Member]
Disclosure of contingent liabilities [line items]
Legal actions	3
Claim amount	₩ 1,245					4,321
Description	Lawsuit on claim for labor and others
Litigations in progress [member] \| POSCO ENGINEERING & CONSTRUCTION DO BRAZIL LTDA. [member] \| Brazil [Member]
Disclosure of contingent liabilities [line items]
Legal actions	104
Claim amount	₩ 43,806					R$ 152077
Description	Lawsuit on claim for payment on construction and others
Litigations in progress [member] \| POSCO ASSAN TST STEEL INDUSTRY [member] \| Turkey [Member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 383				₺ 1,965
Description	Lawsuit on compensation
Litigations in progress [member] \| HONG KONG POSCO E&C (CHINA) INVESTMENT Co., Ltd [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount \| ₩	₩ 3,305
Description	Lawsuit on claim for payment
Litigations in progress [member] \| POSCO Asia Co., Ltd. [member] \| US [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 1,099	950
Description	Lawsuit on claim for receivable
Litigations in progress [member] \| Zhangjiagang Pohang Stainless Steel Co., Ltd. [member] \| China [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 134			¥ 807
Description	Lawsuit on claim for labor
Litigations in progress [member] \| POSCO CHEMCAL CO LTD [Member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount \| ₩	₩ 15,383
Description	Calculation of stock purchase value
Litigations in progress [member] \| POSCO M-TECH [member] \| Korea [member]
Disclosure of contingent liabilities [line items]
Legal actions	2
Claim amount \| ₩	₩ 425
Description	Lawsuit on claim for damages
Litigations in progress [member] \| POSCO Engineering and Construction India Private Limited [member] \| India, Rupees
Disclosure of contingent liabilities [line items]
Legal actions	3
Claim amount	₩ 454		₨ 27,995
Description	Lawsuit on claim for payment
Litigations in progress [member] \| POSCO INTERNATIONAL AMERICA CORP [Member] \| US [member]
Disclosure of contingent liabilities [line items]
Legal actions	1
Claim amount	₩ 174	$ 150
Description	Lawsuit over injury

Commitments and Contingencies_4

Commitments and Contingencies - Details of Other Major contingencies (Detail)	12 Months Ended
	Dec. 31, 2019
Posco [member]
Disclosure of contingent liabilities [line items]
Description	POSCO has provided 3 blank checks to Korea Energy Agency as collateral for long-term foreign currency borrowings.
POSCO INTERNATIONAL CORPORATION [Member]
Disclosure of contingent liabilities [line items]
Description	As of December 31, 2019, POSCO INTERNATIONAL Corporation (Formerly, POSCO DAEWOO Corporation) has provided 33 blank promissory notes and 20 blank checks to Korea Energy Agency and others as collateral for the guarantee on performance for contracts and others.
POSCO ENGINEERING & CONSTRUCTION CO., LTD. [member]
Disclosure of contingent liabilities [line items]
Description	As of December 31, 2019, POSCO ENGINEERING & CONSTRUCTION CO., LTD. has provided 26 blank checks and 4 blank promissory notes as collateral for agreements and outstanding loans, and has provided joint guarantee of ￦9,887,559 million for guarantee that partners had issued from Korea Housing & Urban Guarantee Corporation and others.
POSCO ICT [member]
Disclosure of contingent liabilities [line items]
Description	As of December 31, 2019, POSCO ICT has provided 2 blank promissory notes and 6 blank checks to financial institutions as collateral for the guarantee on performance for contracts and others.

Additional Information of Cas_3

Additional Information of Cash Flow Statements - Changes in Operating Assets and Liabilities (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from (used in) operating activities [abstract]
Trade accounts and notes receivable	₩ 286,121	₩ 17,806	₩ 63,075
Other receivables	(163,234)	(20,786)	113,740
Inventories	1,136,819	(1,451,009)	(1,435,170)
Other current assets	42,337	1,118	110,688
Other non-currentassets	(30,010)	5,974	12,455
Trade accounts and notes payable	(732,741)	379,742	(607,999)
Other payables	2,762	(111,893)	(26,922)
Other current liabilities	(173,762)	(197,154)	338,273
Provisions	(75,514)	(119,617)	(145,763)
Payments of severance benefits	(152,275)	(189,165)	(185,220)
Plan assets	(217,953)	(245,214)	3,815
Other non-currentliabilities	(36,595)	(175,528)	(82,605)
Changes in operating cash flows	₩ (114,045)	₩ (2,105,726)	₩ (1,841,633)

Additional Information of Cas_4

Additional Information of Cash Flow Statements - Changes in Liabilities Arising from Financial Activities (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Short-term borrowings [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning	₩ 7,487,780	₩ 8,174,818
Changes from financing cash flows	(2,194,727)	(854,554)
Changes arising from obtaining or losing control of subsidiaries or other business	(45,589)	(342)
The effect of changes in foreign exchange rates	238,869	167,858
Ending	5,486,333	7,487,780
Long-term borrowings [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning	12,721,490	12,888,839
Changes from financing cash flows	1,900,132	(373,862)
Changes arising from obtaining or losing control of subsidiaries or other business	(88,966)
The effect of changes in foreign exchange rates	415,028	200,308
Amortization of discount on debentures issued	7,596	6,205
Ending	14,955,280	12,721,490
Dividend payable [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning	8,673	7,213
Changes from financing cash flows	(962,712)	(770,099)
Changes arising from obtaining or losing control of subsidiaries or other business	324
The effect of changes in foreign exchange rates	(649)	(5,573)
Decrease in retained earnings	889,900	704,444
Decrease in non-controllinginterest	67,569	72,688
Ending	3,105	8,673
Finance lease liabilities [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning	94,754	93,018
Changes from financing cash flows	(167,427)	(14,955)
The effect of changes in foreign exchange rates	(1,867)	(7,766)
Increase in finance lease assets	72,640	24,457
Initial application of IFRS No.16	677,370
Ending	675,470	94,754
Derivatives that hedge long-term borrowings [member]
Disclosure of reconciliation of liabilities arising from financing activities [line items]
Beginning	43,417	119,320
Changes from financing cash flows	7,657	(17,237)
Changes in fair values	(117,023)	(58,666)
Ending	₩ (65,949)	₩ 43,417

Operating Segments - Informatio

Operating Segments - Information about Reportable Segments (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of operating segments [line items]
Revenues	₩ 64,785,709	₩ 65,154,636	₩ 60,186,867
Interest income	352,384	337,258	212,451
Interest expenses	(755,711)	(741,296)	(653,115)
Depreciation and amortization	(3,461,115)	(3,267,629)	(3,297,420)
Impairment loss on property, plant and equipment and others	(704,756)	(1,451,397)	(302,967)
Impairment loss on available-for-sale financial assets			(123,214)
Share of profit or loss of investment in associates and JVs	273,741	112,635	10,540
Investments in associates	1,864,509	1,738,692
Income tax expense	(1,088,369)	(1,683,630)	(1,185,740)
Segment profit (loss)	2,038,165	1,932,386	2,909,311
Assets	79,370,808	78,776,991
Liabilities	31,607,510	32,104,377
Reportable segments [member]
Disclosure of operating segments [line items]
Revenues	101,104,207	102,258,628	95,059,704
Interest income	399,592	373,926	280,488
Interest expenses	(871,655)	(863,560)	(757,963)
Depreciation and amortization	(3,425,677)	(3,325,415)	(3,360,366)
Impairment loss on property, plant and equipment and others	(634,745)	(1,343,360)	(336,719)
Impairment loss on available-for-sale financial assets			(127,319)
Share of profit or loss of investment in associates and JVs	(1,027,435)	(1,049,335)	(1,721)
Impairment loss on investment in associates and JVs		(1,049,335)
Investments in associates			19,113,739
Income tax expense	(1,035,769)	(1,664,258)	(1,274,696)
Segment profit (loss)	1,324,046	1,331,419	3,160,761
Assets	102,502,209	101,878,001	101,542,757
Investment in subsidiaries, associates and joint ventures	18,650,051	18,922,074
Acquisition of non-currentassets	2,903,434	2,652,860	2,670,224
Liabilities	40,324,920	40,264,320	39,809,138
Reportable segments [member] \| External customers [member]
Disclosure of operating segments [line items]
Revenues	64,366,848	64,977,777	60,655,100
Reportable segments [member] \| Internal customers [member]
Disclosure of operating segments [line items]
Revenues	36,737,359	37,280,851	34,404,604
Reportable segments [member] \| Intersegment [member]
Disclosure of operating segments [line items]
Revenues	23,640,576	24,344,571	22,823,501
Reportable segments [member] \| Steel [member]
Disclosure of operating segments [line items]
Revenues	49,808,443	50,421,222	47,611,378
Interest income	211,715	199,016	128,827
Interest expenses	(529,743)	(468,681)	(422,357)
Depreciation and amortization	(2,892,901)	(2,812,666)	(2,856,133)
Impairment loss on property, plant and equipment and others	(497,583)	(1,057,474)	(149,840)
Impairment loss on available-for-sale financial assets			(95,261)
Share of profit or loss of investment in associates and JVs	(865,769)		8,352
Impairment loss on investment in associates and JVs		(733,879)
Investments in associates			16,116,654
Income tax expense	(725,448)	(1,307,292)	(977,853)
Segment profit (loss)	585,948	1,268,313	2,790,855
Assets	71,153,809	70,976,493	70,017,816
Investment in subsidiaries, associates and joint ventures	15,650,654	16,099,692
Acquisition of non-currentassets	2,275,103	2,239,467	2,033,184
Liabilities	21,101,474	20,289,037	19,057,249
Reportable segments [member] \| Steel [member] \| External customers [member]
Disclosure of operating segments [line items]
Revenues	32,078,453	32,358,009	30,230,368
Reportable segments [member] \| Steel [member] \| Internal customers [member]
Disclosure of operating segments [line items]
Revenues	17,729,990	18,063,213	17,381,010
Reportable segments [member] \| Steel [member] \| Intersegment [member]
Disclosure of operating segments [line items]
Revenues	12,184,743	12,496,287	12,004,614
Reportable segments [member] \| Trading [member]
Disclosure of operating segments [line items]
Revenues	37,624,818	38,318,855	34,878,203
Interest income	41,739	36,437	32,799
Interest expenses	(183,129)	(189,165)	(121,967)
Depreciation and amortization	(276,817)	(210,493)	(206,490)
Impairment loss on property, plant and equipment and others	(131,914)	(86,085)	(140,839)
Share of profit or loss of investment in associates and JVs	(76,038)
Impairment loss on investment in associates and JVs		(160,085)
Investments in associates			1,134,798
Income tax expense	(119,044)	(52,914)	(109,710)
Segment profit (loss)	165,348	49,264	112,661
Assets	14,482,538	15,550,854	14,139,098
Investment in subsidiaries, associates and joint ventures	1,409,764	1,379,045
Acquisition of non-currentassets	192,805	132,017	286,185
Liabilities	10,184,521	11,454,079	10,386,294
Reportable segments [member] \| Trading [member] \| External customers [member]
Disclosure of operating segments [line items]
Revenues	22,157,131	22,407,717	20,802,207
Reportable segments [member] \| Trading [member] \| Internal customers [member]
Disclosure of operating segments [line items]
Revenues	15,467,687	15,911,138	14,075,996
Reportable segments [member] \| Trading [member] \| Intersegment [member]
Disclosure of operating segments [line items]
Revenues	8,130,503	8,743,666	8,043,643
Reportable segments [member] \| Construction [member]
Disclosure of operating segments [line items]
Revenues	7,688,005	7,320,734	7,285,530
Interest income	118,102	115,019	100,922
Interest expenses	(77,005)	(111,101)	(112,983)
Depreciation and amortization	(29,266)	(36,840)	(42,123)
Impairment loss on property, plant and equipment and others	(1,490)	(82,521)	(37,476)
Impairment loss on available-for-sale financial assets			(18,637)
Share of profit or loss of investment in associates and JVs	(85,628)		(8,555)
Impairment loss on investment in associates and JVs		(155,371)
Investments in associates			668,392
Income tax expense	(86,106)	(238,441)	(109,961)
Segment profit (loss)	27,789	234	24,545
Assets	7,653,637	7,333,221	8,609,753
Investment in subsidiaries, associates and joint ventures	527,418	511,230
Acquisition of non-currentassets	30,563	49,095	99,190
Liabilities	4,584,423	4,386,852	5,744,693
Reportable segments [member] \| Construction [member] \| External customers [member]
Disclosure of operating segments [line items]
Revenues	6,944,629	6,769,410	6,886,606
Reportable segments [member] \| Construction [member] \| Internal customers [member]
Disclosure of operating segments [line items]
Revenues	743,376	551,324	398,924
Reportable segments [member] \| Construction [member] \| Intersegment [member]
Disclosure of operating segments [line items]
Revenues	686,881	465,057	329,215
Reportable segments [member] \| Other reportable segment [member]
Disclosure of operating segments [line items]
Revenues	5,982,941	6,197,817	5,284,593
Interest income	28,036	23,454	17,940
Interest expenses	(81,778)	(94,613)	(100,656)
Depreciation and amortization	(226,693)	(265,416)	(255,620)
Impairment loss on property, plant and equipment and others	(3,758)	(117,280)	(8,564)
Impairment loss on available-for-sale financial assets			(13,421)
Share of profit or loss of investment in associates and JVs			(1,518)
Investments in associates			1,193,895
Income tax expense	(105,171)	(65,611)	(77,172)
Segment profit (loss)	544,961	13,608	232,700
Assets	9,212,225	8,017,433	8,776,090
Investment in subsidiaries, associates and joint ventures	1,062,215	932,107
Acquisition of non-currentassets	404,963	232,281	251,665
Liabilities	4,454,502	4,134,352	4,620,902
Reportable segments [member] \| Other reportable segment [member] \| External customers [member]
Disclosure of operating segments [line items]
Revenues	3,186,635	3,442,641	2,735,919
Reportable segments [member] \| Other reportable segment [member] \| Internal customers [member]
Disclosure of operating segments [line items]
Revenues	2,796,306	2,755,176	2,548,674
Reportable segments [member] \| Other reportable segment [member] \| Intersegment [member]
Disclosure of operating segments [line items]
Revenues	₩ 2,638,449	₩ 2,639,561	₩ 2,446,029

Operating Segments - Reconcilia

Operating Segments - Reconciliation of Segment Revenues, Profit or Loss, Assets and Liabilities and Other Significant Items (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of operating segments [line items]
Revenue	₩ 64,785,709	₩ 65,154,636	₩ 60,186,867
Profit before income tax expense	3,126,534	3,616,016	4,095,051
Assets	79,370,808	78,776,991
Liabilities	31,607,510	32,104,377
Interest income	352,384	337,258	212,451
Interest expenses	(755,711)	(741,296)	(653,115)
Depreciation and amortization	(3,461,115)	(3,267,629)	(3,297,420)
Share of profit or loss of investment in associates	273,741	112,635	10,540
Income tax expense	(1,088,369)	(1,683,630)	(1,185,740)
Impairment loss on property, plant and equipment and others	(704,756)	(1,451,397)	(302,967)
Impairment loss on available-for-sale financial assets			(123,214)
Other significant items	(5,383,826)	(6,694,059)	(5,339,465)
Reportable segments [member]
Disclosure of operating segments [line items]
Revenue	101,104,207	102,258,628	95,059,704
Profit before income tax expense	1,324,046	1,331,419	3,160,761
Assets	102,502,209	101,878,001	101,542,757
Liabilities	40,324,920	40,264,320	39,809,138
Interest income	399,592	373,926	280,488
Interest expenses	(871,655)	(863,560)	(757,963)
Depreciation and amortization	(3,425,677)	(3,325,415)	(3,360,366)
Share of profit or loss of investment in associates	(1,027,435)	(1,049,335)	(1,721)
Income tax expense	(1,035,769)	(1,664,258)	(1,274,696)
Impairment loss on property, plant and equipment and others	(634,745)	(1,343,360)	(336,719)
Impairment loss on available-for-sale financial assets			(127,319)
Other significant items	(6,595,689)	(7,872,002)	(5,578,296)
Investments in subsidiaries, associates and joint ventures [member]
Disclosure of operating segments [line items]
Assets	(14,400,831)	(15,272,243)
Goodwill and corporate FV adjustments [member]
Disclosure of operating segments [line items]
Profit before income tax expense	(80,218)	(77,756)	(84,370)
Assets	2,622,409	2,722,115
Liabilities	292,124	321,320
Interest expenses	806	1,035	1,304
Depreciation and amortization	(109,941)	(103,932)	(106,195)
Income tax expense	28,917	25,921	21,270
Impairment loss on property, plant and equipment and others		(779)	(867)
Other significant items	(80,218)	(77,755)	(84,488)
Elimination of inter-segment amounts [member]
Disclosure of operating segments [line items]
Revenue	(36,737,359)	(37,280,851)	(34,404,604)
Profit before income tax expense	738,809	638,401	(102,922)
Assets	(11,665,126)	(11,079,608)
Liabilities	(9,353,090)	(9,096,926)
Interest income	(47,208)	(36,668)	(68,037)
Interest expenses	115,138	121,229	103,544
Depreciation and amortization	74,503	161,718	169,141
Share of profit or loss of investment in associates	1,301,176	1,161,970	12,261
Income tax expense	(63,789)	(32,420)	47,203
Impairment loss on property, plant and equipment and others	(70,011)	(107,258)	34,619
Impairment loss on available-for-sale financial assets			4,105
Other significant items	1,309,809	1,268,571	302,836
Income tax expense [member]
Disclosure of operating segments [line items]
Profit before income tax expense	1,070,641	1,670,757	1,206,223
Basis difference [member]
Disclosure of operating segments [line items]
Revenue	418,861	176,859	(468,233)
Profit before income tax expense	73,256	53,195	(84,641)
Assets	312,147	528,726
Liabilities	343,556	615,663
Income tax expense	(17,728)	(12,873)	20,483
Other significant items	₩ (17,728)	₩ (12,873)	₩ 20,483

Operating Segments - Revenue an

Operating Segments - Revenue and Non-current Assets by Geographic Area (Detail) - KRW (₩) ₩ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disclosure of geographical areas [line items]
Revenue	₩ 64,785,709	₩ 65,154,636	₩ 60,186,867
Non-current assets	35,712,673	36,117,713
Domestic [member]
Disclosure of geographical areas [line items]
Non-current assets	27,742,370	28,298,293
Japan [member]
Disclosure of geographical areas [line items]
Non-current assets	175,719	146,490
China [member]
Disclosure of geographical areas [line items]
Non-current assets	1,307,847	1,185,828
Asia-other [member]
Disclosure of geographical areas [line items]
Non-current assets	4,916,775	5,067,936
North America [member]
Disclosure of geographical areas [line items]
Non-current assets	221,565	173,914
Other countries [member]
Disclosure of geographical areas [line items]
Non-current assets	1,348,397	1,245,252
Basis difference [member]
Disclosure of geographical areas [line items]
Revenue	418,861	176,859	(468,233)
Reportable segments [member]
Disclosure of geographical areas [line items]
Revenue	101,104,207	102,258,628	95,059,704
Reportable segments [member] \| External customers [member]
Disclosure of geographical areas [line items]
Revenue	64,366,848	64,977,777	60,655,100
Reportable segments [member] \| External customers [member] \| Domestic [member]
Disclosure of geographical areas [line items]
Revenue	40,890,972	41,671,930	38,882,220
Reportable segments [member] \| External customers [member] \| Japan [member]
Disclosure of geographical areas [line items]
Revenue	2,202,075	2,084,061	2,200,405
Reportable segments [member] \| External customers [member] \| China [member]
Disclosure of geographical areas [line items]
Revenue	7,165,271	6,945,266	6,731,214
Reportable segments [member] \| External customers [member] \| Asia-other [member]
Disclosure of geographical areas [line items]
Revenue	8,976,593	8,904,532	7,750,553
Reportable segments [member] \| External customers [member] \| North America [member]
Disclosure of geographical areas [line items]
Revenue	1,711,859	1,834,534	1,725,120
Reportable segments [member] \| External customers [member] \| Other countries [member]
Disclosure of geographical areas [line items]
Revenue	₩ 3,420,078	₩ 3,537,454	₩ 3,365,588

Events after the Reporting Pe_2

Events after the Reporting Period - Additional Information (Detail) € in Millions, ₩ in Millions, $ in Millions	Feb. 25, 2020KRW (₩)	Jan. 17, 2020USD ($)	Jan. 17, 2020EUR (€)	Dec. 31, 2019KRW (₩)
Disclosure of non-adjusting events after reporting period [line items]
Non guaranteed bonds issued \| €			€ 500
Repayment of convertible preferred stock	₩ 160,000
Guarantee arrangement payment				₩ 149,200
Repayment of principal funds				₩ 534,600
Bottom of range [member]
Disclosure of non-adjusting events after reporting period [line items]
Non guaranteed bonds issued \| $		$ 440
Top of range [member]
Disclosure of non-adjusting events after reporting period [line items]
Non guaranteed bonds issued \| $		$ 500