United Airlines 10-K18 Feb 222021 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
Cover Page - USD ($) $ in Billions	Dec. 31, 2021	Feb. 10, 2022	Jun. 30, 2021
Document Information [Line Items]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-06033
Entity Registrant Name	United Airlines Holdings, Inc.
Entity Address, Address Line One	233 South Wacker Drive,
Entity Address, City or Town	Chicago,
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60606
City Area Code	(872)
Local Phone Number	825-4000
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-2675207
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 16.9
Entity Common Stock, Shares Outstanding		324,626,332
Documents Incorporated by Reference	Certain information required by Items 10, 11, 12 and 13 of Part III of this Form 10-K is incorporated by reference for United Airlines Holdings, Inc. from its definitive proxy statement for its 2022 Annual Meeting of Stockholders.
Document Fiscal Period Focus	FY
Amendment Flag	false
Document Fiscal Year Focus	2021
Entity Central Index Key	0000100517
Common Stock
Document Information [Line Items]
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	UAL
Security Exchange Name	NASDAQ
Preferred Stock Purchase Rights
Document Information [Line Items]
Title of 12(b) Security	Preferred Stock Purchase Rights
United Airlines, Inc.
Document Information [Line Items]
Entity File Number	001-10323
Entity Registrant Name	United Airlines, Inc.
Entity Address, Address Line One	233 South Wacker Drive,
Entity Address, City or Town	Chicago,
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60606
City Area Code	(872)
Local Phone Number	825-4000
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	74-2099724
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,000
Entity Central Index Key	0000319687

Audit Information

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2021
Audit Information [Abstract]
Auditor Name	Ernst & Young LLP
Auditor Location	Chicago, Illinois
Auditor Firm ID	42

Statements of Consolidated Oper

Statements of Consolidated Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating revenue:
Total operating revenue	$ 24,634	$ 15,355	$ 43,259
Operating expense:
Salaries and related costs	9,566	9,522	12,071
Aircraft fuel	5,755	3,153	8,953
Depreciation and amortization	2,485	2,488	2,288
Landing fees and other rent	2,416	2,127	2,543
Regional capacity purchase	2,147	2,039	2,849
Aircraft maintenance materials and outside repairs	1,316	858	1,794
Distribution expenses	677	459	1,651
Aircraft rent	228	198	288
Special charges (credits)	(3,367)	(2,616)	246
Other operating expenses	4,433	3,486	6,275
Total operating expense	25,656	21,714	38,958
Operating income (loss)	(1,022)	(6,359)	4,301
Nonoperating income (expense):
Interest expense	(1,657)	(1,063)	(731)
Interest capitalized	80	71	85
Interest income	36	50	133
Unrealized gains (losses) on investments, net	(34)	(194)	153
Miscellaneous, net	40	(1,327)	(27)
Total nonoperating expense, net	(1,535)	(2,463)	(387)
Income (loss) before income taxes	(2,557)	(8,822)	3,914
Income tax expense (benefit)	(593)	(1,753)	905
Net income (loss)	$ (1,964)	$ (7,069)	$ 3,009
Earnings (loss) per share, basic (in dollars per share)	$ (6.10)	$ (25.30)	$ 11.63
Earnings (loss) per share, diluted (in dollars per share)	$ (6.10)	$ (25.30)	$ 11.58
Passenger revenue
Operating revenue:
Total operating revenue	$ 20,197	$ 11,805	$ 39,625
Cargo
Operating revenue:
Total operating revenue	2,349	1,648	1,179
Other operating revenue
Operating revenue:
Total operating revenue	$ 2,088	$ 1,902	$ 2,455

Statements of Consolidated Comp

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ (1,964)	$ (7,069)	$ 3,009
Other comprehensive income (loss), net of tax:
Employee benefit plans	199	(421)	80
Investments and other	(2)	0	5
Total other comprehensive income (loss), net of tax	197	(421)	85
Total comprehensive income (loss), net	$ (1,767)	$ (7,490)	$ 3,094

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 18,283	$ 11,269	$ 2,762
Short-term investments	123	414
Restricted cash	37	255
Receivables, less allowance for credit losses (2021—$28; 2020—$78)	1,663	1,295
Aircraft fuel, spare parts and supplies, less obsolescence allowance (2021—$546; 2020—$478)	983	932
Prepaid expenses and other	745	635
Total current assets	21,834	14,800
Operating property and equipment:
Flight equipment	39,584	38,218
Other property and equipment	8,764	8,511
Purchase deposits for flight equipment	2,215	1,166
Total operating property and equipment	50,563	47,895
Less—Accumulated depreciation and amortization	(18,489)	(16,429)
Total operating property and equipment, net	32,074	31,466
Operating lease right-of-use assets	4,645	4,537
Other assets:
Goodwill	4,527	4,527
Intangibles, less accumulated amortization (2021—$1,544; 2020—$1,495)	2,803	2,838
Restricted cash	213	218
Deferred income taxes	659	131
Notes receivable, less allowance for credit losses (2021—$622; 2020—$522)	76	31
Investments in affiliates and other, net	1,344	1,000
Total other assets	9,622	8,745
Total assets	68,175	59,548
Current liabilities:
Accounts payable	2,562	1,595
Accrued salaries and benefits	2,121	1,960
Advance ticket sales	6,354	4,833
Frequent flyer deferred revenue	2,239	908
Current maturities of long-term debt	3,002	1,911
Current maturities of other financial liabilities	834	18
Current maturities of operating leases	556	612
Current maturities of finance leases	76	182
Other	560	706
Total current liabilities	18,304	12,725
Long-term debt	30,361	24,836
Long-term obligations under operating leases	5,152	4,986
Long-term obligations under finance leases	219	224
Other liabilities and deferred credits:
Frequent flyer deferred revenue	4,043	5,067
Pension liability	1,920	2,460
Postretirement benefit liability	1,000	994
Other financial liabilities	863	1,140
Other	1,284	1,156
Total other liabilities and deferred credits	9,110	10,817
Commitments and contingencies
Stockholders' equity:
Preferred stock	0	0
Common stock	4	4
Additional capital invested	9,156	8,366
Stock held in treasury, at cost	(3,814)	(3,897)
Retained earnings	625	2,626
Accumulated other comprehensive loss	(942)	(1,139)
Total stockholders' equity	5,029	5,960	$ 11,531	$ 10,042
Total liabilities and stockholders' equity	$ 68,175	$ 59,548

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Receivables, allowance for doubtful accounts	$ 28	$ 78
Aircraft fuel, spare parts and supplies, obsolescence allowance	546	478
Intangibles, accumulated amortization	1,544	1,495
Allowance for credit losses on notes receivable	$ 622	$ 522
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, authorized (in shares)	1,000,000,000	1,000,000,000
Common shares, outstanding (in shares)	323,810,825	311,845,232
United Airlines, Inc.
Receivables, allowance for doubtful accounts	$ 28	$ 78
Aircraft fuel, spare parts and supplies, obsolescence allowance	546	478
Intangibles, accumulated amortization	1,544	1,495
Allowance for credit losses on notes receivable	$ 622	$ 522
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, authorized (in shares)	1,000	1,000
Common shares, issued (in shares)	1,000	1,000
Common shares, outstanding (in shares)	1,000	1,000

Statements of Consolidated Cash

Statements of Consolidated Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities:
Net income (loss)	$ (1,964)	$ (7,069)	$ 3,009
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities -
Deferred income tax (benefit)	(583)	(1,741)	882
Depreciation and amortization	2,485	2,488	2,288
Operating and non-operating special charges, non-cash portion	32	1,448	175
Unrealized (gains) losses on investments	34	194	(153)
Other operating activities	393	320	185
Changes in operating assets and liabilities -
(Increase) decrease in receivables	(448)	135	44
(Increase) decrease in other assets	(292)	484	(252)
Increase in advance ticket sales	1,521	14	438
Increase in frequent flyer deferred revenue	307	699	271
Increase (decrease) in accounts payable	985	(1,079)	324
Decrease in other liabilities	(403)	(26)	(302)
Net cash provided by (used in) operating activities	2,067	(4,133)	6,909
Investing Activities:
Capital expenditures, net of flight equipment purchase deposit returns	(2,107)	(1,727)	(4,528)
Purchases of short-term and other investments	(68)	(552)	(2,933)
Proceeds from sale of short-term and other investments	397	2,319	2,996
Proceeds from sale of property and equipment	107	6	49
Loans made to others	0	0	(174)
Other, net	(1)	4	30
Net cash provided by (used in) investing activities	(1,672)	50	(4,560)
Financing Activities:
Repurchases of common stock	0	(353)	(1,645)
Proceeds from issuance of debt, net of discounts and fees	11,096	15,676	1,786
Proceeds from equity issuance	532	2,103	0
Payments of long-term debt, finance leases and other financing liabilities	(5,205)	(4,449)	(1,391)
Other, net	(27)	(20)	(30)
Net cash provided by (used in) financing activities	6,396	12,957	(1,280)
Net increase in cash, cash equivalents and restricted cash	6,791	8,874	1,069
Cash, cash equivalents and restricted cash at beginning of year	11,742	2,868	1,799
Cash, cash equivalents and restricted cash at end of year	18,533	11,742	2,868
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt, finance leases and other	814	1,968	515
Right-of-use assets acquired through operating leases	771	198	498
Equity interest in Avianca Group International Limited ("AVG") received in consideration for a loan	164	0	0
Lease modifications and lease conversions	123	527	(2)
Notes receivable and warrants received for entering into aircraft and other ancillary business agreements	131	0	0
Cash Paid (Refunded) During the Period for:
Interest	1,424	874	648
Income taxes	$ 0	$ (29)	$ 29

Statements of Consolidated Stoc

Statements of Consolidated Stockholders' Equity - USD ($) $ in Millions		Total	Adoption of New Accounting Standard	[1]	Common Stock	Additional Capital Invested	Treasury Stock	Retained Earnings	Retained EarningsAdoption of New Accounting Standard	[1]	Accumulated Other Comprehensive Income (Loss)
Balance (in shares) at Dec. 31, 2018					269,900,000
Balance at Dec. 31, 2018		$ 10,042			$ 3	$ 6,120	$ (1,993)	$ 6,715			$ (803)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		3,009						3,009
Other comprehensive income (loss)		85									85
Stock-settled share-based compensation		66				66
Repurchases of common stock (in shares)					(19,200,000)
Repurchases of common stock		(1,641)					(1,641)
Stock issued for share-based awards, net of shares withheld for tax (in shares)					500,000
Stock issued for share-based awards, net of shares withheld for tax		(30)				(57)	35	(8)
Balance (in shares) at Dec. 31, 2019					251,200,000
Balance at Dec. 31, 2019		11,531			$ 3	6,129	(3,599)	9,716			(718)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(7,069)						(7,069)
Other comprehensive income (loss)		(421)									(421)
Stock-settled share-based compensation		97				97
Issuance of common stock (in shares)					64,600,000
Issuance of common stock		2,103			$ 1	2,102
Repurchases of common stock (in shares)					(4,400,000)
Repurchases of common stock		(342)					(342)
Stock issued for share-based awards, net of shares withheld for tax (in shares)					400,000
Stock issued for share-based awards, net of shares withheld for tax		(19)				(59)	44	(4)
Warrants issued		$ 97				97
Balance (in shares) at Dec. 31, 2020		311,845,232			311,800,000
Balance at Dec. 31, 2020		$ 5,960	$ (17)		$ 4	8,366	(3,897)	2,626	$ (17)		(1,139)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	[1]	Accounting Standards Update 2016-13 [Member]
Net income (loss)		$ (1,964)						(1,964)
Other comprehensive income (loss)		197									197
Stock-settled share-based compensation		232				232
Issuance of common stock (in shares)					11,000,000
Issuance of common stock		532				532
Stock issued for share-based awards, net of shares withheld for tax (in shares)					1,000,000
Stock issued for share-based awards, net of shares withheld for tax		(27)				(73)	83	(37)
Warrants issued		$ 99				99
Balance (in shares) at Dec. 31, 2021		323,810,825			323,800,000
Balance at Dec. 31, 2021		$ 5,029			$ 4	$ 9,156	$ (3,814)	$ 625			$ (942)

[1]	Transition adjustment due to the adoption of Accounting Standards Update No. 2016-13, Financial Instruments — Credit Losses .

Statements of Consolidated Op_2

Statements of Consolidated Operations - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating revenue:
Total operating revenue	$ 24,634	$ 15,355	$ 43,259
Operating expense:
Salaries and related costs	9,566	9,522	12,071
Aircraft fuel	5,755	3,153	8,953
Depreciation and amortization	2,485	2,488	2,288
Landing fees and other rent	2,416	2,127	2,543
Regional capacity purchase	2,147	2,039	2,849
Aircraft maintenance materials and outside repairs	1,316	858	1,794
Distribution expenses	677	459	1,651
Aircraft rent	228	198	288
Special charges (credits)	(3,367)	(2,616)	246
Other operating expenses	4,433	3,486	6,275
Total operating expense	25,656	21,714	38,958
Operating income (loss)	(1,022)	(6,359)	4,301
Nonoperating income (expense):
Interest expense	(1,657)	(1,063)	(731)
Interest capitalized	80	71	85
Interest income	36	50	133
Unrealized gains (losses) on investments, net	(34)	(194)	153
Miscellaneous, net	40	(1,327)	(27)
Total nonoperating expense, net	(1,535)	(2,463)	(387)
Income (loss) before income taxes	(2,557)	(8,822)	3,914
Income tax expense (benefit)	(593)	(1,753)	905
Net income (loss)	$ (1,964)	$ (7,069)	$ 3,009
Earnings (loss) per share, basic (in dollars per share)	$ (6.10)	$ (25.30)	$ 11.63
Earnings (loss) per share, diluted (in dollars per share)	$ (6.10)	$ (25.30)	$ 11.58
United Airlines, Inc.
Operating revenue:
Total operating revenue	$ 24,634	$ 15,355	$ 43,259
Operating expense:
Salaries and related costs	9,566	9,522	12,071
Aircraft fuel	5,755	3,153	8,953
Depreciation and amortization	2,485	2,488	2,288
Landing fees and other rent	2,416	2,127	2,543
Regional capacity purchase	2,147	2,039	2,849
Aircraft maintenance materials and outside repairs	1,316	858	1,794
Distribution expenses	677	459	1,651
Aircraft rent	228	198	288
Special charges (credits)	(3,367)	(2,616)	246
Other operating expenses	4,431	3,484	6,273
Total operating expense	25,654	21,712	38,956
Operating income (loss)	(1,020)	(6,357)	4,303
Nonoperating income (expense):
Interest expense	(1,657)	(1,063)	(731)
Interest capitalized	80	71	85
Interest income	36	50	133
Unrealized gains (losses) on investments, net	(34)	(194)	153
Miscellaneous, net	40	(1,327)	(27)
Total nonoperating expense, net	(1,535)	(2,463)	(387)
Income (loss) before income taxes	(2,555)	(8,820)	3,916
Income tax expense (benefit)	(593)	(1,753)	905
Net income (loss)	(1,962)	(7,067)	3,011
Passenger revenue
Operating revenue:
Total operating revenue	20,197	11,805	39,625
Passenger revenue \| United Airlines, Inc.
Operating revenue:
Total operating revenue	20,197	11,805	39,625
Cargo
Operating revenue:
Total operating revenue	2,349	1,648	1,179
Cargo \| United Airlines, Inc.
Operating revenue:
Total operating revenue	2,349	1,648	1,179
Other operating revenue
Operating revenue:
Total operating revenue	2,088	1,902	2,455
Other operating revenue \| United Airlines, Inc.
Operating revenue:
Total operating revenue	$ 2,088	$ 1,902	$ 2,455

Statements of Consolidated Co_2

Statements of Consolidated Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income (loss)	$ (1,964)	$ (7,069)	$ 3,009
Other comprehensive income (loss), net of tax:
Employee benefit plans	199	(421)	80
Investments and other	(2)	0	5
Total other comprehensive income (loss), net of tax	197	(421)	85
Total comprehensive income (loss), net	(1,767)	(7,490)	3,094
United Airlines, Inc.
Net income (loss)	(1,962)	(7,067)	3,011
Other comprehensive income (loss), net of tax:
Employee benefit plans	199	(421)	80
Investments and other	(2)	0	5
Total other comprehensive income (loss), net of tax	197	(421)	85
Total comprehensive income (loss), net	$ (1,765)	$ (7,488)	$ 3,096

Consolidated Balance Sheets_2

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 18,283	$ 11,269
Short-term investments	123	414
Restricted cash	37	255
Receivables, less allowance for credit losses (2021—$28; 2020—$78)	1,663	1,295
Aircraft fuel, spare parts and supplies, less obsolescence allowance (2021—$546; 2020—$478)	983	932
Prepaid expenses and other	745	635
Total current assets	21,834	14,800
Operating property and equipment:
Flight equipment	39,584	38,218
Other property and equipment	8,764	8,511
Purchase deposits for flight equipment	2,215	1,166
Total operating property and equipment	50,563	47,895
Less—Accumulated depreciation and amortization	(18,489)	(16,429)
Total operating property and equipment, net	32,074	31,466
Operating lease right-of-use assets	4,645	4,537
Other assets:
Goodwill	4,527	4,527
Intangibles, less accumulated amortization (2021—$1,544; 2020—$1,495)	2,803	2,838
Restricted cash	213	218
Deferred income taxes	659	131
Notes receivable, less allowance for credit losses (2021—$622; 2020—$522)	76	31
Investments in affiliates and other, net	1,344	1,000
Total other assets	9,622	8,745
Total assets	68,175	59,548
Current liabilities:
Accounts payable	2,562	1,595
Accrued salaries and benefits	2,121	1,960
Advance ticket sales	6,354	4,833
Frequent flyer deferred revenue	2,239	908
Current maturities of long-term debt	3,002	1,911
Current maturities of other financial liabilities	834	18
Current maturities of operating leases	556	612
Current maturities of finance leases	76	182
Other	560	706
Total current liabilities	18,304	12,725
Long-term debt	30,361	24,836
Long-term obligations under operating leases	5,152	4,986
Long-term obligations under finance leases	219	224
Other liabilities and deferred credits:
Frequent flyer deferred revenue	4,043	5,067
Pension liability	1,920	2,460
Postretirement benefit liability	1,000	994
Other financial liabilities	863	1,140
Other	1,284	1,156
Total other liabilities and deferred credits	9,110	10,817
Commitments and contingencies
Stockholders' equity:
Preferred stock	0	0
Common stock	4	4
Additional capital invested	9,156	8,366
Stock held in treasury, at cost	(3,814)	(3,897)
Retained earnings	625	2,626
Accumulated other comprehensive loss	(942)	(1,139)
Total stockholders' equity	5,029	5,960
Total liabilities and stockholders' equity	68,175	59,548
United Airlines, Inc.
Current assets:
Cash and cash equivalents	18,283	11,269
Short-term investments	123	414
Restricted cash	37	255
Receivables, less allowance for credit losses (2021—$28; 2020—$78)	1,663	1,295
Aircraft fuel, spare parts and supplies, less obsolescence allowance (2021—$546; 2020—$478)	983	932
Prepaid expenses and other	745	635
Total current assets	21,834	14,800
Operating property and equipment:
Flight equipment	39,584	38,218
Other property and equipment	8,764	8,511
Purchase deposits for flight equipment	2,215	1,166
Total operating property and equipment	50,563	47,895
Less—Accumulated depreciation and amortization	(18,489)	(16,429)
Total operating property and equipment, net	32,074	31,466
Operating lease right-of-use assets	4,645	4,537
Other assets:
Goodwill	4,527	4,527
Intangibles, less accumulated amortization (2021—$1,544; 2020—$1,495)	2,803	2,838
Restricted cash	213	218
Deferred income taxes	631	103
Notes receivable, less allowance for credit losses (2021—$622; 2020—$522)	76	31
Investments in affiliates and other, net	1,344	1,000
Total other assets	9,594	8,717
Total assets	68,147	59,520
Current liabilities:
Accounts payable	2,562	1,595
Accrued salaries and benefits	2,121	1,960
Advance ticket sales	6,354	4,833
Frequent flyer deferred revenue	2,239	908
Current maturities of long-term debt	3,002	1,911
Current maturities of other financial liabilities	834	18
Current maturities of operating leases	556	612
Current maturities of finance leases	76	182
Other	563	710
Total current liabilities	18,307	12,729
Long-term debt	30,361	24,836
Long-term obligations under operating leases	5,152	4,986
Long-term obligations under finance leases	219	224
Other liabilities and deferred credits:
Frequent flyer deferred revenue	4,043	5,067
Pension liability	1,920	2,460
Postretirement benefit liability	1,000	994
Other financial liabilities	863	1,140
Other	1,284	1,156
Total other liabilities and deferred credits	9,110	10,817
Commitments and contingencies
Stockholders' equity:
Common stock	0	0
Additional capital invested	317	85
Retained earnings	2,977	4,939
Accumulated other comprehensive loss	(942)	(1,139)
Payable to parent	2,646	2,043
Total stockholders' equity	4,998	5,928
Total liabilities and stockholders' equity	$ 68,147	$ 59,520

Consolidated Balance Sheets (_2

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Receivables, allowance for doubtful accounts	$ 28	$ 78
Aircraft fuel, spare parts and supplies, obsolescence allowance	546	478
Intangibles, accumulated amortization	1,544	1,495
Allowance for credit losses on notes receivable	$ 622	$ 522
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, authorized (in shares)	1,000,000,000	1,000,000,000
Common shares, outstanding (in shares)	323,810,825	311,845,232
United Airlines, Inc.
Receivables, allowance for doubtful accounts	$ 28	$ 78
Aircraft fuel, spare parts and supplies, obsolescence allowance	546	478
Intangibles, accumulated amortization	1,544	1,495
Allowance for credit losses on notes receivable	$ 622	$ 522
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, authorized (in shares)	1,000	1,000
Common shares, issued (in shares)	1,000	1,000
Common shares, outstanding (in shares)	1,000	1,000

Statements of Consolidated Ca_2

Statements of Consolidated Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities:
Net income (loss)	$ (1,964)	$ (7,069)	$ 3,009
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities -
Deferred income tax (benefit)	(583)	(1,741)	882
Depreciation and amortization	2,485	2,488	2,288
Operating and non-operating special charges, non-cash portion	32	1,448	175
Unrealized (gains) losses on investments	34	194	(153)
Other operating activities	393	320	185
Changes in operating assets and liabilities -
(Increase) decrease in receivables	(448)	135	44
(Increase) decrease in other assets	(292)	484	(252)
Increase in advance ticket sales	1,521	14	438
Increase in frequent flyer deferred revenue	307	699	271
Increase (decrease) in accounts payable	985	(1,079)	324
Decrease in other liabilities	(403)	(26)	(302)
Net cash provided by (used in) operating activities	2,067	(4,133)	6,909
Investing Activities:
Capital expenditures, net of flight equipment purchase deposit returns	(2,107)	(1,727)	(4,528)
Purchases of short-term and other investments	(68)	(552)	(2,933)
Proceeds from sale of short-term and other investments	397	2,319	2,996
Proceeds from sale of property and equipment	107	6	49
Loans made to others	0	0	(174)
Other, net	(1)	4	30
Net cash provided by (used in) investing activities	(1,672)	50	(4,560)
Financing Activities:
Repurchases of common stock	0	(353)	(1,645)
Proceeds from issuance of debt, net of discounts and fees	11,096	15,676	1,786
Proceeds from equity issuance	532	2,103	0
Payments of long-term debt, finance leases and other financing liabilities	(5,205)	(4,449)	(1,391)
Other, net	(27)	(20)	(30)
Net cash provided by (used in) financing activities	6,396	12,957	(1,280)
Net increase in cash, cash equivalents and restricted cash	6,791	8,874	1,069
Cash, cash equivalents and restricted cash at beginning of year	11,742	2,868	1,799
Cash, cash equivalents and restricted cash at end of year	18,533	11,742	2,868
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt, finance leases and other	814	1,968	515
Right-of-use assets acquired through operating leases	771	198	498
Equity interest in Avianca Group International Limited ("AVG") received in consideration for a loan	164	0	0
Notes receivable and warrants received for entering into aircraft and other ancillary business agreements	131	0	0
Lease modifications and lease conversions	123	527	(2)
Cash Paid (Refunded) During the Period for:
Interest	1,424	874	648
Income taxes	0	(29)	29
United Airlines, Inc.
Operating Activities:
Net income (loss)	(1,962)	(7,067)	3,011
Adjustments to reconcile net income (loss) to net cash provided by (used in) operating activities -
Deferred income tax (benefit)	(583)	(1,741)	882
Depreciation and amortization	2,485	2,488	2,288
Operating and non-operating special charges, non-cash portion	32	1,448	175
Unrealized (gains) losses on investments	34	194	(153)
Other operating activities	393	320	186
Changes in operating assets and liabilities -
(Increase) decrease in receivables	(448)	135	44
Increase in intercompany receivables	(28)	(14)	(33)
(Increase) decrease in other assets	(293)	484	(252)
Increase in advance ticket sales	1,521	14	438
Increase in frequent flyer deferred revenue	307	699	271
Increase (decrease) in accounts payable	985	(1,079)	324
Decrease in other liabilities	(403)	(26)	(302)
Net cash provided by (used in) operating activities	2,040	(4,145)	6,879
Investing Activities:
Capital expenditures, net of flight equipment purchase deposit returns	(2,107)	(1,727)	(4,528)
Purchases of short-term and other investments	(68)	(552)	(2,933)
Proceeds from sale of short-term and other investments	397	2,319	2,996
Proceeds from sale of property and equipment	107	6	49
Loans made to others	0	0	(174)
Other, net	(1)	4	30
Net cash provided by (used in) investing activities	(1,672)	50	(4,560)
Financing Activities:
Proceeds from issuance of debt, net of discounts and fees	11,096	15,676	1,786
Proceeds from equity issuance	532	2,103	0
Payments of long-term debt, finance leases and other financing liabilities	(5,205)	(4,449)	(1,391)
Dividend to UAL	0	(353)	(1,645)
Other, net	0	(2)	0
Net cash provided by (used in) financing activities	6,423	12,975	(1,250)
Net increase in cash, cash equivalents and restricted cash	6,791	8,880	1,069
Cash, cash equivalents and restricted cash at beginning of year	11,742	2,862	1,793
Cash, cash equivalents and restricted cash at end of year	18,533	11,742	2,862
Investing and Financing Activities Not Affecting Cash:
Property and equipment acquired through the issuance of debt, finance leases and other	814	1,968	515
Right-of-use assets acquired through operating leases	771	198	498
Equity interest in Avianca Group International Limited ("AVG") received in consideration for a loan	164	0	0
Notes receivable and warrants received for entering into aircraft and other ancillary business agreements	131	0	0
Lease modifications and lease conversions	123	527	(2)
Cash Paid (Refunded) During the Period for:
Interest	1,424	874	648
Income taxes	$ 0	$ (29)	$ 29

Statements of Consolidated St_2

Statements of Consolidated Stockholders' Equity - USD ($) $ in Millions	Total		United Airlines, Inc.		Adoption of New Accounting Standard	[1]	Adoption of New Accounting StandardUnited Airlines, Inc.	[2]	Additional Capital Invested	Additional Capital InvestedUnited Airlines, Inc.	Retained Earnings	Retained EarningsUnited Airlines, Inc.	Retained EarningsAdoption of New Accounting Standard	[1]	Retained EarningsAdoption of New Accounting StandardUnited Airlines, Inc.	[2]	Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss)United Airlines, Inc.	(Receivable from) Payable to Related Parties, NetUnited Airlines, Inc.
Balance at Dec. 31, 2018	$ 10,042		$ 10,004						$ 6,120	$ 598	$ 6,715	$ 10,319					$ (803)	$ (803)	$ (110)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3,009		3,011								3,009	3,011
Other comprehensive income (loss)	85		85														85	85
Dividend to UAL			(1,641)							(664)		(977)
Stock-settled share-based compensation	66		66						66	66
Other			(33)																(33)
Balance at Dec. 31, 2019	11,531		11,492						6,129	0	9,716	12,353					(718)	(718)	(143)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(7,069)		(7,067)								(7,069)	(7,067)
Other comprehensive income (loss)	(421)		(421)														(421)	(421)
Dividend to UAL			(342)							(12)		(330)
Stock-settled share-based compensation	97		97						97	97
Impact of UAL common stock issuance	2,103		2,103						2,102										2,103
Other			83																83
Balance at Dec. 31, 2020	$ 5,960		$ 5,928		$ (17)		$ (17)		8,366	85	2,626	4,939	$ (17)		$ (17)		(1,139)	(1,139)	2,043
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-13 [Member]	[1]	Accounting Standards Update 2016-13 [Member]	[2]
Net income (loss)	$ (1,964)		$ (1,962)								(1,964)	(1,962)
Other comprehensive income (loss)	197		197														197	197
Stock-settled share-based compensation	232		232						232	232		0
Impact of UAL common stock issuance	532		532						532										532
Other			71																71
Balance at Dec. 31, 2021	$ 5,029		$ 4,998						$ 9,156	$ 317	$ 625	$ 2,977					$ (942)	$ (942)	$ 2,646

[1]	Transition adjustment due to the adoption of Accounting Standards Update No. 2016-13, Financial Instruments — Credit Losses .
[2]	Transition adjustment due to the adoption of Accounting Standards Update No. 2016-13, Financial Instruments — Credit Losses .

Overview

Overview	12 Months Ended
Overview	Dec. 31, 2021
Unusual or Infrequent Items, or Both [Abstract]
Overview	Overview United Airlines Holdings, Inc. (together with its consolidated subsidiaries, "UAL" or the "Company") is a holding company and its principal, wholly-owned subsidiary is United Airlines, Inc. (together with its consolidated subsidiaries, "United"). As UAL consolidates United for financial statement purposes, disclosures that relate to activities of United also apply to UAL, unless otherwise noted. United's operating revenues and operating expenses comprise nearly 100% of UAL's revenues and operating expenses. In addition, United comprises approximately the entire balance of UAL's assets, liabilities and operating cash flows. When appropriate, UAL and United are named specifically for their individual contractual obligations and related disclosures and any significant differences between the operations and results of UAL and United are separately disclosed and explained. We sometimes use the words "we," "our," "us," and the "Company" in this report for disclosures that relate to all of UAL and United.

Significant Accounting Policies

Significant Accounting Policies	12 Months Ended
Significant Accounting Policies	Dec. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies	SIGNIFICANT ACCOUNTING POLICIES (a) Use of Estimates— The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. Actual results could differ from those estimates. (b) Revenue Recognitio n— Passenger revenue is recognized when transportation is provided and Cargo revenue is recognized when shipments arrive at their destination. Other operating revenue is recognized as the related performance obligations are satisfied. Passenger tickets and related ancillary services sold by the Company for flights are purchased primarily via credit card transactions, with payments collected by the Company in advance of the performance of related services. The Company initially records ticket sales in its Advance ticket sales liability, deferring revenue recognition until the travel occurs. For travel that has more than one flight segment, the Company deems each segment as a separate performance obligation and recognizes revenue for each segment as travel occurs. Tickets sold by other airlines where the Company provides the transportation are recognized as passenger revenue at the estimated value to be billed to the other airline when travel is provided. Differences between amounts billed and the actual amounts may be rejected and rebilled or written off if the amount recorded was different from the original estimate. When necessary, the Company records a reserve against its billings and payables with other airlines based on historical experience. The Company sells certain tickets with connecting flights with one or more segments operated by its other airline partners. For segments operated by its other airline partners, the Company has determined that it is acting as an agent on behalf of the other airlines as they are responsible for their portion of the contract (i.e. transportation of the passenger). The Company, as the agent, recognizes revenue within Other operating revenue at the time of the travel for the net amount representing commission to be retained by the Company for any segments flown by other airlines. Refundable tickets expire after one year from the date of issuance. Non-refundable tickets generally expire on the date of the intended travel, unless the date is extended by notification from the customer on or before the intended travel date. United initially capitalizes the costs of selling airline travel tickets and then recognizes those costs as Distribution expense at the time of travel. Passenger ticket costs include credit card fees, travel agency and other commissions paid, as well as global distribution systems booking fees. Advance Ticket Sales. Advance ticket sales represent the Company's liability to provide air transportation in the future. All tickets sold at any given point of time have travel dates extending up to 12 months. The Company defers amounts related to future travel in its Advance ticket sales liability account. The Company's Advance ticket sales liability also includes credits issued to customers on electronic travel certificates ("ETCs") and future flight credits ("FFCs"), primarily for ticket cancellations, which can be applied towards a purchase of a new ticket. ETCs are valid up to two years from the date of issuance; however, all ETCs due to expire prior to December 31, 2022 have been extended until December 31, 2022. FFCs are valid for 12 months from the original ticket date; however, all FFCs issued on or before December 31, 2021 have been extended to be valid until December 31, 2022. As of December 31, 2021, the Company's Advance ticket sales liability included $3.2 billion related to ETCs and FFCs. The Company estimates the value of Advance ticket sales that will expire unused ("breakage") and recognizes revenue at the scheduled flight date. To determine breakage, the Company uses its historical experience with expired tickets and other facts, such as recent aging trends, program changes and modifications that could affect the ultimate expiration patterns of tickets. Given the uncertainty of travel demand caused by COVID-19, a significant portion of the ETCs and FFCs may expire unused in future periods and get recognized as revenue from breakage. The Company will update its breakage estimates as future information is received. Changes in estimates of breakage are recognized prospectively in proportion to the remaining usage of the related tickets. In the years ended December 31, 2021, 2020 and 2019, the Company recognized approximately $1.8 billion, $3.0 billion and $3.4 billion, respectively, of passenger revenue for tickets that were included in Advance ticket sales at the beginning of those periods. Revenue by Geography. The Company further disaggregates revenue by geographic regions. Operating segments are defined as components of an enterprise with separate financial information, which are evaluated regularly by the chief operating decision maker and are used in resource allocation and performance assessments. The Company deploys its aircraft across its route network through a single route scheduling system to maximize its value. When making resource allocation decisions, the Company's chief operating decision maker evaluates flight profitability data, which considers aircraft type and route economics. The Company's chief operating decision maker makes resource allocation decisions to maximize the Company's consolidated financial results. Managing the Company as one segment allows management the opportunity to maximize the value of its route network. The Company's operating revenue by principal geographic region (as defined by the U.S. Department of Transportation) for the years ended December 31 is presented in the table below (in millions): 2021 2020 2019 Domestic (U.S. and Canada) $ 16,845 $ 9,911 $ 26,960 Atlantic 3,414 2,226 7,387 Pacific 1,507 1,706 5,132 Latin America 2,868 1,512 3,780 Total $ 24,634 $ 15,355 $ 43,259 The Company attributes revenue among the geographic areas based upon the origin and destination of each flight segment. The Company's operations involve an insignificant level of revenue-producing assets in geographic regions as the overwhelming majority of the Company's revenue-producing assets (primarily U.S. registered aircraft) can be deployed in any of its geographic regions. Ancillary Fees. The Company charges fees, separately from ticket sales, for certain ancillary services that are directly related to passengers' travel, such as baggage fees, premium seat fees, inflight amenities fees, and other ticket-related fees. These ancillary fees are part of the travel performance obligation and, as such, are recognized as passenger revenue when the travel occurs. The Company recorded $2.2 billion, $1.3 billion and $3.6 billion of ancillary fees within passenger revenue in the years ended December 31, 2021, 2020 and 2019, respectively. (c) Ticket Taxes— Certain governmental taxes are imposed on the Company's ticket sales through a fee included in ticket prices. The Company collects these fees and remits them to the appropriate government agency. These fees are recorded on a net basis and, as a result, are excluded from revenue. (d) Frequent Flyer Accounting— United's MileagePlus loyalty program builds customer loyalty by offering awards, benefits and services to program participants. Members in this program earn miles for travel on United, United Express, Star Alliance members and certain other airlines that participate in the program. Members can also earn miles by purchasing goods and services from our network of non-airline partners. We have contracts to sell miles to these partners with the terms extending from one Miles Earned in Conjunction with Travel. When frequent flyers earn miles for flights, the Company recognizes a portion of the ticket sales as revenue when the travel occurs and defers a portion of the ticket sale representing the value of the related miles as a separate performance obligation. The Company determines the estimated selling price of travel and miles as if each element is sold on a separate basis. The total consideration from each ticket sale is then allocated to each of these elements, individually, on a pro-rata basis. At the time of travel, the Company records the portion allocated to the miles to Frequent flyer deferred revenue on the Company's consolidated balance sheet and subsequently recognizes it into revenue when miles are redeemed for air travel and non-air travel awards. Estimated Selling Price of Miles . The Company's estimated selling price of miles is based on an equivalent ticket value, which incorporates the expected redemption of miles, as the best estimate of selling price for these miles. The equivalent ticket value is based on the prior 12 months' weighted average equivalent ticket value of similar fares as those used to settle award redemptions while taking into consideration such factors as redemption pattern, cabin class, loyalty status and geographic region. The estimated selling price of miles is adjusted by breakage that considers a number of factors, including redemption patterns of various customer groups. Estimate of Miles Not Expected to be Redeemed ("Breakage") . The Company's breakage model is based on the assumption that the likelihood that an account will redeem its miles can be estimated based on a consideration of the account's historical behavior. The Company uses a logit regression model to estimate the probability that an account will redeem its current miles balance. The Company reviews its breakage estimates annually based upon the latest available information. The Company's estimate of the expected breakage of miles requires management judgment and current and future changes to breakage assumptions, or to program rules and program redemption opportunities, may result in material changes to the deferred revenue balance as well as recognized revenues from the program. For the portion of the outstanding miles that we estimate will not be redeemed, we recognize the associated value proportionally as the remaining miles are redeemed. Co-Brand Agreement . United has a contract (the "Co-Brand Agreement") to sell MileagePlus miles to its co-branded credit card partner JPMorgan Chase Bank USA, N.A. ("Chase"). Chase awards miles to MileagePlus members based on their credit card activity. United identified the following significant separately identifiable performance obligations in the Co-Brand Agreement: • MileagePlus miles awarded – United has a performance obligation to provide MileagePlus cardholders with miles to be used for air travel and non-travel award redemptions. The Company records Passenger revenue related to the travel awards when the transportation is provided and records Other revenue related to the non-travel awards when the goods or services are delivered. The Company records the cost associated with non-travel awards in Other operating revenue, as an agent. • Marketing – United has a performance obligation to provide Chase access to United's customer list and the use of United's brand. Marketing revenue is recorded to Other operating revenue as miles are delivered to Chase. • Advertising – United has a performance obligation to provide advertising in support of the MileagePlus card in various customer contact points such as United's website, email promotions, direct mail campaigns, airport advertising and in-flight advertising. Advertising revenue is recorded to Other operating revenue as miles are delivered to Chase. • Other travel-related benefits – United's performance obligations are comprised of various items such as waived bag fees, seat upgrades and lounge passes. Lounge passes are recorded to Other operating revenue as customers use the lounge passes. Bag fees and seat upgrades are recorded to Passenger revenue at the time of the associated travel. We account for all the payments received under the Co-Brand Agreement by allocating them to the separately identifiable performance obligations. The fair value of the separately identifiable performance obligations is determined using management's estimated selling price of each component. The objective of using the estimated selling price based methodology is to determine the price at which we would transact a sale if the product or service were sold on a stand-alone basis. Accordingly, we determine our best estimate of selling price by considering multiple inputs and methods including, but not limited to, discounted cash flows, brand value, volume discounts, published selling prices, number of miles awarded and number of miles redeemed. The Company estimated the selling prices and volumes over the term of the Co-Brand Agreement in order to determine the allocation of proceeds to each of the components to be delivered. We also evaluate volumes on an annual basis, which may result in a change in the allocation of the estimated consideration from the Co-Brand Agreement on a prospective basis. Frequent Flyer Deferred Revenue. Miles in MileagePlus members' accounts are combined into one homogeneous pool and are thus not separately identifiable, for award redemption purposes, between miles earned in the current period and those in their beginning balance. Of the miles expected to be redeemed, the majority of these miles have historically been redeemed within two years. The table below presents a roll forward of Frequent flyer deferred revenue (in millions): Twelve Months Ended 2021 2020 Total Frequent flyer deferred revenue - beginning balance $ 5,975 $ 5,276 Total miles awarded 1,545 1,336 Travel miles redeemed (Passenger revenue) (1,171) (568) Non-travel miles redeemed (Other operating revenue) (67) (69) Total Frequent flyer deferred revenue - ending balance $ 6,282 $ 5,975 In the years ended December 31, 2021, 2020 and 2019, the Company recognized, in Other operating revenue, $1.8 billion, $1.7 billion and $2.0 billion, respectively, related to the marketing, advertising, non-travel miles redeemed (net of related costs) and other travel-related benefits of the mileage revenue associated with our various partner agreements including, but not limited to, our Co-Brand Agreement. The portion related to the MileagePlus miles awarded of the total amounts received is deferred and presented in the table above as an increase to the frequent flyer liability. We determine the current portion of our frequent flyer liability based on expected redemptions in the next 12 months. (e) Cash and Cash Equivalents and Restricted Cash— Highly liquid investments with a maturity of three months or less on their acquisition date are classified as cash and cash equivalents. Restricted cash is classified as short-term or long-term in the consolidated balance sheets based on the expected timing of return of the assets to the Company or payment to an outside party. Restricted cash-current— The December 31, 2021 balance includes amounts to be used for the payment of fees, principal and interest on the $6.8 billion of senior secured notes and a secured term loan facility (the "MileagePlus Financing") secured by substantially all of the assets of Mileage Plus Holdings, LLC ("MPH"), a direct wholly-owned subsidiary of United. Restricted cash-non-current— The December 31, 2021 balance primarily includes collateral associated with the MileagePlus Financing, collateral for letters of credit and collateral associated with facility leases and other insurance-related obligations. The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the statements of consolidated cash flows (in millions): UAL United At December 31, At December 31, 2021 2020 2019 2021 2020 2019 Current assets: Cash and cash equivalents $ 18,283 $ 11,269 $ 2,762 $ 18,283 $ 11,269 $ 2,756 Restricted cash 37 255 — 37 255 — Other assets: Restricted cash 213 218 106 213 218 106 Total cash, cash equivalents and restricted cash shown in the statement of consolidated cash flows $ 18,533 $ 11,742 $ 2,868 $ 18,533 $ 11,742 $ 2,862 (f) Investments— Debt investments are classified as available-for-sale and are stated at fair value. Realized gains and losses on sales of these investments are reflected in Miscellaneous, net in the consolidated statements of operations. Unrealized gains and losses on available-for-sale securities are reflected as a component of accumulated other comprehensive income (loss). Equity investments are accounted for under the equity method if we are able to exercise significant influence over an investee. Equity investments for which we do not have significant influence are recorded at fair value or at cost, if fair value is not readily determinable, with adjustments for observable changes in price or impairments (referred to as the measurement alternative). Changes in fair value are recorded in Unrealized gains (losses) on investments, net in the consolidated statements of operations. See Note 9 of this report for additional information related to investments. (g) Accounts Receivable— Accounts receivable primarily consist of amounts due from credit card companies, non-airline partners, and cargo customers. We provide an allowance for credit losses expected to be incurred. We base our allowance on various factors including, but not limited to, aging, payment history, write-offs, macro-economic indicators and other credit monitoring indicators. Credit loss expense and write-offs related to trade receivables were not material for the years ended December 31, 2021 and 2020. (h) Aircraft Fuel, Spare Parts and Supplies— The Company accounts for aircraft fuel, spare parts and supplies at average cost and provides an obsolescence allowance for aircraft spare parts with an assumed residual value of 10% of original cost. (i) Property and Equipment— The Company records additions to owned operating property and equipment at cost when acquired. Property under finance leases and the related obligation for future lease payments are recorded at an amount equal to the initial present value of those lease payments. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized as property and equipment. We periodically receive credits in connection with the acquisition of aircraft and engines including those related to contractual damages related to delays in delivery. These credits are deferred until the aircraft and engines are delivered and then applied as a reduction to the cost of the related equipment. Depreciation and amortization of owned depreciable assets is based on the straight-line method over the assets' estimated useful lives. Leasehold improvements are amortized over the remaining term of the lease, including estimated facility renewal options when renewal is reasonably certain at key airports, or the estimated useful life of the related asset, whichever is less. Properties under finance leases are amortized using the straight-line method over the life of the lease or, in the case of certain aircraft, over their estimated useful lives, whichever is shorter. Amortization of finance lease assets is included in depreciation and amortization expense. The estimated useful lives of property and equipment are as follows: Estimated Useful Life (in years) Aircraft, spare engines and related rotable parts 25 to 30 Aircraft seats 10 to 15 Buildings 25 to 45 Other property and equipment 3 to 15 Computer software 5 to 15 Building improvements 1 to 40 As of December 31, 2021 and 2020, the Company had a carrying value of computer software of $499 million and $548 million, respectively. For the years ended December 31, 2021, 2020 and 2019, the Company's amortization expense related to computer software was $182 million, $172 million and $135 million, respectively. Aircraft, spare engines and related rotable parts were assumed to have residual values of approximately 10% of original cost, and other categories of property and equipment were assumed to have no residual value. (j) Long-Lived Asset Impairments— The Company evaluates the carrying value of long-lived assets subject to amortization whenever events or changes in circumstances indicate that an impairment may exist. For purposes of this testing, the Company has generally identified the aircraft fleet type as the lowest level of identifiable cash flows for its mainline fleet and the contract level for its regional fleet under capacity purchase agreements ("CPAs"). An impairment charge is recognized when the asset's carrying value exceeds its net undiscounted future cash flows. The amount of the charge is the difference between the asset's carrying value and fair market value. In February 2021, the Company voluntarily and temporarily removed all 52 Boeing 777-200/200ER aircraft powered by Pratt & Whitney 4000 series engines from its schedule due to an engine failure incident with one of its aircraft. The Company viewed this incident as an indicator of potential impairment. Accordingly, as required under relevant accounting standards, United performed forecasted cash flow analyses and determined that the carrying value of the Boeing 777-200/200ER fleet is expected to be recoverable from future cash flows expected to be generated by that fleet and, consequently, no impairment was recorded. The Company recorded impairment charges related to certain of its aircraft, related engines and spare parts of $97 million, $94 million, and $81 million for the years ended December 31, 2021, 2020 and 2019, respectively. See Note 14 of this report for additional information related to impairments. (k) Intangibles— The Company has finite-lived and indefinite-lived intangible assets, including goodwill. Finite-lived intangible assets are amortized over their estimated useful lives. Goodwill and indefinite-lived intangible assets are not amortized but are reviewed for impairment on an annual basis as of October 1, or more frequently if events or circumstances indicate that the asset may be impaired. We value goodwill and indefinite-lived intangible assets primarily using market and income approach valuation techniques. These measurements include the following key assumptions: (1) forecasted revenues, expenses and cash flows, (2) terminal period revenue growth and cash flows, (3) an estimated weighted average cost of capital, (4) assumed discount rates depending on the asset and (5) a tax rate. These assumptions are consistent with those that hypothetical market participants would use. Because we are required to make estimates and assumptions when evaluating goodwill and indefinite-lived intangible assets for impairment, actual transaction amounts may differ materially from these estimates. In 2021, the Company evaluated its intangible assets for possible impairments. For certain of its intangible assets, including the Company's China routes and alliances, the Company performed a quantitative assessment which involved determining the fair value of the asset and comparing that amount to the asset's carrying value. For all other intangible assets, the Company performed a qualitative assessment of whether it was more likely than not that an impairment had occurred. To determine fair value, the Company used discounted cash flow methods appropriate for each asset. Key inputs into the models included forecasted capacity, revenues, fuel costs, other operating costs and an overall discount rate. The assumptions used for future projections include that demand will continue to recover throughout 2022 and beyond. These assumptions are inherently uncertain as they relate to future events and circumstances. See Note 14 of this report for additional information related to impairments. The following table presents information about the Company's goodwill and other intangible assets at December 31 (in millions): 2021 2020 Gross Accumulated Gross Accumulated Goodwill $ 4,527 $ 4,527 Indefinite-lived intangible assets Route authorities $ 1,020 $ 1,020 Airport slots 574 560 Tradenames and logos 593 593 Alliances 404 404 Total $ 2,591 $ 2,577 Finite-lived intangible assets Frequent flyer database $ 1,177 $ 1,008 $ 1,177 $ 971 Hubs 145 118 145 111 Contracts 120 120 120 116 Other 314 298 314 297 Total $ 1,756 $ 1,544 $ 1,756 $ 1,495 Amortization expense in 2021, 2020 and 2019 was $49 million, $55 million and $60 million, respectively. Projected amortization expense in 2022, 2023, 2024, 2025 and 2026 is $40 million, $37 million, $32 million, $28 million and $18 million, respectively. (l) Labor Costs— The Company records expenses associated with new or amendable labor agreements when the amounts are probable and estimable. These include costs associated with lump sum cash payments that would be made in conjunction with the ratification of labor agreements. To the extent these upfront costs are in lieu of future pay increases, they would be capitalized and amortized over the term of the labor agreements. If not, these amounts would be expensed. (m) Share-Based Compensation— The Company measures the cost of employee services received in exchange for an award of equity instruments based on the grant date fair value of the award. The resulting cost is recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period. Obligations for cash-settled restricted stock units ("RSUs") are remeasured at fair value throughout the requisite service period at the close of the reporting period based upon UAL's stock price. In addition to the service requirement, certain RSUs have performance metrics that must be achieved prior to vesting. These awards are accrued based on the expected level of achievement at each reporting period. An adjustment is recorded each reporting period to adjust compensation expense based on the then current level of expected performance achievement for the performance-based awards. See Note 4 of this report for additional information on UAL's share-based compensation plans. (n) Maintenance and Repairs— The cost of maintenance and repairs, including the cost of minor replacements, is charged to expense as incurred, except for costs incurred under our power-by-the-hour ("PBTH") engine maintenance agreements. PBTH contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Under PBTH agreements, the Company recognizes expense at a level rate per engine hour, unless the level of service effort and the related payments during the period are substantially consistent, in which case the Company recognizes expense based on the amounts paid. (o) Advertising— Advertising costs, which are included in Other operating expenses, are expensed as incurred. Advertising expenses were $99 million, $87 million and $212 million for the years ended December 31, 2021, 2020 and 2019, respectively. (p) Third-Party Business— The Company has third-party business revenue that includes ground handling, maintenance services, flight academy and frequent flyer award non-travel redemptions. Third-party business revenue is recorded in Other operating revenue. Expenses associated with these third-party business activities are recorded in Other operating expenses, except for non-travel mileage redemption. Non-travel mileage redemption expenses are recorded to Other operating revenue. (q) Uncertain Income Tax Positions— The Company has recorded reserves for income taxes and associated interest that may become payable in future years. Although management believes that its positions taken on income tax matters are reasonable, the Company nevertheless established tax and interest reserves in recognition that various taxing authorities may challenge certain of the positions taken by the Company, potentially resulting in additional liabilities for taxes and interest. The Company's uncertain tax position reserves are reviewed periodically and are adjusted as events occur that affect its estimates, such as the availability of new information, the lapsing of applicable statutes of limitation, the conclusion of tax audits, the measurement of additional estimated liability, the identification of new tax matters, the release of administrative tax guidance affecting its estimates of tax liabilities, or the rendering of relevant court decisions. The Company records penalties and interest relating to uncertain tax positions as part of income tax expense in its consolidated statements of operations. See Note 6 of this report for additional information on UAL's uncertain tax positions.

Common Stockholders' Equity and

Common Stockholders' Equity and Preferred Securities	12 Months Ended
Common Stockholders' Equity and Preferred Securities	Dec. 31, 2021
Equity [Abstract]
Common Stockholders' Equity and Preferred Securities	COMMON STOCKHOLDERS' EQUITY AND PREFERRED SECURITIES On April 24, 2020, UAL's Board of Directors terminated its share repurchase program. Under the agreements entered into pursuant to the Coronavirus Aid, Relief, and Economic Security Act (the "CARES Act"), the Company and its business are subject to certain restrictions, including restrictions on the ability to repurchase UAL's equity securities through September 30, 2022. During 2021, UAL entered into two Payroll Support Program Extension Agreements (collectively, the "PSP2 and PSP3 Agreements") with U.S. Treasury Department ("Treasury") pursuant to which UAL issued to Treasury warrants to purchase up to approximately 3.5 million shares of UAL common stock (collectively, the "PSP2 and PSP3 Warrants"). The fair value of the PSP2 and PSP3 Warrants was calculated using a Black-Scholes options pricing model, and approximately $99 million was recorded within stockholders' equity with an offset to the CARES Act grant credit. The PSP2 and PSP3 Warrants are exercisable either through net share settlement in cash or in shares of UAL common stock, at UAL's option. The PSP2 and PSP3 Warrants contain customary anti-dilution provisions and registration rights and are freely transferable. Pursuant to the terms of the PSP2 and PSP3 Warrants, warrant holders do not have any voting rights. As of December 31, 2021 , the Company had the following warrants outstanding: Warrant Description Number of Shares of UAL Common Stock (in millions) Exercise Price Expiration Dates PSP1 Warrants (a) 4.8 $ 31.50 4/20/2025 — 9/30/2025 CARES Act Loan Warrants (b) 1.7 31.50 9/28/2025 PSP2 Warrants 2.0 43.26 1/15/2026 — 4/29/2026 PSP3 Warrants 1.5 53.92 4/29/2026 — 6/10/2026 Total 10.0 (a) Warrants issued in fiscal year 2020 in connection with the $1.5 billion 10-year senior unsecured promissory note with Treasury provided under the Payroll Support Program of the CARES Act ("PSP1 Note"). (b) Warrants issued in fiscal year 2020 in connection with the $520 million Loan and Guarantee Agreement, dated as of September 28, 2020, among United, UAL, Treasury and the Bank of New York Mellon, as administrative agent, as amended (the "CARES Act Loan"), which was entered into pursuant to the loan program established pursuant to the CARES Act. In 2020, UAL entered into an underwriting agreement with Morgan Stanley & Co. LLC and Barclays Capital Inc. relating to the issuance and sale by UAL of approximately 43 million shares of its common stock at a price to the public of $26.50 per share, resulting in total proceeds of approximately $1.1 billion. On June 15, 2020, UAL entered into an equity distribution agreement relating to the issuance and sale from time to time by UAL (the "2020 ATM Offering") of up to 28 million shares of UAL common stock. During 2020, approximately 21 million shares were sold in the 2020 ATM Offering at an average price of $46.70 per share, with net proceeds to the Company totaling approximately $989 million. In 2021, the Company sold the remaining authorized amount of approximately 7 million shares at an average price of $42.98 per share, with net proceeds to the Company of approximately $282 million. On March 3, 2021, the Company entered into an equity distribution agreement (the "Distribution Agreement") with several financial institutions (collectively, the "Managers"), relating to the issuance and sale from time to time by UAL (the "2021 ATM Offering"), through the Managers, of up to 37 million shares of UAL common stock (the "2021 ATM Shares"). Sales of the 2021 ATM Shares under the Distribution Agreement may be made in any transactions that are deemed to be "at the market offerings" as defined in Rule 415 under the Securities Act of 1933, as amended. Under the terms of the Distribution Agreement, UAL may also sell the 2021 ATM Shares to any Manager, as principal for its own account, at a price agreed upon at the time of sale. If UAL sells the 2021 ATM Shares to a Manager as principal, UAL will enter into a separate terms agreement with such Manager. During 2021, approximately 4 million shares were sold in the 2021 ATM Offering at an average price of $57.50 per share, with net proceeds to the Company totaling approximately $250 million. At December 31, 2021, approximately 6 million shares of UAL's common stock were reserved for future issuance related to the issuance of equity-based awards under the Company's incentive compensation plans.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
Earnings (Loss) Per Share	Dec. 31, 2021
Earnings Per Share [Abstract]
Common Stockholders' Equity and Preferred Securities	EARNINGS (LOSS) PER SHAREThe computations of UAL's basic and diluted earnings (loss) per share are set forth below for the years ended December 31 (in millions, except per share amounts): 2021 2020 2019 Earnings (loss) available to common stockholders $ (1,964) $ (7,069) $ 3,009 Basic weighted-average shares outstanding 321.9 279.4 258.8 Dilutive effect of employee stock awards — — 1.1 Diluted weighted-average shares outstanding 321.9 279.4 259.9 Earnings (loss) per share, basic $ (6.10) $ (25.30) $ 11.63 Earnings (loss) per share, diluted $ (6.10) $ (25.30) $ 11.58 Potentially dilutive securities (a) Stock warrants 0.9 — — Employee stock awards 0.7 1.0 0.1 (a) Weighted-average potentially dilutive securities outstanding excluded from the computation of diluted earnings per share because the securities would have had an antidilutive effect.

Share-Based Compensation Plans

Share-Based Compensation Plans	12 Months Ended
Share-Based Compensation Plans	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Share-Based Compensation Plans	SHARE-BASED COMPENSATION PLANS UAL maintains share-based compensation plans for our management employees and our non-employee directors. During 2021, UAL's Board of Directors and stockholders approved the United Airlines Holdings, Inc. 2021 Incentive Compensation Plan (the "2021 Plan"). The 2021 Plan is an incentive compensation plan that allows the Company to use different forms of equity incentives to attract, retain and reward officers and employees. Under the 2021 Plan, the Company may grant: nonqualified stock options; incentive stock options (within the meaning of Section 422 of the Internal Revenue Code of 1986); stock appreciation rights ("SARs"); restricted stock ("RSAs"); RSUs; performance units; cash incentive awards and other equity-based and equity-related awards. An award (other than an option, SAR or cash incentive award) may provide the holder with dividends or dividend equivalents. The 2021 Plan replaces the United Continental Holdings, Inc. 2017 Incentive Compensation Plan (the "2017 Plan"). Any awards granted under the 2017 Plan prior to the approval of the 2021 Plan remain in effect pursuant to their terms. The number of shares of UAL common stock that remained available for issuance under the 2017 Plan as of the effective date of the 2021 Plan are now available for issuance under the 2021 Plan. All awards are recorded as either equity or a liability in the Company's consolidated balance sheets. The share-based compensation expense is recorded in salaries and related costs. During 2021, UAL granted share-based compensation awards pursuant to both the 2017 Plan and the 2021 Plan. These share-based compensation awards included approximately 3 million RSUs consisting of approximately 1 million time-vested RSUs and approximately 2 million performance-based RSUs. A majority of the time-vested RSUs vest equally in 25% increments every 6 months over a two The following table provides information related to UAL's share-based compensation plan cost for the years ended December 31 (in millions): 2021 2020 2019 Compensation cost: RSUs $ 236 $ 106 $ 98 Stock options 2 2 1 RSAs — — 1 Total $ 238 $ 108 $ 100 The table below summarizes UAL's unearned compensation and weighted-average remaining period to recognize costs for all outstanding share-based awards that are probable of being achieved as of December 31, 2021 (in millions, except as noted): Unearned Compensation Weighted-Average RSUs $ 60 0.7 Stock options 6 3.9 Total $ 66 RSUs. As of December 31, 2021, UAL had recorded a liability of approximately $7 million related to its cash-settled RSUs. UAL paid approximately $29 million, $26 million and $41 million related to its cash-settled RSUs during 2021, 2020 and 2019, respectively. The table below summarizes UAL's RSU activity for the years ended December 31 (shares in millions): Liability Awards Equity Awards RSUs RSUs Weighted- Outstanding at December 31, 2018 1.9 1.8 $ 66.29 Granted 0.1 1.1 86.72 Vested (0.5) (0.8) 64.85 Forfeited (0.9) (0.1) 76.48 Outstanding at December 31, 2019 0.6 2.0 78.03 Granted 0.1 2.4 40.80 Vested (0.3) (0.8) 74.54 Forfeited — (0.4) 54.21 Outstanding at December 31, 2020 0.4 3.2 53.41 Granted 0.4 2.9 52.18 Vested (0.6) (1.5) 51.35 Forfeited — (0.2) 46.77 Outstanding at December 31, 2021 0.2 4.4 53.63 The fair value of RSUs and RSAs that vested in 2021, 2020 and 2019 was approximately $104 million, $87 million and $99 million, respectively. The last vesting of RSAs occurred in 2019 and the Company has not granted RSAs since 2016. Stock Options. UAL did not grant any stock option awards during either 2020 or 2021. In 2019, UAL granted an award of approximately 307,000 premium-priced stock options with an exercise price that was 25% higher than the closing price of UAL's common stock on the date of grant, representing an exercise price of $110.21. Expense related to each portion of an option grant is recognized on a straight-line basis over the specific vesting period for those options. As of December 31, 2021, there were approximately 0.7 million outstanding stock option awards, 0.3 million of which were exercisable, with weighted-average exercise prices of $82.12 and $59.05, respectively, weighted-average remaining contractual lives (in years) of 5.3 and 2.9, respectively, and intrinsic values of zero as all of the strike prices exceeded the closing stock price on that date.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
Accumulated Other Comprehensive Income (Loss)	Dec. 31, 2021
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) ("AOCI") The tables below present the components of the Company's AOCI, net of tax (in millions): Pension and Investments and Other Deferred Taxes (a) Total Balance at December 31, 2018 $ (663) $ (4) $ (136) $ (803) Change in value 105 7 (24) 88 Amounts reclassified to earnings (2) (b) (1) — (3) Balance at December 31, 2019 (560) 2 (160) (718) Change in value (993) — 221 (772) Amounts reclassified to earnings 451 (b) — (100) 351 Balance at December 31, 2020 (1,102) 2 (39) (1,139) Change in value 239 (2) (53) 184 Amounts reclassified to earnings 16 (b) — (3) 13 Balance at December 31, 2021 $ (847) $ — $ (95) $ (942) (a) Relates primarily to pension and other postretirement benefit liabilities and includes approximately $285 million of deferred income tax expense that will not be recognized in net income until these obligations are fully extinguished. We consider all income sources, including other comprehensive income, in determining the amount of tax benefit allocated to results from operations. (b) This AOCI component is included in the computation of net periodic pension and other postretirement costs. See Note 7 of this report for additional information on pensions and other postretirement liabilities.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The income tax provision (benefit) differed from amounts computed at the statutory federal income tax rate and consisted of the following significant components (in millions) : UAL and United 2021 2020 2019 Income tax provision (benefit) at statutory rate $ (537) $ (1,852) $ 822 State income tax provision (benefit), net of federal income tax benefit (34) (110) 50 Foreign tax rate differential — — (90) Global intangible low-taxed income — — 90 Nondeductible employee meals 7 5 12 Valuation allowance (38) 197 (4) Other, net 9 7 25 $ (593) $ (1,753) $ 905 Current $ (10) $ (12) $ 23 Deferred (583) (1,741) 882 $ (593) $ (1,753) $ 905 Temporary differences and carryforwards that give rise to deferred tax assets and liabilities at December 31, 2021 and 2020 were as follows (in millions): UAL United 2021 2020 2021 2020 Deferred income tax asset (liability): Federal and state net operating loss ("NOL") carryforwards $ 2,229 $ 2,476 $ 2,201 $ 2,448 Deferred revenue 2,349 1,409 2,349 1,409 Employee benefits, including pension, postretirement and medical 986 1,103 986 1,103 Operating lease liabilities 1,272 1,247 1,272 1,247 Other financing liabilities 327 260 327 260 Other 535 362 535 362 Less: Valuation allowance (210) (247) (210) (247) Total deferred tax assets $ 7,488 $ 6,610 $ 7,460 $ 6,582 Depreciation $ (5,122) $ (4,789) $ (5,122) $ (4,789) Operating lease right-of-use asset (1,051) (1,028) (1,051) (1,028) Intangibles (656) (662) (656) (662) Total deferred tax liabilities $ (6,829) $ (6,479) $ (6,829) $ (6,479) Net deferred tax asset $ 659 $ 131 $ 631 $ 103 United and its domestic consolidated subsidiaries file a consolidated federal income tax return with UAL. Under an intercompany tax allocation policy, United and its subsidiaries compute, record and pay UAL for their own tax liability as if they were separate companies filing separate returns. In determining their own tax liabilities, United and each of its subsidiaries take into account all tax credits or benefits generated and utilized as separate companies and they are each compensated for the aforementioned tax benefits only if they would be able to use those benefits on a separate company basis. The Company's federal and state NOL and tax credit carryforwards relate to current and prior years' NOLs and credits, which may be used to reduce tax liabilities in future years. These tax benefits are mostly attributable to federal pre-tax NOL carryforwards of $9.9 billion ($2.1 billion tax effected) for UAL. If not utilized these federal pre-tax NOLs will expire as follows (in billions): $0.5 in 2028, $0.4 in 2029, $0.2 in 2032 and $0.4 in 2033. The remaining $8.4 billion of NOLs has no expiration date. State pre-tax NOLs of $3.3 billion ($0.2 billion tax effected) expire over a five twenty one one A tax valuation allowance is recognized if it is more likely than not that some portion or all of the deferred tax assets will not be realized. The Company's management assesses available positive and negative evidence regarding the Company's ability to realize its deferred tax assets and records a valuation allowance when it is more likely than not that deferred tax assets will not be realized. In order to form a conclusion, management considers positive evidence in the form of taxable income in prior carryback years, reversing temporary differences, tax planning strategies and projections of future taxable income during the periods in which those temporary differences become deductible, as well as negative evidence such as historical losses. Although the Company incurred losses in 2021 and 2020, management determined that these results were not indicative of future results due to the impact of the COVID-19 pandemic on its operations. The Company concluded that the positive evidence outweighs the negative evidence, primarily driven by approval and distribution of COVID-19 vaccines as well as increased confidence with the timing of the recovery. One of the Company's largest deferred tax assets was its federal pre-tax NOLs which were $9.9 billion ($2.1 billion tax effected) at December 31, 2021. The majority of the NOLs do not expire and the Company expects to realize the benefits of the NOLs through the reversal of certain existing deferred tax liabilities of $6.2 billion and the remaining $1.3 billion (the income tax equivalent to approximately two years of average pre-COVID-19 pre-tax income) through projected future taxable income. Therefore, we have not recorded a valuation allowance on our deferred tax assets other than the capital loss carryforwards and certain state attributes that have short expiration periods. While the Company expects to generate sufficient future income to fully utilize its deferred tax assets (including NOLs), the Company may have to record a valuation allowance, which could be material, against deferred tax assets if negative evidence such as prolonged losses or reduced forecasted income outweigh positive evidence. Assumptions about future taxable income are consistent with the plans and estimates used to manage our business. Management will continue to evaluate future financial performance to determine whether such performance is both sustained and significant enough to provide sufficient evidence to support not recording valuation allowance on these NOLs. As of December 31, 2021, the Company has recorded $183 million of valuation allowance against its capital loss deferred tax assets. Capital losses have a limited carryforward period of five years, and they can be utilized only to the extent of capital gains. The Company does not anticipate generating sufficient capital gains to utilize the losses before they expire, therefore, a valuation allowance is necessary as of December 31, 2021. Additionally, the Company recorded a valuation allowance of $27 million on certain state deferred tax assets primarily due to state NOLs that have short expiration periods. The Company's unrecognized tax benefits related to uncertain tax positions were $55 million, $57 million and $53 million at December 31, 2021, 2020 and 2019, respectively. Included in the ending balance at December 31, 2021 is $55 million that would affect the Company's effective tax rate if recognized. The changes in unrecognized tax benefits relating to settlements with taxing authorities, unrecognized tax benefits as a result of tax positions taken during a prior period and unrecognized tax benefits relating from a lapse of the statute of limitations were immaterial during 2021, 2020 and 2019. The Company does not expect significant increases or decreases in their unrecognized tax benefits within the next 12 months. There are no material amounts included in the balance at December 31, 2021 for tax positions for which the ultimate deductibility is highly certain but for which there is uncertainty about the timing of such deductibility. The Company's federal income tax returns for tax years after 2002 remain subject to examination by the Internal Revenue Service (the "IRS") and state taxing jurisdictions. The IRS concluded its audit of the 2016 and 2017 tax years with no material adjustments.

Pension and Other Postretiremen

Pension and Other Postretirement Plans	12 Months Ended
Pension and Other Postretirement Plans	Dec. 31, 2021
Retirement Benefits [Abstract]
Pension and Other Postretirement Plans	PENSION AND OTHER POSTRETIREMENT PLANS The following summarizes the significant pension and other postretirement plans of United: Pension Plans. United maintains two primary defined benefit pension plans, one covering certain pilot employees and another covering certain U.S. non-pilot employees. Each of these plans provide benefits based on a combination of years of benefit accruals service and an employee's final average compensation. Additional benefit accruals are frozen under the plan covering certain pilot employees and for management and administrative employees covered under the non-pilot plan. Benefit accruals for certain non-pilot employees continue. United maintains additional defined benefit pension plans, which cover certain international employees. The Company did not have any minimum required contributions for 2021; however, during the third quarter of 2021, the Company made a voluntary contribution of $375 million to its U.S. domestic tax-qualified defined benefit pension plan covering certain U.S. non-pilot employees. Other Postretirement Plans. United maintains postretirement medical programs which provide medical benefits to certain retirees and eligible dependents, as well as life insurance benefits to certain retirees participating in the plan. Benefits provided are subject to applicable contributions, co-payments, deductibles and other limits as described in the specific plan documentation. In 2021 and 2020, the Company offered several voluntary leave programs and voluntary separation programs ("Voluntary Programs") to certain eligible employees, which in some cases included a partially-paid leave of absence with active health benefits and travel privileges. Under these Voluntary Programs, employees generally separated (or will separate) from employment with certain post-employment health benefits and travel privileges. Included in the Voluntary Programs offered during the first quarter of 2021, the Company offered special separation benefits in the form of additional subsidies for retiree medical costs for certain U.S.-based front-line employees. The subsidies are in the form of a one-time contribution to a notional Retiree Health Account of $125,000 for full-time employees and $75,000 for part-time employees. As a result, the Company recorded $31 million for those additional benefits in 2021. During the second and third quarters of 2020, the Company offered certain of its eligible front-line employees special separation benefits in the form of additional years of pension service and additional subsidies for retiree medical costs (based on employee group, age and completed years of service) as a part of the Voluntary Programs. As a result, the Company recorded, in 2020, $54 million for those additional pension benefits and $201 million for those additional retiree medical benefits. Also, the Company recognized, in 2020, $430 million in settlement losses related to the defined benefit pension plan covering certain U.S. non-pilot employees. Actuarial assumption changes are reflected as a component of the net actuarial (gain) loss during 2021 and 2020. The 2021 actuarial gains were mainly related to an increase in the discount rate applied at December 31, 2021 compared to December 31, 2020. Actuarial (gains) losses will be amortized over the average remaining service life of the covered active employees or the average life expectancy of inactive participants. The following tables set forth the reconciliation of the beginning and ending balances of the benefit obligation and plan assets, the funded status and the amounts recognized in these financial statements for the defined benefit and other postretirement plans (in millions): Pension Benefits Year Ended December 31, 2021 Year Ended December 31, 2020 Accumulated benefit obligation: $ 5,496 $ 5,387 Change in projected benefit obligation: Projected benefit obligation at beginning of year $ 6,525 $ 6,398 Service cost 239 216 Interest cost 184 209 Actuarial (gain) loss (188) 1,181 Special termination benefit — 54 Benefits paid (263) (1,445) Curtailment (12) (105) Other (12) 17 Projected benefit obligation at end of year $ 6,473 $ 6,525 Change in plan assets: Fair value of plan assets at beginning of year $ 4,069 $ 4,964 Actual return on plan assets 437 521 Employer contributions 387 16 Benefits paid (263) (1,445) Other (4) 13 Fair value of plan assets at end of year $ 4,626 $ 4,069 Funded status—Net amount recognized $ (1,847) $ (2,456) Pension Benefits December 31, 2021 December 31, 2020 Amounts recognized in the consolidated balance sheets consist of: Noncurrent asset $ 75 $ 8 Current liability (2) (4) Noncurrent liability (1,920) (2,460) Total liability $ (1,847) $ (2,456) Amounts recognized in accumulated other comprehensive loss consist of: Net actuarial loss $ (1,406) $ (1,924) Prior service cost (1) (3) Total accumulated other comprehensive loss $ (1,407) $ (1,927) Other Postretirement Benefits Year Ended December 31, 2021 Year Ended December 31, 2020 Change in benefit obligation: Benefit obligation at beginning of year $ 1,082 $ 842 Service cost 10 10 Interest cost 25 28 Plan participants' contributions 66 58 Benefits paid (199) (164) Actuarial loss 114 107 Special termination benefit 31 201 Benefit obligation at end of year $ 1,129 $ 1,082 Change in plan assets: Fair value of plan assets at beginning of year $ 51 $ 52 Actual return on plan assets 1 1 Employer contributions 130 104 Plan participants' contributions 66 58 Benefits paid (199) (164) Fair value of plan assets at end of year 49 51 Funded status—Net amount recognized $ (1,080) $ (1,031) Other Postretirement Benefits December 31, 2021 December 31, 2020 Amounts recognized in the consolidated balance sheets consist of: Current liability $ (80) $ (37) Noncurrent liability (1,000) (994) Total liability $ (1,080) $ (1,031) Amounts recognized in accumulated other comprehensive income consist of: Net actuarial gain $ 113 $ 255 Prior service credit 447 570 Total accumulated other comprehensive income $ 560 $ 825 The following information relates to all pension plans with an accumulated benefit obligation and a projected benefit obligation in excess of plan assets at December 31 (in millions): 2021 2020 Projected benefit obligation $ 6,231 $ 6,250 Accumulated benefit obligation 5,255 5,163 Fair value of plan assets 4,309 3,786 Net periodic benefit cost for the years ended December 31 included the following components (in millions): 2021 2020 2019 Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Service cost $ 239 $ 10 $ 216 $ 10 $ 184 $ 10 Interest cost 184 25 209 28 226 47 Expected return on plan assets (283) (1) (328) (1) (291) (1) Amortization of unrecognized actuarial (gain) loss 170 (28) 162 (40) 118 (52) Amortization of prior service credits — (123) — (124) — (73) Settlement loss - Voluntary Programs — — 430 — — — Special termination benefit - Voluntary Programs — 31 54 201 — — Curtailment (8) — 1 — — — Other 5 — 22 — 5 — Net periodic benefit cost (credit) $ 307 $ (86) $ 766 $ 74 $ 242 $ (69) Service cost is recorded in Salaries and related costs on the statement of consolidated operations. All other components of net periodic benefit costs are recorded in Miscellaneous, net on the statement of consolidated operations. The assumptions used for the benefit plans were as follows: Pension Benefits Assumptions used to determine benefit obligations 2021 2020 Discount rate 2.90 % 2.72 % Rate of compensation increase 3.83 % 3.88 % Assumptions used to determine net expense Discount rate 2.72 % 3.51 % Expected return on plan assets 7.28 % 7.31 % Rate of compensation increase 3.88 % 3.88 % A 50 basis points decrease in the weighted average discount rate would have increased the Company's December 31, 2021 pension benefit liability by approximately $0.7 billion and increased the estimated 2021 pension benefit expense by approximately $85 million. Other Postretirement Benefits Assumptions used to determine benefit obligations 2021 2020 Discount rate 2.82 % 2.43 % Assumptions used to determine net expense Discount rate 2.43 % 3.35 % Expected return on plan assets 3.00 % 3.00 % Health care cost trend rate assumed for next year 5.70 % 5.80 % Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2033) 4.50 % 4.50 % A 50 basis points decrease in the weighted average discount rate would have increased the Company's December 31, 2021 postretirement benefit liability by approximately $46 million and increased the estimated 2021 benefits expense by approximately $2 million. The Company used the Society of Actuaries' PRI-2012 Private Retirement Plans Mortality Tables projected generationally using the Society of Actuaries' MP-2021 projection scale. The Company selected the 2021 discount rate for substantially all of its plans by using a hypothetical portfolio of high-quality bonds at December 31, 2021 that would provide the necessary cash flows to match projected benefit payments. We develop our expected long-term rate of return assumption for our defined benefit plans based on historical experience and by evaluating input from the trustee managing the plans' assets. Our expected long-term rate of return on plan assets for these plans is based on a target allocation of assets, which is based on our goal of earning the highest rate of return while maintaining risk at acceptable levels. The plans strive to have assets sufficiently diversified so that adverse or unexpected results from one security class will not have an unduly detrimental impact on the entire portfolio. Plan fiduciaries regularly review our actual asset allocation and the pension plans' investments are periodically rebalanced to our targeted allocation when considered appropriate. United's plan assets are allocated within the following guidelines: Percent of Total Expected Long-Term Equity securities 30-45 % 10 % Fixed-income securities 35-50 4 Alternatives 15-25 7 A 50 basis points decrease in the expected long-term rate of return on plan assets would have increased estimated 2021 pension expense by approximately $20 million. Fair Value Information. Accounting standards require us to use valuation techniques to measure fair value that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs are prioritized as follows: Level 1 Unadjusted quoted prices in active markets for assets or liabilities identical to those to be reported at fair value Level 2 Other inputs that are observable directly or indirectly, such as quoted prices for similar assets or liabilities or market-corroborated inputs Level 3 Unobservable inputs for which there is little or no market data and which require us to develop our own assumptions about how market participants would price the assets or liabilities Assets and liabilities measured at fair value are based on the valuation techniques identified in the tables below. The valuation techniques are as follows: (a) Market approach. Prices and other relevant information generated by market transactions involving identical or comparable assets and liabilities; and (b) Income approach. Techniques to convert future amounts to a single current value based on market expectations (including present value techniques, option-pricing and excess earnings models). The following tables present information about United's pension and other postretirement plan assets at December 31 (in millions): 2021 2020 Pension Plan Assets: Total Level 1 Level 2 Level 3 Assets Measured at NAV(a) Total Level 1 Level 2 Level 3 Assets Measured at NAV(a) Equity securities funds $ 1,754 $ 71 $ 44 $ 147 $ 1,492 $ 1,606 $ 55 $ 125 $ 96 $ 1,330 Fixed-income securities 1,850 — 739 15 1,096 1,644 — 548 49 1,047 Alternatives 847 — — 216 631 669 — — 195 474 Other investments 175 108 59 8 — 150 132 8 10 — Total $ 4,626 $ 179 $ 842 $ 386 $ 3,219 $ 4,069 $ 187 $ 681 $ 350 $ 2,851 Other Postretirement Benefit Plan Assets: Deposit administration fund $ 49 $ — $ — $ 49 $ — $ 51 $ — $ — $ 51 $ — (a) In accordance with the relevant accounting standards, certain investments that are measured at fair value using the net asset value ("NAV") per share (or its equivalent) have not been classified in the fair value hierarchy. These investments are commingled funds that invest in equity securities and fixed-income instruments including bonds, debt securities, and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. Redemption periods for these investments range from daily to semiannually. Equity and Fixed-Income. Equities include investments in both developed market and emerging market equity securities. Fixed-income includes primarily U.S. and non-U.S. government fixed-income securities and non-U.S. corporate fixed-income securities, as well as securitized debt securities. Deposit Administration Fund. This investment is a stable value investment product structured to provide investment income. Alternatives. Alternative investments consist primarily of investments in hedge funds, real estate and private equity interests. Other investments. Other investments consist of primarily cash, as well as insurance contracts. The reconciliation of United's benefit plan assets measured at fair value using unobservable inputs (Level 3) for the years ended December 31, 2021 and 2020 is as follows (in millions): 2021 2020 Balance at beginning of year $ 401 $ 409 Actual return (loss) on plan assets: Sold during the year 2 4 Held at year end 48 13 Purchases, sales, issuances and settlements (net) (14) (25) Balance at end of year $ 437 $ 401 Funding requirements for tax-qualified defined benefit pension plans are determined by government regulations. The Company does not expect any minimum required contributions for 2022. The Company expects to make approximately $124 million in contributions to United's postretirement plans in 2022. The estimated future benefit payments, net of expected participant contributions, in United's pension plans and other postretirement benefit plans as of December 31, 2021 are as follows (in millions): Pension Other Postretirement 2022 $ 546 $ 131 2023 321 124 2024 320 107 2025 349 98 2026 374 92 Years 2027 – 2031 2,070 365 Defined Contribution Plans. United offers several defined contribution plans to its employees. Depending upon the employee group, employer contributions consist of matching contributions and/or non-elective employer contributions. United's employer contribution percentages to its primary 401(k) defined contribution plans vary from 1% to 16% of eligible earnings depending on the terms of each plan. United recorded expenses for its primary 401(k) defined contribution plans of $651 million, $687 million and $735 million in the years ended December 31, 2021, 2020 and 2019, respectively. Multi-Employer Plans. United's participation in the IAM National Pension Plan ("IAM Plan") for the annual period ended December 31, 2021 is outlined in the table below. In addition to the additional required contributions described in table below, contributions in 2021 were affected by COVID-19 impacts on United's operations and consequently employee hours paid. The risks of participating in these multi-employer plans are different from single-employer plans, as United may be subject to additional risks that others do not meet their obligations, which in certain circumstances could revert to United. The IAM Plan reported $494 million in employers' contributions for the year ended December 31, 2020. For 2020, the Company's contributions to the IAM Plan represented more than 5% of total contributions to the IAM Plan. The 2021 information is not available as the applicable Form 5500 is not final for the plan year. Pension Fund IAM National Pension Fund ("Fund") EIN/ Pension Plan Number 51-6031295 — 002 Pension Protection Act Zone Status (2021 and 2020) Critical (2021 and 2020). A plan is in "critical" status if the funded percentage is less than 65 percent. On April 17, 2019, the IAM National Pension Fund Board of Trustees voluntarily elected for the Fund to be in critical status effective for the plan year beginning January 1, 2019 to strengthen the Fund's financial health. The Fund's funded percentage was 85.1% as of January 1, 2020. FIP/RP Status Pending/Implemented A 10-year Rehabilitation Plan effective, January 1, 2022, was adopted on April 17, 2019 that requires the Company to make an additional contribution of 2.5% of the hourly contribution rate, compounded annually for the length of the Rehabilitation Plan, effective June 1, 2019. United's Contributions $58 million, $53 million and $59 million in the years ended December 31, 2021, 2020 and 2019, respectively Surcharge Imposed No Expiration Date of Collective Bargaining Agreement N/A Profit Sharing. Substantially all employees participate in profit sharing based on a percentage of pre-tax earnings, excluding special charges, profit sharing expense and share-based compensation. Profit sharing percentages range from 5% to 20% depending on the work group, and in some cases profit sharing percentages vary above and below certain pre-tax margin thresholds. Eligible U.S. co-workers in each participating work group receive a profit sharing payout using a formula based on the ratio of each qualified co-worker's annual eligible earnings to the eligible earnings of all qualified co-workers in all domestic work groups. Eligible non-U.S. co-workers receive profit sharing based on the calculation under the U.S. profit sharing plan for management and administrative employees. As a result of the pre-tax losses in 2021 and 2020, no profit sharing was recorded. However, the Company recorded profit sharing and related payroll tax expense of $491 million in 2019. Profit sharing expense is recorded as a component of Salaries and related costs in the Company's statements of consolidated operations.

Notes Receivable

Notes Receivable	12 Months Ended
Notes Receivable	Dec. 31, 2021
Receivables [Abstract]
Notes Receivables	NOTES RECEIVABLE BRW Term Loan. In November 2018, United, as lender, entered into a Term Loan Agreement (the "BRW Term Loan Agreement") with, among others, BRW Aviation Holding LLC and BRW Aviation LLC ("BRW"), as guarantor and borrower, respectively. BRW Aviation Holding LLC and BRW are affiliates of Synergy Aerospace Corporation ("Synergy"), and BRW was the majority shareholder of Avianca Holdings S.A. ("AVH"). Pursuant to the BRW Term Loan Agreement, United provided to BRW a $456 million term loan (the "BRW Term Loan"), secured by a pledge of BRW's equity, as well as BRW's 516 million common shares of AVH (which were eligible to be converted into the same number of preferred shares, which could have been deposited with the depositary for AVH's American Depositary Receipts ("ADRs"), the class of AVH securities that traded on the New York Stock Exchange (the "NYSE"), in exchange for 64.5 million ADRs) (such shares and equity, collectively, the "BRW Loan Collateral"). AVH and certain of its affiliates filed voluntary reorganization proceedings under Chapter 11 of the United States Bankruptcy Code in the U.S. Bankruptcy Court for the Southern District of New York on May 10, 2020 (the "AVH Reorganization Proceedings"). AVH successfully completed its financial restructuring process and emerged from Chapter 11 on December 1, 2021 as AVG. The common shares of AVH are in the process of being cancelled and extinguished and holders, including BRW, were not entitled to any recovery upon AVH's exit from bankruptcy. BRW is not a shareholder in the emerged entity. See Note 9 of this report for additional information on the Company's investment in AVG. In 2020, United recorded a full credit loss allowance against the $515 million carrying value of the BRW Term Loan and related receivables. United recorded the allowance based on United's assessment of AVH's financial uncertainty due to its high level of leverage and the fact that the airline had ceased operations due to the COVID-19 pandemic. The credit loss allowance was recorded as part of Nonoperating income (expense): Miscellaneous, net on the Company's statements of consolidated operations. Boom Note . The Company received a note receivable (the "Boom Note") from Boom Technology, Inc. ("Boom") related to a commercial agreement to add supersonic aircraft to its global fleet as well as a cooperative sustainability initiative. As of December 31, 2021, the Boom Note had a carrying value of $44 million and was recorded in Investments in affiliates and other, less allowance for credit losses on the Company's consolidated balance sheet. The initial value of the Boom Note was recorded as a deferred credit that will either be recognized into income or as a reduction to the cost of the aircraft received in future periods. Other. The Company has $32 million of other notes receivable, net of allowance for credit losses, the majority of which is from certain of its regional carriers.

Investments and Fair Value Meas

Investments and Fair Value Measurements	12 Months Ended
Investments and Fair Value Measurements	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Investments and Fair Value Measurements	INVESTMENTS AND FAIR VALUE MEASUREMENTS Fair Value Information. Accounting standards require us to use valuation techniques to measure fair value that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs are described in Note 7 of this report. The table below presents disclosures about the fair value of financial assets and liabilities measured at fair value on a recurring basis in the Company's financial statements as of December 31 (in millions): 2021 2020 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 18,283 $ 18,283 $ — $ — $ 11,269 $ 11,269 $ — $ — Restricted cash - current (Note 1) 37 37 — — 255 255 — — Restricted cash - non-current (Note 1) 213 213 — — 218 218 — — Short-term investments: Corporate debt 95 — 95 — 330 — 330 — Asset-backed securities 26 — 26 — 51 — 51 — U.S. government and agency notes 2 — 2 — 33 — 33 — Long-term investments: Equity securities 229 229 — — 241 205 — 36 Investments presented in the table above have the same fair value as their carrying value. Short-term investments — T he short-term investments ("STIs") shown in the table above are classified as available-for-sale. The STIs had maturities of less than two years as of December 31, 2021. Equity securities — Represents equity and equity-linked securities (such as vested warrants) that make up United's investments in Azul Linhas Aéreas Brasileiras S.A., Clear Secure, Inc. and Archer Aviation Inc. ("Archer"). The Company received equity securities in exchange for assisting Archer in the development of battery-powered, short haul aircraft. The Company will account for equity securities it receives from Archer as a deferred credit that will either be recognized into income or as a reduction to the cost of the aircraft received in future periods. Other fair value information - The table below presents the carrying values and estimated fair values of financial instruments not presented in the tables above as of December 31 (in millions). Carrying amounts include any related discounts, premiums and issuance costs: 2021 2020 Carrying Amount Fair Value Carrying Amount Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Long-term debt $ 33,363 $ 34,550 $ — $ 29,088 $ 5,462 $ 26,747 $ 27,441 $ — $ 21,985 $ 5,456 Fair value of the financial instruments included in the tables above was determined as follows: Description Fair Value Methodology Cash and cash equivalents and The carrying amounts of these assets approximate fair value. Short-term investments and Fair value is based on (a) the trading prices of the investment or similar Long-term debt Fair values were based on either market prices or the discounted amount of future cash flows using our current incremental rate of borrowing for similar liabilities or assets. Investments in Regional Carriers. United holds investments in several regional carriers that fly or used to fly for the Company as United Express under its CPAs. The combined carrying value of the investments was approximately $171 million as of December 31, 2021. United accounts for each investment using the equity method. Each investment and United's ownership stake are listed below. • Champlain Enterprises, LLC ("Champlain"). United owns a 40% minority ownership stake in Champlain. Champlain does business as CommutAir. CommutAir currently operates 75 regional aircraft under a CPA that has a term through 2026. • Republic Airways Holdings Inc. ("Republic Holdings"). United holds a 19% minority interest in Republic Holdings. Republic Holdings is the parent company of Republic Airways Inc. ("Republic"). Republic currently operates 66 regional aircraft under CPAs that have terms through 2036. • ManaAir, LLC ("ManaAir"). United holds a 49.9% minority ownership stake in ManaAir. ManaAir is the parent company of ExpressJet Airlines LLC ("ExpressJet"). The Company terminated its CPA with ExpressJet. ExpressJet flew its last commercial flight on behalf of United, on September 30, 2020. Other Investments. United holds other equity investments in companies with emerging technologies and sustainable solutions, such as Fulcrum BioEnergy, Inc., Boom, Alder Fuels LLC, Heart Aerospace Incorporated and ZeroAvia, Inc., which do not have readily determinable fair values. We account for these investments at cost less impairment, adjusted for observable price changes in orderly transactions for an identical or similar investment of the same issuer. As of December 31, 2021, the carrying value of these investments was $84 million. AVG Investment . In consideration for the Company's agreement to convert its portion of the debtor-in-possession term loan under the terms of that certain Equity Conversion and Commitment Agreement dated September 1, 2020 (as amended from time to time) as part of the AVH Reorganization Proceedings, in December 2021 the Company received warrants to purchase equity in the reorganized AVG for a de minimus amount. The Company subsequently exercised the warrants in full and on December 29, 2021 received common stock representing 16.4% of AVG's outstanding equity, the carrying value of which was $164 million as of December 31, 2021. We account for this investment at cost less impairment, adjusted for observable price changes in orderly transactions for an identical or similar investment of the same issuer.

Debt

Debt	12 Months Ended
Debt	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt	DEBT (In millions) Maturity Dates Interest Rate(s) at December 31, 2021 At December 31, 2021 2020 Aircraft notes (a) 2022 — 2033 0.62 % — 6.90 % $ 13,293 $ 14,538 MileagePlus Senior Secured Notes 2027 6.50 % 3,800 3,800 MileagePlus Term Loan Facility (a) 2027 6.25 % 3,000 3,000 2026 and 2029 Notes 2026 — 2029 4.38 % — 4.63 % 4,000 — 2021 Term Loans (a) 2028 4.50 % 4,963 — Revolving Credit Facility — 1,000 CARES Act Loan — 520 Term Loan Facility — 1,444 Unsecured Notes (b) 2022 — 2025 4.25 % — 5.00 % 1,041 1,050 PSP Notes (c) 2030 — 2031 1.00 % 3,181 1,501 Other unsecured debt 2023 — 2029 0.00 % — 5.75 % 598 448 33,876 27,301 Less: unamortized debt discount, premiums and debt issuance costs (513) (554) Less: current portion of long-term debt (3,002) (1,911) Long-term debt, net $ 30,361 $ 24,836 (a) Financing includes variable rate debt based on LIBOR (or another index rate), generally subject to a floor, plus a specified margin ranging from 0.49% to 5.25%. (b) On January 14, 2022, the Company gave notice for the redemption of all $400 million outstanding principal amount of the 4.250% senior notes due 2022 (the "2022 Notes"), scheduled to occur on February 28, 2022. The redemption price will be calculated in accordance with the terms of the indenture governing the 2022 Notes, and will include accrued and unpaid interest on the principal amount being redeemed to such redemption date. (c) Includes PSP1 Note, PSP2 Note and PSP3 Note. The table below presents the Company's contractual principal payments (not including debt discount or debt issuance costs) at December 31, 2021 under then-outstanding long-term debt agreements in each of the next five calendar years (in millions): 2022 $ 3,002 2023 2,853 2024 3,908 2025 3,378 2026 5,134 After 2026 15,601 $ 33,876 2026 and 2029 Notes . On April 21, 2021, United issued, through a private offering to eligible purchasers, $4.0 billion in aggregate principal amount of two series of notes, consisting of $2.0 billion in aggregate principal amount of 4.375% senior secured notes due 2026 (the "2026 Notes") and $2.0 billion in aggregate principal amount of 4.625% senior secured notes due 2029 (the "2029 Notes" and, together with the 2026 Notes, the "2026 and 2029 Notes"). The 2026 Notes, issued at a price of 100% of their principal amount, bear interest at a rate of 4.375% per annum and will mature on April 15, 2026. The 2029 Notes, issued at a price of 100% of their principal amount, bear interest at a rate of 4.625% per annum and will mature on April 15, 2029. The 2026 and 2029 Notes are guaranteed on an unsecured basis by UAL. 2021 Loan Facilities. Concurrently with the closing of the offering of the 2026 and 2029 Notes, United also entered into a new Term Loan Credit and Guaranty Agreement (the "2021 Term Loan Facility") initially providing term loans (the "2021 Term Loans") up to an aggregate amount of $5.0 billion and a new Revolving Credit and Guaranty Agreement (the "2021 Revolving Credit Facility" and, together with the 2021 Term Loan Facility, the "2021 Loan Facilities") initially providing revolving loan commitments of up to $1.75 billion. United borrowed the full amount of the 2021 Term Loans on April 21, 2021, which bear interest at a variable rate equal to LIBOR (but not less than 0.75% per annum) plus a margin of 3.75% per annum. The principal amount of the 2021 Term Loan Facility must be repaid in consecutive quarterly installments of 0.25% of the original principal amount thereof with the balance due at maturity. Borrowings under the 2021 Revolving Credit Facility bear interest at a variable rate equal to LIBOR plus a margin of 3.00% to 3.50% per annum. United pays a commitment fee equal to 0.75% per annum on the undrawn amount available under the 2021 Revolving Credit Facility. No borrowings were outstanding under the 2021 Revolving Credit Facility at December 31, 2021. United used the net proceeds from the offering of the 2026 and 2029 Notes and borrowings under the 2021 Term Loan Facility (i) to repay in full the $1.4 billion aggregate principal amount outstanding under the term loan facility (the "2017 Term Loan Facility") included in the Amended and Restated Credit and Guaranty Agreement, dated as of March 29, 2017 (the "2017 Credit Agreement"), the $1.0 billion aggregate principal amount outstanding under the revolving credit facility (the "2017 Revolving Credit Facility") included in the 2017 Credit Agreement and the $520 million aggregate principal amount outstanding under the CARES Act Loan and, together with the 2017 Term Loan Facility and the 2017 Revolving Credit Facility, the "2017 Loan Facilities"), (ii) to pay fees and expenses relating to the offering of the 2026 and 2029 Notes and (iii) for United's general corporate purposes. As a result of such repayments, the 2017 Loan Facilities were terminated on April 21, 2021, and no further borrowings may be made thereunder. PSP2 Note. During 2021, UAL issued an $870 million indebtedness evidenced by a 10-year senior unsecured promissory note (the "PSP2 Note") to Treasury. The PSP2 Note is guaranteed by United and will mature on January 15, 2031 (the "PSP2 Note Maturity Date"). If any subsidiary of UAL (other than United) guarantees other unsecured indebtedness of UAL with a principal balance in excess of a specified amount, then such subsidiary shall be required to guarantee the obligations of UAL under the PSP2 Note. UAL may, at its option, prepay the PSP2 Note, at any time, and from time to time, at par. UAL is required to prepay the PSP2 Note upon the occurrence of certain change of control triggering events. The PSP2 Note does not require any amortization and is to be repaid in full on the PSP2 Note Maturity Date. Interest on the PSP2 Note is payable semi-annually in arrears on the last business day of March and September of each year, beginning on March 31, 2021, at a rate of 1.00% in years 1 through 5, and at the Secured Overnight Financing Rate (SOFR) plus 2.00% in years 6 through 10. PSP3 Note. During 2021, UAL issued an $810 million indebtedness evidenced by a 10-year senior unsecured promissory note (the "PSP3 Note") to Treasury. The PSP3 Note is guaranteed by United and will mature on April 29, 2031 (the "PSP3 Note Maturity Date"). If any subsidiary of UAL (other than United) guarantees other unsecured indebtedness of UAL with a principal balance in excess of a specified amount, then such subsidiary shall be required to guarantee the obligations of UAL under the PSP3 Note. UAL may, at its option, prepay the PSP3 Note, at any time, and from time to time, at par. UAL is required to prepay the PSP3 Note upon the occurrence of certain change of control triggering events. The PSP3 Note does not require any amortization and is to be repaid in full on the PSP3 Note Maturity Date. Interest on the PSP3 Note is payable semi-annually in arrears on the last business day of March and September of each year, beginning on September 30, 2021, at a rate of 1.00% in years 1 through 5, and at the Secured Overnight Financing Rate (SOFR) plus 2.00% in years 6 through 10. Aircraft Notes. As of December 31, 2021, United had $11.2 billion principal amount of equipment notes outstanding issued under EETC financings. Generally, the structure of these EETC financings consists of pass-through trusts created by United to issue pass-through certificates, which represent fractional undivided interests in the respective pass-through trusts and are not obligations of United. The proceeds of the issuance of the pass-through certificates are used to purchase equipment notes which are issued by United and secured by aircraft and, in certain structures, spare engines and spare parts. United is responsible for the payment obligations under the equipment notes. In certain EETC structures, proceeds received from the sale of pass-through certificates are initially held by a depositary in escrow for the benefit of the certificate holders until United issues equipment notes to the trust, which purchases such notes with a portion of the escrowed funds. These escrowed funds are not guaranteed by United and are not reported as debt on United's consolidated balance sheet because the proceeds held by the depositary are not United's assets. The Company records the debt obligation upon issuance of the equipment notes rather than upon the initial issuance of the pass-through certificates. Certain details of the pass-through trusts with proceeds received from issuance of debt in 2021 are as follows (in millions, except stated interest rate): EETC Issuance Date Class Face Amount Final expected distribution date Stated interest rate Total proceeds received from issuance of debt and recorded as debt as of December 31, 2021 February 2021 B $ 600 January 2026 4.88% $ 600 Our debt agreements contain customary terms and conditions as well as various affirmative, negative and financial covenants that, among other things, restrict the ability of the Company and its subsidiaries to incur additional indebtedness and pay dividends or repurchase stock. As of December 31, 2021, the Company was in compliance with its respective debt covenants. The collateral, covenants and cross default provisions of the Company's principal debt instruments that contain such provisions are summarized in the table below: Debt Instrument Collateral, Covenants and Cross Default Provisions Various equipment notes and other notes payable Secured by certain aircraft, spare engines and spare parts. The indentures contain events of default that are customary for aircraft financings, including in certain cases cross default to other related aircraft. 2021 Loan Facilities Secured on a senior basis by security interests granted by the Company to the collateral trustee for the benefit of the lenders under the 2021 Loan Facilities, among other parties, on the following: (i) all of the Company's route authorities granted by the U.S. Department of Transportation to operate scheduled service between any international airport located in the United States and any international airport located in any country other than the United States (except Cuba), (ii) the Company's rights to substantially all of its landing and take-off slots at foreign and domestic airports, including at John F. Kennedy International Airport, LaGuardia Airport and Ronald Reagan Washington National Airport (subject to certain exclusions), and (iii) the Company's rights to use or occupy space at airport terminals, each to the extent necessary at the relevant time for servicing scheduled air carrier service authorized by an applicable route authority. The 2021 Loan Facilities contain negative covenants that, among other things, limit our ability under certain circumstances to create liens on the collateral, make certain dividends, conduct stock repurchases, make certain restricted investments and other restricted payments, and consolidate, merge, sell, or otherwise dispose of all or substantially all of our assets. The 2021 Loan Facilities also contain financial covenants that require the Company to maintain at least $2.0 billion of unrestricted liquidity at all times, which includes unrestricted cash, short-term investments and any undrawn amounts under any revolving credit facility, and to maintain a minimum ratio of appraised value of collateral to the outstanding debt secured by such collateral (including under the 2021 Loan Facilities) of 1.6 to 1.0, tested semi-annually. The 2021 Loan Facilities contain events of default customary for similar financings, including a cross-payment default and cross-acceleration to other material indebtedness. 2026 and 2029 Notes The 2026 and 2029 Notes are secured on a senior basis by security interests granted by the Company to the collateral trustee for the benefit of the holders of the 2026 and 2029 Notes, among other parties, on the following: (i) all of the Company's route authorities granted by the U.S. Department of Transportation to operate scheduled service between any international airport located in the United States and any international airport located in any country other than the United States (except Cuba), (ii) the Company's rights to substantially all of its landing and take-off slots at foreign and domestic airports, including at John F. Kennedy International Airport, LaGuardia Airport and Ronald Reagan Washington National Airport (subject to certain exclusions), and (iii) the Company's rights to use or occupy space at airport terminals, each to the extent necessary at the relevant time for servicing scheduled air carrier service authorized by an applicable route authority. The indenture for these 2026 and 2029 Notes contains covenants that, among other things, limit our ability under certain circumstances to create liens on the Collateral, make certain dividends, stock repurchases, restricted investments and other restricted payments, and consolidate, merge, sell, or otherwise dispose of all or substantially all of our assets. The indenture also contains a financial covenant that requires UAL to pay special interest in an additional amount equal to 2.0% per year of the principal amount of the 2026 and 2029 Notes for so long as it is unable to demonstrate that it maintains a minimum ratio of appraised value of collateral to the outstanding debt secured by such collateral (including the 2026 and 2029 Notes) of 1.6 to 1.0, tested semi-annually. The indenture contains events of default customary for similar financings, including a cross-payment default and cross-acceleration to other material indebtedness. MileagePlus Notes Secured by first-priority security interests in substantially all of the assets of the Issuers, other than excluded property and subject to certain permitted liens, including security interests in specified cash accounts that include the accounts into which MileagePlus revenues are or will be paid by the Company's marketing partners and by the Company. CARES Act Loan Though the CARES Act Loan was terminated and repaid in full on April 20, 2021, United and its affiliates agreed in the corresponding term loan and guarantee agreement to comply with certain surviving provisions (i) prohibiting the payment of dividends and the repurchase of certain equity until April 20, 2022, (ii) requiring compliance with certain continuation of service requirements until March 1, 2022, and (iii) restricting the payment of certain executive compensation until April 20, 2022. PSP Notes The PSP Notes represent senior unsecured indebtedness of UAL. The PSP Notes are guaranteed by United. If any subsidiary of UAL (other than United) becomes, or is required to become, an obligor on unsecured indebtedness of UAL or any of its subsidiaries with a principal balance in excess of a specified amount, then such subsidiary shall be required to guarantee the obligations of the Company under the PSP Notes. Pursuant to the PSP Agreements, the Company and its affiliates will be required to comply with certain provisions including, among others, prohibiting certain reductions in employee wages, salaries and benefits; provisions prohibiting the payment of dividends and the repurchase of certain equity until September 30, 2022; audit and reporting requirements; provisions to comply with certain continuation of service requirements until March 1, 2022; and provisions restricting the payment of certain executive compensation until April 1, 2023. Unsecured notes The indentures for these notes contain covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indentures) to incur additional indebtedness and make certain dividends, stock repurchases, restricted investments and other restricted payments.

Leases and Capacity Purchase Ag

Leases and Capacity Purchase Agreements	12 Months Ended
Leases and Capacity Purchase Agreements	Dec. 31, 2021
Leases [Abstract]
Leases and Capacity Purchase Agreements	LEASES AND CAPACITY PURCHASE AGREEMENTS United leases aircraft, airport passenger terminal space, aircraft hangars and related maintenance facilities, cargo terminals, other airport facilities, other commercial real estate, office and computer equipment and vehicles, among other items. Certain of these leases include provisions for variable lease payments which are based on several factors, including, but not limited to, relative leased square footage, available seat miles, enplaned passengers, passenger facility charges, terminal equipment usage fees, departures, and airports' annual operating budgets. Due to the variable nature of the rates, these leases are not recorded on our balance sheet as a right-of-use asset and lease liability. For leases with terms greater than 12 months, we record the related right-of-use asset and lease liability at the present value of fixed lease payments over the lease term. To the extent a lease agreement includes an extension option that is reasonably certain to be exercised, we have recognized those amounts as part of our right-of-use assets and lease liabilities. Leases with an initial term of 12 months or less with purchase options or extension options that are not reasonably certain to be exercised are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the term of the lease. We combine lease and non-lease components, such as common area maintenance costs, in calculating the right-of-use assets and lease liabilities for all asset groups except for our CPAs, which contain embedded leases for regional aircraft. In addition to the lease component cost for regional aircraft, our CPAs also include non-lease components primarily related to the regional carriers' operating costs incurred in providing regional aircraft services. We allocate consideration for the lease components and non-lease components of each CPA based on their relative standalone values. Lease Cost . The Company's lease cost for the years ended December 31 included the following components (in millions): 2021 2020 2019 Operating lease cost $ 958 $ 933 $ 1,038 Variable and short-term lease cost 2,291 1,968 2,548 Amortization of finance lease assets 89 88 68 Interest on finance lease liabilities 16 16 85 Sublease income (26) (23) (32) Total lease cost $ 3,328 $ 2,982 $ 3,707 Lease terms and commitments . United's leases include aircraft leases for aircraft that are directly leased by United and aircraft that are operated by regional carriers on United's behalf under CPAs (but excluding aircraft owned by United) and non-aircraft leases. Aircraft operating leases relate to leases of 118 mainline and 282 regional aircraft while finance leases relate to leases of 25 mainline and 58 regional aircraft. United's aircraft leases have remaining lease terms of 1 month to 12 years with expiration dates ranging from 2022 through 2033. Under the terms of most aircraft leases, United has the right to purchase the aircraft at the end of the lease term, in some cases at fair market value, and in others, at a percentage of cost. Non-aircraft leases have remaining lease terms of 1 month to 31 years, with expiration dates ranging from 2022 through 2053. The table below summarizes the Company's scheduled future minimum lease payments under operating and finance leases, recorded on the balance sheet, as of December 31, 2021 (in millions): Operating Leases Finance Leases 2022 $ 857 $ 89 2023 825 57 2024 775 53 2025 655 41 2026 637 26 After 2026 3,982 72 Minimum lease payments 7,731 338 Imputed interest (2,023) (43) Present value of minimum lease payments 5,708 295 Less: current maturities of lease obligations (556) (76) Long-term lease obligations $ 5,152 $ 219 As of December 31, 2021, we have additional leases of approximately $415 million for several regional aircraft under CPAs and airport facilities and office space leases that have not yet commenced. These leases will commence in 2022 through 2024 with lease terms of up to 12 years. In August 2021, at the request of United, the City of Houston, Texas issued its approximately $289 million special facilities revenue bonds for the purpose of (a) financing the costs of construction of a multi-terminal baggage handling system, tenant improvements, fixtures, equipment, personnel areas and related facilities, as well as an early baggage system building (together with a related fire pump room) at George Bush Intercontinental Airport (IAH), all to be installed by and for use by United and (b) paying related costs of issuance. The bonds bear interest at 4.0% per annum, payable semiannually, commencing in January 2022 through the July 2041 maturity date. United is accounting for the payments for these special facilities revenue bonds as lease payments under an operating lease recognized as a right-of-use asset and lease liability on the Company's balance sheet. In 2020, United entered into agreements with third parties to finance through sale and leaseback transactions new Boeing model 787 aircraft and Boeing model 737 MAX aircraft subject to purchase agreements between United and Boeing. In connection with the delivery of each aircraft from Boeing, United assigned its right to purchase such aircraft to the buyer, and simultaneous with the buyer's purchase from Boeing, United entered into a long-term lease for such aircraft with the buyer as lessor. Twenty-four Boeing model aircraft were delivered in 2021 under these transactions (and each is presently subject to a long-term lease to United). Upon delivery of aircraft in these sale and leaseback transactions in 2021, the Company accounted for seven of these aircraft, which have a repurchase option at a price other than fair value, as part of Flight equipment on the Company's consolidated balance sheet and the related obligation recorded in Current maturities of other financial liabilities and Other financial liabilities since they do not qualify for sale recognition. The remaining 17 aircraft that qualified for sale recognition were recorded as Operating lease right-of-use assets and Current/Long-term obligations under operating leases on the Company's consolidated balance sheet after recognition of related gains on such sale. See Note 14 of this report for additional information. In 2021, under these sale and leaseback agreements, United gave notice of its intent to exercise repurchase options in 2022 for six Boeing 787 aircraft. The liabilities associated with these aircraft are reflected in Current maturities of other financial liabilities on the Company's consolidated balance sheet at December 31, 2021. In January 2022, the Company gave notice of its intent to exercise repurchase options in 2023 for eight Boeing 737 MAX aircraft under these sale and leaseback agreements. The liabilities associated with these aircraft are reflected in Other financial liabilities on the Company's consolidated balance sheet at December 31, 2021. Our lease agreements do not provide a readily determinable implicit rate nor is it available to us from our lessors. Instead, we estimate United's incremental borrowing rate based on information available at lease commencement in order to discount lease payments to present value. The table below presents additional information related to our leases as of December 31: 2021 2020 Weighted-average remaining lease term - operating leases 10 years 11 years Weighted-average remaining lease term - finance leases 6 years 4 years Weighted-average discount rate - operating leases 5.0 % 5.1 % Weighted-average discount rate - finance leases 4.8 % 4.4 % The table below presents supplemental cash flow information related to leases during the year ended December 31 (in millions): 2021 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 977 $ 788 $ 902 Operating cash flows for finance leases 18 20 70 Financing cash flows for finance leases 216 66 151 Regional CPAs. United has contractual relationships with various regional carriers to provide regional aircraft service branded as United Express. Under these CPAs, the Company pays the regional carriers contractually agreed fees (carrier costs) for operating these flights plus a variable rate adjustment based on agreed performance metrics, subject to annual adjustments. The fees are based on specific rates multiplied by specific operating statistics (e.g., block hours, departures), as well as fixed monthly amounts. Under these CPAs, the Company is also responsible for all fuel costs incurred, as well as landing fees and other costs, which are either passed through by the regional carrier to the Company without any markup or directly incurred by the Company. In some cases, the Company owns some or all of the aircraft subject to the CPA and leases such aircraft to the regional carrier. United's CPAs are for 518 regional aircraft as of December 31, 2021, and the CPAs have terms expiring through 2036. Aircraft operated under CPAs include aircraft leased directly from the regional carriers and those owned by United and operated by the regional carriers. See Part I, Item 2. Properties, of this report for additional information. In September 2021, United entered into a new CPA with Republic for Republic to operate 38 Embraer E175LL aircraft on United's behalf starting in 2022 for a 12-year term. The new Embraer E175LL aircraft will replace the Embraer E170 aircraft currently being flown by Republic for United. United recorded approximately $0.6 billion, $0.6 billion and $1.0 billion in expenses related to its CPAs with its regional carriers in which United is a minority shareholder, for the years ended December 31, 2021, 2020 and 2019, respectively. There were approximately $102 million and $68 million in accounts payable due to these companies as of December 31, 2021 and December 31, 2020, respectively. There were no material accounts receivables due from these companies as of December 31, 2021 and December 31, 2020. The CPAs with these related parties were executed in the ordinary course of business. Our future commitments under our CPAs are dependent on numerous variables, and are, therefore, difficult to predict. The most important of these variables is the number of scheduled block hours. Although we are not required to purchase a minimum number of block hours under certain of our CPAs, we have set forth below estimates of our future payments under the CPAs based on our assumptions. United's estimates of its future payments under all of the CPAs do not include the portion of the underlying obligation for any aircraft leased to a regional carrier or deemed to be leased from other regional carriers and facility rent that are disclosed as part of operating leases above. For purposes of calculating these estimates, we have assumed (1) the number of block hours flown is based on our anticipated level of flight activity or at any contractual minimum utilization levels if applicable, whichever is higher, (2) that we will reduce the fleet as rapidly as contractually allowed under each CPA, (3) that aircraft utilization, stage length and load factors will remain constant, (4) that each carrier's operational performance will remain at recent historic levels and (5) an annual projected inflation rate. These amounts exclude variable pass-through costs such as fuel and landing fees, among others. Based on these assumptions as of December 31, 2021, our future payments through the end of the terms of our CPAs are presented in the table below (in billions): 2022 $ 2.1 2023 2.1 2024 2.0 2025 1.7 2026 1.5 After 2026 4.2 $ 13.6 The actual amounts we pay to our regional operators under CPAs could differ materially from these estimates. For example, a 10% increase or decrease in scheduled block hours for all of United's regional operators (whether as a result of changes in average daily utilization or otherwise) in 2022 would result in a corresponding change in annual cash obligations under the CPAs of approximately $125 million.
Leases and Capacity Purchase Agreements	LEASES AND CAPACITY PURCHASE AGREEMENTS United leases aircraft, airport passenger terminal space, aircraft hangars and related maintenance facilities, cargo terminals, other airport facilities, other commercial real estate, office and computer equipment and vehicles, among other items. Certain of these leases include provisions for variable lease payments which are based on several factors, including, but not limited to, relative leased square footage, available seat miles, enplaned passengers, passenger facility charges, terminal equipment usage fees, departures, and airports' annual operating budgets. Due to the variable nature of the rates, these leases are not recorded on our balance sheet as a right-of-use asset and lease liability. For leases with terms greater than 12 months, we record the related right-of-use asset and lease liability at the present value of fixed lease payments over the lease term. To the extent a lease agreement includes an extension option that is reasonably certain to be exercised, we have recognized those amounts as part of our right-of-use assets and lease liabilities. Leases with an initial term of 12 months or less with purchase options or extension options that are not reasonably certain to be exercised are not recorded on the balance sheet; we recognize lease expense for these leases on a straight-line basis over the term of the lease. We combine lease and non-lease components, such as common area maintenance costs, in calculating the right-of-use assets and lease liabilities for all asset groups except for our CPAs, which contain embedded leases for regional aircraft. In addition to the lease component cost for regional aircraft, our CPAs also include non-lease components primarily related to the regional carriers' operating costs incurred in providing regional aircraft services. We allocate consideration for the lease components and non-lease components of each CPA based on their relative standalone values. Lease Cost . The Company's lease cost for the years ended December 31 included the following components (in millions): 2021 2020 2019 Operating lease cost $ 958 $ 933 $ 1,038 Variable and short-term lease cost 2,291 1,968 2,548 Amortization of finance lease assets 89 88 68 Interest on finance lease liabilities 16 16 85 Sublease income (26) (23) (32) Total lease cost $ 3,328 $ 2,982 $ 3,707 Lease terms and commitments . United's leases include aircraft leases for aircraft that are directly leased by United and aircraft that are operated by regional carriers on United's behalf under CPAs (but excluding aircraft owned by United) and non-aircraft leases. Aircraft operating leases relate to leases of 118 mainline and 282 regional aircraft while finance leases relate to leases of 25 mainline and 58 regional aircraft. United's aircraft leases have remaining lease terms of 1 month to 12 years with expiration dates ranging from 2022 through 2033. Under the terms of most aircraft leases, United has the right to purchase the aircraft at the end of the lease term, in some cases at fair market value, and in others, at a percentage of cost. Non-aircraft leases have remaining lease terms of 1 month to 31 years, with expiration dates ranging from 2022 through 2053. The table below summarizes the Company's scheduled future minimum lease payments under operating and finance leases, recorded on the balance sheet, as of December 31, 2021 (in millions): Operating Leases Finance Leases 2022 $ 857 $ 89 2023 825 57 2024 775 53 2025 655 41 2026 637 26 After 2026 3,982 72 Minimum lease payments 7,731 338 Imputed interest (2,023) (43) Present value of minimum lease payments 5,708 295 Less: current maturities of lease obligations (556) (76) Long-term lease obligations $ 5,152 $ 219 As of December 31, 2021, we have additional leases of approximately $415 million for several regional aircraft under CPAs and airport facilities and office space leases that have not yet commenced. These leases will commence in 2022 through 2024 with lease terms of up to 12 years. In August 2021, at the request of United, the City of Houston, Texas issued its approximately $289 million special facilities revenue bonds for the purpose of (a) financing the costs of construction of a multi-terminal baggage handling system, tenant improvements, fixtures, equipment, personnel areas and related facilities, as well as an early baggage system building (together with a related fire pump room) at George Bush Intercontinental Airport (IAH), all to be installed by and for use by United and (b) paying related costs of issuance. The bonds bear interest at 4.0% per annum, payable semiannually, commencing in January 2022 through the July 2041 maturity date. United is accounting for the payments for these special facilities revenue bonds as lease payments under an operating lease recognized as a right-of-use asset and lease liability on the Company's balance sheet. In 2020, United entered into agreements with third parties to finance through sale and leaseback transactions new Boeing model 787 aircraft and Boeing model 737 MAX aircraft subject to purchase agreements between United and Boeing. In connection with the delivery of each aircraft from Boeing, United assigned its right to purchase such aircraft to the buyer, and simultaneous with the buyer's purchase from Boeing, United entered into a long-term lease for such aircraft with the buyer as lessor. Twenty-four Boeing model aircraft were delivered in 2021 under these transactions (and each is presently subject to a long-term lease to United). Upon delivery of aircraft in these sale and leaseback transactions in 2021, the Company accounted for seven of these aircraft, which have a repurchase option at a price other than fair value, as part of Flight equipment on the Company's consolidated balance sheet and the related obligation recorded in Current maturities of other financial liabilities and Other financial liabilities since they do not qualify for sale recognition. The remaining 17 aircraft that qualified for sale recognition were recorded as Operating lease right-of-use assets and Current/Long-term obligations under operating leases on the Company's consolidated balance sheet after recognition of related gains on such sale. See Note 14 of this report for additional information. In 2021, under these sale and leaseback agreements, United gave notice of its intent to exercise repurchase options in 2022 for six Boeing 787 aircraft. The liabilities associated with these aircraft are reflected in Current maturities of other financial liabilities on the Company's consolidated balance sheet at December 31, 2021. In January 2022, the Company gave notice of its intent to exercise repurchase options in 2023 for eight Boeing 737 MAX aircraft under these sale and leaseback agreements. The liabilities associated with these aircraft are reflected in Other financial liabilities on the Company's consolidated balance sheet at December 31, 2021. Our lease agreements do not provide a readily determinable implicit rate nor is it available to us from our lessors. Instead, we estimate United's incremental borrowing rate based on information available at lease commencement in order to discount lease payments to present value. The table below presents additional information related to our leases as of December 31: 2021 2020 Weighted-average remaining lease term - operating leases 10 years 11 years Weighted-average remaining lease term - finance leases 6 years 4 years Weighted-average discount rate - operating leases 5.0 % 5.1 % Weighted-average discount rate - finance leases 4.8 % 4.4 % The table below presents supplemental cash flow information related to leases during the year ended December 31 (in millions): 2021 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 977 $ 788 $ 902 Operating cash flows for finance leases 18 20 70 Financing cash flows for finance leases 216 66 151 Regional CPAs. United has contractual relationships with various regional carriers to provide regional aircraft service branded as United Express. Under these CPAs, the Company pays the regional carriers contractually agreed fees (carrier costs) for operating these flights plus a variable rate adjustment based on agreed performance metrics, subject to annual adjustments. The fees are based on specific rates multiplied by specific operating statistics (e.g., block hours, departures), as well as fixed monthly amounts. Under these CPAs, the Company is also responsible for all fuel costs incurred, as well as landing fees and other costs, which are either passed through by the regional carrier to the Company without any markup or directly incurred by the Company. In some cases, the Company owns some or all of the aircraft subject to the CPA and leases such aircraft to the regional carrier. United's CPAs are for 518 regional aircraft as of December 31, 2021, and the CPAs have terms expiring through 2036. Aircraft operated under CPAs include aircraft leased directly from the regional carriers and those owned by United and operated by the regional carriers. See Part I, Item 2. Properties, of this report for additional information. In September 2021, United entered into a new CPA with Republic for Republic to operate 38 Embraer E175LL aircraft on United's behalf starting in 2022 for a 12-year term. The new Embraer E175LL aircraft will replace the Embraer E170 aircraft currently being flown by Republic for United. United recorded approximately $0.6 billion, $0.6 billion and $1.0 billion in expenses related to its CPAs with its regional carriers in which United is a minority shareholder, for the years ended December 31, 2021, 2020 and 2019, respectively. There were approximately $102 million and $68 million in accounts payable due to these companies as of December 31, 2021 and December 31, 2020, respectively. There were no material accounts receivables due from these companies as of December 31, 2021 and December 31, 2020. The CPAs with these related parties were executed in the ordinary course of business. Our future commitments under our CPAs are dependent on numerous variables, and are, therefore, difficult to predict. The most important of these variables is the number of scheduled block hours. Although we are not required to purchase a minimum number of block hours under certain of our CPAs, we have set forth below estimates of our future payments under the CPAs based on our assumptions. United's estimates of its future payments under all of the CPAs do not include the portion of the underlying obligation for any aircraft leased to a regional carrier or deemed to be leased from other regional carriers and facility rent that are disclosed as part of operating leases above. For purposes of calculating these estimates, we have assumed (1) the number of block hours flown is based on our anticipated level of flight activity or at any contractual minimum utilization levels if applicable, whichever is higher, (2) that we will reduce the fleet as rapidly as contractually allowed under each CPA, (3) that aircraft utilization, stage length and load factors will remain constant, (4) that each carrier's operational performance will remain at recent historic levels and (5) an annual projected inflation rate. These amounts exclude variable pass-through costs such as fuel and landing fees, among others. Based on these assumptions as of December 31, 2021, our future payments through the end of the terms of our CPAs are presented in the table below (in billions): 2022 $ 2.1 2023 2.1 2024 2.0 2025 1.7 2026 1.5 After 2026 4.2 $ 13.6 The actual amounts we pay to our regional operators under CPAs could differ materially from these estimates. For example, a 10% increase or decrease in scheduled block hours for all of United's regional operators (whether as a result of changes in average daily utilization or otherwise) in 2022 would result in a corresponding change in annual cash obligations under the CPAs of approximately $125 million.

Variable Interest Entities ("VI

Variable Interest Entities ("VIE")	12 Months Ended
Variable Interest Entities ("VIE")	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities (VIE)	VARIABLE INTEREST ENTITIES ("VIE") Variable interests are contractual, ownership or other monetary interests in an entity that change with fluctuations in the fair value of the entity's net assets exclusive of variable interests. A VIE can arise from items such as lease agreements, loan arrangements, guarantees or service contracts. An entity is a VIE if (a) the entity lacks sufficient equity or (b) the entity's equity holders lack power or the obligation and right as equity holders to absorb the entity's expected losses or to receive its expected residual returns. If an entity is determined to be a VIE, the entity must be consolidated by the primary beneficiary. The primary beneficiary is the holder of the variable interests that has the power to direct the activities of a VIE that (i) most significantly impact the VIE's economic performance and (ii) has the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the VIE. Therefore, the Company must identify which activities most significantly impact the VIE's economic performance and determine whether it, or another party, has the power to direct those activities. Airport Leases . United is the lessee of real property under long-term operating leases at a number of airports where we are also the guarantor of approximately $2.1 billion of tax-exempt special facilities revenue bonds and interest thereon as of December 31, 2021. These leases are typically with municipalities or other governmental entities, which are excluded from the consolidation requirements concerning a VIE. To the extent United's leases and related guarantees are with a separate legal entity other than a governmental entity, United is not the primary beneficiary because the lease terms are consistent with market terms at the inception of the lease and the lease does not include a residual value guarantee, fixed-price purchase option, or similar feature. See Note 13 of this report for more information regarding United's guarantee of the tax-exempt special facilities revenue bonds. EETCs. United evaluated whether the pass-through trusts formed for its EETC financings, treated as either debt or aircraft operating leases, are VIEs required to be consolidated by United under applicable accounting guidance, and determined that the pass-through trusts are VIEs. Based on United's analysis as described below, United determined that it does not have a variable interest in the pass-through trusts. The primary risk of the pass-through trusts is credit risk (i.e. the risk that United, the issuer of the equipment notes, may be unable to make its principal and interest payments). The primary purpose of the pass-through trust structure is to enhance the credit worthiness of United's debt obligation through certain bankruptcy protection provisions, a liquidity facility (in certain of the EETC structures) and improved loan-to-value ratios for more senior debt classes. These credit enhancements lower United's total borrowing cost. Pass-through trusts are established to receive principal and interest payments on the equipment notes purchased by the pass-through trusts from United and remit these proceeds to the pass-through trusts' certificate holders. United does not invest in or obtain a financial interest in the pass-through trusts. Rather, United has an obligation to make interest and principal payments on its equipment notes held by the pass-through trusts. United does not intend to have any voting or non-voting equity interest in the pass-through trusts or to absorb variability from the pass-through trusts. Based on this analysis, the Company determined that it is not required to consolidate the pass-through trusts. ManaAir . United concluded that ManaAir is a VIE as of December 31, 2021. United holds a variable interest in ManaAir in the form of equity interest, but United is not the primary beneficiary because it does not have power to direct the activities that most significantly impact ManaAir's economic performance.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Commitments. As of December 31, 2021, United had firm commitments and options to purchase aircraft from The Boeing Company ("Boeing") and Airbus S.A.S. ("Airbus") presented in the table below: Scheduled Aircraft Deliveries Aircraft Type Number of Firm 2022 2023 After 2023 Airbus A321XLR 50 — — 50 Airbus A321neo 70 — 12 58 Airbus A350 45 — — 45 Boeing 737 MAX 367 53 109 205 Boeing 787 8 8 — — (a) United also has options and purchase rights for additional aircraft. The aircraft listed in the table above are scheduled for delivery through 2030. To the extent the Company and the aircraft manufacturers with whom the Company has existing orders for new aircraft agree to modify the contracts governing those orders, or to the extent rights are exercised pursuant to the relevant agreements to modify the timing of deliveries, the amount and timing of the Company's future capital commitments could change. The table below summarizes United's commitments as of December 31, 2021, which include aircraft and related spare engines, aircraft improvements and all non-aircraft capital commitments (in billions): 2022 $ 5.7 2023 6.9 2024 5.0 2025 4.3 2026 3.3 After 2026 8.9 $ 34.1 Legal and Environmental. The Company has certain contingencies resulting from litigation and claims incident to the ordinary course of business. As of December 31, 2021, management believes, after considering a number of factors, including (but not limited to) the information currently available, the views of legal counsel, the nature of contingencies to which the Company is subject and prior experience, that its defenses and assertions in pending legal proceedings have merit and t he ultimate disposition of any pending matter will not materially affect the Company's financial position, results of operations or cash flows. The Company records liabilities for legal and environmental claims when it is probable that a loss has been incurred and the amount is reasonably estimable. These amounts are recorded based on the Company's assessments of the likelihood of their eventual disposition. Guarantees and Indemnifications. In the normal course of business, the Company enters into numerous real estate leasing and aircraft financing arrangements that have various guarantees included in the contracts. These guarantees are primarily in the form of indemnities under which the Company typically indemnifies the lessors and any tax/financing parties against liabilities that arise out of or relate to the use, operation or maintenance of the leased premises or financed aircraft. Currently, the Company believes that any future payments required under these guarantees or indemnities would be immaterial, as most liabilities and related indemnities are covered by insurance (subject to deductibles). Additionally, certain real estate leases include indemnities for any environmental liability that may arise out of or relate to the use of the leased premises. As of December 31, 2021, United is the guarantor of approximately $2.1 billion in aggregate principal amount of tax-exempt special facilities revenue bonds and interest thereon. These bonds, issued by various airport municipalities, are payable solely from rentals paid under long-term agreements with the respective governing bodies. The leasing arrangements associated with these obligations are accounted for as operating leases recognized on the Company's consolidated balance sheet with the associated expense recorded on a straight-line basis over the expected lease term. The obligations associated with these tax-exempt special facilities revenue bonds are included in our lease commitments disclosed in Note 11 of this report. All of these bonds are due between 2023 and 2041. As of December 31, 2021, United is the guarantor of $106 million of aircraft mortgage debt issued by one of United's regional carriers. The aircraft mortgage debt is subject to similar increased cost provisions as described below for the Company's debt, and the Company would potentially be responsible for those costs under the guarantees. As of December 31, 2021, United had $371 million of surety bonds securing various insurance related obligations with expiration dates through 2025. Increased Cost Provisions. In United's financing transactions that include loans in which United is the borrower, United typically agrees to reimburse lenders for any reduced returns with respect to the loans due to any change in capital requirements and, in the case of loans with respect to which the interest rate is based on LIBOR, for certain other increased costs that the lenders incur in carrying these loans as a result of any change in law, subject, in most cases, to obligations of the lenders to take certain limited steps to mitigate the requirement for, or the amount of, such increased costs. At December 31, 2021, the Company had $13.2 billion of floating rate debt with remaining terms of up to 11 years that are subject to these increased cost provisions. In several financing transactions involving loans or leases from non-U.S. entities, with remaining terms of up to 11 years and an aggregate balance of $10.1 billion, the Company bears the risk of any change in tax laws that would subject loan or lease payments thereunder to non-U.S. entities to withholding taxes, subject to customary exclusions. Fuel Consortia. United participates in numerous fuel consortia with other air carriers at major airports to reduce the costs of fuel distribution and storage. Interline agreements govern the rights and responsibilities of the consortia members and provide for the allocation of the overall costs to operate the consortia based on usage. The consortia (and in limited cases, the participating carriers) have entered into long-term agreements to lease certain airport fuel storage and distribution facilities that are typically financed through tax-exempt bonds, either special facilities lease revenue bonds or general airport revenue bonds, issued by various local municipalities. In general, each consortium lease agreement requires the consortium to make lease payments in amounts sufficient to pay the maturing principal and interest payments on the bonds. As of December 31, 2021, approximately $1.8 billion principal amount of such bonds were secured by significant fuel facility leases in which United participates, as to which United and each of the signatory airlines has provided indirect guarantees of the debt. As of December 31, 2021, the Company's contingent exposure was approximately $343 million principal amount of such bonds based on its recent consortia participation. The Company's contingent exposure could increase if the participation of other air carriers decreases. The guarantees will expire when the tax-exempt bonds are paid in full, which ranges from 2022 to 2056. The Company concluded it was not necessary to record a liability for these indirect guarantees. Regional Capacity Purchase. As of December 31, 2021, United had 251 call options to purchase regional jet aircraft being operated by certain of its regional carriers with contract dates extending until 2029. These call options are exercisable upon wrongful termination or breach of contract, among other conditions. Credit Card Processing Agreements. The Company has agreements with financial institutions that process customer credit card transactions for the sale of air travel and other services. Under certain of the Company's credit card processing agreements, the financial institutions in certain circumstances have the right to require that the Company maintain a reserve equal to a portion of advance ticket sales that has been processed by that financial institution, but for which the Company has not yet provided the air transportation. Such financial institutions may require additional cash or other collateral reserves to be established or additional withholding of payments related to receivables collected if the Company does not maintain certain minimum levels of unrestricted cash, cash equivalents and short-term investments (collectively, "Unrestricted Liquidity"). The Company's current level of Unrestricted Liquidity is substantially in excess of these minimum levels. Labor Negotiations. As of December 31, 2021, United, including its subsidiaries, had approximately 84,100 employees. Approximately 85% of United's employees were represented by various U.S. labor organizations. This total includes employees who elected to voluntarily separate from the Company pursuant to the Voluntary Programs but who are still on pre-separation leave of absence with pay and benefits.

Special Charges (Credits) and U

Special Charges (Credits) and Unrealized (Gains) Losses on Investments	12 Months Ended
	Dec. 31, 2021
Restructuring and Related Activities [Abstract]
SPECIAL CHARGES (CHARGES) AND UNREALIZED (GAINS) LOSSES ON INVESTMENTS	SPECIAL CHARGES (CREDITS) AND UNREALIZED (GAINS) LOSSES ON INVESTMENTS Special charges (credits) and unrealized (gains) and losses on investments in the statements of consolidated operations consisted of the following for the years ended December 31 (in millions): Operating: 2021 2020 2019 CARES Act grant $ (4,021) $ (3,536) $ — Severance and benefit costs 438 575 16 Impairment of assets 97 318 171 (Gains) losses on sale of assets and other special charges 119 27 59 Total operating special charges (credits) (3,367) (2,616) 246 Nonoperating unrealized (gains) losses on investments, net 34 194 (153) Nonoperating debt extinguishment and modification fees 50 — — Nonoperating special termination benefits and settlement losses 31 687 — Nonoperating credit loss on BRW Term Loan and related guarantee — 697 — Total nonoperating special charges and unrealized (gains) losses on investments, net 115 1,578 (153) Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net (3,252) (1,038) 93 Income tax expense (benefit), net of valuation allowance 728 404 (21) Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net of income taxes $ (2,524) $ (634) $ 72 2021 CARES Act grant. During 2021, the Company received approximately $5.8 billion in funding pursuant to the PSP2 Agreement and the PSP3 Agreement, which included an approximately $1.7 billion unsecured loan . The Company recorded $4.0 billion as grant income in Special charges (credits). The Company also recorded $99 million for the PSP2 Warrants and PSP3 Warrants issued to Treasury as part of the PSP2 Agreement and PSP3 Agreement, within stockholders' equity, as an offset to the grant income. Severance and benefit costs . During 2021, the Company recorded $438 million of charges related to pay continuation and benefits-related costs provided to employees who chose to voluntarily separate from the Company. The Company offered, based on employee group, age and completed years of service, pay continuation, health care coverage, and travel benefits. Approximately 4,500 employees elected to voluntarily separate from the Company. Impairment of assets . During 2021, the Company recorded the following impairment charges: • $61 million, primarily comprised of impairment charges for 13 Airbus A319 aircraft and 13 Boeing 737-700 airframes as a result of current market conditions for used aircraft, along with charges for cancelled induction projects related to these aircraft. These aircraft are all considered held for sale and classified as part of other assets. • $36 million of impairments related to 64 Embraer EMB 145LR aircraft and related spare engines that United retired from its regional fleet. The decision to retire these aircraft was triggered by the United Next aircraft order. Almost all of these aircraft are classified as held for sale. (Gains) losses on sale of assets and other special charges. During 2021, the Company recorded net charges of $119 million primarily related to a one-time bonus paid to employees for their continued efforts during the COVID-19 pandemic, incentives for its employees to receive a COVID-19 vaccination and the termination of the lease associated with three floors of its headquarters at the Willis Tower in Chicago, partially offset by gains primarily related to the sale of its former headquarters in suburban Chicago, aircraft sale-leaseback transactions and aircraft component manufacturer credits. Nonoperating unrealized (gains) losses on investments, net . During 2021, the Company recorded losses of $34 million primarily for the change in the market value of its investments in equity securities. Nonoperating debt extinguishment and modification fees. During 2021, the Company recorded $50 million of charges for fees and discounts related to the entry into the 2021 Loan Facilities and the prepayment of the 2017 Loan Facilities. Nonoperating special termination benefits and settlement losses. During 2021, as part of the first quarter Voluntary Programs, the Company recorded $31 million of special termination benefits in the form of additional subsidies for retiree medical costs for certain U.S.-based front-line employees. The subsidies were in the form of a one-time contribution to a notional Retiree Health Account of $125,000 for full-time employees and $75,000 for part-time employees. See Note 7 of this report for additional information. 2020 CARES Act grant. During 2020, the Company received approximately $5.1 billion in funding pursuant to the Payroll Support Program under the CARES Act, which consisted of a $3.6 billion grant and a $1.5 billion unsecured loan. The Company recorded $3.5 billion as grant income in Special charges (credits). The Company also recorded $66 million for warrants issued to Treasury, within stockholders' equity, as an offset to the grant income. Severance and benefit costs . During 2020, the Company recorded $575 million related to its workforce reduction and voluntary plans for employee severance, pay continuance from voluntary retirements and benefits-related costs. Impairment of assets . During 2020, the Company recorded the following impairment charges: • $130 million for its China routes which were primarily caused by the COVID-19 pandemic, the Company's subsequent suspension of flights to China and a further delay in the expected return of full capacity to the China markets. • $94 million related to 11 permanently-grounded Boeing 757-200 aircraft and the related engines and spare parts. • $38 million related to the right-of-use asset associated with the embedded aircraft lease in one of the Company's CPAs. This impairment was primarily due to the impact to cash flows from the pandemic and the relatively short remaining term under the CPA. • $56 million related to various cancelled facility, aircraft induction and information technology capital projects. The decisions driving these impairments were the result of the COVID-19 pandemic's impact on the Company's operations. (Gains) losses on sale of assets and other special charges. During 2020, the Company recorded losses on certain asset sales and charges for legal reserves, partially offset by gains on aircraft sale-leaseback transactions. Nonoperating unrealized gains (losses) on investments, net. During 2020, the Company recorded losses of $194 million primarily for changes in the fair value of its investments in equity securities. Nonoperating special termination benefits and settlement losses. During 2020, the Company recorded $687 million of settlement losses related to the Company's primary defined benefit pension plan covering certain U.S. non-pilot employees, and special termination benefits offered, under Voluntary Programs. See Note 7 of this report for additional information. Nonoperating credit loss on BRW Term Loan and related guarantee. During 2020, the Company recorded a $697 million expected credit loss allowance for the BRW Term Loan and related guarantee. See Note 8 of this report for additional information. 2019 Severance and benefit costs . During 2019, the Company recorded $14 million of management severance and $2 million of severance and benefit costs related to a voluntary early-out program for its technicians and related employees represented by the International Brotherhood of Teamsters. Impairment of assets. During 2019, the Company recorded a $90 million impairment charge associated with its Hong Kong routes. The Company determined the fair value of the Hong Kong routes using a variation of the income approach known as the excess earnings method, which discounts an asset's projected future net cash flows to determine the current fair value. Also during 2019, the Company recorded a $43 million impairment primarily for surplus Boeing 767 aircraft engines removed from operations, an $18 million charge primarily for the write-off of unexercised aircraft purchase options, and $20 million in other aircraft impairments. (Gains) losses on sale of assets and other special charges. During 2019, the Company recorded charges of $25 million related to contract terminations, $18 million for the settlement of certain legal matters, $14 million for costs related to the transition of fleet types within a regional carrier contract and $2 million of other charges. Nonoperating unrealized gains (losses) on investments, net. During 2019, the Company recorded gains of $153 million primarily for the change in market value of certain of its equity investments.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
Schedule II - Valuation and Qualifying Accounts	Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	Schedule II Valuation and Qualifying Accounts For the Years Ended December 31, 2021, 2020 and 2019 (In millions) Description Balance at Additions Deductions Other Balance at Allowance for credit losses - receivables: 2021 $ 78 $ 3 $ 53 $ — $ 28 2020 9 70 16 15 78 2019 8 17 16 — 9 Obsolescence allowance—spare parts: 2021 $ 478 $ 79 $ 11 $ — $ 546 2020 425 88 35 — 478 2019 412 76 63 — 425 Allowance for credit losses - notes receivable: 2021 $ 522 $ 1 $ — $ 99 $ 622 2020 — 518 — 4 522 Valuation allowance for deferred tax assets: 2021 $ 247 $ (38) $ — $ 1 $ 210 2020 58 197 8 — 247 2019 59 — 1 — 58

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2021
Accounting Policies [Abstract]
Use of Estimates	Use of Estimates— The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America ("GAAP") requires management to make estimates and assumptions that affect the amounts reported in these financial statements and accompanying notes. Actual results could differ from those estimates.
Revenue Recognition	Revenue Recognitio n— Passenger revenue is recognized when transportation is provided and Cargo revenue is recognized when shipments arrive at their destination. Other operating revenue is recognized as the related performance obligations are satisfied. Passenger tickets and related ancillary services sold by the Company for flights are purchased primarily via credit card transactions, with payments collected by the Company in advance of the performance of related services. The Company initially records ticket sales in its Advance ticket sales liability, deferring revenue recognition until the travel occurs. For travel that has more than one flight segment, the Company deems each segment as a separate performance obligation and recognizes revenue for each segment as travel occurs. Tickets sold by other airlines where the Company provides the transportation are recognized as passenger revenue at the estimated value to be billed to the other airline when travel is provided. Differences between amounts billed and the actual amounts may be rejected and rebilled or written off if the amount recorded was different from the original estimate. When necessary, the Company records a reserve against its billings and payables with other airlines based on historical experience. The Company sells certain tickets with connecting flights with one or more segments operated by its other airline partners. For segments operated by its other airline partners, the Company has determined that it is acting as an agent on behalf of the other airlines as they are responsible for their portion of the contract (i.e. transportation of the passenger). The Company, as the agent, recognizes revenue within Other operating revenue at the time of the travel for the net amount representing commission to be retained by the Company for any segments flown by other airlines. Refundable tickets expire after one year from the date of issuance. Non-refundable tickets generally expire on the date of the intended travel, unless the date is extended by notification from the customer on or before the intended travel date. United initially capitalizes the costs of selling airline travel tickets and then recognizes those costs as Distribution expense at the time of travel. Passenger ticket costs include credit card fees, travel agency and other commissions paid, as well as global distribution systems booking fees. Advance Ticket Sales. Advance ticket sales represent the Company's liability to provide air transportation in the future. All tickets sold at any given point of time have travel dates extending up to 12 months. The Company defers amounts related to future travel in its Advance ticket sales liability account. The Company's Advance ticket sales liability also includes credits issued to customers on electronic travel certificates ("ETCs") and future flight credits ("FFCs"), primarily for ticket cancellations, which can be applied towards a purchase of a new ticket. ETCs are valid up to two years from the date of issuance; however, all ETCs due to expire prior to December 31, 2022 have been extended until December 31, 2022. FFCs are valid for 12 months from the original ticket date; however, all FFCs issued on or before December 31, 2021 have been extended to be valid until December 31, 2022. As of December 31, 2021, the Company's Advance ticket sales liability included $3.2 billion related to ETCs and FFCs. The Company estimates the value of Advance ticket sales that will expire unused ("breakage") and recognizes revenue at the scheduled flight date. To determine breakage, the Company uses its historical experience with expired tickets and other facts, such as recent aging trends, program changes and modifications that could affect the ultimate expiration patterns of tickets. Given the uncertainty of travel demand caused by COVID-19, a significant portion of the ETCs and FFCs may expire unused in future periods and get recognized as revenue from breakage. The Company will update its breakage estimates as future information is received. Changes in estimates of breakage are recognized prospectively in proportion to the remaining usage of the related tickets. In the years ended December 31, 2021, 2020 and 2019, the Company recognized approximately $1.8 billion, $3.0 billion and $3.4 billion, respectively, of passenger revenue for tickets that were included in Advance ticket sales at the beginning of those periods. Revenue by Geography. The Company further disaggregates revenue by geographic regions. Operating segments are defined as components of an enterprise with separate financial information, which are evaluated regularly by the chief operating decision maker and are used in resource allocation and performance assessments. The Company deploys its aircraft across its route network through a single route scheduling system to maximize its value. When making resource allocation decisions, the Company's chief operating decision maker evaluates flight profitability data, which considers aircraft type and route economics. The Company's chief operating decision maker makes resource allocation decisions to maximize the Company's consolidated financial results. Managing the Company as one segment allows management the opportunity to maximize the value of its route network. Ancillary Fees.
Ticket Taxes	Ticket Taxes— Certain governmental taxes are imposed on the Company's ticket sales through a fee included in ticket prices. The Company collects these fees and remits them to the appropriate government agency. These fees are recorded on a net basis and, as a result, are excluded from revenue.
Frequent Flyer Accounting	Frequent Flyer Accounting— United's MileagePlus loyalty program builds customer loyalty by offering awards, benefits and services to program participants. Members in this program earn miles for travel on United, United Express, Star Alliance members and certain other airlines that participate in the program. Members can also earn miles by purchasing goods and services from our network of non-airline partners. We have contracts to sell miles to these partners with the terms extending from one Miles Earned in Conjunction with Travel. When frequent flyers earn miles for flights, the Company recognizes a portion of the ticket sales as revenue when the travel occurs and defers a portion of the ticket sale representing the value of the related miles as a separate performance obligation. The Company determines the estimated selling price of travel and miles as if each element is sold on a separate basis. The total consideration from each ticket sale is then allocated to each of these elements, individually, on a pro-rata basis. At the time of travel, the Company records the portion allocated to the miles to Frequent flyer deferred revenue on the Company's consolidated balance sheet and subsequently recognizes it into revenue when miles are redeemed for air travel and non-air travel awards. Estimated Selling Price of Miles . The Company's estimated selling price of miles is based on an equivalent ticket value, which incorporates the expected redemption of miles, as the best estimate of selling price for these miles. The equivalent ticket value is based on the prior 12 months' weighted average equivalent ticket value of similar fares as those used to settle award redemptions while taking into consideration such factors as redemption pattern, cabin class, loyalty status and geographic region. The estimated selling price of miles is adjusted by breakage that considers a number of factors, including redemption patterns of various customer groups. Estimate of Miles Not Expected to be Redeemed ("Breakage") . The Company's breakage model is based on the assumption that the likelihood that an account will redeem its miles can be estimated based on a consideration of the account's historical behavior. The Company uses a logit regression model to estimate the probability that an account will redeem its current miles balance. The Company reviews its breakage estimates annually based upon the latest available information. The Company's estimate of the expected breakage of miles requires management judgment and current and future changes to breakage assumptions, or to program rules and program redemption opportunities, may result in material changes to the deferred revenue balance as well as recognized revenues from the program. For the portion of the outstanding miles that we estimate will not be redeemed, we recognize the associated value proportionally as the remaining miles are redeemed. Co-Brand Agreement . United has a contract (the "Co-Brand Agreement") to sell MileagePlus miles to its co-branded credit card partner JPMorgan Chase Bank USA, N.A. ("Chase"). Chase awards miles to MileagePlus members based on their credit card activity. United identified the following significant separately identifiable performance obligations in the Co-Brand Agreement: • MileagePlus miles awarded – United has a performance obligation to provide MileagePlus cardholders with miles to be used for air travel and non-travel award redemptions. The Company records Passenger revenue related to the travel awards when the transportation is provided and records Other revenue related to the non-travel awards when the goods or services are delivered. The Company records the cost associated with non-travel awards in Other operating revenue, as an agent. • Marketing – United has a performance obligation to provide Chase access to United's customer list and the use of United's brand. Marketing revenue is recorded to Other operating revenue as miles are delivered to Chase. • Advertising – United has a performance obligation to provide advertising in support of the MileagePlus card in various customer contact points such as United's website, email promotions, direct mail campaigns, airport advertising and in-flight advertising. Advertising revenue is recorded to Other operating revenue as miles are delivered to Chase. • Other travel-related benefits – United's performance obligations are comprised of various items such as waived bag fees, seat upgrades and lounge passes. Lounge passes are recorded to Other operating revenue as customers use the lounge passes. Bag fees and seat upgrades are recorded to Passenger revenue at the time of the associated travel. We account for all the payments received under the Co-Brand Agreement by allocating them to the separately identifiable performance obligations. The fair value of the separately identifiable performance obligations is determined using management's estimated selling price of each component. The objective of using the estimated selling price based methodology is to determine the price at which we would transact a sale if the product or service were sold on a stand-alone basis. Accordingly, we determine our best estimate of selling price by considering multiple inputs and methods including, but not limited to, discounted cash flows, brand value, volume discounts, published selling prices, number of miles awarded and number of miles redeemed. The Company estimated the selling prices and volumes over the term of the Co-Brand Agreement in order to determine the allocation of proceeds to each of the components to be delivered. We also evaluate volumes on an annual basis, which may result in a change in the allocation of the estimated consideration from the Co-Brand Agreement on a prospective basis.
Cash and Cash Equivalents and Restricted Cash	Cash and Cash Equivalents and Restricted Cash— Highly liquid investments with a maturity of three months or less on their acquisition date are classified as cash and cash equivalents. Restricted cash is classified as short-term or long-term in the consolidated balance sheets based on the expected timing of return of the assets to the Company or payment to an outside party. Restricted cash-current— The December 31, 2021 balance includes amounts to be used for the payment of fees, principal and interest on the $6.8 billion of senior secured notes and a secured term loan facility (the "MileagePlus Financing") secured by substantially all of the assets of Mileage Plus Holdings, LLC ("MPH"), a direct wholly-owned subsidiary of United. Restricted cash-non-current— The December 31, 2021 balance primarily includes collateral associated with the MileagePlus Financing, collateral for letters of credit and collateral associated with facility leases and other insurance-related obligations.
Investments	Investments— Debt investments are classified as available-for-sale and are stated at fair value. Realized gains and losses on sales of these investments are reflected in Miscellaneous, net in the consolidated statements of operations. Unrealized gains and losses on available-for-sale securities are reflected as a component of accumulated other comprehensive income (loss). Equity investments are accounted for under the equity method if we are able to exercise significant influence over an investee. Equity investments for which we do not have significant influence are recorded at fair value or at cost, if fair value is not readily determinable, with adjustments for observable changes in
Accounts Receivable	Accounts Receivable—Accounts receivable primarily consist of amounts due from credit card companies, non-airline partners, and cargo customers. We provide an allowance for credit losses expected to be incurred. We base our allowance on various factors including, but not limited to, aging, payment history, write-offs, macro-economic indicators and other credit monitoring indicators.
Aircraft Fuel, Spare Parts and Supplies	Aircraft Fuel, Spare Parts and Supplies— The Company accounts for aircraft fuel, spare parts and supplies at average cost and provides an obsolescence allowance for aircraft spare parts with an assumed residual value of 10% of original cost.
Property and Equipment	Property and Equipment— The Company records additions to owned operating property and equipment at cost when acquired. Property under finance leases and the related obligation for future lease payments are recorded at an amount equal to the initial present value of those lease payments. Modifications that enhance the operating performance or extend the useful lives of airframes or engines are capitalized as property and equipment. We periodically receive credits in connection with the acquisition of aircraft and engines including those related to contractual damages related to delays in delivery. These credits are deferred until the aircraft and engines are delivered and then applied as a reduction to the cost of the related equipment.
Long-Lived Asset Impairments	Long-Lived Asset Impairments— The Company evaluates the carrying value of long-lived assets subject to amortization whenever events or changes in circumstances indicate that an impairment may exist. For purposes of this testing, the Company has generally identified the aircraft fleet type as the lowest level of identifiable cash flows for its mainline fleet and the contract level for its regional fleet under capacity purchase agreements ("CPAs"). An impairment charge is recognized when the asset's carrying value exceeds its net undiscounted future cash flows. The amount of the charge is the difference between the asset's carrying value and fair market value.
Intangibles	Intangibles— The Company has finite-lived and indefinite-lived intangible assets, including goodwill. Finite-lived intangible assets are amortized over their estimated useful lives. Goodwill and indefinite-lived intangible assets are not amortized but are reviewed for impairment on an annual basis as of October 1, or more frequently if events or circumstances indicate that the asset may be impaired.
Labor Costs	Labor Costs— The Company records expenses associated with new or amendable labor agreements when the amounts are probable and estimable. These include costs associated with lump sum cash payments that would be made in conjunction with the ratification of labor agreements. To the extent these upfront costs are in lieu of future pay
Share-Based Compensation	Share-Based Compensation— The Company measures the cost of employee services received in exchange for an award of equity instruments based on the grant date fair value of the award. The resulting cost is recognized over the period during which an employee is required to provide service in exchange for the award, usually the vesting period. Obligations for cash-settled restricted stock units ("RSUs") are remeasured at fair value throughout the requisite service period at the close of the reporting period based upon UAL's stock price. In addition to the service requirement, certain RSUs have performance metrics that must be achieved prior to vesting. These awards are accrued based on the expected level of achievement at each reporting period. An adjustment is recorded each reporting period to adjust compensation expense based on the then current level of expected performance achievement for the performance-based awards. See Note 4 of this report for additional information on UAL's share-based compensation plans.
Maintenance and Repairs	Maintenance and Repairs— The cost of maintenance and repairs, including the cost of minor replacements, is charged to expense as incurred, except for costs incurred under our power-by-the-hour ("PBTH") engine maintenance agreements. PBTH contracts transfer certain risk to third-party service providers and fix the amount we pay per flight hour or per cycle to the service provider in exchange for maintenance and repairs under a predefined maintenance program. Under PBTH agreements, the Company recognizes expense at a level rate per engine hour, unless the level of service effort and the related payments during the period are substantially consistent, in which case the Company recognizes expense based on the amounts paid.
Advertising	Advertising—Advertising costs, which are included in Other operating expenses, are expensed as incurred.
Third-Party Business	Third-Party Business— The Company has third-party business revenue that includes ground handling, maintenance services, flight academy and frequent flyer award non-travel redemptions. Third-party business revenue is recorded in Other operating revenue. Expenses associated with these third-party business activities are recorded in Other operating expenses, except for non-travel mileage redemption. Non-travel mileage redemption expenses are recorded to Other operating revenue.
Uncertain Income Tax Positions	Uncertain Income Tax Positions—The Company has recorded reserves for income taxes and associated interest that may become payable in future years. Although management believes that its positions taken on income tax matters are reasonable, the Company nevertheless established tax and interest reserves in recognition that various taxing authorities may challenge certain of the positions taken by the Company, potentially resulting in additional liabilities for taxes and interest. The Company's uncertain tax position reserves are reviewed periodically and are adjusted as events occur that affect its estimates, such as the availability of new information, the lapsing of applicable statutes of limitation, the conclusion of tax audits, the measurement of additional estimated liability, the identification of new tax matters, the release of administrative tax guidance affecting its estimates of tax liabilities, or the rendering of relevant court decisions. The Company records penalties and interest relating to uncertain tax positions as part of income tax expense in its consolidated statements of operations.
Fair Value Information	Accounting standards require us to use valuation techniques to measure fair value that maximize the use of observable inputs and minimize the use of unobservable inputs. These inputs are prioritized as follows: Level 1 Unadjusted quoted prices in active markets for assets or liabilities identical to those to be reported at fair value Level 2 Other inputs that are observable directly or indirectly, such as quoted prices for similar assets or liabilities or market-corroborated inputs Level 3 Unobservable inputs for which there is little or no market data and which require us to develop our own assumptions about how market participants would price the assets or liabilities Assets and liabilities measured at fair value are based on the valuation techniques identified in the tables below. The valuation techniques are as follows: (a) Market approach. Prices and other relevant information generated by market transactions involving identical or comparable assets and liabilities; and (b) Income approach. Techniques to convert future amounts to a single current value based on market expectations (including present value techniques, option-pricing and excess earnings models).

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	12 Months Ended
Significant Accounting Policies (Tables)	Dec. 31, 2021
Accounting Policies [Abstract]
Operating Revenue by Principal Geographic Region	The Company's operating revenue by principal geographic region (as defined by the U.S. Department of Transportation) for the years ended December 31 is presented in the table below (in millions): 2021 2020 2019 Domestic (U.S. and Canada) $ 16,845 $ 9,911 $ 26,960 Atlantic 3,414 2,226 7,387 Pacific 1,507 1,706 5,132 Latin America 2,868 1,512 3,780 Total $ 24,634 $ 15,355 $ 43,259
Roll Forward of Frequent Flyer Deferred Revenue	The table below presents a roll forward of Frequent flyer deferred revenue (in millions): Twelve Months Ended 2021 2020 Total Frequent flyer deferred revenue - beginning balance $ 5,975 $ 5,276 Total miles awarded 1,545 1,336 Travel miles redeemed (Passenger revenue) (1,171) (568) Non-travel miles redeemed (Other operating revenue) (67) (69) Total Frequent flyer deferred revenue - ending balance $ 6,282 $ 5,975
Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the statements of consolidated cash flows (in millions): UAL United At December 31, At December 31, 2021 2020 2019 2021 2020 2019 Current assets: Cash and cash equivalents $ 18,283 $ 11,269 $ 2,762 $ 18,283 $ 11,269 $ 2,756 Restricted cash 37 255 — 37 255 — Other assets: Restricted cash 213 218 106 213 218 106 Total cash, cash equivalents and restricted cash shown in the statement of consolidated cash flows $ 18,533 $ 11,742 $ 2,868 $ 18,533 $ 11,742 $ 2,862
Reconciliation of Cash, Cash Equivalents and Restricted Cash	The following table provides a reconciliation of cash, cash equivalents and restricted cash reported within the consolidated balance sheets that sum to the total of the same such amounts shown in the statements of consolidated cash flows (in millions): UAL United At December 31, At December 31, 2021 2020 2019 2021 2020 2019 Current assets: Cash and cash equivalents $ 18,283 $ 11,269 $ 2,762 $ 18,283 $ 11,269 $ 2,756 Restricted cash 37 255 — 37 255 — Other assets: Restricted cash 213 218 106 213 218 106 Total cash, cash equivalents and restricted cash shown in the statement of consolidated cash flows $ 18,533 $ 11,742 $ 2,868 $ 18,533 $ 11,742 $ 2,862
Estimated Useful Lives of Property and Equipment	The estimated useful lives of property and equipment are as follows: Estimated Useful Life (in years) Aircraft, spare engines and related rotable parts 25 to 30 Aircraft seats 10 to 15 Buildings 25 to 45 Other property and equipment 3 to 15 Computer software 5 to 15 Building improvements 1 to 40
Information about Goodwill and Other Intangible Assets	The following table presents information about the Company's goodwill and other intangible assets at December 31 (in millions): 2021 2020 Gross Accumulated Gross Accumulated Goodwill $ 4,527 $ 4,527 Indefinite-lived intangible assets Route authorities $ 1,020 $ 1,020 Airport slots 574 560 Tradenames and logos 593 593 Alliances 404 404 Total $ 2,591 $ 2,577 Finite-lived intangible assets Frequent flyer database $ 1,177 $ 1,008 $ 1,177 $ 971 Hubs 145 118 145 111 Contracts 120 120 120 116 Other 314 298 314 297 Total $ 1,756 $ 1,544 $ 1,756 $ 1,495

Common Stockholders' Equity a_2

Common Stockholders' Equity and Preferred Securities (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Summary of Warrants Outstanding	As of December 31, 2021 , the Company had the following warrants outstanding: Warrant Description Number of Shares of UAL Common Stock (in millions) Exercise Price Expiration Dates PSP1 Warrants (a) 4.8 $ 31.50 4/20/2025 — 9/30/2025 CARES Act Loan Warrants (b) 1.7 31.50 9/28/2025 PSP2 Warrants 2.0 43.26 1/15/2026 — 4/29/2026 PSP3 Warrants 1.5 53.92 4/29/2026 — 6/10/2026 Total 10.0 (a) Warrants issued in fiscal year 2020 in connection with the $1.5 billion 10-year senior unsecured promissory note with Treasury provided under the Payroll Support Program of the CARES Act ("PSP1 Note"). (b) Warrants issued in fiscal year 2020 in connection with the $520 million Loan and Guarantee Agreement, dated as of September 28, 2020, among United, UAL, Treasury and the Bank of New York Mellon, as administrative agent, as amended (the "CARES Act Loan"), which was entered into pursuant to the loan program established pursuant to the CARES Act.

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
Earnings (Loss) Per Share (Tables)	Dec. 31, 2021
Earnings Per Share [Abstract]
Computation of Earnings Per Share	The computations of UAL's basic and diluted earnings (loss) per share are set forth below for the years ended December 31 (in millions, except per share amounts): 2021 2020 2019 Earnings (loss) available to common stockholders $ (1,964) $ (7,069) $ 3,009 Basic weighted-average shares outstanding 321.9 279.4 258.8 Dilutive effect of employee stock awards — — 1.1 Diluted weighted-average shares outstanding 321.9 279.4 259.9 Earnings (loss) per share, basic $ (6.10) $ (25.30) $ 11.63 Earnings (loss) per share, diluted $ (6.10) $ (25.30) $ 11.58 Potentially dilutive securities (a) Stock warrants 0.9 — — Employee stock awards 0.7 1.0 0.1 (a) Weighted-average potentially dilutive securities outstanding excluded from the computation of diluted earnings per share because the securities would have had an antidilutive effect.

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	12 Months Ended
Share-Based Compensation Plans (Tables)	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Information Related to Share-Based Compensation Plan Cost	The following table provides information related to UAL's share-based compensation plan cost for the years ended December 31 (in millions): 2021 2020 2019 Compensation cost: RSUs $ 236 $ 106 $ 98 Stock options 2 2 1 RSAs — — 1 Total $ 238 $ 108 $ 100
Summary of Unearned Compensation and Weighted-Average Remaining Period to Recognize Costs	The table below summarizes UAL's unearned compensation and weighted-average remaining period to recognize costs for all outstanding share-based awards that are probable of being achieved as of December 31, 2021 (in millions, except as noted): Unearned Compensation Weighted-Average RSUs $ 60 0.7 Stock options 6 3.9 Total $ 66
Summary of RSU and Restricted Stock Activity	The table below summarizes UAL's RSU activity for the years ended December 31 (shares in millions): Liability Awards Equity Awards RSUs RSUs Weighted- Outstanding at December 31, 2018 1.9 1.8 $ 66.29 Granted 0.1 1.1 86.72 Vested (0.5) (0.8) 64.85 Forfeited (0.9) (0.1) 76.48 Outstanding at December 31, 2019 0.6 2.0 78.03 Granted 0.1 2.4 40.80 Vested (0.3) (0.8) 74.54 Forfeited — (0.4) 54.21 Outstanding at December 31, 2020 0.4 3.2 53.41 Granted 0.4 2.9 52.18 Vested (0.6) (1.5) 51.35 Forfeited — (0.2) 46.77 Outstanding at December 31, 2021 0.2 4.4 53.63

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
Accumulated Other Comprehensive Income (Loss) (Tables)	Dec. 31, 2021
Equity [Abstract]
Components of AOCI	The tables below present the components of the Company's AOCI, net of tax (in millions): Pension and Investments and Other Deferred Taxes (a) Total Balance at December 31, 2018 $ (663) $ (4) $ (136) $ (803) Change in value 105 7 (24) 88 Amounts reclassified to earnings (2) (b) (1) — (3) Balance at December 31, 2019 (560) 2 (160) (718) Change in value (993) — 221 (772) Amounts reclassified to earnings 451 (b) — (100) 351 Balance at December 31, 2020 (1,102) 2 (39) (1,139) Change in value 239 (2) (53) 184 Amounts reclassified to earnings 16 (b) — (3) 13 Balance at December 31, 2021 $ (847) $ — $ (95) $ (942) (a) Relates primarily to pension and other postretirement benefit liabilities and includes approximately $285 million of deferred income tax expense that will not be recognized in net income until these obligations are fully extinguished. We consider all income sources, including other comprehensive income, in determining the amount of tax benefit allocated to results from operations. (b) This AOCI component is included in the computation of net periodic pension and other postretirement costs. See Note 7 of this report for additional information on pensions and other postretirement liabilities.

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Tax Provision (Benefit) Differed from Amounts Computed at the Statutory Federal Income Tax Rate and Significant Components	The income tax provision (benefit) differed from amounts computed at the statutory federal income tax rate and consisted of the following significant components (in millions) : UAL and United 2021 2020 2019 Income tax provision (benefit) at statutory rate $ (537) $ (1,852) $ 822 State income tax provision (benefit), net of federal income tax benefit (34) (110) 50 Foreign tax rate differential — — (90) Global intangible low-taxed income — — 90 Nondeductible employee meals 7 5 12 Valuation allowance (38) 197 (4) Other, net 9 7 25 $ (593) $ (1,753) $ 905 Current $ (10) $ (12) $ 23 Deferred (583) (1,741) 882 $ (593) $ (1,753) $ 905
Temporary Differences and Carryforwards Giving Rise to Deferred Tax Assets and Liabilities	Temporary differences and carryforwards that give rise to deferred tax assets and liabilities at December 31, 2021 and 2020 were as follows (in millions): UAL United 2021 2020 2021 2020 Deferred income tax asset (liability): Federal and state net operating loss ("NOL") carryforwards $ 2,229 $ 2,476 $ 2,201 $ 2,448 Deferred revenue 2,349 1,409 2,349 1,409 Employee benefits, including pension, postretirement and medical 986 1,103 986 1,103 Operating lease liabilities 1,272 1,247 1,272 1,247 Other financing liabilities 327 260 327 260 Other 535 362 535 362 Less: Valuation allowance (210) (247) (210) (247) Total deferred tax assets $ 7,488 $ 6,610 $ 7,460 $ 6,582 Depreciation $ (5,122) $ (4,789) $ (5,122) $ (4,789) Operating lease right-of-use asset (1,051) (1,028) (1,051) (1,028) Intangibles (656) (662) (656) (662) Total deferred tax liabilities $ (6,829) $ (6,479) $ (6,829) $ (6,479) Net deferred tax asset $ 659 $ 131 $ 631 $ 103

Pension and Other Postretirem_2

Pension and Other Postretirement Plans (Tables)	12 Months Ended
Pension and Other Postretirement Plans (Tables)	Dec. 31, 2021
Retirement Benefits [Abstract]
Reconciliation of the Change in Benefit Obligation and Plan Assets and Funded Status	The following tables set forth the reconciliation of the beginning and ending balances of the benefit obligation and plan assets, the funded status and the amounts recognized in these financial statements for the defined benefit and other postretirement plans (in millions): Pension Benefits Year Ended December 31, 2021 Year Ended December 31, 2020 Accumulated benefit obligation: $ 5,496 $ 5,387 Change in projected benefit obligation: Projected benefit obligation at beginning of year $ 6,525 $ 6,398 Service cost 239 216 Interest cost 184 209 Actuarial (gain) loss (188) 1,181 Special termination benefit — 54 Benefits paid (263) (1,445) Curtailment (12) (105) Other (12) 17 Projected benefit obligation at end of year $ 6,473 $ 6,525 Change in plan assets: Fair value of plan assets at beginning of year $ 4,069 $ 4,964 Actual return on plan assets 437 521 Employer contributions 387 16 Benefits paid (263) (1,445) Other (4) 13 Fair value of plan assets at end of year $ 4,626 $ 4,069 Funded status—Net amount recognized $ (1,847) $ (2,456) Pension Benefits December 31, 2021 December 31, 2020 Amounts recognized in the consolidated balance sheets consist of: Noncurrent asset $ 75 $ 8 Current liability (2) (4) Noncurrent liability (1,920) (2,460) Total liability $ (1,847) $ (2,456) Amounts recognized in accumulated other comprehensive loss consist of: Net actuarial loss $ (1,406) $ (1,924) Prior service cost (1) (3) Total accumulated other comprehensive loss $ (1,407) $ (1,927) Other Postretirement Benefits Year Ended December 31, 2021 Year Ended December 31, 2020 Change in benefit obligation: Benefit obligation at beginning of year $ 1,082 $ 842 Service cost 10 10 Interest cost 25 28 Plan participants' contributions 66 58 Benefits paid (199) (164) Actuarial loss 114 107 Special termination benefit 31 201 Benefit obligation at end of year $ 1,129 $ 1,082 Change in plan assets: Fair value of plan assets at beginning of year $ 51 $ 52 Actual return on plan assets 1 1 Employer contributions 130 104 Plan participants' contributions 66 58 Benefits paid (199) (164) Fair value of plan assets at end of year 49 51 Funded status—Net amount recognized $ (1,080) $ (1,031)
Amounts Recognized in Consolidated Balance Sheet and Accumulated Other Comprehensive Income (Loss)	Other Postretirement Benefits December 31, 2021 December 31, 2020 Amounts recognized in the consolidated balance sheets consist of: Current liability $ (80) $ (37) Noncurrent liability (1,000) (994) Total liability $ (1,080) $ (1,031) Amounts recognized in accumulated other comprehensive income consist of: Net actuarial gain $ 113 $ 255 Prior service credit 447 570 Total accumulated other comprehensive income $ 560 $ 825
Accumulated Benefit Obligation and Projected Benefit Obligation in Excess of Plan Assets	The following information relates to all pension plans with an accumulated benefit obligation and a projected benefit obligation in excess of plan assets at December 31 (in millions): 2021 2020 Projected benefit obligation $ 6,231 $ 6,250 Accumulated benefit obligation 5,255 5,163 Fair value of plan assets 4,309 3,786
Components Of Net Periodic Benefit Cost	Net periodic benefit cost for the years ended December 31 included the following components (in millions): 2021 2020 2019 Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Pension Benefits Other Postretirement Benefits Service cost $ 239 $ 10 $ 216 $ 10 $ 184 $ 10 Interest cost 184 25 209 28 226 47 Expected return on plan assets (283) (1) (328) (1) (291) (1) Amortization of unrecognized actuarial (gain) loss 170 (28) 162 (40) 118 (52) Amortization of prior service credits — (123) — (124) — (73) Settlement loss - Voluntary Programs — — 430 — — — Special termination benefit - Voluntary Programs — 31 54 201 — — Curtailment (8) — 1 — — — Other 5 — 22 — 5 — Net periodic benefit cost (credit) $ 307 $ (86) $ 766 $ 74 $ 242 $ (69)
Assumptions Used for Benefit Plans	The assumptions used for the benefit plans were as follows: Pension Benefits Assumptions used to determine benefit obligations 2021 2020 Discount rate 2.90 % 2.72 % Rate of compensation increase 3.83 % 3.88 % Assumptions used to determine net expense Discount rate 2.72 % 3.51 % Expected return on plan assets 7.28 % 7.31 % Rate of compensation increase 3.88 % 3.88 % Other Postretirement Benefits Assumptions used to determine benefit obligations 2021 2020 Discount rate 2.82 % 2.43 % Assumptions used to determine net expense Discount rate 2.43 % 3.35 % Expected return on plan assets 3.00 % 3.00 % Health care cost trend rate assumed for next year 5.70 % 5.80 % Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2033) 4.50 % 4.50 %
Allocation of Plan Assets	United's plan assets are allocated within the following guidelines: Percent of Total Expected Long-Term Equity securities 30-45 % 10 % Fixed-income securities 35-50 4 Alternatives 15-25 7
Pension and Other Postretirement Plan Assets	The following tables present information about United's pension and other postretirement plan assets at December 31 (in millions): 2021 2020 Pension Plan Assets: Total Level 1 Level 2 Level 3 Assets Measured at NAV(a) Total Level 1 Level 2 Level 3 Assets Measured at NAV(a) Equity securities funds $ 1,754 $ 71 $ 44 $ 147 $ 1,492 $ 1,606 $ 55 $ 125 $ 96 $ 1,330 Fixed-income securities 1,850 — 739 15 1,096 1,644 — 548 49 1,047 Alternatives 847 — — 216 631 669 — — 195 474 Other investments 175 108 59 8 — 150 132 8 10 — Total $ 4,626 $ 179 $ 842 $ 386 $ 3,219 $ 4,069 $ 187 $ 681 $ 350 $ 2,851 Other Postretirement Benefit Plan Assets: Deposit administration fund $ 49 $ — $ — $ 49 $ — $ 51 $ — $ — $ 51 $ — (a) In accordance with the relevant accounting standards, certain investments that are measured at fair value using the net asset value ("NAV") per share (or its equivalent) have not been classified in the fair value hierarchy. These investments are commingled funds that invest in equity securities and fixed-income instruments including bonds, debt securities, and other similar instruments issued by various U.S. and non-U.S. public- or private-sector entities. Redemption periods for these investments range from daily to semiannually.
Defined Benefit Plan Assets Measured at Fair Value Using Unobservable Inputs	The reconciliation of United's benefit plan assets measured at fair value using unobservable inputs (Level 3) for the years ended December 31, 2021 and 2020 is as follows (in millions): 2021 2020 Balance at beginning of year $ 401 $ 409 Actual return (loss) on plan assets: Sold during the year 2 4 Held at year end 48 13 Purchases, sales, issuances and settlements (net) (14) (25) Balance at end of year $ 437 $ 401
Estimated Future Benefit Payments	The estimated future benefit payments, net of expected participant contributions, in United's pension plans and other postretirement benefit plans as of December 31, 2021 are as follows (in millions): Pension Other Postretirement 2022 $ 546 $ 131 2023 321 124 2024 320 107 2025 349 98 2026 374 92 Years 2027 – 2031 2,070 365
Participation in the IAM National Pension Plan	United's participation in the IAM National Pension Plan ("IAM Plan") for the annual period ended December 31, 2021 is outlined in the table below. In addition to the additional required contributions described in table below, contributions in 2021 were affected by COVID-19 impacts on United's operations and consequently employee hours paid. The risks of participating in these multi-employer plans are different from single-employer plans, as United may be subject to additional risks that others do not meet their obligations, which in certain circumstances could revert to United. The IAM Plan reported $494 million in employers' contributions for the year ended December 31, 2020. For 2020, the Company's contributions to the IAM Plan represented more than 5% of total contributions to the IAM Plan. The 2021 information is not available as the applicable Form 5500 is not final for the plan year. Pension Fund IAM National Pension Fund ("Fund") EIN/ Pension Plan Number 51-6031295 — 002 Pension Protection Act Zone Status (2021 and 2020) Critical (2021 and 2020). A plan is in "critical" status if the funded percentage is less than 65 percent. On April 17, 2019, the IAM National Pension Fund Board of Trustees voluntarily elected for the Fund to be in critical status effective for the plan year beginning January 1, 2019 to strengthen the Fund's financial health. The Fund's funded percentage was 85.1% as of January 1, 2020. FIP/RP Status Pending/Implemented A 10-year Rehabilitation Plan effective, January 1, 2022, was adopted on April 17, 2019 that requires the Company to make an additional contribution of 2.5% of the hourly contribution rate, compounded annually for the length of the Rehabilitation Plan, effective June 1, 2019. United's Contributions $58 million, $53 million and $59 million in the years ended December 31, 2021, 2020 and 2019, respectively Surcharge Imposed No Expiration Date of Collective Bargaining Agreement N/A

Investments and Fair Value Me_2

Investments and Fair Value Measurements (Tables)	12 Months Ended
Investments and Fair Value Measurements (Tables)	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The table below presents disclosures about the fair value of financial assets and liabilities measured at fair value on a recurring basis in the Company's financial statements as of December 31 (in millions): 2021 2020 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Cash and cash equivalents $ 18,283 $ 18,283 $ — $ — $ 11,269 $ 11,269 $ — $ — Restricted cash - current (Note 1) 37 37 — — 255 255 — — Restricted cash - non-current (Note 1) 213 213 — — 218 218 — — Short-term investments: Corporate debt 95 — 95 — 330 — 330 — Asset-backed securities 26 — 26 — 51 — 51 — U.S. government and agency notes 2 — 2 — 33 — 33 — Long-term investments: Equity securities 229 229 — — 241 205 — 36
Carrying Values and Estimated Fair Values of Financial Instruments	The table below presents the carrying values and estimated fair values of financial instruments not presented in the tables above as of December 31 (in millions). Carrying amounts include any related discounts, premiums and issuance costs: 2021 2020 Carrying Amount Fair Value Carrying Amount Fair Value Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Long-term debt $ 33,363 $ 34,550 $ — $ 29,088 $ 5,462 $ 26,747 $ 27,441 $ — $ 21,985 $ 5,456
Description of Fair Value of Financial Instruments and Fair Value Methodology	Fair value of the financial instruments included in the tables above was determined as follows: Description Fair Value Methodology Cash and cash equivalents and The carrying amounts of these assets approximate fair value. Short-term investments and Fair value is based on (a) the trading prices of the investment or similar Long-term debt Fair values were based on either market prices or the discounted amount of future cash flows using our current incremental rate of borrowing for similar liabilities or assets.

Debt (Tables)

Debt (Tables)	12 Months Ended
Debt (Tables)	Dec. 31, 2021
Debt Disclosure [Abstract]
Summary of Long-Term Debt	(In millions) Maturity Dates Interest Rate(s) at December 31, 2021 At December 31, 2021 2020 Aircraft notes (a) 2022 — 2033 0.62 % — 6.90 % $ 13,293 $ 14,538 MileagePlus Senior Secured Notes 2027 6.50 % 3,800 3,800 MileagePlus Term Loan Facility (a) 2027 6.25 % 3,000 3,000 2026 and 2029 Notes 2026 — 2029 4.38 % — 4.63 % 4,000 — 2021 Term Loans (a) 2028 4.50 % 4,963 — Revolving Credit Facility — 1,000 CARES Act Loan — 520 Term Loan Facility — 1,444 Unsecured Notes (b) 2022 — 2025 4.25 % — 5.00 % 1,041 1,050 PSP Notes (c) 2030 — 2031 1.00 % 3,181 1,501 Other unsecured debt 2023 — 2029 0.00 % — 5.75 % 598 448 33,876 27,301 Less: unamortized debt discount, premiums and debt issuance costs (513) (554) Less: current portion of long-term debt (3,002) (1,911) Long-term debt, net $ 30,361 $ 24,836 (a) Financing includes variable rate debt based on LIBOR (or another index rate), generally subject to a floor, plus a specified margin ranging from 0.49% to 5.25%. (b) On January 14, 2022, the Company gave notice for the redemption of all $400 million outstanding principal amount of the 4.250% senior notes due 2022 (the "2022 Notes"), scheduled to occur on February 28, 2022. The redemption price will be calculated in accordance with the terms of the indenture governing the 2022 Notes, and will include accrued and unpaid interest on the principal amount being redeemed to such redemption date. (c) Includes PSP1 Note, PSP2 Note and PSP3 Note.
Contractual Principal Payments under Outstanding Long-Term Debt Agreements	The table below presents the Company's contractual principal payments (not including debt discount or debt issuance costs) at December 31, 2021 under then-outstanding long-term debt agreements in each of the next five calendar years (in millions): 2022 $ 3,002 2023 2,853 2024 3,908 2025 3,378 2026 5,134 After 2026 15,601 $ 33,876
Details of Pass Through Trusts	Certain details of the pass-through trusts with proceeds received from issuance of debt in 2021 are as follows (in millions, except stated interest rate): EETC Issuance Date Class Face Amount Final expected distribution date Stated interest rate Total proceeds received from issuance of debt and recorded as debt as of December 31, 2021 February 2021 B $ 600 January 2026 4.88% $ 600
Summary of Collateral Covenants and Cross Default Provisions	The collateral, covenants and cross default provisions of the Company's principal debt instruments that contain such provisions are summarized in the table below: Debt Instrument Collateral, Covenants and Cross Default Provisions Various equipment notes and other notes payable Secured by certain aircraft, spare engines and spare parts. The indentures contain events of default that are customary for aircraft financings, including in certain cases cross default to other related aircraft. 2021 Loan Facilities Secured on a senior basis by security interests granted by the Company to the collateral trustee for the benefit of the lenders under the 2021 Loan Facilities, among other parties, on the following: (i) all of the Company's route authorities granted by the U.S. Department of Transportation to operate scheduled service between any international airport located in the United States and any international airport located in any country other than the United States (except Cuba), (ii) the Company's rights to substantially all of its landing and take-off slots at foreign and domestic airports, including at John F. Kennedy International Airport, LaGuardia Airport and Ronald Reagan Washington National Airport (subject to certain exclusions), and (iii) the Company's rights to use or occupy space at airport terminals, each to the extent necessary at the relevant time for servicing scheduled air carrier service authorized by an applicable route authority. The 2021 Loan Facilities contain negative covenants that, among other things, limit our ability under certain circumstances to create liens on the collateral, make certain dividends, conduct stock repurchases, make certain restricted investments and other restricted payments, and consolidate, merge, sell, or otherwise dispose of all or substantially all of our assets. The 2021 Loan Facilities also contain financial covenants that require the Company to maintain at least $2.0 billion of unrestricted liquidity at all times, which includes unrestricted cash, short-term investments and any undrawn amounts under any revolving credit facility, and to maintain a minimum ratio of appraised value of collateral to the outstanding debt secured by such collateral (including under the 2021 Loan Facilities) of 1.6 to 1.0, tested semi-annually. The 2021 Loan Facilities contain events of default customary for similar financings, including a cross-payment default and cross-acceleration to other material indebtedness. 2026 and 2029 Notes The 2026 and 2029 Notes are secured on a senior basis by security interests granted by the Company to the collateral trustee for the benefit of the holders of the 2026 and 2029 Notes, among other parties, on the following: (i) all of the Company's route authorities granted by the U.S. Department of Transportation to operate scheduled service between any international airport located in the United States and any international airport located in any country other than the United States (except Cuba), (ii) the Company's rights to substantially all of its landing and take-off slots at foreign and domestic airports, including at John F. Kennedy International Airport, LaGuardia Airport and Ronald Reagan Washington National Airport (subject to certain exclusions), and (iii) the Company's rights to use or occupy space at airport terminals, each to the extent necessary at the relevant time for servicing scheduled air carrier service authorized by an applicable route authority. The indenture for these 2026 and 2029 Notes contains covenants that, among other things, limit our ability under certain circumstances to create liens on the Collateral, make certain dividends, stock repurchases, restricted investments and other restricted payments, and consolidate, merge, sell, or otherwise dispose of all or substantially all of our assets. The indenture also contains a financial covenant that requires UAL to pay special interest in an additional amount equal to 2.0% per year of the principal amount of the 2026 and 2029 Notes for so long as it is unable to demonstrate that it maintains a minimum ratio of appraised value of collateral to the outstanding debt secured by such collateral (including the 2026 and 2029 Notes) of 1.6 to 1.0, tested semi-annually. The indenture contains events of default customary for similar financings, including a cross-payment default and cross-acceleration to other material indebtedness. MileagePlus Notes Secured by first-priority security interests in substantially all of the assets of the Issuers, other than excluded property and subject to certain permitted liens, including security interests in specified cash accounts that include the accounts into which MileagePlus revenues are or will be paid by the Company's marketing partners and by the Company. CARES Act Loan Though the CARES Act Loan was terminated and repaid in full on April 20, 2021, United and its affiliates agreed in the corresponding term loan and guarantee agreement to comply with certain surviving provisions (i) prohibiting the payment of dividends and the repurchase of certain equity until April 20, 2022, (ii) requiring compliance with certain continuation of service requirements until March 1, 2022, and (iii) restricting the payment of certain executive compensation until April 20, 2022. PSP Notes The PSP Notes represent senior unsecured indebtedness of UAL. The PSP Notes are guaranteed by United. If any subsidiary of UAL (other than United) becomes, or is required to become, an obligor on unsecured indebtedness of UAL or any of its subsidiaries with a principal balance in excess of a specified amount, then such subsidiary shall be required to guarantee the obligations of the Company under the PSP Notes. Pursuant to the PSP Agreements, the Company and its affiliates will be required to comply with certain provisions including, among others, prohibiting certain reductions in employee wages, salaries and benefits; provisions prohibiting the payment of dividends and the repurchase of certain equity until September 30, 2022; audit and reporting requirements; provisions to comply with certain continuation of service requirements until March 1, 2022; and provisions restricting the payment of certain executive compensation until April 1, 2023. Unsecured notes The indentures for these notes contain covenants that, among other things, restrict the ability of the Company and its restricted subsidiaries (as defined in the indentures) to incur additional indebtedness and make certain dividends, stock repurchases, restricted investments and other restricted payments.

Leases and Capacity Purchase _2

Leases and Capacity Purchase Agreements (Tables)	12 Months Ended
Leases and Capacity Purchase Agreements (Tables)	Dec. 31, 2021
Leases [Abstract]
Components of Lease Cost	The Company's lease cost for the years ended December 31 included the following components (in millions): 2021 2020 2019 Operating lease cost $ 958 $ 933 $ 1,038 Variable and short-term lease cost 2,291 1,968 2,548 Amortization of finance lease assets 89 88 68 Interest on finance lease liabilities 16 16 85 Sublease income (26) (23) (32) Total lease cost $ 3,328 $ 2,982 $ 3,707
Summary of Scheduled Future Minimum Lease Payments under Operating Leases	The table below summarizes the Company's scheduled future minimum lease payments under operating and finance leases, recorded on the balance sheet, as of December 31, 2021 (in millions): Operating Leases Finance Leases 2022 $ 857 $ 89 2023 825 57 2024 775 53 2025 655 41 2026 637 26 After 2026 3,982 72 Minimum lease payments 7,731 338 Imputed interest (2,023) (43) Present value of minimum lease payments 5,708 295 Less: current maturities of lease obligations (556) (76) Long-term lease obligations $ 5,152 $ 219
Summary of Scheduled Future Minimum Lease Payments under Finance Leases	The table below summarizes the Company's scheduled future minimum lease payments under operating and finance leases, recorded on the balance sheet, as of December 31, 2021 (in millions): Operating Leases Finance Leases 2022 $ 857 $ 89 2023 825 57 2024 775 53 2025 655 41 2026 637 26 After 2026 3,982 72 Minimum lease payments 7,731 338 Imputed interest (2,023) (43) Present value of minimum lease payments 5,708 295 Less: current maturities of lease obligations (556) (76) Long-term lease obligations $ 5,152 $ 219
Additional Information Related to Leases	The table below presents additional information related to our leases as of December 31: 2021 2020 Weighted-average remaining lease term - operating leases 10 years 11 years Weighted-average remaining lease term - finance leases 6 years 4 years Weighted-average discount rate - operating leases 5.0 % 5.1 % Weighted-average discount rate - finance leases 4.8 % 4.4 %
Supplemental Cash Flow Information Related to Leases	The table below presents supplemental cash flow information related to leases during the year ended December 31 (in millions): 2021 2020 2019 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 977 $ 788 $ 902 Operating cash flows for finance leases 18 20 70 Financing cash flows for finance leases 216 66 151
Future Lease Payment Under Terms of Capacity Purchase Agreement	Based on these assumptions as of December 31, 2021, our future payments through the end of the terms of our CPAs are presented in the table below (in billions): 2022 $ 2.1 2023 2.1 2024 2.0 2025 1.7 2026 1.5 After 2026 4.2 $ 13.6

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Summary of Commitments to Purchase Aircraft	As of December 31, 2021, United had firm commitments and options to purchase aircraft from The Boeing Company ("Boeing") and Airbus S.A.S. ("Airbus") presented in the table below: Scheduled Aircraft Deliveries Aircraft Type Number of Firm 2022 2023 After 2023 Airbus A321XLR 50 — — 50 Airbus A321neo 70 — 12 58 Airbus A350 45 — — 45 Boeing 737 MAX 367 53 109 205 Boeing 787 8 8 — — (a) United also has options and purchase rights for additional aircraft. The table below summarizes United's commitments as of December 31, 2021, which include aircraft and related spare engines, aircraft improvements and all non-aircraft capital commitments (in billions): 2022 $ 5.7 2023 6.9 2024 5.0 2025 4.3 2026 3.3 After 2026 8.9 $ 34.1

Special Charges (Credits) and_2

Special Charges (Credits) and Unrealized (Gains) Losses on Investments (Tables)	12 Months Ended
	Dec. 31, 2021
Restructuring and Related Activities [Abstract]
Components of Special Charges	Special charges (credits) and unrealized (gains) and losses on investments in the statements of consolidated operations consisted of the following for the years ended December 31 (in millions): Operating: 2021 2020 2019 CARES Act grant $ (4,021) $ (3,536) $ — Severance and benefit costs 438 575 16 Impairment of assets 97 318 171 (Gains) losses on sale of assets and other special charges 119 27 59 Total operating special charges (credits) (3,367) (2,616) 246 Nonoperating unrealized (gains) losses on investments, net 34 194 (153) Nonoperating debt extinguishment and modification fees 50 — — Nonoperating special termination benefits and settlement losses 31 687 — Nonoperating credit loss on BRW Term Loan and related guarantee — 697 — Total nonoperating special charges and unrealized (gains) losses on investments, net 115 1,578 (153) Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net (3,252) (1,038) 93 Income tax expense (benefit), net of valuation allowance 728 404 (21) Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net of income taxes $ (2,524) $ (634) $ 72

Significant Accounting Polici_4

Significant Accounting Policies - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)segment	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Feb. 28, 2021aircraft
Summary Of Significant Accounting Policies [Line Items]
Expiration period for refundable tickets	1 year
Number of operating segments \| segment	1
Revenue	$ 24,634	$ 15,355	$ 43,259
Period over which miles are expected to be redeemed	two years
Senior secured notes	$ 6,800
Carrying value of computer software	499	548
Impairment, long-lived asset	97	94	81
Amortization expense	49	55	60
Projected amortization expense in 2022	40
Projected amortization expense in 2023	37
Projected amortization expense in 2024	32
Projected amortization expense in 2025	28
Projected amortization expense in 2026	18
Advertising expense	$ 99	87	212
Boeing 777-200/200ER
Summary Of Significant Accounting Policies [Line Items]
Number of aircraft temporarily removed \| aircraft				52
Minimum
Summary Of Significant Accounting Policies [Line Items]
Frequent flier program expiration period	1 year
Maximum
Summary Of Significant Accounting Policies [Line Items]
Frequent flier program expiration period	8 years
Computer software
Summary Of Significant Accounting Policies [Line Items]
Depreciation expense	$ 182	172	135
Advance Ticket Sales
Summary Of Significant Accounting Policies [Line Items]
Expiration period for advance ticket sales	12 months
Contract liabilities	$ 3,200
Revenue recognized	1,800	3,000	3,400
Ancillary Fees Recorded within Passenger Revenues
Summary Of Significant Accounting Policies [Line Items]
Revenue	2,200	1,300	3,600
Other Operating Revenue
Summary Of Significant Accounting Policies [Line Items]
Revenue	2,088	1,902	2,455
Other Operating Revenue \| Chase and Other Partner Agreements
Summary Of Significant Accounting Policies [Line Items]
Revenue	$ 1,800	$ 1,700	$ 2,000

Significant Accounting Polici_5

Significant Accounting Policies - Operating Revenue by Principal Geographic Region (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 24,634	$ 15,355	$ 43,259
Domestic (U.S. and Canada)
Disaggregation of Revenue [Line Items]
Total operating revenue	16,845	9,911	26,960
Atlantic
Disaggregation of Revenue [Line Items]
Total operating revenue	3,414	2,226	7,387
Pacific
Disaggregation of Revenue [Line Items]
Total operating revenue	1,507	1,706	5,132
Latin America
Disaggregation of Revenue [Line Items]
Total operating revenue	$ 2,868	$ 1,512	$ 3,780

Significant Accounting Polici_6

Significant Accounting Policies - Roll Forward of Frequent Flier Deferred Revenue (Details) - Frequent Flyer - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Movement in Deferred Revenue [Roll Forward]
Total Frequent flyer deferred revenue - beginning balance	$ 5,975	$ 5,276
Total miles awarded	1,545	1,336
Travel miles redeemed (Passenger revenue)	(1,171)	(568)
Non-travel miles redeemed (Other operating revenue)	(67)	(69)
Total Frequent flyer deferred revenue - ending balance	$ 6,282	$ 5,975

Significant Accounting Polici_7

Significant Accounting Policies - Reconciliation of Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 18,283	$ 11,269	$ 2,762
Restricted cash	37	255	0
Other assets:
Restricted cash	213	218	106
Total cash, cash equivalents and restricted cash shown in the statement of consolidated cash flows	18,533	11,742	2,868	$ 1,799
United Airlines, Inc.
Current assets:
Cash and cash equivalents	18,283	11,269	2,756
Restricted cash	37	255	0
Other assets:
Restricted cash	213	218	106
Total cash, cash equivalents and restricted cash shown in the statement of consolidated cash flows	$ 18,533	$ 11,742	$ 2,862	$ 1,793

Significant Accounting Polici_8

Significant Accounting Policies - Estimated Useful Lives of Property and Equipment (Details)	12 Months Ended
	Dec. 31, 2021
Aircraft, spare engines and related rotable parts \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	25 years
Aircraft, spare engines and related rotable parts \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	30 years
Aircraft seats \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	10 years
Aircraft seats \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Buildings \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	25 years
Buildings \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	45 years
Other property and equipment \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	3 years
Other property and equipment \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Computer software \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	5 years
Computer software \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	15 years
Building improvements \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful life	1 year
Building improvements \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful life	40 years

Significant Accounting Polici_9

Significant Accounting Policies - Information about Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Goodwill	$ 4,527	$ 4,527
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	2,591	2,577
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,756	1,756
Accumulated Amortization	1,544	1,495
Route authorities
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	1,020	1,020
Airport slots and gates
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	574	560
Tradenames and logos
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	593	593
Alliances
Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	404	404
Frequent flyer database
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	1,177	1,177
Accumulated Amortization	1,008	971
Hubs
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	145	145
Accumulated Amortization	118	111
Contracts
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	120	120
Accumulated Amortization	120	116
Other
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	314	314
Accumulated Amortization	$ 298	$ 297

Common Stockholders' Equity a_3

Common Stockholders' Equity and Preferred Securities - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Mar. 03, 2021	Jun. 15, 2020
Class of Stock [Line Items]
Warrants issued	$ 99	$ 97
Proceeds from the issuance of common stock		$ 1,100
Common stock reserved for future issuance (in shares)	6,000,000
Junior preferred stock outstanding (in shares)	2
Junior preferred stock par value per share (in dollars per share)	$ 0.01
Preferred stock authorized to issue (in shares)	250,000,000
2020 ATM Offering
Class of Stock [Line Items]
Sale of common stock (in shares)		21,000,000
Share price (in dollars per share)		$ 46.70
Proceeds from the issuance of common stock		$ 989
Public Offering
Class of Stock [Line Items]
Sale of common stock (in shares)		43,000,000
Share price (in dollars per share)		$ 26.50
Equity Distribution Agreement
Class of Stock [Line Items]
Sale of common stock (in shares)	7,000,000
Share price (in dollars per share)	$ 42.98
Proceeds from the issuance of common stock	$ 282
Number of shares issuable under Equity Distribution Agreement (up to) (in shares)				28,000,000
2021 ATM Offering
Class of Stock [Line Items]
Sale of common stock (in shares)	4,000,000
Share price (in dollars per share)	$ 57.50
Proceeds from the issuance of common stock	$ 250
Number of shares issuable under Equity Distribution Agreement (up to) (in shares)			37,000,000
Payroll Support Program 2 & 3 (PSP 2 & 3) Warrants
Class of Stock [Line Items]
Number of warrants issuable under agreement (up to)	3,500,000
Warrants issued	$ 99

Common Stockholders' Equity a_4

Common Stockholders' Equity and Preferred Securities - Summary of Warrants Outstanding (Details) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Class of Warrant or Right [Line Items]
Number of shares of common stock (in shares)	10
Unsecured Debt \| PSP2 Note
Class of Warrant or Right [Line Items]
Aggregate principal amount	$ 870,000,000
Term of debt	10 years
Unsecured Debt \| Payroll Support Program 1 (PSP1) Note
Class of Warrant or Right [Line Items]
Aggregate principal amount	$ 1,500,000,000
Term of debt	10 years
Line of Credit \| CARES Act Credit Agreement
Class of Warrant or Right [Line Items]
Aggregate principal amount		$ 520,000,000
PSP1 Warrants
Class of Warrant or Right [Line Items]
Number of shares of common stock (in shares)	4.8
Exercise price (in dollars per share)	$ 31.50
CARES Act Loan Warrants
Class of Warrant or Right [Line Items]
Number of shares of common stock (in shares)	1.7
Exercise price (in dollars per share)	$ 31.50
PSP2 Warrants
Class of Warrant or Right [Line Items]
Number of shares of common stock (in shares)	2
Exercise price (in dollars per share)	$ 43.26
PSP3 Warrants
Class of Warrant or Right [Line Items]
Number of shares of common stock (in shares)	1.5
Exercise price (in dollars per share)	$ 53.92

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings (loss) available to common stockholders	$ (1,964)	$ (7,069)	$ 3,009
Basic weighted-average shares outstanding (in shares)	321.9	279.4	258.8
Effect of share-based awards (in shares)	0	0	1.1
Diluted weighted-average shares outstanding (in shares)	321.9	279.4	259.9
Earnings (loss) per share, basic (in dollars per share)	$ (6.10)	$ (25.30)	$ 11.63
Earnings (loss) per share, diluted (in dollars per share)	$ (6.10)	$ (25.30)	$ 11.58
Stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	0.9	0	0
Employee stock awards
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities	0.7	1	0.1

Share-Based Compensation Plan_2

Share-Based Compensation Plans - Narrative (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of RSUs and restricted stock vested in period	$ 104	$ 87	$ 99
Stock option awards outstanding (in shares)	700
Stock option awards exercisable (in shares)	300
Weighted-average exercise price of stock options outstanding (in dollars per share)	$ 82.12
Weighted-average exercise price of stock options exercisable (in dollars per share)	$ 59.05
Weighted average remaining contractual lives of stock options outstanding	5 years 3 months 18 days
Weighted average remaining contractual lives of stock options exercisable	2 years 10 months 24 days
Intrinsic value of stock options outstanding	$ 0
Intrinsic value of stock options exercisable	$ 0
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	3,000
Award vesting period	2 years
Number of days used to compute performance period average closing price of restricted stock units	20 days
Liabilities related to share based payments	$ 7
Payment related to share-based liabilities	$ 29	$ 26	$ 41
RSUs \| Share-based Payment Arrangement, Tranche One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%
RSUs \| Share-based Payment Arrangement, Tranche Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%
RSUs \| Share-based Payment Arrangement, Tranche Three
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%
RSUs \| Share-based Payment Arrangement, Tranche Four
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage	25.00%
Time-Vested RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	1,000
Performance-Based RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted (in shares)	2,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted (in shares)	0	0	307
Percentage of premium of the grant date fair market value			25.00%
Weighted-average grant date exercise price of stock options granted (in dollars per share)			$ 110.21

Share-Based Compensation Plan_3

Share-Based Compensation Plans - Information Related to Share-Based Compensation Plan Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 238	$ 108	$ 100
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	236	106	98
RSAs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	0	0	1
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost	$ 2	$ 2	$ 1

Share-Based Compensation Plan_4

Share-Based Compensation Plans - Summary of Unearned Compensation and Weighted-Average Remaining Period to Recognize Costs (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned compensation	$ 66
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned compensation	$ 60
Weighted average remaining period	8 months 12 days
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unearned compensation	$ 6
Weighted average remaining period	3 years 10 months 24 days

Share-Based Compensation Plan_5

Share-Based Compensation Plans - Summary of RSU and Restricted Stock Activity (Details) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Liability Awards - RSUs
Awards
Outstanding (in shares)	0.4	0.6	1.9
Granted (in shares)	0.4	0.1	0.1
Vested (in shares)	(0.6)	(0.3)	(0.5)
Forfeited (in shares)	0	0	(0.9)
Outstanding (in shares)	0.2	0.4	0.6
Equity Awards - RSUs
Awards
Outstanding (in shares)	3.2	2	1.8
Granted (in shares)	2.9	2.4	1.1
Vested (in shares)	(1.5)	(0.8)	(0.8)
Forfeited (in shares)	(0.2)	(0.4)	(0.1)
Outstanding (in shares)	4.4	3.2	2
Weighted- Average Grant Price
Outstanding (in dollars per share)	$ 53.41	$ 78.03	$ 66.29
Granted (in dollars per share)	52.18	40.80	86.72
Vested (in dollars per share)	51.35	74.54	64.85
Forfeited (in dollars per share)	46.77	54.21	76.48
Outstanding (in dollars per share)	$ 53.63	$ 53.41	$ 78.03

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Components of the Company's AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, deferred taxes	$ (39)	$ (160)	$ (136)
Balance	5,960	11,531	10,042
Change in value, deferred tax	(53)	221	(24)
Change in value	184	(772)	88
Amounts reclassified to earnings, deferred taxes	(3)	(100)	0
Amounts reclassified to earnings	13	351	(3)
Balance, deferred taxes	(95)	(39)	(160)
Balance	5,029	5,960	11,531
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance	(1,139)	(718)	(803)
Balance	(942)	(1,139)	(718)
Deferred income tax expense	285
Pension and Other Postretirement Liabilities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, before tax	(1,102)	(560)	(663)
Change in value, before tax	239	(993)	105
Amounts reclassified to earnings, before tax	16	451	(2)
Balance, before tax	(847)	(1,102)	(560)
Investments and Other
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance, before tax	2	2	(4)
Change in value, before tax	(2)	0	7
Amounts reclassified to earnings, before tax	0	0	(1)
Balance, before tax	$ 0	$ 2	$ 2

Income Taxes - Income Tax Provi

Income Taxes - Income Tax Provision (Benefit) Differed from Amounts Computed at the Statutory Federal Income Tax Rate and Significant Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Income tax provision (benefit) at statutory rate	$ (537)	$ (1,852)	$ 822
State income tax provision (benefit), net of federal income tax benefit	(34)	(110)	50
Foreign tax rate differential	0	0	(90)
Global intangible low-taxed income	0	0	90
Nondeductible employee meals	7	5	12
Valuation allowance	(38)	197	(4)
Other, net	9	7	25
Income tax expense (benefit)	(593)	(1,753)	905
Current	(10)	(12)	23
Deferred	(583)	(1,741)	882
United Airlines, Inc.
Income Taxes [Line Items]
Income tax expense (benefit)	(593)	(1,753)	905
Deferred	$ (583)	$ (1,741)	$ 882

Income Taxes - Temporary Differ

Income Taxes - Temporary Differences and Carryforwards Giving Rise to Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Deferred income tax asset (liability):
Federal and state net operating loss ("NOL") carryforwards	$ 2,229	$ 2,476
Deferred revenue	2,349	1,409
Employee benefits, including pension, postretirement and medical	986	1,103
Operating lease liabilities	1,272	1,247
Other financing liabilities	327	260
Other	535	362
Less: Valuation allowance	(210)	(247)
Total deferred tax assets	7,488	6,610
Depreciation	(5,122)	(4,789)
Operating lease right-of-use asset	(1,051)	(1,028)
Intangibles	(656)	(662)
Total deferred tax liabilities	(6,829)	(6,479)
Net deferred tax asset	659	131
United Airlines, Inc.
Deferred income tax asset (liability):
Federal and state net operating loss ("NOL") carryforwards	2,201	2,448
Deferred revenue	2,349	1,409
Employee benefits, including pension, postretirement and medical	986	1,103
Operating lease liabilities	1,272	1,247
Other financing liabilities	327	260
Other	535	362
Less: Valuation allowance	(210)	(247)
Total deferred tax assets	7,460	6,582
Depreciation	(5,122)	(4,789)
Operating lease right-of-use asset	(1,051)	(1,028)
Intangibles	(656)	(662)
Total deferred tax liabilities	(6,829)	(6,479)
Net deferred tax asset	$ 631	$ 103

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Capital loss carryforwards, valuation allowance	$ 183
Unrecognized tax benefits	55	$ 57	$ 53
Unrecognized tax benefits that would impact effective tax rate if recognized	55
Federal
Income Taxes [Line Items]
NOL carryforwards	9,900
Tax effected amount of NOLs	2,100
Tax credits	40
Deferred tax asset, portion to be utilized against deferred tax liabilities	6,200
Deferred tax asset, portion to be utilized against future taxable income	1,300
Federal \| United Airlines, Inc.
Income Taxes [Line Items]
NOL carryforwards	9,900
Tax effected amount of NOLs	2,100
NOLs without an expiration date	$ 8,400
Federal \| Minimum
Income Taxes [Line Items]
Tax credit expiration period	1 year
Federal \| Maximum
Income Taxes [Line Items]
Tax credit expiration period	18 years
Federal \| 2028 \| United Airlines, Inc.
Income Taxes [Line Items]
NOL carryforwards	$ 500
Federal \| 2029 \| United Airlines, Inc.
Income Taxes [Line Items]
NOL carryforwards	400
Federal \| 2032 \| United Airlines, Inc.
Income Taxes [Line Items]
NOL carryforwards	200
Federal \| 2033 \| United Airlines, Inc.
Income Taxes [Line Items]
NOL carryforwards	400
State
Income Taxes [Line Items]
Tax credits	45
NOL and tax credit carryforwards, valuation allowance	27
State \| United Airlines, Inc.
Income Taxes [Line Items]
NOL carryforwards	3,300
Tax effected amount of NOLs	$ 200
State \| Minimum
Income Taxes [Line Items]
Tax credit expiration period	1 year
State \| Minimum \| United Airlines, Inc.
Income Taxes [Line Items]
NOL expiration period	5 years
State \| Maximum
Income Taxes [Line Items]
Tax credit expiration period	11 years
State \| Maximum \| United Airlines, Inc.
Income Taxes [Line Items]
NOL expiration period	20 years

Pension and Other Postretirem_3

Pension and Other Postretirement Plans - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Sep. 30, 2021	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Defined benefit plan, plan assets, employer discretionary contribution amount	$ 375,000
Settlement losses related to defined benefit pension plans			$ 31,000	$ 687,000	$ 0
Profit sharing and payroll tax expense			0	0	491,000
Employee Separation \| Voluntary Separation Leave Programs
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Charges for special termination benefits (charges) under VSPs			31,000
Full-Time Employees \| Employee Separation \| Voluntary Separation Leave Programs
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Restructuring programs, one-time contribution per employee		$ 125	125
Part-Time Employees \| Employee Separation \| Voluntary Separation Leave Programs
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Restructuring programs, one-time contribution per employee		$ 75	$ 75
Minimum
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Percentage of pre-tax earnings paid for profit sharing plan			5.00%
Maximum
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Percentage of pre-tax earnings paid for profit sharing plan			20.00%
IAM National Pension Plan
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Multi-employer plan contributions				494,000
United Airlines, Inc.
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Expense for defined contribution plans			$ 651,000	687,000	735,000
United Airlines, Inc. \| Minimum
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Employer contribution percentage			1.00%
United Airlines, Inc. \| Maximum
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Employer contribution percentage			16.00%
Pension Benefits
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Charges for special termination benefits (charges) under VSPs			$ 0	(54,000)	0
Settlement losses				430,000
Increase in postretirement benefit liability if there was a 50 basis point decrease in the weighted average discount rate			700,000
Increase in benefits expense if there was a 50 basis point decrease in the weighted average discount rate			85,000
Decrease in expected long-term rate of return on plan assets if there was a 50 basis point decrease in the weighted average discount rate			20,000
Other Postretirement Benefits
Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items]
Charges for special termination benefits (charges) under VSPs			(31,000)	$ (201,000)	$ 0
Increase in postretirement benefit liability if there was a 50 basis point decrease in the weighted average discount rate			46,000
Increase in benefits expense if there was a 50 basis point decrease in the weighted average discount rate			2,000
Expected employer contributions to pension and postretirement plans			$ 124,000

Pension and Other Postretirem_4

Pension and Other Postretirement Plans - Reconciliation of the Change in Benefit Obligation and Plan Asset, Funded Status and Amounts Recognized in the Financial Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligation	$ 5,496	$ 5,387
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	6,525	6,398
Service cost	239	216	$ 184
Interest cost	184	209	226
Actuarial (gain) loss	(188)	1,181
Special termination benefit	0	54
Benefits paid	(263)	(1,445)
Curtailment	(12)	(105)
Other	(12)	17
Projected benefit obligation at end of year	6,473	6,525	6,398
Change in plan assets:
Fair value of plan assets at beginning of year	4,069	4,964
Actual return on plan assets	437	521
Employer contributions	387	16
Benefits paid	(263)	(1,445)
Other	(4)	13
Fair value of plan assets at end of year	4,626	4,069	4,964
Funded status—Net amount recognized	(1,847)	(2,456)
Amounts recognized in the consolidated balance sheets consist of:
Noncurrent asset	75	8
Current liability	(2)	(4)
Noncurrent liability	(1,920)	(2,460)
Total liability	(1,847)	(2,456)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	(1,406)	(1,924)
Prior service cost	(1)	(3)
Total accumulated other comprehensive loss	(1,407)	(1,927)
Other Postretirement Benefits
Change in projected benefit obligation:
Projected benefit obligation at beginning of year	1,082	842
Service cost	10	10	10
Interest cost	25	28	47
Actuarial (gain) loss	114	107
Special termination benefit	31	201
Benefits paid	(199)	(164)
Projected benefit obligation at end of year	1,129	1,082	842
Change in plan assets:
Fair value of plan assets at beginning of year	51	52
Actual return on plan assets	1	1
Employer contributions	130	104
Plan participants' contributions	66	58
Benefits paid	(199)	(164)
Fair value of plan assets at end of year	49	51	$ 52
Funded status—Net amount recognized	(1,080)	(1,031)
Amounts recognized in the consolidated balance sheets consist of:
Current liability	(80)	(37)
Noncurrent liability	(1,000)	(994)
Total liability	(1,080)	(1,031)
Amounts recognized in accumulated other comprehensive loss consist of:
Net actuarial loss	113	255
Prior service cost	447	570
Total accumulated other comprehensive loss	560	825
Plan participants' contributions	$ 66	$ 58

Pension and Other Postretirem_5

Pension and Other Postretirement Plans - Accumulated Benefit Obligation and Projected Benefit Obligation in Excess of Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Retirement Benefits [Abstract]
Projected benefit obligation	$ 6,231	$ 6,250
Accumulated benefit obligation	5,255	5,163
Fair value of plan assets	$ 4,309	$ 3,786

Pension and Other Postretirem_6

Pension and Other Postretirement Plans - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 239	$ 216	$ 184
Interest cost	184	209	226
Expected return on plan assets	(283)	(328)	(291)
Amortization of unrecognized actuarial (gain) loss	170	162	118
Amortization of prior service credits	0	0	0
Settlement loss - Voluntary Programs	0	430	0
Special termination benefit - Voluntary Programs	0	54	0
Curtailment	(8)	1	0
Other	5	22	5
Net periodic benefit cost (credit)	307	766	242
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	10	10	10
Interest cost	25	28	47
Expected return on plan assets	(1)	(1)	(1)
Amortization of unrecognized actuarial (gain) loss	(28)	(40)	(52)
Amortization of prior service credits	(123)	(124)	(73)
Settlement loss - Voluntary Programs	0	0	0
Special termination benefit - Voluntary Programs	31	201	0
Curtailment	0	0	0
Other	0	0	0
Net periodic benefit cost (credit)	$ (86)	$ 74	$ (69)

Pension and Other Postretirem_7

Pension and Other Postretirement Plans - Assumptions Used for Benefit Plans (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Assumptions used to determine benefit obligations
Discount rate	2.90%	2.72%
Rate of compensation increase	3.83%	3.88%
Assumptions used to determine net expense
Discount rate	2.72%	3.51%
Expected return on plan assets	7.28%	7.31%
Rate of compensation increase	3.88%	3.88%
Other Postretirement Benefits
Assumptions used to determine benefit obligations
Discount rate	2.82%	2.43%
Assumptions used to determine net expense
Discount rate	2.43%	3.35%
Expected return on plan assets	3.00%	3.00%
Health care cost trend rate assumed for next year	5.70%	5.80%
Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2033)	4.50%	4.50%

Pension and Other Postretirem_8

Pension and Other Postretirement Plans - Allocation of Plan Assets (Details) - United Airlines, Inc.	12 Months Ended
	Dec. 31, 2021
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return	10.00%
Equity securities \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Percent of total	30.00%
Equity securities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Percent of total	45.00%
Fixed-income securities
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return	4.00%
Fixed-income securities \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Percent of total	35.00%
Fixed-income securities \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Percent of total	50.00%
Alternatives
Defined Benefit Plan Disclosure [Line Items]
Expected long-term rate of return	7.00%
Alternatives \| Minimum
Defined Benefit Plan Disclosure [Line Items]
Percent of total	15.00%
Alternatives \| Maximum
Defined Benefit Plan Disclosure [Line Items]
Percent of total	25.00%

Pension and Other Postretirem_9

Pension and Other Postretirement Plans - Pension and Other Postretirement Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Level 3
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	$ 437	$ 401	$ 409
Pension Benefits
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	4,626	4,069	4,964
Pension Benefits \| Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	179	187
Pension Benefits \| Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	842	681
Pension Benefits \| Level 3
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	386	350
Pension Benefits \| Assets Measured at NAV
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	3,219	2,851
Pension Benefits \| Equity securities funds
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	1,754	1,606
Pension Benefits \| Equity securities funds \| Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	71	55
Pension Benefits \| Equity securities funds \| Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	44	125
Pension Benefits \| Equity securities funds \| Level 3
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	147	96
Pension Benefits \| Equity securities funds \| Assets Measured at NAV
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	1,492	1,330
Pension Benefits \| Fixed-income securities
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	1,850	1,644
Pension Benefits \| Fixed-income securities \| Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Pension Benefits \| Fixed-income securities \| Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	739	548
Pension Benefits \| Fixed-income securities \| Level 3
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	15	49
Pension Benefits \| Fixed-income securities \| Assets Measured at NAV
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	1,096	1,047
Pension Benefits \| Alternatives
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	847	669
Pension Benefits \| Alternatives \| Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Pension Benefits \| Alternatives \| Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Pension Benefits \| Alternatives \| Level 3
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	216	195
Pension Benefits \| Alternatives \| Assets Measured at NAV
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	631	474
Pension Benefits \| Other investments
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	175	150
Pension Benefits \| Other investments \| Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	108	132
Pension Benefits \| Other investments \| Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	59	8
Pension Benefits \| Other investments \| Level 3
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	8	10
Pension Benefits \| Other investments \| Assets Measured at NAV
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Postretirement Benefits
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	49	51	$ 52
Other Postretirement Benefits \| Deposit administration fund
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	49	51
Other Postretirement Benefits \| Deposit administration fund \| Level 1
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Postretirement Benefits \| Deposit administration fund \| Level 2
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Other Postretirement Benefits \| Deposit administration fund \| Level 3
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	49	51
Other Postretirement Benefits \| Deposit administration fund \| Assets Measured at NAV
Defined Contribution Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	$ 0

Pension and Other Postretire_10

Pension and Other Postretirement Plans - Defined Benefit Plan Assets Measured at Fair Value Using Unobservable Inputs (Details) - Level 3 - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Fair value of plan assets at beginning of year	$ 401	$ 409
Actual return (loss) on plan assets:
Sold during the year	2	4
Held at year end	48	13
Purchases, sales, issuances and settlements (net)	(14)	(25)
Fair value of plan assets at end of year	$ 437	$ 401

Pension and Other Postretire_11

Pension and Other Postretirement Plans - Estimated Future Benefit Payments (Details) $ in Millions	Dec. 31, 2021USD ($)
Pension Benefits
Pension and Other Postretirement
2022	$ 546
2023	321
2024	320
2025	349
2026	374
Years 2027 – 2031	2,070
Other Postretirement Benefits
Pension and Other Postretirement
2022	131
2023	124
2024	107
2025	98
2026	92
Years 2027 – 2031	$ 365

Pension and Other Postretire_12

Pension and Other Postretirement Plans - Participation in the IAM National Pension Plan (Details) - IAM National Pension Plan - Pension Benefits - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2020
Multiemployer Plans [Line Items]
Plan length	10 years
Additional contribution as a percentage of the hourly contribution rate	0.025%
Surcharge imposed	No
United Airlines, Inc.
Multiemployer Plans [Line Items]
Funded percentage				85.10%
Contributions	$ 58	$ 53	$ 59

Notes Receivable (Details)

Notes Receivable (Details) shares in Millions, adr in Millions	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Nov. 30, 2018USD ($)adrshares
BRW \| Term Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loan amount			$ 456,000,000
Number of shares pledged as collateral (in shares) \| shares			516
Implied value equivalent of shares pledged as collateral (in ADRs) \| adr			64.5
Carrying amount of loan receivable		$ 515,000,000
Boom Technology, Inc.
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount of loan receivable	$ 44,000,000
Other Notes Receivable Counterparties
Accounts, Notes, Loans and Financing Receivable [Line Items]
Carrying amount of loan receivable	$ 32,000,000

Investments and Fair Value Me_3

Investments and Fair Value Measurements - Fair Value of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Measured on a Recurring Basis - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 18,283	$ 11,269
Restricted cash - current	37	255
Restricted cash - non-current	213	218
Equity securities	229	241
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	18,283	11,269
Restricted cash - current	37	255
Restricted cash - non-current	213	218
Equity securities	229	205
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Restricted cash - current	0	0
Restricted cash - non-current	0	0
Equity securities	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	0	0
Restricted cash - current	0	0
Restricted cash - non-current	0	0
Equity securities	0	36
Corporate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	95	330
Corporate debt \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Corporate debt \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	95	330
Corporate debt \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Asset-backed securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	26	51
Asset-backed securities \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
Asset-backed securities \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	26	51
Asset-backed securities \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
U.S. government and agency notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	2	33
U.S. government and agency notes \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	0	0
U.S. government and agency notes \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	2	33
U.S. government and agency notes \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short-term investments	$ 0	$ 0

Investments and Fair Value Me_4

Investments and Fair Value Measurements - Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)aircraft	Dec. 29, 2021
Fair Value [Line Items]
Investments in securities accounted for under the equity method	$ 171
Champlain
Fair Value [Line Items]
Number of regional aircraft \| aircraft	75
Republic
Fair Value [Line Items]
Number of regional aircraft \| aircraft	66
Champlain
Fair Value [Line Items]
Ownership stake	40.00%
Republic
Fair Value [Line Items]
Ownership stake	19.00%
ManaAir
Fair Value [Line Items]
Ownership stake	49.90%
AVG
Fair Value [Line Items]
Ownership stake		16.40%
Carrying value of other investment	$ 164
Fulcrum BioEnergy, Inc., Boom, Alder Fuels LLC, Heart Aerospace Incorporated and ZeroAvia, Inc.
Fair Value [Line Items]
Carrying value of other investment	$ 84

Investments and Fair Value Me_5

Investments and Fair Value Measurements - Carrying Amounts and Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, carrying amount	$ 33,363	$ 26,747
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	34,550	27,441
Fair Value \| Level 1
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	0	0
Fair Value \| Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	29,088	21,985
Fair Value \| Level 3
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, fair value	$ 5,462	$ 5,456

Debt - Summary of Long-Term Deb

Debt - Summary of Long-Term Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Jan. 14, 2022	Dec. 31, 2020
Debt Instrument [Line Items]
Long term debt	$ 33,876		$ 27,301
Less: unamortized debt discount, premiums and debt issuance costs	(513)		(554)
Less: current portion of long-term debt	(3,002)		(1,911)
Long-term debt, net	30,361		24,836
Secured Debt \| Revolving Credit Facility
Debt Instrument [Line Items]
Long term debt	$ 0		1,000
Secured Debt \| Revolving Credit Facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.49%
Secured Debt \| Revolving Credit Facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	5.25%
Secured Debt \| Aircraft notes
Debt Instrument [Line Items]
Long term debt	$ 13,293		14,538
Secured Debt \| Aircraft notes \| Minimum
Debt Instrument [Line Items]
Fixed interest rate	0.62%
Secured Debt \| Aircraft notes \| Maximum
Debt Instrument [Line Items]
Fixed interest rate	6.90%
Secured Debt \| Aircraft notes \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.49%
Secured Debt \| Aircraft notes \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	5.25%
Secured Debt \| MileagePlus Senior Secured Notes
Debt Instrument [Line Items]
Long term debt	$ 3,800		3,800
Fixed interest rate	6.50%
Secured Debt \| MileagePlus Term Loan Facility
Debt Instrument [Line Items]
Long term debt	$ 3,000		3,000
Fixed interest rate	6.25%
Secured Debt \| MileagePlus Term Loan Facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.49%
Secured Debt \| MileagePlus Term Loan Facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	5.25%
Secured Debt \| 2026 and 2029 Notes
Debt Instrument [Line Items]
Long term debt	$ 4,000		0
Secured Debt \| 2026 and 2029 Notes \| Minimum
Debt Instrument [Line Items]
Fixed interest rate	4.38%
Secured Debt \| 2026 and 2029 Notes \| Maximum
Debt Instrument [Line Items]
Fixed interest rate	4.63%
Secured Debt \| 2021 Term Loans
Debt Instrument [Line Items]
Long term debt	$ 4,963		0
Fixed interest rate	4.50%
Secured Debt \| CARES Act Term Loan Facility
Debt Instrument [Line Items]
Long term debt	$ 0		520
Secured Debt \| CARES Act Term Loan Facility \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.49%
Secured Debt \| CARES Act Term Loan Facility \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	5.25%
Secured Debt \| Term loan
Debt Instrument [Line Items]
Long term debt	$ 0		1,444
Secured Debt \| Term loan \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	0.49%
Secured Debt \| Term loan \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	5.25%
Unsecured \| Notes (b)
Debt Instrument [Line Items]
Long term debt	$ 1,041		1,050
Unsecured \| Notes (b) \| Minimum
Debt Instrument [Line Items]
Fixed interest rate	4.25%
Unsecured \| Notes (b) \| Maximum
Debt Instrument [Line Items]
Fixed interest rate	5.00%
Unsecured \| PSP Notes
Debt Instrument [Line Items]
Long term debt	$ 3,181		1,501
Fixed interest rate	1.00%
Unsecured \| Other unsecured debt
Debt Instrument [Line Items]
Long term debt	$ 598		$ 448
Unsecured \| Other unsecured debt \| Minimum
Debt Instrument [Line Items]
Fixed interest rate	0.00%
Unsecured \| Other unsecured debt \| Maximum
Debt Instrument [Line Items]
Fixed interest rate	5.75%
Unsecured \| 2022 Notes \| Subsequent Event
Debt Instrument [Line Items]
Long term debt		$ 400
Fixed interest rate		4.25%

Debt - Contractual Principal Pa

Debt - Contractual Principal Payments under Outstanding Long-Term Debt Agreements (Details) - UAL and United $ in Millions	Dec. 31, 2021USD ($)
Debt Instrument [Line Items]
2022	$ 3,002
2023	2,853
2024	3,908
2025	3,378
2026	5,134
After 2026	15,601
Long-term debt	$ 33,876

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($)	Apr. 21, 2021	Dec. 31, 2021
2026 Notes and 2029 Notes \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 4,000,000,000
2026 Notes \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 2,000,000,000
Stated interest rate	4.375%
Issuance price as a percent of principal amount	100.00%
2029 Notes \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 2,000,000,000
Stated interest rate	4.625%
Issuance price as a percent of principal amount	100.00%
PSP2 Note \| Unsecured Debt
Debt Instrument [Line Items]
Aggregate principal amount		$ 870,000,000
Term of debt		10 years
PSP2 Note \| Years One through Five \| Unsecured Debt
Debt Instrument [Line Items]
Stated interest rate		1.00%
PSP2 Note \| Years Six through Ten \| Unsecured Debt \| SOFR
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
PSP3 Note \| Unsecured Debt
Debt Instrument [Line Items]
Aggregate principal amount		$ 810,000,000
Term of debt		10 years
PSP3 Note \| Years One through Five \| Unsecured Debt
Debt Instrument [Line Items]
Stated interest rate		1.00%
PSP3 Note \| Years Six through Ten \| Unsecured Debt \| SOFR
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
Term Loan B Facility due 2028 \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 5,000,000,000
Quarterly installment repayment as a percent of the original principal amount	0.25%
Term Loan B Facility due 2028 \| Secured Debt \| LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	3.75%
Variable rate floor	0.75%
Term loan \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 1,400,000,000
Term loan \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.49%
Term loan \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		5.25%
CARES Act Term Loan Facility \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 520,000,000
CARES Act Term Loan Facility \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.49%
CARES Act Term Loan Facility \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		5.25%
Borrowings Financing Aircraft Purchases
Debt Instrument [Line Items]
Long term debt		$ 11,200,000,000
Revolving Credit Facility \| Secured Debt \| United Airlines, Inc.
Debt Instrument [Line Items]
Available under revolving credit facility		$ 1,750,000,000
Revolving Credit Facility \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate		0.49%
Revolving Credit Facility \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate		5.25%
Revolving Credit Facility \| Senior Secured Revolving Credit Facility due 2025 \| Secured Debt
Debt Instrument [Line Items]
Commitment fee percentage	0.75%
Revolving Credit Facility \| Senior Secured Revolving Credit Facility due 2025 \| Secured Debt \| LIBOR \| Minimum
Debt Instrument [Line Items]
Basis spread on variable rate	3.00%
Revolving Credit Facility \| Senior Secured Revolving Credit Facility due 2025 \| Secured Debt \| LIBOR \| Maximum
Debt Instrument [Line Items]
Basis spread on variable rate	3.50%
Revolving Credit Facility \| Credit Agreement \| Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 1,000,000,000

Debt - Details of Pass Through

Debt - Details of Pass Through Trusts (Details) - USD ($)	12 Months Ended
Debt - Details of Pass Through Trusts (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Proceeds received from issuance of debt	$ 11,096,000,000	$ 15,676,000,000	$ 1,786,000,000
Class B EETC - Issued February 2021 \| Pass-Through Certificates
Debt Instrument [Line Items]
Face Amount	$ 600,000,000
Stated interest rate	4.88%
Proceeds received from issuance of debt	$ 600,000,000

Debt - Summary of Collateral Co

Debt - Summary of Collateral Covenants and Cross Default Provisions (Details) - Line of Credit $ in Billions	Dec. 31, 2021USD ($)
Credit Agreement
Debt Instrument [Line Items]
Unrestricted liquidity required for credit agreement	$ 2
Minimum ratio of appraised value of collateral for Credit Agreement	1.6
2026 Notes and 2029 Notes
Debt Instrument [Line Items]
Additional interest required if minimum ratio is not met, percent	2.00%
Minimum ratio of appraised value of collateral for Credit Agreement	1.6

Leases and Capacity Purchase _3

Leases and Capacity Purchase Agreements - Components of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 958	$ 933	$ 1,038
Variable and short-term lease cost	2,291	1,968	2,548
Amortization of finance lease assets	89	88	68
Interest on finance lease liabilities	16	16	85
Sublease income	(26)	(23)	(32)
Total lease cost	$ 3,328	$ 2,982	$ 3,707

Leases and Capacity Purchase _4

Leases and Capacity Purchase Agreements - Narrative (Details) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2021aircraft	Dec. 31, 2022USD ($)	Dec. 31, 2021USD ($)aircraft	Dec. 31, 2020USD ($)aircraft	Dec. 31, 2019USD ($)	Aug. 31, 2021USD ($)
Lessee, Lease, Description [Line Items]
Additional leases that have not yet commenced \| $			$ 415
Lease terms of additional leases that have not yet commenced (up to)			12 years
Number of aircraft included in flight equipment			7
Number of aircraft qualified for sale recorded as operating lease right-of-use assets and current/long-term obligations			17
Special Facility Revenue Bonds \| Secured Debt
Lessee, Lease, Description [Line Items]
Fixed interest rate						4.00%
Special Facility Revenue Bonds \| Secured Debt \| City of Houston
Lessee, Lease, Description [Line Items]
Aggregate principal amount \| $						$ 289
Boeing 787-9 and Boeing 737 MAX
Lessee, Lease, Description [Line Items]
Number of aircraft delivered under sale and leaseback transaction				24
Boeing 787
Lessee, Lease, Description [Line Items]
Number of aircraft acquired with exercised purchase options			6
Boeing 737 MAX
Lessee, Lease, Description [Line Items]
Number of aircraft acquired with exercised purchase options			8
Embraer E175
Lessee, Lease, Description [Line Items]
Number of regional aircraft	38
United Airlines, Inc. \| Embraer E175
Lessee, Lease, Description [Line Items]
Long-term purchase commitment, period	12 years
United Airlines, Inc. \| Cash Collateralized Letters of Credit
Lessee, Lease, Description [Line Items]
Number of regional aircraft			518
Mainline Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft subject to operating leases			118
Number of aircraft subject to finance leases			25
Regional Aircraft
Lessee, Lease, Description [Line Items]
Number of aircraft subject to operating leases			282
Number of aircraft subject to finance leases			58
Regional Aircraft \| United Airlines, Inc. \| Capacity Purchase Agreements
Lessee, Lease, Description [Line Items]
Expenses \| $			$ 600	$ 600	$ 1,000
Accounts payable \| $			$ 102	$ 68
Minimum \| Mainline Aircraft
Lessee, Lease, Description [Line Items]
Initial term of operating leases			1 month
Minimum \| Non-Aircraft
Lessee, Lease, Description [Line Items]
Initial term of operating leases			1 month
Maximum \| Mainline Aircraft
Lessee, Lease, Description [Line Items]
Initial term of operating leases			12 years
Maximum \| Non-Aircraft
Lessee, Lease, Description [Line Items]
Initial term of operating leases			31 years
Forecast \| Capacity Purchase Agreements
Lessee, Lease, Description [Line Items]
Scheduled block hours increase (decrease) percentage		10.00%
Change in cash obligation \| $		$ 125

Leases and Capacity Purchase _5

Leases and Capacity Purchase Agreements - Summary of Scheduled Future Minimum Lease Payments under Operating and Finance Leases (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Operating Leases
2022	$ 857
2023	825
2024	775
2025	655
2026	637
After 2026	3,982
Minimum lease payments	7,731
Imputed interest	(2,023)
Present value of minimum lease payments	5,708
Less: current maturities of lease obligations	(556)	$ (612)
Long-term lease obligations	5,152	4,986
Finance Leases
2022	89
2023	57
2024	53
2025	41
2026	26
After 2026	72
Minimum lease payments	338
Imputed interest	(43)
Present value of minimum lease payments	295
Less: current maturities of lease obligations	(76)	(182)
Long-term lease obligations	$ 219	$ 224

Leases and Capacity Purchase _6

Leases and Capacity Purchase Agreements - Additional Information Related to Leases (Details)	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Weighted-average remaining lease term - operating leases	10 years	11 years
Weighted-average remaining lease term - finance leases	6 years	4 years
Weighted-average discount rate - operating leases	5.00%	5.10%
Weighted-average discount rate - finance leases	4.80%	4.40%

Leases and Capacity Purchase _7

Leases and Capacity Purchase Agreements - Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$ 977	$ 788	$ 902
Operating cash flows for finance leases	18	20	70
Financing cash flows for finance leases	$ 216	$ 66	$ 151

Leases and Capacity Purchase _8

Leases and Capacity Purchase Agreements - Future Lease Payment under Terms of Capacity Purchase Agreement (Details) $ in Billions	Dec. 31, 2021USD ($)
Leases [Abstract]
2022	$ 2.1
2023	2.1
2024	2
2025	1.7
2026	1.5
After 2026	4.2
Total	$ 13.6

Variable Interest Entities ("_2

Variable Interest Entities ("VIE") (Details) $ in Billions	Dec. 31, 2021USD ($)
Tax-Exempt Special Facilities Revenue Bonds
Variable Interest Entity [Line Items]
Underlying debt and interest	$ 2.1

Commitments and Contingencies -

Commitments and Contingencies - Firm Commitments and Options to Purchase Aircraft (Details)	Dec. 31, 2021aircraftCommitmentaircraft
Airbus A321XLR
Long-term Purchase Commitment [Line Items]
Number of firm commitments \| aircraftCommitment	50
Scheduled aircraft deliveries in 2022	0
Scheduled aircraft deliveries in 2023	0
Scheduled aircraft deliveries after 2023	50
Airbus A321neo
Long-term Purchase Commitment [Line Items]
Number of firm commitments \| aircraftCommitment	70
Scheduled aircraft deliveries in 2022	0
Scheduled aircraft deliveries in 2023	12
Scheduled aircraft deliveries after 2023	58
Airbus A350
Long-term Purchase Commitment [Line Items]
Number of firm commitments \| aircraftCommitment	45
Scheduled aircraft deliveries in 2022	0
Scheduled aircraft deliveries in 2023	0
Scheduled aircraft deliveries after 2023	45
Boeing 737 MAX
Long-term Purchase Commitment [Line Items]
Number of firm commitments \| aircraftCommitment	367
Scheduled aircraft deliveries in 2022	53
Scheduled aircraft deliveries in 2023	109
Scheduled aircraft deliveries after 2023	205
Boeing 787
Long-term Purchase Commitment [Line Items]
Number of firm commitments \| aircraftCommitment	8
Scheduled aircraft deliveries in 2022	8
Scheduled aircraft deliveries in 2023	0
Scheduled aircraft deliveries after 2023	0

Commitments and Contingencies_2

Commitments and Contingencies - Narrative (Details)	12 Months Ended
Commitments and Contingencies - Narrative (Details)	Dec. 31, 2021USD ($)employeeoption
Commitments and Contingencies [Line Items]
Aggregate balance	$ 13,600,000,000
Number of call options to purchase regional jet aircraft \| option	251
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Number of employees \| employee	84,100
Percentage of employees represented by various U.S. labor organizations	85.00%
United Airlines, Inc. \| Surety Bonds
Commitments and Contingencies [Line Items]
Contingent liabilities based on participation	$ 371,000,000
Tax-Exempt Special Facilities Revenue Bonds
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure	2,100,000,000
Tax-Exempt Special Facilities Revenue Bonds \| Indirect Guarantee of Indebtedness
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure	343,000,000
Contingent liabilities based on participation	1,800,000,000
Aircraft Mortgage Debt
Commitments and Contingencies [Line Items]
Guarantor obligations, maximum exposure	$ 106,000,000
Loans And Leases From Non U S Entities
Commitments and Contingencies [Line Items]
Debt instrument, remaining terms	11 years
Aggregate balance	$ 10,100,000,000
Floating Rate Debt
Commitments and Contingencies [Line Items]
Aggregate principal amount	$ 13,200,000,000
Debt instrument, remaining terms	11 years

Commitments and Contingencies_3

Commitments and Contingencies - Summary of Commitments Related to the Acquisition of Aircraft (Details) $ in Billions	Dec. 31, 2021USD ($)
Commitments and Contingencies Disclosure [Abstract]
2022	$ 5.7
2023	6.9
2024	5
2025	4.3
2026	3.3
After 2026	8.9
Total	$ 34.1

Special Charges (Credits) and_3

Special Charges (Credits) and Unrealized (Gains) Losses on Investments - Components of Special Charges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating:
CARES Act grant	$ (4,021)	$ (3,536)	$ 0
Severance and benefit costs	438	575	16
Impairment of assets	97	318	171
(Gains) losses on sale of assets and other special charges	119	27	59
Total operating special charges (credits)	(3,367)	(2,616)	246
Nonoperating unrealized (gains) losses on investments, net	34	194	(153)
Nonoperating debt extinguishment and modification fees	50	0	0
Nonoperating special termination benefits and settlement losses	31	687	0
Nonoperating credit loss on BRW Term Loan and related guarantee	0	697	0
Total nonoperating special charges and unrealized (gains) losses on investments, net	115	1,578	(153)
Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net	(3,252)	(1,038)	93
Income tax expense (benefit), net of valuation allowance	728	404	(21)
Total operating and nonoperating special charges (credits) and unrealized (gains) losses on investments, net of income taxes	$ (2,524)	$ (634)	$ 72

Special Charges (Credits) and_4

Special Charges (Credits) and Unrealized (Gains) Losses on Investments - Narrative (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)employeeaircraft	Dec. 31, 2020USD ($)plane	Dec. 31, 2019USD ($)
Special Charges [Line Items]
Cash received under the Payroll Support Program		$ 5,800,000	$ 5,100,000
Proceeds from the issuance of an unsecured loan		1,700,000	1,500,000
Proceeds from issuance of warrants			66,000
Severance and benefit expenses		438,000	575,000	$ 16,000
Impairment of assets		$ 97,000	318,000	171,000
Number of aircraft and spare engines retired \| aircraft		64
Gain (loss) on net charges		$ 119,000
Nonoperating unrealized (gains) losses on investments, net		34,000	194,000	(153,000)
Extinguishment of debt, amount		50,000
Grant income			3,600,000
Impairment of right-of-use assets			38,000
Impairments related to cancelled projects			56,000
Settlement losses related to defined benefit pension plans		31,000	687,000	0
Expected credit loss allowance recorded		$ 0	697,000	0
Write-off of unexercised aircraft purchase				18,000
Other miscellaneous impairments				20,000
Charges related to contract terminations				25,000
Charges for the settlement of certain legal matters				18,000
Fleet type transaction costs				14,000
Other charges				2,000
Employee Separation \| Voluntary Separation Leave Programs
Special Charges [Line Items]
Number of employees electing to voluntarily separate from the company \| employee		4,500
Special termination benefits		$ 31,000
Employee Separation \| Voluntary Separation Leave Programs \| Full-Time Employees
Special Charges [Line Items]
Restructuring programs, one-time contribution per employee	$ 125	125
Employee Separation \| Voluntary Separation Leave Programs \| Part-Time Employees
Special Charges [Line Items]
Restructuring programs, one-time contribution per employee	$ 75	75
Payroll Support Program 2 & 3 (PSP 2 & 3) Warrants
Special Charges [Line Items]
Proceeds from issuance of warrants		99,000
Payroll Support Program 2 and 3 (PSP 2 & 3) Note
Special Charges [Line Items]
Grant Income		4,000,000	3,500,000
International Brotherhood of Teamsters
Special Charges [Line Items]
Severance and benefit expenses				2,000
Management
Special Charges [Line Items]
Severance and benefit expenses				14,000
Aircraft Engines
Special Charges [Line Items]
Tangible asset impairment charges				43,000
Hong Kong Routes
Special Charges [Line Items]
Intangible assets impairment charges				$ 90,000
Airbus A319 & Boeing 737-700
Special Charges [Line Items]
Impairment of assets		$ 61,000
Airbus A319
Special Charges [Line Items]
Number of aircraft held for sale \| aircraft		13
Boeing 737-700
Special Charges [Line Items]
Number of aircraft held for sale \| aircraft		13
Embraer EMB 145LR
Special Charges [Line Items]
Impairment of assets		$ 36,000
Boeing 757-200
Special Charges [Line Items]
Tangible asset impairment charges			$ 94,000
Number of planes permanently grounded \| plane			11
Routes
Special Charges [Line Items]
Intangible assets impairment charges			$ 130,000

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts (Details) - UAL and United - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 78	$ 9	$ 8
Additions Charged to Costs and Expenses	3	70	17
Deductions	53	16	16
Other	0	15	0
Balance at End of Period	28	78	9
Obsolescence allowance-spare parts
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	478	425	412
Additions Charged to Costs and Expenses	79	88	76
Deductions	11	35	63
Other	0	0	0
Balance at End of Period	546	478	425
Allowance for credit losses - notes receivable
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	522	0
Additions Charged to Costs and Expenses	1	518
Deductions	0	0
Other	99	4
Balance at End of Period	622	522	0
Valuation allowance for deferred tax assets
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	247	58	59
Additions Charged to Costs and Expenses	(38)	197	0
Deductions	0	8	1
Other	1	0	0
Balance at End of Period	$ 210	$ 247	$ 58