Rambus (RMBS) 10-K26 Feb 202019 FY Annual reportFinancial data

Company Profile

Cover Page

Cover Page - USD ($) $ in Billions	12 Months Ended
Cover Page - USD ($) $ in Billions	Dec. 31, 2019	Jan. 31, 2020	Jun. 30, 2019
Cover page.
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	000-22339
Entity Registrant Name	RAMBUS INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3112828
Entity Address, Address Line One	1050 Enterprise Way
Entity Address, Address Line Two	Suite 700
Entity Address, City or Town	Sunnyvale
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94089
City Area Code	408
Local Phone Number	462-8000
Title of 12(b) Security	Common Stock, $.001 Par Value
Trading Symbol	RMBS
Security Exchange Name	NASDAQ
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
Entity Shell Company	false
Entity Public Float			$ 1.1
Entity Common Stock, Shares Outstanding		112,429,523
Entity Central Index Key	0000917273
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 102,176	$ 115,924
Marketable securities	305,488	161,840
Accounts receivable	44,039	50,863
Unbilled receivables	184,366	176,613
Prepaids and other current assets	18,524	15,738
Inventories	10,086	6,772
Total current assets	664,679	527,750
Intangible assets, net	54,900	59,936
Goodwill	183,465	207,178
Property, plant and equipment, net	44,714	57,028
Operating lease right-of-use assets	37,020	0
Deferred tax assets	4,574	4,435
Unbilled receivables, long-term	343,703	497,003
Other assets	5,931	7,825
Total assets	1,338,986	1,361,155
Current liabilities:
Accounts payable	9,549	7,392
Accrued salaries and benefits	20,291	16,938
Deferred revenue	11,947	19,374
Income taxes payable, short-term	19,142	16,390
Operating lease liabilities	6,357	0
Other current liabilities	18,893	9,191
Total current liabilities	86,179	69,285
Convertible notes, long-term	148,788	141,934
Long-term imputed financing obligation	0	36,297
Long-term operating lease liabilities	39,889	0
Long-term income taxes payable	60,094	77,280
Deferred tax liabilities	13,846	18,960
Other long-term liabilities	19,272	5,287
Total liabilities	368,068	349,043
Commitments and contingencies (Notes 10, 13 and 20)
Stockholders’ equity:
Convertible preferred stock, $.001 par value: Authorized: 5,000,000 shares; Issued and outstanding: no shares at December 31, 2019 and December 31, 2018	0	0
Common Stock, $.001 par value: Authorized: 500,000,000 shares; Issued and outstanding: 112,131,352 shares at December 31, 2019 and 109,017,708 shares at December 31, 2018	112	109
Additional paid in capital	1,261,142	1,226,588
Accumulated deficit	(290,244)	(204,294)
Accumulated other comprehensive loss	(92)	(10,291)
Total stockholders’ equity	970,918	1,012,112
Total liabilities and stockholders’ equity	$ 1,338,986	$ 1,361,155

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Stockholders' equity:
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, Authorized shares	5,000,000	5,000,000
Convertible preferred stock, Issued shares	0	0
Convertible preferred stock, outstanding shares	0	0
Common Stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common Stock, Authorized shares	500,000,000	500,000,000
Common Stock, Issued shares	112,131,352	109,017,708
Common Stock, outstanding shares	112,131,352	109,017,708

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues [Abstract]
Revenue from Contract with Customer, Including Assessed Tax		$ 224,027	$ 231,201	$ 393,096
Operating costs and expenses:
Cost of product revenue	[1]	27,156	18,299	23,783
Cost of contract and other revenue		24,219	35,402	55,364
Research and development	[1]	156,815	158,339	149,135
Sales, general and administrative	[1]	104,116	103,911	110,940
Restructuring charges		8,821	2,217	0
Loss from divestiture		7,439	0	0
Gain from sale of intellectual property		0	0	(533)
Total operating costs and expenses		328,566	318,168	338,689
Operating income (loss)		(104,539)	(86,967)	54,407
Interest income (expense), net		27,375	32,621	1,384
Loss on extinguishment of debt		0	0	(1,082)
Interest expense		(9,852)	(16,282)	(13,720)
Interest and other income (expense), net		17,523	16,339	(13,418)
Income (loss) before income taxes		(87,016)	(70,628)	40,989
Provision for income taxes		3,403	87,329	63,851
Net loss		$ (90,419)	$ (157,957)	$ (22,862)
Net loss per share:
Basic (in dollars per share)		$ (0.81)	$ (1.46)	$ (0.21)
Diluted (in dollars per share)		$ (0.81)	$ (1.46)	$ (0.21)
Weighted average shares used in per share calculations:
Basic (in shares)		110,948	108,450	110,198
Diluted (in shares)		110,948	108,450	110,198
Royalty [Member]
Revenues [Abstract]
Revenue from Contract with Customer, Including Assessed Tax		$ 90,785	$ 130,452	$ 289,594
Product Revenue [Member]
Revenues [Abstract]
Revenue from Contract with Customer, Including Assessed Tax		72,972	38,690	36,509
Contract and other Revenue [Member]
Revenues [Abstract]
Revenue from Contract with Customer, Including Assessed Tax		$ 60,270	$ 62,059	$ 66,993

[1]	* Includes stock-based compensation: Cost of product revenue $ 4 $ 8 $ 78 Research and development $ 11,032 $ 12,582 $ 12,185 Sales, general and administrative $ 15,440 $ 9,146 $ 15,140

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cost of product revenue
Stock-based compensation	$ 4	$ 8	$ 78
Research and development
Stock-based compensation	11,032	12,582	12,185
Sales, general and administrative
Stock-based compensation	$ 15,440	$ 9,146	$ 15,140

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss	$ (90,419)	$ (157,957)	$ (22,862)
Other comprehensive income (loss):
Foreign currency translation adjustment	10,145	(4,447)	7,798
Unrealized gain (loss) on marketable securities, net of tax	54	(747)	613
Total comprehensive loss	$ (80,220)	$ (163,151)	$ (14,451)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain (Loss)	1.125% convertible notes	1.125% convertible notesAdditional Paid-in Capital	1.375% convertible notes	1.375% convertible notesAdditional Paid-in Capital
Balance (in shares) at Dec. 31, 2016		111,054,000
Balance at Dec. 31, 2016	$ 552,782	$ 111	$ 1,181,230	$ (615,051)	$ (13,508)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(22,862)	0	0	(22,862)	0
Foreign currency translation adjustment	7,798				7,798
Unrealized gain (loss) on marketable securities, net of tax	613	0	0	0	613
Issuance of common stock upon exercise of options, equity stock and employee stock purchase plan	10,733	$ 3	10,730	0	0
Issuance of common stock upon exercise of options, equity stock and stock units, and employee stock purchase plan (in shares)		2,727,000
Stock Repurchased and Retired During Period, Shares		(4,017,000)
Stock Repurchased and Retired During Period, Value		$ (4)	(13,477)	(36,557)	0
Repurchase and retirement of common stock under repurchase plan, including prepayment under accelerated share repurchase program	(50,038)
Stock-based compensation	27,403	$ 0	27,403	0	0
Adjustments to Additional Paid in Capital, Equity Component of Convertible Debt						$ (16,651)	$ (16,651)	$ 33,913	$ 33,913
Adjustments to Additional Paid in Capital, Purchase of convertible note hedges	(33,523)								$ (33,523)
Adjustments to Additional Paid in Capital, Warrant Issued	23,173		23,173
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income	38,243			38,243
Balance (in shares) at Dec. 31, 2017		109,764,000
Balance at Dec. 31, 2017	571,584	$ 110	1,212,798	(636,227)	(5,097)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(157,957)	0	0	(157,957)	0
Foreign currency translation adjustment	(4,447)				(4,447)
Unrealized gain (loss) on marketable securities, net of tax	(747)	0	0	0	(747)
Issuance of common stock upon exercise of options, equity stock and employee stock purchase plan	4,630	$ 3	4,627	0	0
Issuance of common stock upon exercise of options, equity stock and stock units, and employee stock purchase plan (in shares)		2,616,000
Stock Repurchased and Retired During Period, Shares		(3,786,000)
Stock Repurchased and Retired During Period, Value	(37,500)	$ (4)	(12,573)	(37,456)	0
Repurchase and retirement of common stock under repurchase plan, including prepayment under accelerated share repurchase program	(50,033)
Stock-based compensation	21,736	$ 0	21,736	0	0
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income \| Accounting Standards Update 2016-01	1,058			1,058
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income \| Accounting Standards Update 2014-09	626,288			626,288
Debt Conversion, Converted Instrument, Shares Issued		424,000
Balance (in shares) at Dec. 31, 2018		109,018,000
Balance at Dec. 31, 2018	1,012,112	$ 109	1,226,588	(204,294)	(10,291)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(90,419)	0	0	(90,419)	0
Foreign currency translation adjustment	10,145				10,145
Unrealized gain (loss) on marketable securities, net of tax	54	0	0	0	54
Issuance of common stock upon exercise of options, equity stock and employee stock purchase plan	8,081	$ 3	8,078	0	0
Issuance of common stock upon exercise of options, equity stock and stock units, and employee stock purchase plan (in shares)		3,113,000
Stock-based compensation	26,476	$ 0	26,476	0	0
New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Net Income \| Accounting Standards Update 2016-02	4,469			4,469
Balance (in shares) at Dec. 31, 2019		112,131,000
Balance at Dec. 31, 2019	$ 970,918	$ 112	$ 1,261,142	$ (290,244)	$ (92)

CONSOLIDATED STATEMENTS OF ST_2

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Parenthetical)	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 17, 2017
Convertible senior notes \| 1.375% convertible notes
Stated Interest rate (as a percent)	1.375%	1.375%	1.375%	1.375%

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	12 Months Ended
CONSOLIDATED STATEMENTS OF CASH FLOWS $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Statement of Cash Flows [Abstract]
Restricted Cash, Current	$ 342	$ 328	$ 0
Cash flows from operating activities:
Net income (loss)	(90,419)	(157,957)	(22,862)
Adjustments to reconcile net loss to net cash provided by operating activities:
Stock-based compensation	26,476	21,736	27,403
Depreciation expense and amortization of operating leases' right of use assets	23,507	10,745	13,275
Amortization of intangible assets	17,058	29,341	41,962
Non-cash interest expense and amortization of convertible debt issuance costs	6,854	9,243	7,578
Loss on extinguishment of debt	0	0	1,082
Deferred tax (benefit) provision	(1,816)	79,954	39,535
Non-cash restructuring	0	670	0
Loss from divestiture	7,439	0	0
Gain (Loss) on Disposition of Other Assets	0	(1,266)	0
Available-for-sale Securities, Gross Realized Gain (Loss), Excluding Other than Temporary Impairments	0	(291)	0
Gain (Loss) on Sale of Equity Investments	696	67	0
Gain from sale of intellectual property and property, plant and equipment, net	157	395	227
Change in operating assets and liabilities, net of effects of acquisitions and divestiture:
Accounts receivable	4,994	(24,933)	(1,110)
Increase (Decrease) in Unbilled Receivables	151,513	145,164	0
Prepaid expenses and other assets	4,064	(4,084)	4,354
Inventories	(3,353)	(1,856)	473
Accounts payable	2,934	(2,268)	(651)
Accrued salaries and benefits and other accrued liabilities	7,135	(3,221)	4,703
Increase (Decrease) in Income Taxes Payable	(15,925)	(14,550)	861
Deferred revenue	(3,497)	228	607
Increase (decrease) in operating lease liabilities	(9,282)	0	0
Net cash provided by operating activities	128,535	87,117	117,437
Cash flows from investing activities:
Purchases of property, plant and equipment	(6,472)	(10,762)	(9,385)
Payments to Acquire Intangible Assets	0	350	120
Purchases of marketable securities	(657,433)	(282,117)	(102,497)
Maturities of marketable securities	507,385	223,079	32,048
Proceeds from sale of marketable securities	6,758	0	4,450
Proceeds from sale of intellectual property and property, plant and equipment, net	29	10	33
Proceeds from Divestiture of Businesses, Net of Cash Divested	76,039	0	0
Proceeds from Sale of Other Assets	0	3,754	0
Proceeds from Sale of Available-for-sale Securities, Equity	0	1,350	0
Payments to Acquire Investments	(1,000)	(3,000)	0
Acquisition of businesses, net of cash acquired	(66,780)	0	0
Net cash used in investing activities	(141,474)	(68,036)	(75,471)
Cash flows from financing activities:
Proceeds from Issuance of Senior Long-term Debt	0	0	172,500
Payments of Debt Issuance Costs	0	0	(3,277)
Payments for Hedge, Financing Activities	0	0	(33,523)
Proceeds from Issuance of Warrants	0	0	23,173
Repayment of senior convertible notes	0	(81,207)	(72,257)
Proceeds received from issuance of common stock under employee stock plans	15,104	11,402	15,826
Payments under Installment	(8,379)	0	0
Principal payments against financing lease obligation	0	(1,080)	(860)
Repurchase and retirement of common stock, including prepayment under accelerated share repurchase program	0	(50,033)	(50,038)
Payments Related to Tax Withholding for Share-based Compensation	(7,023)	(6,766)	(5,099)
Net cash provided by (used in) financing activities	(298)	(127,684)	46,445
Effect of exchange rate changes on cash and cash equivalents	(497)	(989)	2,139
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(13,734)	(109,592)	90,550
Cash, cash equivalents and restricted cash at beginning of year	116,252	225,844	135,294
Cash, cash equivalents and restricted cash at end of year	102,518	116,252	225,844
Cash paid during the period for:
Interest	2,372	3,044	1,553
Income taxes, net of refunds	17,835	23,581	22,733
Non-cash investing and financing activities:
Property, plant and equipment received and accrued in accounts payable and other accrued liabilities	$ 29,844	$ 8,225	$ 1,092

Cash flow supplement - parenthe

Cash flow supplement - parenthetical (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Restricted Cash, Current	$ 342	$ 328	$ 0

Formation and Business of the C

Formation and Business of the Company	12 Months Ended
Formation and Business of the Company	Dec. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Formation and Business of the Company	Formation and Business of the Company Rambus Inc. (the “Company” or “Rambus”) was incorporated in California in March 1990 and reincorporated in Delaware in March 1997. In addition to licensing, the Company is creating new business opportunities through offering products and services where its goal is to perpetuate strong company operating performance and long-term stockholder value. The Company generates revenue by licensing its inventions and solutions, selling its semiconductor products and providing services to market-leading companies. Rambus is a premier Silicon IP and Chip provider, delivering high-speed interface and embedded security solutions to make data faster and safer. With 30 years of innovation, the Company continues to develop and license the foundational technology essential to all modern system on chips (SoCs) and computing systems. The Company delivers a broad range of semiconductor solutions including architecture licenses, high-speed physical and digital controller Interface IP cores, Security IP cores and protocols, and memory interface Chips.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
Summary of Significant Accounting Policies	Dec. 31, 2019
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Financial Statement Presentation The accompanying consolidated financial statements include the accounts of Rambus and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in the accompanying consolidated financial statements. Investments in entities with more than 20% ownership by Rambus and in which Rambus has the ability to significantly influence the operations of the investee (but not control) are accounted for using the equity method and are included in other assets. Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates. Reclassifications Certain prior year balances were reclassified to conform to the current year’s presentation. None of these reclassifications had an impact on reported net income or cash flows for any of the periods presented. Revenue Recognition The Company adopted the New Revenue Standard on January 1, 2018 and all the related amendments using the modified retrospective method. The Company recognized the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of accumulated deficit as of January 1, 2018. The comparative information for 2017 has not been recast and continues to be reported under the accounting standards in effect for that period. The Company recognizes revenue upon transfer of control of promised goods and services in an amount that reflects the consideration it expects to receive in exchange for those goods and services. Substantially all of the goods and services are distinct and are accounted for as separate performance obligations. Where an arrangement includes multiple performance obligations, the transaction price is allocated to these on a relative standalone selling price basis. The Company has established standalone selling prices for all of its offerings - specifically, the same pricing methodology is consistently applied to all licensing arrangements; all services offerings are priced within tightly controlled bands and all contracts that include support and maintenance state a renewal rate or price that is systematically enforced. Cost of Revenue Cost of revenue includes cost of professional services, materials, including cost of wafers processed by third-party foundries, cost associated with packaging and assembly, test and shipping, cost of personnel, including stock-based compensation, and equipment associated with manufacturing support, logistics and quality assurance, warranty cost, amortization of existing technology, write-down of inventories, amortization of production mask costs, overhead and an allocated portion of occupancy costs. Leases The Company leases office space, domestically and internationally, under operating leases. The Company’s leases have remaining lease terms between one year and ten years . Operating leases are included in operating lease right-of-use (“ROU”) assets, operating lease liabilities, and long-term operating lease liabilities in the Company’s consolidated balance sheets. The Company does not have any finance leases. The Company determines if an arrangement is a lease, or contains a lease, at inception. The Company assesses all relevant facts and circumstances in making the determination of the existence of a lease. For leases with terms greater than 12 months, the Company records the related asset and obligation at the present value of lease payments over the term. Many of the Company’s leases include rental escalation clauses, renewal options and/or termination options that are factored into the determination of lease payments when appropriate. Leases with an initial term of 12 months or less are not recorded on the balance sheet, and the Company does not separate non-lease components from lease components. Operating lease costs are included in research and development and selling, general and administrative costs on the statement of operations. Goodwill Goodwill represents the excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired in each business combination. Goodwill is not subject to amortization, but is subject to at least an annual assessment for impairment. The Company performs its impairment analysis of goodwill on an annual basis during the fourth quarter of the year unless conditions arise that warrant a more frequent evaluation. When goodwill is assessed for impairment, the Company has the option to perform an assessment of qualitative factors of impairment (optional assessment) prior to necessitating a quantitative impairment test. Should the optional assessment be used for any given year, qualitative factors to consider for a reporting unit include: cost factors; financial performance; legal, regulatory, contractual, political, business, or other factors; entity specific factors; industry and market considerations; macroeconomic conditions; and other relevant events and factors affecting the reporting unit. If the Company determines in the qualitative assessment that it is more likely than not that the fair value of the reporting unit is less than its carrying value, a quantitative test is then performed. Otherwise, no further testing is required. For a reporting unit tested using a quantitative approach, the Company compares the fair value of the reporting unit with the carrying amount of the reporting unit, including goodwill. The fair value of the reporting unit is estimated using an income approach. Under the income approach, the Company measures fair value of the reporting unit based on a projected cash flow method using a discount rate determined by its management which is commensurate with the risk inherent in its current business model. The Company’s discounted cash flow projections are based on its annual financial forecasts developed internally by management for use in managing its business. If the fair value of the reporting unit exceeds its carrying value, goodwill is not impaired and no further testing is required. If the fair value of the reporting unit is less than the carrying value, then the amount of goodwill impairment will be the amount by which the reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The Company performed its annual goodwill impairment analysis as of December 31, 2019 and determined that there was no impairment of its goodwill. For the years ended December 31, 2018 and 2017, the Company did not recognize any goodwill impairment charges. Intangible Assets Intangible assets are comprised of existing technology, customer contracts and contractual relationships, and other definite-lived and indefinite-lived intangible assets. Identifiable intangible assets resulting from the acquisitions of entities accounted for using the purchase method of accounting are estimated by management based on the fair value of assets received. Identifiable definite-lived intangible assets are being amortized over the period of estimated benefit using the straight-line method and estimated useful lives ranging from six months to ten years . Acquired indefinite-lived intangible assets related to the Company’s in-process research and development (“IPR&D”) are capitalized and subject to impairment testing until completion or abandonment of the projects. Upon successful completion of each project, the Company makes a separate determination of the useful life of the acquired indefinite-lived intangible assets and the related amortization is recorded as an expense over the estimated useful life of the specific projects. Indefinite-lived intangible assets are subject to at least an annual assessment for impairment, applying a fair-value based test. Under the income approach, the Company measures fair value of the indefinite-lived intangible assets based on a projected cash flow method using a discount rate determined by its management which is commensurate with the risk inherent in its current business model. The Company’s discounted cash flow projections are based on its annual financial forecasts developed internally by management for use in managing its business. If the fair value of the indefinite-lived intangible assets exceeds its carrying value, the indefinite-lived intangible assets are not impaired and no further testing is required. If the implied fair value of the indefinite-lived intangible assets is less than the carrying value, the difference is recorded as an impairment loss. Inventories Inventories are stated at the lower of cost or net realizable value. Cost is computed using standard cost, which approximates actual cost, on a first-in, first-out basis. Inventories are reduced for write-downs based on periodic reviews for evidence of slow-moving or obsolete parts. The write-down is based on comparison between inventory on hand and estimated future sales for each specific product. Once written down, inventory write-downs are not reversed until the inventory is sold or scrapped. Inventory write-downs are also established when conditions indicate that the net realizable value is less than cost due to physical deterioration, obsolescence, changes in price level or other causes. Property, Plant and Equipment Property, plant and equipment include computer equipment, computer software, machinery, leasehold improvements, furniture and fixtures and buildings. Computer equipment, computer software, machinery, and furniture and fixtures are stated at cost and generally depreciated on a straight-line basis over an estimated useful life of three years , three years to five years , two years or seven years , and three years , respectively. The buildings were depreciated on a straight-line basis over an estimated useful life of approximately 39 years . Refer to Note 11, “Balance Sheet Details,” and Note 13, “Commitments and Contingencies,” for additional details. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the initial terms of the leases. Upon disposal, assets and related accumulated depreciation are removed from the accounts and the related gain or loss is included in the results from operations. Definite-Lived and Indefinite-Lived Asset Impairment The Company evaluates definite-lived and indefinite-lived assets (including property, plant and equipment and intangible assets) for impairment whenever events or changes in circumstances indicate the carrying value of an asset group may not be recoverable. The carrying value is not recoverable if it exceeds the undiscounted cash flows resulting from the use of the asset group and its eventual disposition. The Company’s estimates of future cash flows attributable to its asset groups require significant judgment based on its historical and anticipated results and are subject to many factors. Factors that the Company considers important which could trigger an impairment review include significant negative industry or economic trends, significant loss of clients, and significant changes in the manner of its use of the acquired assets or the strategy for its overall business. When the Company determines that the carrying value of the asset groups may not be recoverable based upon the existence of one or more of the above indicators of impairment, the Company measures the potential impairment based on a projected discounted cash flow method using a discount rate determined by the Company to be commensurate with the risk inherent in the Company’s current business model. An impairment loss is recognized only if the carrying amount of the asset group is not recoverable and exceeds its fair value. The impairment charge is recorded to reduce the pre-impairment carrying amount of the assets based on the relative carrying amount of those assets, though not to reduce the carrying amount of an asset below its fair value. Different assumptions and judgments could materially affect the calculation of the fair value of the assets. During 2019 , 2018 and 2017, the Company did not recognize any impairment of its definite-lived and indefinite-lived assets. Income Taxes Income taxes are accounted for using an asset and liability approach, which requires the recognition of deferred tax assets and liabilities for expected future tax events that have been recognized differently in Rambus’ consolidated financial statements and tax returns. The measurement of current and deferred tax assets and liabilities is based on provisions of the enacted tax law and the effects of future changes in tax laws or rates are not anticipated. A valuation allowance is established when necessary to reduce deferred tax assets to amounts expected to be realized based on available evidence. In addition, the calculation of the Company’s tax liabilities involves dealing with uncertainties in the application of complex tax regulations. As a result, the Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in its tax return. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes. Stock-Based Compensation and Equity Incentive Plans The Company maintained stock plans covering a broad range of equity grants including stock options, nonvested equity stock and equity stock units and performance based instruments. In addition, the Company sponsors an Employee Stock Purchase Plan (“ESPP”), whereby eligible employees are entitled to purchase Common Stock semi-annually, by means of limited payroll deductions, at a 15% discount from the fair market value of the Common Stock as of specific dates. The Company determines compensation expense associated with restricted stock units based on the fair value of its common stock on the date of grant. The Company determines compensation expense associated with stock options based on the estimated grant date fair value method using the Black-Scholes Merton valuation model. The Company generally recognizes compensation expense using a straight-line amortization method over the respective vesting period for awards that are ultimately expected to vest. Stock-based compensation expense for 2019 , 2018 and 2017 has been reduced for estimated forfeitures. When estimating forfeitures, the Company considers voluntary termination behaviors as well as trends of actual option forfeitures. Cash and Cash Equivalents Cash equivalents are highly liquid investments with original maturity of three months or less at the date of purchase. The Company maintains its cash balances with high quality financial institutions. Cash equivalents are invested in highly-rated and highly-liquid money market securities and certain U.S. government sponsored obligations. Marketable Securities Available-for-sale securities are carried at fair value, based on quoted market prices, with the unrealized gains or losses reported, net of tax, in stockholders’ equity as part of accumulated other comprehensive income (loss). The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, both of which are included in interest and other income, net. Realized gains and losses are recorded on the specific identification method and are included in interest and other income, net. The Company reviews its investments in marketable securities for possible other than temporary impairments on a regular basis. If any loss on investment is believed to be a credit loss, a charge will be recognized in operations. In evaluating whether a credit loss on a debt security has occurred, the Company considers the following factors: 1) the Company’s intent to sell the security, 2) if the Company intends to hold the security, whether or not it is more likely than not that the Company will be required to sell the security before recovery of the security’s amortized cost basis and 3) even if the Company intends to hold the security, whether or not the Company expects the security to recover the entire amortized cost basis. Due to the high credit quality and short term nature of the Company’s investments, there have been no material credit losses recorded to date. The classification of funds between short-term and long-term is based on whether the securities are available for use in operations or other purposes. Fair Value of Financial Instruments The carrying value of cash equivalents, accounts receivable and accounts payable approximate their fair values due to their relatively short maturities as of December 31, 2019 and 2018 . Marketable securities are comprised of available-for-sale securities that are reported at fair value with the related unrealized gains and losses included in accumulated other comprehensive income (loss), a component of stockholders’ equity, net of tax. Fair value of the marketable securities is determined based on quoted market prices. The fair value of the Company’s convertible notes fluctuates with interest rates and with the market price of the common stock, but does not affect the carrying value of the debt on the balance sheet. Research and Development Costs incurred in research and development, which include engineering expenses, such as salaries and related benefits, stock-based compensation, depreciation, professional services and overhead expenses related to the general development of Rambus’ products, are expensed as incurred. Software development costs are capitalized beginning when a product’s technological feasibility has been established and ending when a product is available for general release to customers. Rambus has not capitalized any software development costs since the period between establishing technological feasibility and general customer release is relatively short and as such, these costs have not been material. Computation of Earnings (Loss) Per Share Basic earnings (loss) per share is calculated by dividing the net income (loss) by the weighted average number of common shares outstanding during the period. Diluted earnings (loss) per share is calculated by dividing the earnings (loss) by the weighted average number of common shares and potentially dilutive securities outstanding during the period. Potentially dilutive common shares consist of incremental common shares issuable upon exercise of stock options, employee stock purchases, restricted stock and restricted stock units, and shares issuable upon the conversion of convertible notes. The dilutive effect of outstanding shares is reflected in diluted earnings per share by application of the treasury stock method. This method includes consideration of the amounts to be paid by the employees, the amount of excess tax benefits that would be recognized in equity if the instrument was exercised and the amount of unrecognized stock-based compensation related to future services. No potential dilutive common shares are included in the computation of any diluted per share amount when a net loss is reported. Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources, including foreign currency translation adjustments and unrealized gains and losses on marketable securities. Other comprehensive income (loss), net of tax, is presented in the consolidated statements of comprehensive income (loss). Credit Concentration As of December 31, 2019 and 2018 , the Company’s cash, cash equivalents and marketable securities were invested with various financial institutions in the form of corporate notes, bonds and commercial paper, money market funds, U.S. Treasuries, U.S. Government Agencies, and municipal bonds and notes. The Company’s exposure to market risk for changes in interest rates relates primarily to its investment portfolio. The Company places its investments with high credit issuers and, by investment policy, attempts to limit the amount of credit exposure to any one issuer. As stated in the Company’s investment policy, it will ensure the safety and preservation of the Company’s invested funds by limiting default risk and market risk. The Company has no investments denominated in foreign country currencies and therefore is not subject to foreign exchange risk from these assets. The Company mitigates default risk by investing in high credit quality securities and by positioning its portfolio to respond appropriately to a significant reduction in a credit rating of any investment issuer or guarantor. The portfolio includes only marketable securities with active secondary or resale markets to enable portfolio liquidity. The Company’s note hedge transactions, entered into in connection with the 1.375% convertible senior notes due 2023 (the “2023 Notes”), expose the Company to credit risk to the extent that its counterparties may be unable to meet the terms of the transactions. The Company mitigates this risk by limiting its counterparties to major financial institutions. Refer to Note 12, “Convertible Notes” for further details. The Company’s accounts receivable are derived from revenue earned from customers located in the U.S. and internationally. Refer to Note 7, “Segments and Major Customers” for further details. Foreign Currency Translation and Re-Measurement The Company translates the assets and liabilities of its non-U.S. dollar functional currency subsidiaries into U.S. dollars using exchange rates in effect at the end of each period. Revenue and expenses for these subsidiaries are translated using rates that approximate those in effect during the period. Gains and losses from these translations are recognized in foreign currency translation included in Accumulated Other Comprehensive Gain (Loss) in the consolidated statements of stockholders’ equity. The Company’s subsidiaries that use the U.S. dollar as their functional currency re-measure monetary assets and liabilities at exchange rates in effect at the end of each period, and inventories, property and non-monetary assets and liabilities at historical rates. Additionally, foreign currency transaction gains and losses are included in interest income and other (income) expense, net, in the consolidated statements of operations and were not material in the periods presented. Subsequent to the divestiture of the Company’s Payments and Ticketing businesses, the U.S. dollar is primarily the functional currency of the Company’s foreign subsidiaries. Business Combinations The Company accounts for acquisitions of businesses using the purchase method of accounting, which requires the Company to recognize separately from goodwill the assets acquired and the liabilities assumed at their acquisition date fair values. While the Company uses its best estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date as well as contingent consideration, where applicable, the estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the consolidated statements of operations. Accounting for business combinations requires management to make significant estimates and assumptions, especially at the acquisition date including the Company’s estimates for intangible assets, contractual obligations assumed and pre-acquisition contingencies where applicable. Although, the Company believes the assumptions and estimates made in the past have been reasonable and appropriate, they are based in part on historical experience and information obtained from the management of the acquired companies and are inherently uncertain. Significant estimates and assumptions made by management in estimating the fair value of the existing technologies included revenue growth rates, operating expense margins, technology obsolescence rates and discount rates. Unanticipated events and circumstances may occur that may affect the accuracy or validity of such assumptions, estimates or actual results. Litigation Rambus may be involved in certain legal proceedings. Based upon consultation with outside counsel handling its defense in these matters and an analysis of potential results, if Rambus believes that a loss arising from such matters is probable and can be reasonably estimated, Rambus records the estimated liability in its consolidated financial statements. If only a range of estimated losses can be determined, Rambus records an amount within the range that, in its judgment, reflects the most likely outcome; if none of the estimates within that range is a better estimate than any other amount, Rambus records the low end of the range. Any such accrual would be charged to expense in the appropriate period. Rambus recognizes litigation expenses in the period in which the litigation services were provided.

Recent Accounting Pronouncement

Recent Accounting Pronouncements	12 Months Ended
Recent Accounting Pronouncements	Dec. 31, 2019
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
Recent Accounting Pronouncement	Recent Accounting Pronouncements Recent Accounting Pronouncements Adopted In February 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2016-02, “Leases.” This ASU requires lessees to recognize right-of-use assets and liabilities for operating leases, initially measured at the present value of the lease payments, on the balance sheet. In addition, it requires lessees to recognize a single lease cost, calculated so that the cost of the lease is allocated over the lease term, generally on a straight-line basis. In July 2018, the FASB issued ASU No. 2018-10, “Codification Improvements to Topic 842, Leases,” and ASU No. 2018-11, “Leases (Topic 842),” which allow the application of the new guidance at the beginning of the year of adoption, recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption, in addition to the method of applying the new guidance retrospectively to each prior reporting period presented. The amendments in ASU No. 2018-10 and ASU No. 2018-11 have the same effective and transition requirements as ASU No. 2016-02 (collectively referred to as the “New Leasing Standard”). The Company adopted the New Leasing Standard as of January 1, 2019 using the alternative transition method provided by ASU No. 2018-11 and did not recast comparative periods. The Company elected the package of practical expedients permitted under the transition guidance within the new standard, which among other things, allowed the Company to carry forward the historical lease classification. Additionally, the Company elected the practical expedient related to non-lease components in which the Company will not separate non-lease components from lease components. Finally, the Company made the policy election for the short-term leases exemptions, which allows the Company to not recognize lease assets and liabilities for leases having a term of 12 months or less. Upon adoption, the Company recognized $21.4 million and $23.9 million of lease assets and liabilities, respectively, on its consolidated balance sheet. The difference between the lease assets and lease liabilities, net of the deferred tax impact which was not material, was recorded as an adjustment to the opening accumulated deficit. Additionally, in accordance with the New Leasing Standard, the Company was required to derecognize the Sunnyvale and Ohio facilities as imputed facility obligations (as accounted for under the previous leasing guidance) and recognize these facilities as operating leases on the consolidated balance sheet. This change resulted in no longer recognizing interest expense associated with these imputed facility lease obligations, but instead, recognizing operating lease costs which will be included in operating costs and expenses on the consolidated statement of operations. Furthermore, the Company derecognized $37.6 million of imputed financing obligation related to these facilities and $32.0 million of capitalized building property upon adoption of the New Leasing Standard. The adoption of the New Leasing Standard resulted in a decrease to the Company’s opening accumulated deficit of $4.5 million . Recent Accounting Pronouncements Not Yet Adopted In January 2020, the FASB issued ASU No. 2020-01, “Investments—Equity Securities (Topic 321), Investments—Equity Method and Joint Ventures (Topic 323), and Derivatives and Hedging (Topic 815).” The amendments in this ASU clarify the interaction of the accounting for equity securities under Topic 321 and investments accounted for under the equity method of accounting in Topic 323 and the accounting for certain forward contracts and purchased options accounted for under Topic 815. This ASU is effective for interim and annual reporting periods beginning after December 15, 2020. Early adoption is permitted. The amendments in this ASU should be applied on a prospective basis. The Company is currently evaluating the impact that the adoption of this guidance will have on its consolidated financial statements. In December 2019, the FASB issued ASU No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes.” The amendments in this ASU remove certain exceptions, and clarify and amend existing guidance. This ASU is effective for interim and annual reporting periods beginning after December 15, 2020. Early adoption is permitted. Certain disclosures in ASU No. 2019-12 would need to be applied on a retrospective basis, modified retrospective basis, or prospective basis. The Company is currently evaluating the impact that the adoption of this guidance will have on its consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-13, “Fair Value Measurement (Topic 820): Disclosure Framework-Changes to the Disclosure Requirements for Fair Value Measurement.” The amendments in this ASU remove certain disclosures, modify certain disclosures and add additional disclosures. This ASU is effective for interim and annual reporting periods beginning after December 15, 2019. Early adoption is permitted. Certain disclosures in ASU No. 2018-13 would need to be applied on a retrospective basis and others on a prospective basis. The Company will adopt this ASU effective January 1, 2020 and while the Company is currently evaluating the impact that this guidance will have on its consolidated financial statements, the Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements. In June 2016, the FASB issued ASU No. 2016-13. The purpose of this ASU is to require a financial asset measured at amortized cost basis to be presented at the net amount expected to be collected. Credit losses relating to available-for-sale debt securities should be recorded through an allowance for credit losses. In April 2019, the FASB issued ASU No. 2019-04, “Codification Improvements to Topic 326, Financial Instruments-Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments (ASU 2019-04),” which provided certain improvements to various ASUs, including ASU 2016-13. In May 2019, the FASB issued ASU No. 2019-05, “Financial Instruments-Credit Losses (Topic 326),” which provides an option to irrevocably elect the fair value option for certain financial assets previously measured at amortized cost basis. In November 2019, the FASB issued ASU No. 2019-10, “Financial Instruments-Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842)” which amends certain effective dates. In November 2019, the FASB issued ASU No. 2019-11, “Financial Instruments-Credit Losses (Topic 326),” which provides additional clarifications. These ASUs and the related amendments are effective for interim and annual reporting periods beginning after December 15, 2019. The Company will adopt this ASU on January 1, 2020 and the Company does not expect the adoption of this guidance to have a material impact on its consolidated financial statements.

Revenue Recognition (Notes)

Revenue Recognition (Notes)	12 Months Ended
Revenue Recognition (Notes)	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Rambus’ revenue consists of royalty, product and contract and other revenue. Royalty revenue consists of patent and technology license royalties. Products consist of memory interface chips sold directly and indirectly to module manufacturers and OEMs worldwide through multiple channels, including our direct sales force and distributors. Contract and other revenue consists of software license fees, engineering fees associated with integration of Rambus’ technology solutions into its customers’ products and support and maintenance fees. 1. Royalty Revenue Rambus’ patent and technology licensing arrangements generally range between 1 year and 7 years in duration and generally grant the licensee the right to use the Company’s entire IP portfolio as it evolves over time. These arrangements do not typically grant the licensee the right to terminate for convenience and where such rights exist, termination is prospective, with no refund of fees already paid by the licensee. There is no interdependency or interrelation between the IP included in the portfolio licensed upon contract inception and any IP subsequently made available to the licensee, and the Company would be able to fulfill its promises by transferring the portfolio and the additional IP use rights independently. However, the numbers of additions to, and removals from the portfolio (for example when a patent expires and renewal is not granted to the Company) in any given period have historically been relatively consistent; as such, the Company does not allocate the transaction price between the rights granted at contract inception and those subsequently granted over time as a function of these additions. Patent and technology licensing arrangements result in fixed payments received over time, with guaranteed minimum payments on occasion, variable payments calculated based on the licensee’s sale or use of the IP, or a mix of fixed and variable payments. • For fixed-fee arrangements (including arrangements that include minimum guaranteed amounts), variable royalty arrangements that the Company has concluded are fixed in substance, and the fixed portion of hybrid fixed/variable arrangements, the Company recognizes revenue upon control over the underlying IP use right transferring to the licensee, net of the effect of significant financing components calculated using customer-specific, risk-adjusted lending rates ranging between 3% and 6% , with the related interest income being recognized over time on an effective rate basis. Where a licensee has the contractual right to terminate a fixed-fee arrangement for convenience without any substantive penalty payable upon such termination, the Company applies the guidance in ASU No. 2014-09, Revenue from Contracts with Customers in Accounting Standards Codification (ASC) Topic 606 (“ASC 606” or “the New Revenue Standard”) to the duration of the contract in which the parties have present enforceable rights and obligations and only recognizes revenue for amounts that are due and payable. • For variable arrangements, the Company recognizes revenue based on an estimate of the licensee’s sale or usage of the IP during the period of reference, typically quarterly, with a true-up recorded when the Company receives the actual royalty report from the licensee. 2. Product Revenue Product revenue is recognized upon shipment of product to customers, net of accruals for estimated sales returns and allowances, and to distributors, net of accruals for price protection and rights of return on products unsold by the distributors. To date, none of these accruals have been significant. The Company transacts with direct customers primarily pursuant to standard purchase orders for delivery of products and generally allows customers to cancel or change purchase orders within limited notice periods prior to the scheduled shipment date. 3. Contract and Other Revenue Contract and other revenue consists of software license fees and engineering fees associated with integration of Rambus’ technology solutions into its customers’ related support and maintenance. An initial software arrangement generally consists of a term-based or perpetual license, significant software customization services and support and maintenance services that include post-implementation customer support and the right to unspecified software updates and enhancements on a when and if available basis. The Company recognizes license and customization services revenue based on an over time model, measured using the input method. License and customization services revenue is reported as part of contract and other revenue which was approximately $28 million for the year ended December 31, 2019. Due to the nature of the work performed in these arrangements, the estimation of the over time model is complex and involves significant judgment. The key factor reviewed by management to estimate costs to complete each contract is the estimated man-months necessary to complete the project. The Company recognizes license renewal revenue at the beginning of the renewal period. The Company recognizes revenue from professional services purchased in addition to an initial software arrangement on a cumulative catch-up basis if these services are not distinct from the services provided as part of the initial software arrangement, or as a separate contract if these services are distinct. Prior to the divestiture of the Company’s Payments and Ticketing businesses in 2019, the Company's Payment Product Group derived a significant portion of its revenue from heavily customized software in the mobile market, whereby the Payment Product Group’s software solution interacts with third-party solutions and other payment platforms to provide the functionality the customer requires. Historically, these third-party solutions have evolved at a rapid pace, with the Payment Product Group being required to deliver as part of its support and maintenance services the patches and updates needed to maintain the functionality of its own software offering. As the utility of the solution to the end customer erodes very quickly without these updates, these were viewed as critical and the customized software solution and updates were not separately identifiable. As such, these arrangements were treated as a single performance obligation; revenue was deferred until completion of the customization services, and recognized ratably over the committed support and maintenance term. Prior to the divestiture of the Company’s Payments and Ticketing businesses in 2019, the Company's Ticketing Products Group primarily derived revenue from ticketing services arrangements that systematically consist of a software component, support and maintenance, managed services and hosting services. The software could be hosted by third-party hosting service providers or the Company. All arrangements entered into subsequent to the acquisition (the Company had originally acquired the Payments and Ticketing businesses in 2016) preclude customers from taking possession of the software at any time during the hosting term and the Company had concluded that should a customer that was under contract as of the acquisition date ever request possession of the software, the Ticketing Products Group would have the ability to charge the customer, and enforce a claim to payment of a substantive fee in exchange for such right, and that the costs of setting up the environment needed to run the software would act as a significant disincentive to the customer taking possession of the software. Based on the above, the Company concluded that these services were a single performance obligation, with customers simultaneously receiving and consuming the benefits provided by the Ticketing Products Group’s performance, and recognized ticketing services revenue ratably over the term, commencing upon completion of setup activities. The Company recognized setup fees upon completion. While these activities did not transfer a service to the customer, the Company elected not to defer and amortized these fees over the expected duration of the customer relationship owing to the immateriality of the amounts charged. Significant Judgments Historically and with the exception noted below, no significant judgment has generally been required in determining the amount and timing of revenue from the Company’s contracts with customers. • The Company has adequate tools and controls in place, and substantial experience and expertise in timely and accurately tracking man-months incurred in completing customization and other professional services, and quantifying changes in estimates. Key estimates used in recognizing revenue predominantly consist of the following: • All fixed-fee arrangements result in cash being received after control over the underlying IP use right has transferred to the licensee, and over a period exceeding a year. As such, all these arrangements include a significant financing component. The Company calculates a customer-specific lending rate using a Daily Treasury Yield Curve Rate that changes depending on the date on which the licensing arrangement was entered into and the term (in years) of the arrangement, and takes into consideration a licensee-specific risk profile determined based on a review of the licensee’s “Full Company View” Dun & Bradstreet report obtained on the date the licensing arrangement was signed by the parties, with a risk premium being added to the Daily Treasury Yield Curve Rate considering the overall business risk, financing strength and risk indicators, as listed. • The Company recognizes revenue on variable fee licensing arrangements on the basis of estimates. In connection with the adoption of the New Revenue Standard, the Company has set up specific procedures and controls to ensure timely and accurate quantification of variable royalties, and implemented new systems to enable the preparation of the estimates and reporting of the financial information required by the New Revenue Standard. Contract Balances Timing of revenue recognition may differ from the timing of invoicing to the Company’s customers. The Company records contract assets when revenue is recognized prior to invoicing, and a contract liability when revenue is recognized subsequent to invoicing. The contract assets are primarily related to the Company’s fixed fee IP licensing arrangements and rights to consideration for performance obligations delivered but not billed as of December 31, 2019 . The contract assets are transferred to receivables when the billing occurs. The Company’s contract balances were as follows: As of (In thousands) December 31, 2019 December 31, 2018 Unbilled receivables $ 528,069 $ 673,616 Deferred revenue 11,947 19,566 During the years ended December 31, 2019 and December 31, 2018 , the Company recognized $18.3 million and $20.5 million , respectively, of revenue that was included in the contract balances as of December 31, 2018 and January 1, 2018, respectively. Revenue allocated to remaining performance obligations represents the transaction price allocated to the performance obligations that are unsatisfied, or partially unsatisfied, which includes unearned revenue and amounts that will be invoiced and recognized as revenue in future periods. Contracted but unsatisfied performance obligations were approximately $22.0 million as of December 31, 2019 , which the Company primarily expects to recognize over the next 2 years .

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
Earnings (Loss) Per Share	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings (Loss) Per Share The following table sets forth the computation of basic and diluted income (loss) per share: For the Years Ended December 31, 2019 2018 2017 Net loss per share: Numerator: Net loss $ (90,419 ) $ (157,957 ) $ (22,862 ) Denominator: Weighted-average common shares outstanding - basic 110,948 108,450 110,198 Effect of potential dilutive common shares — — — Weighted-average common shares outstanding - diluted 110,948 108,450 110,198 Basic net loss per share $ (0.81 ) $ (1.46 ) $ (0.21 ) Diluted net loss per share $ (0.81 ) $ (1.46 ) $ (0.21 ) For the years ended December 31, 2019 , 2018 and 2017 , options to purchase approximately 1.0 million , 1.6 million and 1.5 million shares, respectively, were excluded from the calculation because they were anti-dilutive after considering proceeds from exercise, taxes and related unrecognized stock-based compensation expense. For the years ended December 31, 2019 , 2018 and 2017 , an additional 2.4 million , 2.4 million and 3.7 million shares, respectively, have been excluded from the weighted average dilutive shares because there was a net loss for the periods. These shares do not include the Company’s 2023 Notes and the 1.125% convertible senior notes due 2018 (the “2018 Notes”). The par amount of convertible notes is payable in cash equal to the principal amount of the notes plus any accrued and unpaid interest and then the “in-the-money” conversion benefit feature at the conversion price above $18.93 and $12.07, respectively, per share is payable in cash, shares of the Company’s common stock or a combination of both. The Company has the option to pay cash, issue shares of common stock or any combination thereof for the aggregate amount due upon conversion of the notes. The Company’s intent is to settle the principal amount of the notes in cash upon conversion. As a result, upon conversion of the notes, only the amounts payable in excess of the principal amounts of the notes are considered in diluted earnings per share under the treasury stock method. Refer to Note 12, “Convertible Notes” for more details.

Intangible Assets and Goodwill

Intangible Assets and Goodwill	12 Months Ended
Intangible Assets and Goodwill	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets and Goodwill	Intangible Assets and Goodwill Goodwill The following tables present goodwill information for the years ended December 31, 2019 and December 31, 2018 : December 31, Additions to Goodwill (1) Divestiture of Goodwill (2) Effect of Exchange Rates (3) December 31, (In thousands) Total goodwill $ 207,178 $ 30,322 $ (54,494 ) $ 459 $ 183,465 ______________________________________ (1) In August 2019, the Company acquired Northwest Logic, Inc. (“Northwest Logic”), and in December 2019, the Company acquired the Secure Silicon IP and Protocols business from Verimatrix (the “Secure Silicon IP and Protocols business”), which resulted in the Company recognizing additional goodwill. Refer to Note 21, “Acquisitions,” for additional information. (2) Refer to Note 17, “Divestiture,” for additional information. (3) Effect of exchange rates relates to foreign currency translation adjustments for the period. As of December 31, 2019 Gross Carrying Amount Accumulated Impairment Losses Net Carrying Amount (In thousands) Total goodwill $ 205,235 $ (21,770 ) $ 183,465 December 31, Effect of Exchange Rates (1) December 31, (In thousands) Total goodwill $ 209,661 $ (2,483 ) $ 207,178 ______________________________________ (1) Effect of exchange rates relates to foreign currency translation adjustments for the period. As of December 31, 2018 Gross Carrying Amount Accumulated Impairment Losses Net Carrying Amount (In thousands) Total goodwill $ 228,948 $ (21,770 ) $ 207,178 Intangible Assets The components of the Company’s intangible assets as of December 31, 2019 and December 31, 2018 were as follows: As of December 31, 2019 Useful Life Gross Carrying Amount (1) (2) Accumulated Amortization (1) (2) Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 262,789 $ (213,354 ) $ 49,435 Customer contracts and contractual relationships 0.5 to 10 years 36,293 (33,428 ) 2,865 Non-compete agreements and trademarks 3 years 300 (300 ) — IPR&D Not applicable 2,600 — 2,600 Total intangible assets $ 301,982 $ (247,082 ) $ 54,900 _________________________________________ (1) In October 2019, the Company disposed of approximately $20.7 million of net intangible assets in connection with the sale of the legal entities comprising the Company’s Payments and Ticketing businesses. Refer to Note 17, “Divestiture,” for additional information. (2) In August 2019, the Company acquired Northwest Logic, and in December 2019, the Company acquired the Secure Silicon IP and Protocols business, which resulted in the Company recognizing additional intangible assets. Refer to Note 21, “Acquisitions,” for additional information. As of December 31, 2018 Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 258,903 $ (213,824 ) $ 45,079 Customer contracts and contractual relationships 1 to 10 years 67,667 (54,410 ) 13,257 Non-compete agreements and trademarks 3 years 300 (300 ) — IPR&D Not applicable 1,600 — 1,600 Total intangible assets $ 328,470 $ (268,534 ) $ 59,936 During the year ended December 31, 2018, the Company acquired patents related to its memory technology for an immaterial amount. During the year ended December 31, 2018, the Company did not sell any intangible assets. Amortization expense for intangible assets for the years ended December 31, 2019 , 2018 , and 2017 was $17.1 million , $29.3 million , and $42.0 million , respectively. The estimated future amortization expense of intangible assets as of December 31, 2019 was as follows (amounts in thousands): Years Ending December 31: Amount 2020 $ 18,413 2021 14,411 2022 7,444 2023 6,740 2024 5,292 Thereafter — Total amortizable purchased intangible assets 52,300 IPR&D 2,600 Total intangible assets $ 54,900

Segments and Major Customers

Segments and Major Customers	12 Months Ended
Segments and Major Customers	Dec. 31, 2019
Segment Reporting [Abstract]
Business Segments and Major Customers	Segments and Major Customers Operating segments are based upon Rambus’ internal organization structure, the manner in which its operations are managed, the criteria used by its Chief Operating Decision Maker (“CODM”) to evaluate segment performance and availability of separate financial information regularly reviewed for resource allocation and performance assessment. The Company has determined its CODM to be the Chief Executive Officer (“CEO”). In line with the Company’s divestiture of its Payments and Ticketing businesses and its refocus on its semiconductor operations, commencing in the third quarter of 2019, the CEO reviews financial information presented on a consolidated basis for purposes of managing the business, allocating resources, making operating decisions and assessing financial performance. On this basis, the Company is organized and operates as a single segment: high-speed interface IP and chips, and embedded security within the semiconductor space. As of December 31, 2019 , the Company has a single operating and reportable segment. Accordingly, no additional disclosure of segment measures of profit or loss or total assets is applicable for all periods presented. The Company has recast the prior-period segment information to reflect the new segment structure. Accounts receivable from the Company’s major customers representing 10% or more of total accounts receivable at December 31, 2019 and 2018 , respectively, was as follows: As of December 31, 2019 2018 Customer 1 19 % 39 % Customer 2 14 % * Customer 3 * 12 % _________________________________________ * Customer accounted for less than 10% of total accounts receivable in the period Revenue from the Company’s major customers representing 10% or more of total revenue for the years ended December 31, 2019 , 2018 and 2017 were as follows: Years Ended December 31, 2019 2018 2017 Customer A * * 17 % Customer B 10 % * 13 % Customer C * * 13 % Customer D 14 % 15 % * Customer E * 11 % * Revenue from customers in the geographic regions based on the location of contracting parties is as follows: Years Ended December 31, 2019 2018 2017 (In thousands) USA $ 134,526 $ 129,567 $ 165,263 Taiwan 24,118 21,749 9,953 South Korea 3,583 13,421 115,811 Japan 11,877 23,222 23,378 Europe 10,262 15,668 22,597 Canada 3,554 4,960 4,373 Singapore 21,751 19,140 22,554 Asia-Other 14,356 3,474 29,167 Total $ 224,027 $ 231,201 $ 393,096 At December 31, 2019 , of the $44.7 million of total property, plant and equipment, approximately $40.3 million were located in the United States, $3.4 million were located in India and $1.0 million were located in other foreign locations. At December 31, 2018 , of the $57.0 million of total property, plant and equipment, approximately $50.4 million were located in the United States, $3.8 million were located in India and $2.8 million were located in other foreign locations.

Marketable Securities

Marketable Securities	12 Months Ended
Marketable Securities	Dec. 31, 2019
Debt Securities, Available-for-sale [Abstract]
Marketable Securities	Marketable Securities Rambus invests its excess cash and cash equivalents primarily in U.S. government-sponsored obligations, commercial paper, corporate notes and bonds, money market funds and municipal notes and bonds that mature within three years . As of December 31, 2019 and 2018 , all of the Company’s cash equivalents and marketable securities have a remaining maturity of less than one year . All cash equivalents and marketable securities are classified as available-for-sale. Total cash, cash equivalents and marketable securities are summarized as follows: As of December 31, 2019 (Dollars in thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 10,065 $ 10,065 $ — $ — 1.48 % U.S. Government bonds and notes 39,086 39,087 — (1 ) 1.49 % Corporate notes, bonds, commercial paper and other 314,391 314,435 19 (63 ) 1.81 % Total cash equivalents and marketable securities 363,542 363,587 19 (64 ) Cash 44,122 44,122 — — Total cash, cash equivalents and marketable securities $ 407,664 $ 407,709 $ 19 $ (64 ) As of December 31, 2018 (Dollars in thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 10,080 $ 10,080 $ — $ — 2.23 % U.S. Government bonds and notes 32,630 32,634 — (4 ) 2.28 % Corporate notes, bonds, commercial paper and other 183,998 184,095 — (97 ) 2.37 % Total cash equivalents and marketable securities 226,708 226,809 — (101 ) Cash 51,056 51,056 — — Total cash, cash equivalents and marketable securities $ 277,764 $ 277,865 $ — $ (101 ) Available-for-sale securities are reported at fair value on the balance sheets and classified as follows: As of December 31, December 31, (Dollars in thousands) Cash equivalents $ 58,054 $ 64,868 Short term marketable securities 305,488 161,840 Total cash equivalents and marketable securities 363,542 226,708 Cash 44,122 51,056 Total cash, cash equivalents and marketable securities $ 407,664 $ 277,764 The Company continues to invest in highly rated quality, highly liquid debt securities. As of December 31, 2019 , these securities have a remaining maturity of less than one year. The Company holds all of its marketable securities as available-for-sale, marks them to market, and regularly reviews its portfolio to ensure adherence to its investment policy and to monitor individual investments for risk analysis, proper valuation, and unrealized losses that may be other than temporary. The estimated fair value of cash equivalents and marketable securities classified by the length of time that the securities have been in a continuous unrealized loss position at December 31, 2019 and 2018 are as follows: Fair Value Gross Unrealized Loss December 31, December 31, December 31, December 31, (In thousands) Less than one year U.S. Government bonds and notes $ 14,112 $ 32,630 $ (1 ) $ (4 ) Corporate notes, bonds and commercial paper 250,822 183,998 (63 ) (97 ) Total Corporate notes, bonds, and commercial paper and U.S. Government bonds and notes $ 264,934 $ 216,628 $ (64 ) $ (101 ) The gross unrealized loss at December 31, 2019 and 2018 was not material in relation to the Company’s total available-for-sale portfolio. The gross unrealized loss can be primarily attributed to a combination of market conditions as well as the demand for and duration of the U.S. government-sponsored obligations and corporate notes and bonds. The Company has no intent to sell, there is no requirement to sell and the Company believes that it can recover the amortized cost of these investments. The Company has found no evidence of impairment due to credit losses in its portfolio. Therefore, these unrealized losses were recorded in other comprehensive income (loss). However, the Company cannot provide any assurance that its portfolio of cash, cash equivalents and marketable securities will not be impacted by adverse conditions in the financial markets, which may require the Company in the future to record an impairment charge for credit losses which could adversely impact its financial results. Refer to Note 9, “Fair Value of Financial Instruments,” for discussion regarding the fair value of the Company’s cash equivalents and marketable securities.

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
Fair Value of Financial Instruments	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments The fair value measurement statement defines fair value as the price that would be received from selling an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. When determining fair value, the Company considers the principal or most advantageous market in which the Company would transact, and the Company considers assumptions that market participants would use when pricing the asset or liability, such as inherent risk, transfer restrictions, and risk of non-performance. The Company’s financial instruments are measured and recorded at fair value, except for equity method investments and convertible notes. The Company’s non-financial assets, such as goodwill, intangible assets, and property, plant and equipment, are measured at fair value when there is an indicator of impairment and recorded at fair value only when an impairment charge is recognized. The Company’s equity method investments are initially recognized at cost, and the carrying amount is increased or decreased to recognize the Company’s share of the profit or loss of the investee after the date of acquisition. The Company’s share of the investee’s profit or loss is recognized in the Company’s consolidated statements of operations. Distributions received from an investee reduce the carrying amount of the investment. Fair Value Hierarchy The fair value measurement statement requires disclosure that establishes a framework for measuring fair value and expands disclosure about fair value measurements. The statement requires fair value measurement be classified and disclosed in one of the following three categories: Level 1: Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. The Company uses unadjusted quotes to determine fair value. The financial assets in Level 1 include money market funds. Level 2: Quoted prices in markets that are not active, or inputs which are observable, either directly or indirectly, for substantially the full term of the asset or liability. The Company uses observable pricing inputs including benchmark yields, reported trades, and broker/dealer quotes. The financial assets in Level 2 include U.S. government bonds and notes, corporate notes, commercial paper and municipal bonds and notes. Level 3: Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). The Company does not have any financial assets in Level 3 as of December 31, 2019 and 2018 . The Company reviews the pricing inputs by obtaining prices from a different source for the same security on a sample of its portfolio. The Company has not adjusted the pricing inputs it has obtained. The following table presents the financial instruments that are carried at fair value and summarizes the valuation of its cash equivalents and marketable securities by the above pricing levels as of December 31, 2019 and 2018 : As of December 31, 2019 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 10,065 $ 10,065 $ — $ — U.S. Government bonds and notes 39,086 — 39,086 — Corporate notes, bonds, commercial paper and other 314,391 — 314,391 — Total available-for-sale securities $ 363,542 $ 10,065 $ 353,477 $ — As of December 31, 2018 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 10,080 $ 10,080 $ — $ — U.S. Government bonds and notes 32,630 — 32,630 — Corporate notes, bonds, commercial paper and other 183,998 — 183,998 — Total available-for-sale securities $ 226,708 $ 10,080 $ 216,628 $ — The Company monitors its investments for other-than-temporary impairment and records appropriate reductions in carrying value when necessary. The Company monitors its investments for other-than-temporary losses by considering current factors, including the economic environment, market conditions, operational performance and other specific factors relating to the business underlying the investment, reductions in carrying values when necessary and the Company’s ability and intent to hold the investment for a period of time which may be sufficient for anticipated recovery in the market. Any other-than-temporary loss is reported under “Interest and other income (expense), net” in the consolidated statement of operations. During the years ended December 31, 2019 and 2018 , the Company recorded no other-than-temporary impairment charges on its investments. During the second half of 2018, the Company made an investment in a non-marketable equity security of a private company. This equity investment is accounted for under the equity method of accounting, and the Company accounts for its equity method share of the income (loss) on a quarterly basis. As of December 31, 2019 , the Company’s 25.0% ownership percentage amounted to a $3.6 million equity interest in this equity investment. As of December 31, 2018 , the Company’s 27.7% ownership percentage amounted to a $3.3 million equity interest in this equity investment. The Company’s equity interest was included in other assets on the accompanying consolidated balance sheets. The Company recorded immaterial amounts in its consolidated statements of operations representing its share of the investee’s loss for the years ended December 31, 2019 and 2018 . During the years ended December 31, 2019 and 2018 , there were no transfers of financial instruments between different categories of fair value. The following table presents the financial instruments that are not carried at fair value but which require fair value disclosure as of December 31, 2019 and 2018 : As of December 31, 2019 As of December 31, 2018 (in thousands) Face Value Carrying Value Fair Value Face Value Carrying Value Fair Value 1.375% Convertible Senior Notes due 2023 $ 172,500 $ 148,788 $ 174,239 $ 172,500 $ 141,934 $ 150,075 The fair value of the convertible notes at each balance sheet date is determined based on recent quoted market prices for these notes which is a level 2 measurement. As discussed in Note 12, “Convertible Notes,” as of December 31, 2019 , the convertible notes are carried at their face value of $172.5 million , less any unamortized debt discount and unamortized debt issuance costs. The carrying value of other financial instruments, including accounts receivable, accounts payable and other liabilities, approximates fair value due to their short maturities. Information regarding the Company’s goodwill and long-lived assets balances are disclosed in Note 6, “Intangible Assets and Goodwill.”

Leases (Notes)

Leases (Notes)	12 Months Ended
Leases (Notes)	Dec. 31, 2019
Leases [Abstract]
Lessee, Operating Leases	Leases On July 8, 2019, the Company entered into a definitive triple net space lease agreement with 237 North First Street Holdings, LLC (the “Landlord”), whereby the Company will lease approximately 90,000 square feet of office space located at 4453 North First Street in San Jose, California (the “Lease”). The office space will serve as the Company’s corporate headquarters and include engineering, marketing and administrative functions. The Company expects to move to the new premises during the summer of 2020. The Lease has a term of 128 months from the commencement date in October 2019. The starting rent of the Lease is approximately $3.26 per square foot on a triple net basis. The annual base rent increases each year to certain fixed amounts over the course of the term as set forth in the Lease and will be $4.38 per square foot in the eleventh year. In addition to the base rent, the Company will also pay operating expenses, insurance expenses, real estate taxes, and a management fee. The Lease also allows for an option to expand, wherein the Company has the right of first refusal to rent additional space in the building. The Company has a one-time option to extend the Lease for a period of 60 months and may elect to terminate the Lease, via written notice to the Landlord, in the event the office space is damaged or destroyed. Total future required payments under the Lease are approximately $41 million . Pursuant to the terms of the lease, the landlord agreed to reimburse the Company up to $8.9 million , related to a tenant improvement allowance. The lease of the Company’s current Sunnyvale, California headquarters expires on June 30, 2020. Refer to Note 13, “Commitments and Contingencies,” for additional information regarding the Company’s leases. The Company used its incremental borrowing rate to measure the lease liabilities at the adoption date for its existing operating leases that commenced prior to January 1, 2019 which was based on the remaining lease term and remaining lease payments for such leases. On an ongoing basis, as most of the Company’s leases do not provide an implicit rate, the Company will use its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The Company will use the implicit rate when readily determinable. Refer to Note 3, “Recent Accounting Pronouncements” for additional information regarding the adoption of the New Leasing Standard on January 1, 2019. The table below reconciles the undiscounted cash flows for the first five years and total of the remaining years to the operating lease liabilities recorded on the consolidated balance sheet as of December 31, 2019 (in thousands): Years ending December 31, Amount 2020 $ 7,926 2021 8,602 2022 7,381 2023 4,618 2024 3,977 Thereafter 23,314 Total minimum lease payments 55,818 Less: amount of lease payments representing interest (9,572 ) Present value of future minimum lease payments 46,246 Less: current obligations under leases (6,357 ) Long-term lease obligations $ 39,889 As of December 31, 2019 , the weighted-average remaining lease term for the Company’s operating leases was 7.9 years , and the weighted-average discount rate used to determine the present value of the Company’s operating leases was 4.2% . Operating lease costs included in research and development and selling, general and administrative costs on the statement of operations were $9.6 million for the year ended December 31, 2019 . Rent expense, recorded under accounting guidance in effect prior to January 1, 2019 when the New Leasing Standard became effective for the Company, was approximately $5.2 million and $4.4 million for the years ended December 31, 2018 and 2017 , respectively. Cash paid for amounts included in the measurement of operating lease liabilities was $10.4 million for the year ended December 31, 2019 .

Balance Sheet Details

Balance Sheet Details	12 Months Ended
Balance Sheet Details	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Balance Sheet Details	Balance Sheet Details Inventories Inventories consist of the following: As of December 31, 2019 2018 (In thousands) Raw materials $ 3,997 $ 2,583 Work in process 1,455 145 Finished goods 4,634 4,044 Total $ 10,086 $ 6,772 Property, Plant and Equipment, net Property, plant and equipment, net is comprised of the following: As of December 31, 2019 2018 (In thousands) Building (1) $ — $ 40,320 Computer software 50,453 26,127 Computer equipment 36,761 37,223 Furniture and fixtures 16,136 16,286 Leasehold improvements 10,316 10,824 Machinery 10,446 9,097 Construction in progress 1,691 429 Property, plant and equipment, gross 125,803 140,306 Less accumulated depreciation and amortization (81,089 ) (83,278 ) Property, plant and equipment, net $ 44,714 $ 57,028 ______________________________________ (1) Refer to Note 3, “Recent Accounting Pronouncements” and Note 13, “Commitments and Contingencies,” for a discussion related to the Company’s facility leases due to the adoption of the New Leasing Standard on January 1, 2019. Depreciation expense for the years ended December 31, 2019 , 2018 and 2017 was $15.2 million , $10.7 million and $13.3 million , respectively. Accumulated Other Comprehensive Gain (Loss) Accumulated other comprehensive gain (loss) is comprised of the following: As of December 31, 2019 2018 (In thousands) Foreign currency translation adjustments $ 105 $ (10,040 ) Unrealized loss on available-for-sale securities, net of tax (197 ) (251 ) Total $ (92 ) $ (10,291 )

Convertible Notes

Convertible Notes	12 Months Ended
Convertible Notes	Dec. 31, 2019
Debt Disclosure [Abstract]
Convertible Notes	Convertible Notes The Company’s convertible notes are shown in the following table: (Dollars in thousands) As of December 31, 2019 As of December 31, 2018 1.375% Convertible Senior Notes due 2023 $ 172,500 $ 172,500 Unamortized discount - 2023 Notes (22,163 ) (28,517 ) Unamortized debt issuance costs - 2023 Notes (1,549 ) (2,049 ) Total convertible notes $ 148,788 $ 141,934 Less current portion — — Total long-term convertible notes $ 148,788 $ 141,934 1.375% Convertible Senior Notes due 2023. On November 17, 2017, the Company issued $172.5 million aggregate principal amount of 1.375% convertible senior notes pursuant to an indenture (the “2023 Indenture”), by and between the Company and U.S. Bank National Association, as trustee (the “Trustee”). In accounting for the 2023 Notes at issuance, the Company separated the 2023 Notes into liability and equity components pursuant to the accounting standards for convertible debt instruments that may be fully or partially settled in cash upon conversion. As of the date of issuance, the Company determined that the liability component of the 2023 Notes was $137.3 million and the equity component of the 2023 Notes was $35.2 million . The fair value of the liability component was estimated using an interest rate for a similar instrument without a conversion feature. The unamortized discount related to the 2023 Notes is being amortized to interest expense using the effective interest method over approximately five years . The 2023 Notes bear interest at a rate of 1.375% per year, payable semi-annually on February 1 and August 1 of each year, beginning on August 1, 2018. The 2023 Notes will mature on February 1, 2023, unless earlier repurchased by the Company or converted pursuant to their terms. The Company incurred transaction costs of approximately $3.3 million related to the issuance of 2023 Notes. In accounting for these costs, the Company allocated the costs to the liability and equity components in proportion to the allocation of proceeds from the issuance of the 2023 Notes to such components. Transaction costs allocated to the liability component of $2.6 million are netted against the carrying amount of the liability in the consolidated balance sheet and are amortized to interest expense using the effective interest method over the term of the 2023 Notes. The transaction costs allocated to the equity component of $0.7 million were recorded as additional paid-in capital. The initial conversion rate of the 2023 Notes is 52.8318 shares of the Company’s common stock per $1,000 principal amount of 2023 Notes (which is equivalent to an initial conversion price of approximately $18.93 per share). The conversion rate will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a make-whole fundamental change (as defined in the 2023 Indenture), the Company will, in certain circumstances, increase the conversion rate by a number of additional shares for a holder that elects to convert its 2023 Notes in connection with such make-whole fundamental change. Prior to the close of business on the business day immediately preceding November 1, 2022, the 2023 Notes will be convertible only under the following circumstances: (1) during any calendar quarter commencing after March 31, 2018, and only during such calendar quarter, if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) in a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is more than 130% of the conversion price on each applicable trading day; (2) during the five business day period after any five consecutive trading day period in which, for each trading day of that period, the trading price per $1,000 principal amount of 2023 Notes for such trading day was less than 98% of the product of the last reported sale price of the common stock and the conversion rate on each such trading day; (3) upon the occurrence of specified distributions to holders of our common stock; or (4) upon the occurrence of specified corporate transactions. On or after November 1, 2022, until the close of business on the second scheduled trading day immediately preceding the maturity date, holders of the 2023 Notes may convert all or a portion of their 2023 Notes regardless of the foregoing conditions. Upon conversion, the Company will pay cash up to the aggregate principal amount of the 2023 Notes to be converted and pay or deliver, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock, at the Company’s election, in respect of the remainder, if any, of its conversion obligation in excess of the aggregate principal amount of the 2023 Notes being converted. The Company may not redeem the 2023 Notes prior to the maturity date and no sinking fund is provided for the 2023 Notes. Upon the occurrence of a fundamental change (as defined in the 2023 Indenture) prior to the maturity date, holders may require the Company to repurchase all or a portion of the 2023 Notes for cash at a price equal to 100% of the principal amount of the 2023 Notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The 2023 Notes are the Company’s senior unsecured obligations and will rank senior in right of payment to any of the Company’s indebtedness that is expressly subordinated in right of payment to the notes; equal in right of payment with the Company’s existing and future liabilities that are not so subordinated, including its “2018 Notes”; effectively junior in right of payment to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to any existing and future indebtedness and other liabilities (including trade payables, but excluding intercompany obligations and liabilities) and any preferred stock of subsidiaries of the Company. The following events are considered “events of default” with respect to the 2023 Notes, which may result in the acceleration of the maturity of the 2023 Notes: (1) the Company defaults in the payment when due of any principal of any of the 2023 Notes at maturity or upon exercise of a repurchase right or otherwise; (2) the Company defaults in the payment of any interest, including additional interest, if any, on any of the 2023 Notes, when the interest becomes due and payable, and continuance of such default for a period of 30 days; (3) failure by the Company to comply with its obligation to convert the 2023 Notes in accordance with the 2023 Indenture upon exercise of a holder’s conversion right; (4) failure by the Company to give a fundamental change notice or notice of a specified corporate transaction when due with respect to the Notes; (5) failure by the Company to comply with any of its other agreements contained in the 2023 Notes or the 2023 Indenture for a period of 60 days after written notice from the Trustee or the holders of at least 25% in aggregate principal amount of the Notes then outstanding has been received; (6) failure by the Company to pay when due the principal of, or acceleration of, any indebtedness for money borrowed by the Company or any of its Material Subsidiaries (as defined in the 2023 Indenture) in excess of $40.0 million principal amount, if such indebtedness is not discharged, or such acceleration is not annulled, for a period of 30 days after written notice to the Company by the Trustee or to the Company and the Trustee by holders of 25% or more in aggregate principal amount of the 2023 Notes then outstanding in accordance with the 2023 Indenture; and (7) certain events of bankruptcy, insolvency or reorganization of the Company or any of its Material Subsidiaries (as defined in the Indenture). If such an event of default, other than an event of default described in clause (7) above with respect to the Company, occurs and is continuing, the Trustee by written notice to the Company, or the holders of at least 25% in aggregate principal amount of the outstanding Notes by notice to the Company and the Trustee, may, and the Trustee at the request of such holders shall, declare 100% of the principal of and accrued and unpaid interest, if any, on all the Notes then outstanding to be due and payable. If an event of default described in clause (7) above occurs, 100% of the principal of and accrued and unpaid interest on the Notes then outstanding will automatically become due and payable. Note Hedges and Warrants. On November 14, 2017 and November 16, 2017, in connection with the 2023 Notes, the Company entered into privately negotiated convertible note hedge transactions (the “Convertible Note Hedge Transactions”) with respect to the Company’s common stock, par value $0.001 per share (the “Common Stock”), with certain bank counterparties (the “Counterparties”). The Company paid an aggregate amount of approximately $33.5 million to the Counterparties for the Convertible Note Hedge Transactions. The Convertible Note Hedge Transactions cover, subject to anti-dilution adjustments substantially similar to those in the 2023 Notes, approximately 9.1 million shares of Common Stock, the same number of shares underlying the 2023 Notes, at a strike price that corresponds to the initial conversion price of the 2023 Notes, and are exercisable upon conversion of the 2023 Notes. The Convertible Note Hedge Transactions will expire upon the maturity of the 2023 Notes. The Convertible Note Hedge Transactions are intended to reduce the potential economic dilution upon conversion of the 2023 Notes. The Convertible Note Hedge Transactions are separate transactions and are not part of the terms of the 2023 Notes. Holders of the 2023 Notes will not have any rights with respect to the Convertible Note Hedge Transactions. In addition, concurrently with entering into the Convertible Note Hedge Transactions, the Company separately entered into privately negotiated warrant transactions, whereby the Company sold to the Counterparties warrants (the “Warrants”) to acquire, collectively, subject to anti-dilution adjustments, approximately 9.1 million shares of the Common Stock at an initial strike price of approximately $23.30 per share, which represents a premium of 60% over the last reported sale price of the Common Stock of $14.56 on November 14, 2017. The Company received aggregate proceeds of approximately $23.2 million from the sale of the Warrants to the Counterparties. The Warrants are separate transactions and are not part of the 2023 Notes or Convertible Note Hedge Transactions. Holders of the 2023 Notes and Convertible Note Hedge Transactions will not have any rights with respect to the Warrants. The amounts paid and received for the Convertible Note Hedge Transactions and Warrants have been recorded in additional paid-in capital in the consolidated balance sheets. The fair value of the Convertible Note Hedge Transactions and Warrants are not re-measured through earnings each reporting period. The amounts paid for the Convertible Note Hedge Transactions are tax deductible expenses, while the proceeds received from the Warrants are not taxable. Impact to Earnings per Share. The 2023 Notes will have no impact to diluted earnings per share until the average price of our Common Stock exceeds the conversion price of $18.93 per share because the principal amount of the 2023 Notes is required to be settled in cash upon conversion. Under the treasury stock method, in periods the Company reports net income, the Company is required to include the effect of additional shares that may be issued under the 2023 Notes when the price of the Company’s Common Stock exceeds the conversion price. Under this method, the cumulative dilutive effect of the 2023 Notes would be approximately 9.1 million shares if the average price of the Company’s Common Stock is $18.93. However, upon conversion, there will be no economic dilution from the 2023 Notes, as exercise of the Convertible Note Hedge Transactions eliminates any dilution from the 2023 Notes that would have otherwise occurred when the price of the Company’s Common Stock exceeds the conversion price. The Convertible Note Hedge Transactions are required to be excluded from the calculation of diluted earnings per share, as they would be anti-dilutive under the treasury stock method. The warrants will have a dilutive effect when the average share price exceeds the warrant’s strike price of $23.30 per share. However, upon conversion, the Convertible Note Hedge Transactions would neutralize the dilution from the 2023 Notes so that there would only be dilution from the warrants. 1.125% Convertible Senior Notes due 2018. On August 16, 2013, the Company issued $138.0 million aggregate principal amount of 1.125% convertible senior notes pursuant to an indenture (the “2018 Indenture”) by and between the Company and U.S. Bank, National Association as the trustee. The 2018 Notes matured on August 15, 2018 (the “Maturity Date”), subject to earlier repurchase or conversion. In accounting for the 2018 Notes at issuance, the Company separated the 2018 Notes into liability and equity components pursuant to the accounting standards for convertible debt instruments that may be fully or partially settled in cash upon conversion. As of the date of issuance, the Company determined that the liability component of the 2018 Notes was $107.7 million and the equity component of the 2018 Notes was $30.3 million . The fair value of the liability component was estimated using an interest rate for a similar instrument without a conversion feature. The unamortized discount related to the 2018 Notes was amortized to interest expense using the effective interest method over five years through August 2018. The Company paid cash interest at an annual rate of 1.125% of the principal amount at issuance, semi-annually in arrears on February 15 and August 15 of each year, commencing on February 15, 2014. The Company incurred transaction costs of approximately $3.6 million related to the issuance of 2018 Notes. In accounting for these costs, the Company allocated the costs to the liability and equity components in proportion to the allocation of proceeds from the issuance of the 2018 Notes to such components. Transaction costs allocated to the liability component of $2.8 million were recorded as deferred offering costs and were amortized to interest expense using the effective interest method over five years (the expected term of the debt). The transaction costs allocated to the equity component of $0.8 million were recorded as additional paid-in capital. The 2018 Notes were the Company’s general unsecured obligations, ranking equally in right of payment to all of Rambus’ existing and future senior unsecured indebtedness, including the 2023 Notes, and senior in right of payment to any of the Company’s future indebtedness that is expressly subordinated to the 2018 Notes. The 2018 Notes were convertible into shares of the Company’s common stock at an initial conversion rate of 82.8329 shares of common stock per $1,000 principal amount of 2018 Notes, subject to adjustment in certain events. This is equivalent to an initial conversion price of approximately $12.07 per share of common stock. Holders may have surrendered their 2018 Notes for conversion prior to the close of business day immediately preceding May 15, 2018 only under the following circumstances: ( 1) during any calendar quarter commencing after the calendar quarter ending on December 31, 2013 (and only during such calendar quarter), if the closing sale price of the common stock for 20 or more trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter is more than 130% of the conversion price per share of common stock on the last trading day of the preceding calendar quarter; (2) during the five business day period after any five consecutive trading day period (the ‘‘measurement period’’) in which the trading price (as defined below) per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the closing sale price of the Company’s common stock and the conversion rate on each such trading day; (3) upon the occurrence of specified distributions to holders of the Company’s common stock; or (4) upon the occurrence of specified corporate events. On or after May 15, 2018 until the close of business on the second scheduled trading day immediately preceding the Maturity Date, holders may have converted their notes at any time, regardless of the foregoing circumstances. If a holder elected to convert its 2018 Notes in connection with certain fundamental changes, as that term is defined in the 2018 Indenture, that occurred prior to the Maturity Date, the Company would have, in certain circumstances, increased the conversion rate for 2018 Notes converted in connection with such fundamental changes by a specified number of shares of common stock. Upon conversion of the 2018 Notes, the Company will have paid cash up to the aggregate principal amount of the notes to have been converted and paid or delivered, as the case may be, cash, shares of the Company’s common stock or a combination of cash and shares of the Company’s common stock, at the Company’s election, in respect of the remainder, if any, of the Company’s conversion obligation in excess of the aggregate principal amount of the notes converted, as specified in the Indenture. The Company may not have redeemed the 2018 Notes at its option prior to the Maturity Date, and no sinking fund was provided for the 2018 Notes. Upon the occurrence of a fundamental change, holders may have required the Company to repurchase for cash all or any portion of their notes at a repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The following events are considered events of default under the Indenture which may have resulted in the acceleration of the maturity of the 2018 Notes: (1) default in the payment when due of any principal of any of the notes at maturity, upon redemption or upon exercise of a repurchase right or otherwise; (2) default in the payment of any interest, including additional interest, if any, on any of the notes, when the interest became due and payable, and continuance of such default for a period of 30 days; (3) the Company’s failure to deliver cash or cash and shares of the Company’s common stock (including any additional shares deliverable as a result of a conversion in connection with a make-whole fundamental change, as defined in the Indenture) when required by the Indenture; (4) default in the Company’s obligation to provide notice of the occurrence of a fundamental change, make-whole fundamental change or distribution to holders of the Company’s common stock when required by the Indenture; (5) the Company’s failure to comply with any of the Company’s other agreements in the notes or the 2018 Indenture (other than those referred to in clauses (1) through (4) above) for 60 days after the Company’s receipt of written notice to the Company of such default from the trustee or to the Company and the trustee of such default from holders of not less than 25% in aggregate principal amount of the 2018 Notes then outstanding; (6) the Company’s failure to pay when due the principal of, or acceleration of, any indebtedness for money borrowed by the Company or any of the Company’s material subsidiaries in excess of $40 million principal amount, if such indebtedness is not discharged, or such acceleration is not annulled, for a period of 30 days after written notice thereof is delivered to the Company by the trustee or to the Company and the trustee by the holders of 25% or more in aggregate principal amount of the notes then outstanding without such failure to pay having been cured or waived, such acceleration having been rescinded or annulled (if applicable) and such indebtedness not having been paid or discharged; and (7) certain events of bankruptcy, insolvency or reorganization relating to the Company or any of the Company’s material subsidiaries (as defined in the Indenture). If an event of default, other than an event of default described in clause (7) above with respect to the Company, occurred and was continuing, either the trustee or the holders of at least 25% in aggregate principal amount of the notes then outstanding may have declared the principal amount of, and accrued and unpaid interest, including additional interest, if any, on the notes then outstanding to be immediately due and payable. If an event of default described in clause (7) above occurred with respect to the Company, the principal amount of and accrued and unpaid interest, including additional interest, if any, on the notes will have automatically become immediately due and payable. During the third quarter of 2018, the Company paid upon maturity the remaining $81.2 million in aggregate principal amount of the 2018 Notes. Additionally, the Company delivered 423,873 shares of the Company’s common stock as settlement related to the in-the-money conversion feature of the 2018 Notes at maturity. The value of the shares delivered was approximately $5.0 million . During the fourth quarter of 2017, the Company repurchased $56.8 million aggregate principal amount of the 2018 Notes for a price of $72.3 million which resulted in a loss on extinguishment of debt of $1.1 million and $16.6 million being recorded in stockholders’ equity. To determine the impact of the repurchase on stockholders’ equity, the Company first determined the fair value of the liability component of the repurchased 2018 Notes immediately prior to the repurchase. The Company then reduced the amount paid for the repurchased 2018 Notes by the fair value of the liability component and allocated the remaining amount paid to the equity component, which resulted in a reduction to stockholders’ equity. Additional paid-in capital at December 31, 2019 and December 31, 2018 includes $111.3 million and $111.3 million , respectively, for each year related to the equity component of the notes. As of December 31, 2019 , none of the conversion conditions were met related to the 2023 Notes. Therefore, the classification of the entire equity component for the 2023 Notes in permanent equity is appropriate as of December 31, 2019 . Interest expense related to the notes for the years ended December 31, 2019 , 2018 and 2017 was as follows: Years Ended December 31, 2019 2018 2017 (in thousands) 2023 Notes coupon interest at a rate of 1.375% $ 2,372 $ 2,372 $ 290 2023 Notes amortization of discount and debt issuance cost at an additional effective interest rate of 4.9% 6,854 6,486 768 2018 Notes coupon interest at a rate of 1.125% — 377 1,488 2018 Notes amortization of discount and debt issuance cost at an additional effective interest rate of 5.5% — 2,756 6,810 Total interest expense on convertible notes $ 9,226 $ 11,991 $ 9,356

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies On December 15, 2009, the Company entered into a lease agreement for approximately 125,000 square feet of office space located at 1050 Enterprise Way in Sunnyvale, California commencing on July 1, 2010 and expiring on June 30, 2020. The office space is used for the Company’s corporate headquarters, as well as engineering, sales, marketing and administrative operations and activities. The annual base rent for these leases includes certain rent abatement and increases annually over the lease term. The Company has two options to extend the lease for a period of 60 months each and a one-time option to terminate the lease after 84 months in exchange for an early termination fee. Pursuant to the terms of the lease, the landlord agreed to reimburse the Company approximately $9.1 million , which was received by the year ended December 31, 2011. On November 4, 2011, to better plan for future expansion, the Company entered into an amended lease for its Sunnyvale facility for approximately an additional 31,000 square-foot space commencing on March 1, 2012 and expiring on June 30, 2020. Additionally, a tenant improvement allowance to be provided by the landlord was approximately $1.7 million . On September 29, 2012, the Company entered into a second amended Sunnyvale lease to reduce the tenant improvement allowance to approximately $1.5 million . On January 31, 2013, the Company entered into a third amendment to the Sunnyvale lease to surrender the 31,000 square-foot space from the first amendment back to the landlord and recorded a total charge of $2.0 million related to the surrender of the amended lease. Refer to Note 10, “Leases,” for information regarding the Company’s lease agreement for a new corporate headquarters in San Jose, California. On March 8, 2010, the Company entered into a lease agreement for approximately 25,000 square feet of office and manufacturing areas, located in Brecksville, Ohio. The office area was used for the lighting division’s engineering activities while the manufacturing area was used for the manufacture of prototypes. This lease was amended on September 29, 2011 to expand the facility to approximately 51,000 total square feet and the amended lease expired on July 31, 2019. The Company had an option to extend the lease for a period of 60 months . During 2018, the Company closed its lighting division and manufacturing operations in Brecksville, Ohio, and sold the related equipment. Refer to Note 18, “Restructuring and Other Charges,” for additional details. The Company undertook a series of structural improvements to ready the Sunnyvale and Brecksville facilities for its use. Since these improvements were considered structural in nature and the Company was responsible for any cost overruns, for accounting purposes, the Company was treated in substance as the owner of each construction project during the construction period. At the completion of each construction, the Company concluded that it retained sufficient continuing involvement to preclude de-recognition of the building under the FASB authoritative guidance applicable to the sale leasebacks of real estate. As such, prior to January 1, 2019 when the New Leasing Standard became effective for the Company, the Company accounted for the buildings as owned real estate and recorded an imputed financing obligation for its obligations to the legal owners. Upon adoption of the New Leasing Standard, these leases were treated as operating leases. Prior to the adoption of the New Leasing Standard, monthly lease payments on these facilities were allocated between the land element of the lease (which was accounted for as an operating lease) and the imputed financing obligation. The imputed financing obligation was amortized using the effective interest method and the interest rate was determined in accordance with the requirements of sale leaseback accounting. For the years ended December 31, 2018 and 2017, the Company recognized in its Consolidated Statements of Operations $4.3 million and $4.4 million , respectively, of interest expense in connection with the imputed financing obligation on these facilities. As of December 31, 2018, the imputed financing obligation balance in connection with these facilities was $37.6 million , which was primarily classified under long-term imputed financing obligation. As of December 31, 2018, the Company had capitalized $40.3 million in property, plant and equipment based on the estimated fair value of the portion of the pre-construction shell, construction costs related to the build-out of the facilities and capitalized interest during construction period. On November 17, 2017, the Company entered into an Indenture with U.S. Bank, National Association, as trustee, relating to the issuance by the Company of $172.5 million aggregate principal amount of the 2023 Notes. The aggregate principal amount of the 2023 Notes as of December 31, 2019 was $172.5 million , offset by unamortized debt discount and unamortized debt issuance costs of $22.2 million and $1.5 million , respectively, on the accompanying consolidated balance sheets. The unamortized discount related to the 2023 Notes is being amortized to interest expense using the effective method over the remaining 3.1 years until maturity of the 2023 Notes on February 1, 2023. Refer to Note 12, “Convertible Notes,” for additional details. As of December 31, 2019 , the Company’s material contractual obligations were as follows (in thousands): Total 2020 2021 2022 2023 2024 Contractual obligations (1) (2) Other contractual obligations $ 468 $ 234 $ 234 $ — $ — $ — Software licenses (3) 31,530 13,525 11,977 6,028 — — Acquisition retention bonuses (4) 9,998 3,499 3,499 3,000 — — Convertible notes 172,500 — — — 172,500 — Interest payments related to convertible notes 8,308 2,372 2,372 2,372 1,192 — Total $ 222,804 $ 19,630 $ 18,082 $ 11,400 $ 173,692 $ — ______________________________________ (1) The above table does not reflect possible payments in connection with unrecognized tax benefits of approximately $24.6 million including $22.8 million recorded as a reduction of long-term deferred tax assets and $1.8 million in long-term income taxes payable, as of December 31, 2019 . As noted below in Note 19, “Income Taxes,” although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months , the Company cannot reasonably estimate the outcome at this time. (2) For the Company’s lease commitments as of December 31, 2019 , refer to Note 10, “Leases.” (3) The Company has commitments with various software vendors for agreements generally having terms longer than one year . (4) In connection with the acquisitions of Northwest Logic in August 2019 and the Secure Silicon IP and Protocols business in December 2019, the Company is obligated to pay retention bonuses to certain employees subject to certain eligibility and acceleration provisions including the condition of employment. Refer to Note 3, “Recent Accounting Pronouncements” and Note 10, “Leases,” for a discussion related to the Company’s facility leases due to the adoption of the New Leasing Standard on January 1, 2019. Additionally, the Company’s lease-related obligations as of December 31, 2018, as determined under the prior accounting standard, were as follows (in thousands): Total 2019 2020 2021 2022 2023 Lease-related obligations Imputed financing obligation (1) $ 8,081 $ 5,677 $ 2,404 $ — $ — $ — Leases 19,415 5,333 4,883 4,960 3,271 968 Total $ 27,496 $ 11,010 $ 7,287 $ 4,960 $ 3,271 $ 968 _________________________________________ (1) With respect to the imputed financing obligation, the main components of the difference between the amount reflected in the table above and the amount reflected on the consolidated balance sheet are the interest on the imputed financing obligation and the estimated common area expenses over the future periods. The amount includes the amended Ohio lease and the amended Sunnyvale lease. Indemnifications From time to time, the Company indemnifies certain customers as a necessary means of doing business. Indemnification covers customers for losses suffered or incurred by them as a result of any patent, copyright, or other intellectual property infringement or any other claim by any third party arising as result of the applicable agreement with the Company. The Company generally attempts to limit the maximum amount of indemnification that the Company could be required to make under these agreements to the amount of fees received by the Company, however, this is not always possible. The fair value of the liability as of December 31, 2019 and 2018 was not material.

Equity Incentive Plans and Stoc

Equity Incentive Plans and Stock-Based Compensation	12 Months Ended
Equity Incentive Plans and Stock-Based Compensation	Dec. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Equity Incentive Plans and Stock-Based Compensation	Equity Incentive Plans and Stock-Based Compensation Equity Incentive Plans The Company has three equity incentive plans under which grants are currently outstanding: the 2006 Equity Incentive Plan (the “2006 Plan”), the 2015 Equity Incentive Plan (the “2015 Plan”) and the 2019 Inducement Equity Incentive Plan (the “2019 Inducement Plan”). On April 23, 2015, the Company’s stockholders approved the 2015 Plan, which replaced the 2006 Plan. Additionally, in the third quarter of 2019, the Company adopted the 2019 Inducement Plan and, subject to the adjustment provisions of the 2019 Inducement Plan, reserved 400,000 shares of the Company’s common stock for issuance pursuant to equity awards granted under the 2019 Inducement Plan. The 2015 Plan and 2019 Inducement Plan were the Company’s only plans for providing stock-based incentive awards to eligible employees, executive officers, non-employee directors and consultants as of December 31, 2019 . Grants under all plans typically have a requisite service period of 60 months or 48 months , have straight-line vesting schedules and expire not more than 10 years from date of grant. No further awards will be made under the 2006 Plan, but the 2006 Plan will continue to govern awards previously granted under it. In addition, any shares subject to stock options or other awards granted under the 2006 Plan that on or after the effective date of the 2015 Plan are forfeited, cancelled, exchanged or surrendered or terminate under the 2006 Plan will become available for grant under the 2015 Plan. The Board will periodically review actual share consumption under the 2015 Plan and may make a request for additional shares as needed. The 2019 Inducement Plan provides for the grant of equity-based awards, including nonstatutory stock options, restricted stock units, restricted stock, stock appreciation rights, performance shares and performance units, and its terms are substantially similar to the Company’s 2015 Plan. However, awards under the 2019 Inducement Plan may only be granted to individuals who previously have not been employees or non-employee directors of the Company (or who will become employed following a bona fide period of non-employment or service with the Company), as an inducement material to the individuals’ entry into employment with the Company, or, to the extent permitted by Rule 5635(c)(3) of the Nasdaq Listing Rules, in connection with a merger or acquisition. A summary of shares available for grant under the Company’s plans is as follows: Shares Available for Grant Total shares available for grant as of December 31, 2016 7,305,368 Stock options granted (558,426) Stock options forfeited 1,978,042 Nonvested equity stock and stock units granted (1) (2) (5,007,947) Nonvested equity stock and stock units forfeited (1) 1,334,110 Total shares available for grant as of December 31, 2017 5,051,147 Increase in shares approved for issuance 5,500,000 Stock options granted (711,479) Stock options forfeited 877,803 Nonvested equity stock and stock units granted (1) (3) (4,993,802) Nonvested equity stock and stock units forfeited (1) 4,350,377 Total shares available for grant as of December 31, 2018 10,074,046 Increase in shares approved for issuance (5) 400,000 Stock options granted (80,000) Stock options forfeited 426,960 Nonvested equity stock and stock units granted (1) (4) (7,261,845) Nonvested equity stock and stock units forfeited (1) 3,267,702 Total shares available for grant as of December 31, 2019 6,826,863 ______________________________________ (1) For purposes of determining the number of shares available for grant under the 2015 Plan against the maximum number of shares authorized, each restricted stock granted reduces the number of shares available for grant by 1.5 shares and each restricted stock forfeited increases shares available for grant by 1.5 shares. (2) Amount includes 0.4 million shares that had been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below. (3) Amount includes 0.5 million shares that have been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below. (4) Amount includes 1.0 million shares that have been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below. (5) Shares were reserved under the 2019 Inducement Plan adopted in the third quarter of 2019. General Stock Option Information The following table summarizes stock option activity under the Company’s equity incentive plans for the years ended December 31, 2019 , 2018 and 2017 and information regarding stock options outstanding, exercisable, and vested and expected to vest as of December 31, 2019 : Options Outstanding Weighted Average Remaining Contractual Term Number of Shares Weighted Average Exercise Price per Share Aggregate Intrinsic Value (Dollars in thousands, except per share amounts) Outstanding as of December 31, 2016 7,008,833 $ 9.34 Options granted 558,426 $ 12.95 Options exercised (1,278,856) $ 7.34 Options forfeited (1,978,042) $ 10.68 Outstanding as of December 31, 2017 4,310,361 $ 9.78 Options granted 711,479 $ 12.84 Options exercised (908,146) $ 6.70 Options forfeited (877,803) $ 13.73 Outstanding as of December 31, 2018 3,235,891 $ 10.25 Options granted 80,000 $ 13.25 Options exercised (1,249,785) $ 7.79 Options forfeited (426,960) $ 13.71 Outstanding as of December 31, 2019 1,639,146 $ 11.37 4.54 $ 4,631 Vested or expected to vest at December 31, 2019 1,627,218 $ 11.36 4.49 $ 4,621 Options exercisable at December 31, 2019 1,319,210 $ 11.01 3.63 $ 4,327 Employee Stock Purchase Plans During the years ended December 31, 2019 , 2018 , and 2017 , the Company had one employee stock purchase plan, the 2015 Employee Stock Purchase Plan (“2015 ESPP”). Employees generally will be eligible to participate in the plan if they are employed by Rambus for more than 20 hours per week and more than five months in a fiscal year. The 2015 ESPP provides for six month offering periods, with a new offering period commencing on the first trading day on or after May 1 and November 1 of each year. Under the plans, employees may purchase stock at the lower of 85% of the beginning of the offering period (the enrollment date), or the end of each offering period (the purchase date). Employees generally may not purchase more than the number of shares having a value greater than $25,000 in any calendar year, as measured at the purchase date. The Company issued 629,438 shares at a weighted average price of $8.53 per share during the year ended December 31, 2019 . The Company issued 541,395 shares at a weighted average price of $9.99 per share during the year ended December 31, 2018 . The Company issued 615,370 shares at a weighted average price of $10.47 per share during the year ended December 31, 2017 . As of December 31, 2019 , 1,665,440 shares under the ESPP remain available for issuance. Stock-Based Compensation Stock Options During the years ended December 31, 2019 , 2018 and 2017 , Rambus granted 80,000 , 711,479 and 558,426 stock options, respectively, with an estimated total grant-date fair value of $0.3 million , $3.0 million and $2.3 million , respectively. During the years ended December 31, 2019 , 2018 and 2017 , Rambus recorded stock-based compensation related to stock options of $1.0 million , $1.7 million and $2.8 million , respectively. As of December 31, 2019 , there was $2.0 million of total unrecognized compensation cost, net of expected forfeitures, related to unvested stock-based compensation arrangements granted under the stock option plans. This cost is expected to be recognized over a weighted-average period of 2.3 years . The total fair value of options vested for the years ended December 31, 2019 , 2018 and 2017 was $6.7 million , $12.9 million and $17.3 million , respectively. Employee Stock Purchase Plans During the years ended December 31, 2019 , 2018 and 2017 , Rambus recorded stock-based compensation related to the ESPP of $1.5 million , $1.4 million and $1.7 million , respectively. As of December 31, 2019 , there was $0.7 million of total unrecognized compensation cost related to stock-based compensation arrangements granted under the ESPP. That cost is expected to be recognized over four months . There were no tax benefits realized as a result of employee stock option exercises, stock purchase plan purchases, and vesting of equity stock and stock units for the years ended December 31, 2019 and December 31, 2018 . Tax benefits realized as a result of employee stock option exercises, stock purchase plan purchases, and vesting of equity stock and stock units for the year ended December 31, 2017, calculated in accordance with accounting for share-based payments were $1.3 million . Valuation Assumptions Rambus estimates the fair value of stock options using the Black-Scholes-Merton model (“BSM”). The BSM model determines the fair value of stock-based compensation and is affected by Rambus’ stock price on the date of the grant as well as assumptions regarding a number of highly complex and subjective variables. These variables include expected volatility, expected life of the award, expected dividend rate, and expected risk-free rate of return. The assumptions for expected volatility and expected life are the two assumptions that significantly affect the grant date fair value. If actual results differ significantly from these estimates, stock-based compensation expense and Rambus’ results of operations could be materially impacted. The fair value of stock awards is estimated as of the grant date using the BSM option-pricing model assuming a dividend yield of 0% and the additional weighted-average assumptions as listed in the following tables: The following table presents the weighted-average assumptions used to estimate the fair value of stock options granted that contain only service conditions in the periods presented: Stock Option Plan for Years Ended December 31, 2019 2018 2017 Stock Option Plan Expected stock price volatility 33%-36% 24%-32% 24%-32% Risk free interest rate 1.4%-1.6% 2.6%-2.8% 1.8%-2.0% Expected term (in years) 5.1-5.2 5.8 5.3-5.4 Weighted-average fair value of stock options granted $4.36 $4.23 $4.09 Employee Stock Purchase Plan for Years Ended December 31, 2019 2018 2017 Employee Stock Purchase Plan Expected stock price volatility 32% 27%-34% 25%-27% Risk free interest rate 1.6%-2.4% 2.05%-2.5% 0.98%-1.3% Expected term (in years) 0.5 0.5 0.5 Weighted-average fair value of purchase rights granted under the purchase plan $3.13 $2.59 $3.07 Expected Stock Price Volatility: Given the volume of market activity in its market traded options, Rambus determined that it would use the implied volatility of its nearest-to-the-money traded options. The Company believes that the use of implied volatility is more reflective of market conditions and a better indicator of expected volatility than historical volatility. If there is not sufficient volume in its market traded options, the Company will use an equally weighted blend of historical and implied volatility. Risk-free Interest Rate: Rambus bases the risk-free interest rate used in the BSM valuation method on implied yield currently available on the U.S. Treasury zero-coupon issues with an equivalent term. Where the expected terms of Rambus’ stock-based awards do not correspond with the terms for which interest rates are quoted, Rambus uses an approximation based on rates on the closest term currently available. Expected Term: The expected term of options granted represents the period of time that options granted are expected to be outstanding. The expected term was determined based on historical experience of similar awards, giving consideration to the contractual terms of the stock-based awards, vesting schedules and expectations of future employee behavior. The expected term of ESPP grants is based upon the length of each respective purchase period. Nonvested Equity Stock and Stock Units The Company grants nonvested equity stock units to officers, directors and employees. For the years ended December 31, 2019 , 2018 and 2017 , the Company granted nonvested equity stock units totaling 4,233,701 , 2,978,558 and 3,075,396 shares, respectively. These awards have a service condition, generally a service period of four years , except in the case of grants to directors, for which the service period is one year . For the years ended December 31, 2019 , 2018 and 2017 , the fair value of nonvested equity stock units at the date of grant was approximately $43.0 million , $38.1 million and $40.0 million , respectively. During the years ended December 31, 2019 , 2018 and 2017 , the Company granted performance unit awards to certain Company executive officers with vesting subject to the achievement of certain performance conditions. The ultimate number of performance units that can be earned can range from 0% to 200% of target depending on performance relative to target over the applicable period. The shares earned will vest on the third anniversary of the date of grant. The Company’s shares available for grant has been reduced to reflect the shares that could be earned at the maximum target. For the years ended December 31, 2019 , 2018 and 2017 , the Company recorded stock-based compensation expense of approximately $23.9 million , $18.6 million and $22.9 million , respectively, related to all outstanding nonvested equity stock grants. Unrecognized stock-based compensation related to all nonvested equity stock grants, net of an estimate of forfeitures, was approximately $33.2 million at December 31, 2019 . This cost is expected to be recognized over a weighted average period of 2.4 years . The following table reflects the activity related to nonvested equity stock and stock units for the three years ended December 31, 2019 : Nonvested Equity Stock and Stock Units Shares Weighted-Average Grant-Date Fair Value Nonvested at December 31, 2016 4,863,056 $ 12.33 Granted 3,075,396 $ 13.02 Vested (1,216,476) $ 12.15 Forfeited (860,627) $ 12.61 Nonvested at December 31, 2017 5,861,349 $ 12.68 Granted 2,978,558 $ 12.77 Vested (1,713,930) $ 12.39 Forfeited (2,266,842) $ 12.97 Nonvested at December 31, 2018 4,859,135 $ 12.71 Granted 4,233,701 $ 10.17 Vested (1,896,283) $ 12.40 Forfeited (1,907,070) $ 11.33 Nonvested at December 31, 2019 5,289,483 $ 11.27

Stockholders' Equity

Stockholders' Equity	12 Months Ended
Stockholders' Equity	Dec. 31, 2019
Stockholders' Equity Note [Abstract]
Stockholders' Equity	Stockholders’ Equity Share Repurchase Program During the year ended December 31, 2019 , the Company did not repurchase any shares of its common stock under its share repurchase program. On January 21, 2015, the Company’s Board approved a new share repurchase program authorizing the repurchase of up to an aggregate of 20.0 million shares. Share repurchases under the plan may be made through the open market, established plans or privately negotiated transactions in accordance with all applicable securities laws, rules, and regulations. There is no expiration date applicable to the plan. This new stock repurchase program replaced the previous program approved by the Board in February 2010 and canceled the remaining shares outstanding as part of the previous authorization. On March 5, 2018, the Company initiated an accelerated share repurchase program with Citibank N.A. The accelerated share repurchase program was part of the broader share repurchase program previously authorized by the Company’s Board on January 21, 2015. Under the accelerated share repurchase program, the Company pre-paid to Citibank N.A. the $50.0 million purchase price for its common stock and, in turn, the Company received an initial delivery of approximately 3.1 million shares of its common stock from Citibank N.A., in the first quarter of 2018, which were retired and recorded as a $40.0 million reduction to stockholders’ equity. The remaining $10.0 million of the initial payment was recorded as a reduction to stockholders’ equity as an unsettled forward contract indexed to the Company’s stock. During the second quarter of 2018, the accelerated share repurchase program was completed and the Company received an additional 0.7 million shares of its common stock as the final settlement of the accelerated share repurchase program. There were no other repurchases of the Company’s common stock during 2018. On May 1, 2017, the Company initiated an accelerated share repurchase program with Barclays Bank PLC. The accelerated share repurchase program was part of the broader share repurchase program previously authorized by the Company’s Board on January 21, 2015. Under the accelerated share repurchase program, the Company pre-paid to Barclays Bank PLC the $50.0 million purchase price for its common stock and, in turn, the Company received an initial delivery of approximately 3.2 million shares of its common stock from Barclays Bank PLC, in the second quarter of 2017, which were retired and recorded as a $40.0 million reduction to stockholders’ equity. The remaining $10.0 million of the initial payment was recorded as a reduction to stockholders’ equity as an unsettled forward contract indexed to the Company’s stock. The number of shares to be ultimately purchased by the Company was determined based on the volume weighted average price of the common stock during the terms of the transaction, minus an agreed upon discount between the parties. During the fourth quarter of 2017, the accelerated share repurchase program was completed and the Company received an additional 0.8 million shares of its common stock as the final settlement of the accelerated share repurchase program. There were no other repurchases of the Company’s common stock during 2017. As of December 31, 2019 , there remained an outstanding authorization to repurchase approximately 3.6 million shares of the Company’s outstanding common stock under the current share repurchase program. The Company records stock repurchases as a reduction to stockholders’ equity. The Company records a portion of the purchase price of the repurchased shares as an increase to accumulated deficit when the price of the shares repurchased exceeds the average original proceeds per share received from the issuance of common stock. During the year ended December 31, 2018, the cumulative price of $37.5 million was recorded as an increase to accumulated deficit. Convertible Note Hedge Transactions On November 14, 2017 and November 16, 2017, in connection with the 2023 Notes, the Company entered into the Convertible Note Hedge Transactions with respect to the Common Stock, with the Counterparties. The Company paid an aggregate amount of approximately $33.5 million to the Counterparties for the Convertible Note Hedge Transactions. The Convertible Note Hedge Transactions cover, subject to anti-dilution adjustments substantially similar to those in the 2023 Notes, approximately 9.1 million shares of Common Stock, the same number of shares underlying the 2023 Notes, at a strike price that corresponds to the initial conversion price of the 2023 Notes, and are exercisable upon conversion of the 2023 Notes. The Convertible Note Hedge Transactions will expire upon the maturity of the 2023 Notes. The Convertible Note Hedge Transactions are expected generally to reduce the potential dilution to the Common Stock upon conversion of the 2023 Notes and/or offset any cash payments the Company is required to make in excess of the principal amount of the converted 2023 Notes, as the case may be, in the event that the market price per share of the Common Stock, as measured under the terms of the Convertible Note Hedge Transactions, is greater than the strike price of the Convertible Note Hedge Transactions. The Convertible Note Hedge Transactions are separate transactions, entered into by the Company with the Counterparties, and are not part of the terms of the 2023 Notes. Holders of the 2023 Notes will not have any rights with respect to the Convertible Note Hedge Transactions. Refer to Note 12, “Convertible Notes,” for additional details. Warrant Transactions On November 14, 2017 and November 16, 2017, in connection with the 2023 Notes, the Company sold the Warrants to the Counterparties to acquire, collectively, subject to anti-dilution adjustments, approximately 9.1 million shares of the Common Stock at an initial strike price of approximately $23.30 per share, which represents a premium of 60% over the last reported sale price of the Common Stock of $14.56 on November 14, 2017. The Company received aggregate proceeds of approximately $23.2 million from the sale of the Warrants to the Counterparties. The Warrants were sold in private placements to the Counterparties pursuant to an exemption from the registration requirements of the Securities Act afforded by Section 4(a)(2) of the Securities Act. If the market price per share of the Common Stock, as measured under the terms of the Warrants, exceeds the strike price of the Warrants, the Warrants could have a dilutive effect, unless the Company elects, subject to certain conditions, to settle the Warrants in cash. The Warrants are separate transactions, entered into by the Company with the Counterparties, and are not part of the terms of the 2023 Notes. Holders of the 2023 Notes will not have any rights with respect to the Warrants. Refer to Note 12, “Convertible Notes,” for additional details.

Benefit Plans

Benefit Plans	12 Months Ended
Benefit Plans	Dec. 31, 2019
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans Rambus has a 401(k) Profit Sharing Plan (the “401(k) Plan”) qualified under Section 401(k) of the Internal Revenue Code of 1986. Each eligible employee may elect to contribute up to 60% of the employee’s annual compensation to the 401(k) Plan, up to the Internal Revenue Service limit. Rambus, at the discretion of its Board of Directors, may match employee contributions to the 401(k) Plan. The Company matches 50% of eligible employee’s contribution, up to the first 6% of an eligible employee’s qualified earnings. For the years ended December 31, 2019 , 2018 and 2017 , Rambus made matching contributions totaling approximately $2.0 million , $2.1 million and $2.3 million , respectively.

Divestiture (Notes)

Divestiture (Notes)	12 Months Ended
Divestiture (Notes)	Dec. 31, 2019
Discontinued Operations and Disposal Groups [Abstract]
Divestiture	Divestiture During the second quarter of 2019, the Company entered into a share purchase agreement with Visa International Service Association (the “Purchaser”), pursuant to which the Purchaser agreed to acquire all of the outstanding shares of the Company’s subsidiary, Smart Card Software Limited, which comprises the Company’s Payments and Ticketing businesses, which was part of the Company’s former Rambus Security Division (RSD) segment. The decision to sell these businesses reflected the Company’s ongoing review of its business to focus on products and offerings that are core to its semiconductor business. The sale of the legal entities comprising the Company’s Payments and Ticketing businesses was completed in October 2019. The final gross proceeds from the sale amounted to $82.5 million , which included the selling price of $75.0 million and approximately $7.5 million in net working capital adjustments finalized in October 2019. The $7.5 million in net working capital adjustments is net of a final working capital adjustment due to the buyer of approximately $1.1 million , which the Company will pay in cash to the buyer during the first quarter of 2020. The final gross proceeds were offset by approximately $3.8 million in transaction costs for the year ended December 31, 2019 . The Company measured these businesses at the lower of their carrying value or fair value less any costs to sell, and recognized a cumulative impairment of approximately $7.4 million during the year ended December 31, 2019 . In the second quarter of 2019, in order to determine the impairment loss, the Company performed a relative fair value measurement to allocate goodwill to the business units between the disposed Payments and Ticketing businesses and the retained business, which includes Cryptography Research Inc., which was part of the former RSD segment. The fair value of the retained business was estimated by management using a discounted cash flow model. The Company’s cash flow projections for the retained business included significant judgments and assumptions relating to revenue growth rates, projected operating income and the discount rate. The operating results of these businesses did not qualify for reporting as discontinued operations. The reported results and financial position of the businesses did not necessarily reflect the total value of the businesses that the Company realized upon their sale.

Restructuring Charges

Restructuring Charges	12 Months Ended
Restructuring Charges	Dec. 31, 2019
Restructuring and Related Activities [Abstract]
Restructuring Costs	Restructuring and Other Charges The 2019 Plan In June 2019, the Company initiated a restructuring program to reduce overall expenses which is expected to improve future profitability by reducing spending on research and development efforts and sales, general and administrative programs (the “2019 Plan”). In connection with this restructuring program, the Company initiated a plan of termination resulting in a reduction of approximately 80 employees. During the year ended December 31, 2019 , the Company recorded restructuring and other severance-related charges of approximately $8.8 million related primarily to the reduction in workforce. As of December 31, 2019 , the Company’s accrued restructuring balance was approximately $5.0 million . The 2019 Plan is expected to be substantially completed in early 2020. The 2018 Plan On January 30, 2018, the Company announced its plans to close its lighting division and manufacturing operations in Brecksville, Ohio, (“the 2018 Plan”). The Company believed that such business was not core to its strategy and growth objectives. In connection therewith, the Company terminated approximately fifty employees, and began the process to exit the facilities in Ohio and sell the related equipment. The Company expected to record restructuring charges of approximately $2.0 million to $5.0 million related to employee terminations and severance costs and facility related costs. During the year ended December 31, 2018, the Company recorded a net charge of $2.2 million , primarily related to the reduction in workforce, of which $2.0 million was related to the lighting division and $0.2 million was related to corporate support functions. The 2018 Plan was completed as of December 31, 2019. The Company concluded that the closure of its lighting division did not meet the criteria for reporting as discontinued operations. Consequently, the lighting division’s long-lived assets were reclassified as held for sale. As of December 31, 2018, the Company sold all property, plant and equipment from its lighting division reclassified as held for sale on the consolidated balance sheets of approximately $3.5 million and recognized a gain on the disposal of the held for sale assets of approximately $1.2 million included in restructuring charges on the consolidated statements of operations. During 2017, the Company did not initiate any restructuring programs.

Income Taxes

Income Taxes	12 Months Ended
Income Taxes	Dec. 31, 2019
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income Taxes	Income Taxes Income (loss) before taxes consisted of the following: Years Ended December 31, 2019 2018 2017 (In thousands) Domestic $ (81,316 ) $ (63,829 ) $ 46,031 Foreign (5,700 ) (6,799 ) (5,042 ) $ (87,016 ) $ (70,628 ) $ 40,989 The provision for (benefit from) income taxes is comprised of: Years Ended December 31, 2019 2018 2017 (In thousands) Federal: Current $ 2,932 $ 5,451 $ 20,661 Deferred 2,016 82,726 43,678 State: Current 657 333 495 Deferred (1,198 ) 522 (43 ) Foreign: Current 1,708 1,592 1,101 Deferred (2,712 ) (3,295 ) (2,041 ) $ 3,403 $ 87,329 $ 63,851 The differences between Rambus’ effective tax rate and the U.S. federal statutory regular tax rate are as follows: Years Ended December 31, 2019 2018 2017 Expense at U.S. federal statutory rate 21.0 % 21.0 % 35.0 % Expense (benefit) at state statutory rate 0.9 (1.2 ) 0.7 Withholding tax (3.5 ) (7.7 ) 50.1 Foreign rate differential (1.1 ) (0.2 ) 2.8 Research and development (“R&D”) credit 1.2 2.2 (3.9 ) Executive compensation (1.2 ) (0.1 ) 1.8 Stock-based compensation (2.3 ) (2.8 ) 14.9 Foreign tax credit 3.4 7.7 (50.1 ) Foreign derived intangible income deduction 4.6 14.8 — Impact of corporate rate change on deferred taxes — — 50.6 Divestiture 4.8 — — Other (0.2 ) 0.7 1.4 Valuation allowance (31.5 ) (158.0 ) 52.5 (3.9 )% (123.6 )% 155.8 % The components of the net deferred tax assets (liabilities) are as follows: As of December 31, 2019 2018 (In thousands) Deferred tax assets: Depreciation and amortization $ 13,995 $ 13,085 Lease liabilities 10,734 — Other timing differences, accruals and reserves 9,522 8,272 Deferred equity compensation 4,456 6,236 Net operating loss carryovers 20,900 21,259 Tax credits 233,407 253,890 Total gross deferred tax assets 293,014 302,742 Deferred tax liabilities: Lease right-of-use assets (10,400) — Convertible debt (151) (207) Deferred revenue (94,763) (143,182 ) Total gross deferred tax liabilities (105,314) (143,389 ) Total net deferred tax assets 187,700 159,353 Valuation allowance (196,972 ) (173,878 ) Net deferred tax liabilities $ (9,272 ) $ (14,525 ) As of December 31, 2019 2018 (In thousands) Reported as: Non-current deferred tax assets $ 4,574 $ 4,435 Non-current deferred tax liabilities (13,846 ) (18,960 ) Net deferred tax liabilities $ (9,272 ) $ (14,525 ) The Company periodically evaluates the realizability of its net deferred tax assets based on all available evidence, both positive and negative. During the third quarter of 2018, the Company assessed the changes in its underlying facts and circumstances and evaluated the realizability of its existing deferred tax assets based on all available evidence, both positive and negative, and the weight accorded to each, and concluded a full valuation allowance associated with U.S. federal and California deferred tax assets was appropriate. As such, the Company has set up and continues to maintain a full valuation allowance against its U.S. federal deferred tax assets. The following table presents the tax valuation allowance information for the years ended December 31, 2019 , 2018 and 2017 : Balance at Beginning of Period Charged (Credited) to Operations Charged to Other Account* Valuation Allowance Release Valuation Allowance Set up Balance at End of Period Tax Valuation Allowance Year ended December 31, 2017 $ 23,529 — 5,855 — 21,527 $ 50,911 Year ended December 31, 2018 $ 50,911 — 9,238 — 113,729 $ 173,878 Year ended December 31, 2019 $ 173,878 23,094 — — — $ 196,972 ______________________________________ * Amounts not charged to operations are charged to other comprehensive income or retained earnings. As of December 31, 2019 , Rambus had California and other state net operating loss carryforwards of $202.7 million and $36.4 million , respectively. As of December 31, 2019 , Rambus had federal and state capital loss carryforwards of $26.4 million . As of December 31, 2019 , Rambus had federal research and development tax credit carryforwards of $40.6 million , alternative minimum tax credit carryforwards of $1.9 million and foreign tax credits of $186.1 million . As of December 31, 2019 , Rambus had California research and development tax credit carryforwards of $31.5 million . The federal foreign tax credits and research and development credits begin to expire in 2020 and 2019, respectively. Approximately $29.1 million of federal foreign tax credits will expire in 2020. The California net operating losses begin to expire in 2020. The California research and development credits carry forward indefinitely. In the event of a change in ownership, as defined under federal and state tax laws, Rambus’ net operating loss and tax credit carryforwards could be subject to annual limitations. The annual limitations could result in the expiration of the net operating loss and tax credit carryforwards prior to utilization. As of December 31, 2019 , the Company had $115.7 million of unrecognized tax benefits including $22.8 million recorded as a reduction of long-term deferred tax assets, $91 million recorded as a reduction of other assets associated with refundable withholding taxes previously withheld from licensees in South Korea (Korea), and $1.8 million recorded in long-term income taxes payable. As a result of recent court rulings in Korea, the Company has determined that they may be entitled to refund claims for foreign taxes previously withheld from licensees in Korea. The Company recognizes that there are numerous risks and uncertainties associated with the ultimate collection of this refund, and, has therefore established an offsetting reserve for the entire amount of refundable withholding taxes previously withheld in Korea (which had an insignificant impact to the Company’s income tax provision). If recognized, $1.8 million would be recorded as an income tax benefit in the consolidated statement of operations. As of December 31, 2018 , the Company had $23.5 million of unrecognized tax benefits including $21.4 million recorded as a reduction of long-term deferred tax assets and $2.1 million recorded in long term income taxes payable. If recognized, $2.1 million would be recorded as an income tax benefit in the consolidated statement of operations. It is reasonably possible that a reduction of up to $0.1 million of existing unrecognized tax benefits could occur in the next 12 months . A reconciliation of the beginning and ending amounts of unrecognized income tax benefits for the years ended December 31, 2019 , 2018 and 2017 is as follows (amounts in thousands): Years Ended December 31, 2019 2018 2017 Balance at January 1 $ 23,482 $ 22,652 $ 21,925 Tax positions related to current year: Additions 16,485 1,032 1,083 Tax positions related to prior years: Additions 76,158 115 16 Reductions (472 ) (317 ) (372 ) Settlements — — — Balance at December 31 $ 115,653 $ 23,482 $ 22,652 Rambus recognizes interest and penalties related to uncertain tax positions as a component of the income tax provision (benefit). At December 31, 2019 and 2018 , an immaterial amount of interest and penalties are included in long-term income taxes payable. Rambus files income tax returns for the U.S., California, India, the U.K., the Netherlands and various other state and foreign jurisdictions. The U.S. federal returns are subject to examination from 2016 and forward. The California returns are subject to examination from 2010 and forward. In addition, any research and development credit carryforward or net operating loss carryforward generated in prior years and utilized in these or future years may also be subject to examination. The India returns are subject to examination from fiscal year ending March 2012 and forward. The Company is currently under examination by California for the 2010 and 2011 tax years. The Company’s India subsidiary is under examination by the Indian tax administration for tax years beginning with 2011, except for 2014, which was assessed in the Company’s favor. These examinations may result in proposed adjustments to the income taxes as filed during these periods. Management regularly assesses the likelihood of outcomes resulting from income tax examinations to determine the adequacy of their provision for income taxes and believes their provision for unrecognized tax benefits is adequate. Additionally, the Company’s future effective tax rates could be adversely affected by earnings being higher than anticipated in countries where the Company has higher statutory rates or lower than anticipated in countries where it has lower statutory rates, by changes in valuation of its deferred tax assets and liabilities or by changes in tax laws or interpretations of those laws. At December 31, 2019 , no other income taxes (state or foreign) have been provided on undistributed earnings of approximately $14.0 million from the Company’s international subsidiaries since these earnings have been, and under current plans will continue to be, indefinitely reinvested outside the United States. However, if such earnings were distributed, the Company would incur approximately $1.9 million of foreign withholding taxes and an immaterial amount of U.S. taxes.

Litigation and Asserted Claims

Litigation and Asserted Claims	12 Months Ended
Litigation and Asserted Claims	Dec. 31, 2019
LitigationAndAssertedClaimsDisclosureAbstract
Litigation and Asserted Claims	Litigation and Asserted Claims Rambus is not currently a party to any material pending legal proceeding; however, from time to time, Rambus may become involved in legal proceedings or be subject to claims arising in the ordinary course of its business. Although the results of litigation and claims cannot be predicted with certainty, the Company currently believes that the final outcome of these ordinary course matters will not have a material adverse effect on our business, operating results, financial position or cash flows. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management attention and resources and other factors. The Company records a contingent liability when it is probable that a loss has been incurred and the amount is reasonably estimable in accordance with accounting for contingencies.

Acquisitions (Notes)

Acquisitions (Notes)	12 Months Ended
Acquisitions (Notes)	Dec. 31, 2019
Business Combinations [Abstract]
Acquisitions	Acquisitions Northwest Logic, Inc. On July 26, 2019, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Northwest Logic, a leading supplier of memory, PCIe, and MIPI digital controllers. On August 23, 2019 (the “Closing Date”), the Company completed its acquisition of Northwest Logic by acquiring all issued and outstanding shares of Northwest Logic through the merger of a wholly-owned Rambus subsidiary with Northwest Logic. Under the terms of the Merger Agreement, the Company paid approximately $21.9 million in cash, including certain bonus payments and adjustments for working capital. Of the purchase price, $3.0 million of the consideration was deposited into an escrow account to fund indemnification obligations and other contractual provisions, to be released 24 months after the Closing Date. This acquisition allows the Company to further scale, bringing together high-speed design expertise with the physical and digital IP families from renowned market leaders to offer comprehensive memory and SerDes IP solutions for chip designers. The Company integrated Northwest Logic’s offerings and design team into its IP cores technology solutions. As part of the acquisition, the Company agreed to pay $9.0 million to certain Northwest Logic employees in cash over three years following August 23, 2019 (the “Retention Bonus”). The Retention Bonus will be paid in three installments of $3.0 million on each of the dates that are 12 months, 24 months and 36 months following the Closing Date. The Retention Bonus payouts are subject to the condition of continued employment, and therefore treated as compensation and expensed as incurred. As of December 31, 2019 , the Company had incurred approximately $0.7 million in external acquisition costs in connection with the transaction, which were expensed as incurred. The purchase price allocation and related accounting for this acquisition is preliminary. The preliminary fair value estimates for the assets acquired and liabilities assumed were based upon preliminary calculations and valuations and the Company’s estimates and assumptions for the acquisition are subject to change if the Company obtains additional information during the measurement period. In accordance with ASC No. 805, during the measurement period an acquirer shall retrospectively adjust the provisional amounts recognized at the acquisition date to reflect information obtained about facts and circumstances that existed as of the acquisition date that, if known, would have affected the measurement of the amounts recognized as of the acquisition date. Accordingly, the Company has recognized a measurement period adjustment made during the fourth quarter of 2019 to the fair value of certain assets acquired and liabilities assumed as a result of further refinements in the Company’s estimates. This adjustment was retrospectively applied to the August 23, 2019 acquisition date balance sheet. The effect of this adjustment on the preliminary purchase price allocation was an increase in goodwill of $2.1 million and an increase in deferred tax liability, net, of $2.1 million . This adjustment did not have a material impact on the Company’s previously reported results of operations. The fair value of the assets acquired was determined by management primarily by using the multi-period excess earnings method under the income approach. This method reflects the present value of the projected cash flows that are expected to be generated by the existing technologies less charges representing the contribution of other assets to those cash flows. The Company performed a valuation of the net assets acquired as of the Closing Date. The total consideration from the business combination was allocated as of the Closing Date, including the retrospective adjustment made in the fourth quarter of 2019, as follows: Total (in thousands) Cash and cash equivalents $ 159 Accounts receivable 1,679 Prepaid expenses and other current assets 65 Identified intangible assets 8,800 Goodwill 13,477 Operating lease right-of-use asset 178 Other asset 9 Accounts payable (9 ) Operating lease liability (178 ) Other current liabilities (108 ) Deferred tax liability, net (2,133 ) Total $ 21,939 The goodwill arising from the acquisition is primarily attributed to synergies related to the combination of new and complementary technologies of the Company and the assembled workforce of Northwest Logic. This goodwill is not expected to be deductible for tax purposes. The identified intangible assets assumed in the acquisition of Northwest Logic were recognized as follows based upon their estimated fair values as of the acquisition date: Total Estimated Weighted Average Useful Life (in thousands) (in years) Existing technology $ 8,100 5 Customer contracts and contractual relationships 400 2 Customer backlog 300 0.5 Total $ 8,800 Secure Silicon IP and Protocols Business from Verimatrix On September 11, 2019, the Company announced it had signed an asset purchase agreement to acquire the Secure Silicon IP and Protocols business from Verimatrix, formerly Inside Secure, for $65.0 million in cash. On December 8, 2019 (the “Closing Date”), the Company completed its acquisition of the Secure Silicon IP and Protocols business. Under the terms of the Asset Purchase Agreement, as amended, the Company paid approximately $45.0 million in cash at the Closing Date, and will pay up to an additional $20.0 million , currently valued at $1.8 million , subject to certain revenue targets of the transferred business for the calendar year 2020. The addition of the embedded security teams, products and expertise from the Secure Silicon IP and Protocols business augments the Company’s portfolio of mission-critical embedded security products and expands its offerings for data center, AI, networking and automotive. The total adjusted purchase consideration for the acquisition of the Secure Silicon IP and Protocols business was $46.8 million , which consisted of the following: Total (in thousands) Cash consideration transferred at the Closing Date $ 45,000 Fair value of earn-out liability 1,800 Total adjusted purchase price $ 46,800 As part of the acquisition, the Company agreed to pay $1.0 million to certain employees in cash over two years effective January 1, 2020 (the “Retention Bonus”). The Retention Bonus will be paid in arrears in two annual installments of $0.5 million in December 2020 and December 2021, respectively. The Retention Bonus payouts are subject to the condition of continued employment, and therefore treated as compensation and expensed as incurred. As of December 31, 2019 , the Company had incurred approximately $3.1 million in external acquisition costs in connection with the transaction, which were expensed as incurred. The purchase price allocation and related accounting for this acquisition is preliminary. The preliminary fair value estimates for the assets acquired and liabilities assumed were based upon preliminary calculations and valuations and the Company’s estimates and assumptions for the acquisition are subject to change if the Company obtains additional information during the measurement period. The fair value of the assets acquired was determined by management primarily by using the multi-period excess earnings method under the income approach. This method reflects the present value of the projected cash flows that are expected to be generated by the existing technologies less charges representing the contribution of other assets to those cash flows. The Company performed a valuation of the net assets acquired as of the Closing Date. The Company performed a valuation of the net assets acquired as of the Closing Date. The total consideration from the acquisition was allocated as follows: Total (in thousands) Prepaid expenses and other current assets $ 267 Unbilled receivables 6,765 Operating lease right-of-use assets 852 Identified intangible assets 23,500 Goodwill 16,845 Deferred revenue (310 ) Operating lease liabilities (852 ) Other current liabilities (267 ) Total $ 46,800 The goodwill arising from the acquisition is primarily attributed to synergies related to the combination of new and complementary technologies of the Company and the assembled workforce of the Secure Silicon IP and Protocols business. Approximately $15.0 million of the goodwill is expected to be deductible for tax purposes. The identified intangible assets assumed in the acquisition of the Secure Silicon IP and Protocols business were recognized as follows based upon their estimated fair values as of the acquisition date: Total Estimated Weighted Average Useful Life (in thousands) (in years) Existing technology $ 21,600 3 to 5 years Customer contracts and contractual relationships 900 5 years IPR&D 1,000 Not applicable Total $ 23,500 IPR&D consists of one project, primarily relating to the development of Media Access Control Security frame engines, which is part of the Silicon IP solutions. The project is expected to be completed over the next twelve months. The acquired IPR&D will not be amortized until completion of the related product which is determined by when the underlying project reaches technological feasibility and commences commercial production. Upon completion, the IPR&D project will be amortized over its useful life, which is expected to range between three years and five years . Unaudited Pro Forma Combined Consolidated Financial Information The following unaudited pro forma financial information presents the combined results of operations for the Company and Northwest Logic as if the acquisition had occurred on January 1, 2018. The unaudited pro forma financial information has been prepared for comparative purposes only and does not purport to be indicative of the actual operating results that would have been recorded had the acquisition actually taken place on January 1, 2018, and should not be taken as indicative of future consolidated operating results. Additionally, the unaudited pro forma financial results do not include any anticipated synergies or other expected benefits from the acquisition (unaudited, in thousands, except per share amounts): Years Ended December 31, 2019 2018 Revenue $ 231,492 $ 241,049 Net loss $ (90,688 ) $ (160,742 ) Net loss per share - diluted $ (0.82 ) $ (1.48 ) Pro forma loss for 2019 was adjusted to exclude $0.7 million of acquisition-related costs incurred in 2019. Consequently, pro forma loss for 2018 was adjusted to include these costs. Pro forma financial information on the combined results of operations for the Company and the Secure Silicon IP and Protocols business as if the acquisition had occurred on January 1, 2018 has not been presented as it was impracticable to prepare full financial statements for the Secure Silicon IP and Protocols business, given that the Secure Silicon IP and Protocols business had not been managed as a stand-alone business and thus stand-alone financial statements were not readily available. Additionally, the revenue recognized from the Northwest Logic and Secure Silicon IP and Protocols business acquisitions is not material to the Company’s consolidated financial statements during the year ended December 31, 2019, either individually or in the aggregate. Furthermore, the Company does not track operating results from these businesses separately.

CONSOLIDATED SUPPLEMENTARY FINA

CONSOLIDATED SUPPLEMENTARY FINANCIAL DATA (Unaudited)	12 Months Ended
CONSOLIDATED SUPPLEMENTARY FINANCIAL DATA (Unaudited)	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
CONSOLIDATED SUPPLEMENTARY FINANCIAL DATA (Unaudited)	Supplementary Financial Data RAMBUS INC. CONSOLIDATED SUPPLEMENTARY FINANCIAL DATA Quarterly Statements of Operations (Unaudited) Dec. 31, 2019 Sept. 30, 2019 June 30, 2019 March 31, 2019 Dec. 31, 2018 Sept. 30, 2018 June 30, 2018 March 31, 2018 (In thousands, except for per share amounts) Total revenue $ 59,947 $ 57,399 $ 58,297 $ 48,384 $ 68,563 $ 59,754 $ 56,458 $ 46,426 Total operating costs and expenses $ 73,158 $ 80,272 $ 95,343 $ 79,793 $ 72,763 $ 78,921 $ 76,445 $ 90,039 Operating loss $ (13,211 ) $ (22,873 ) $ (37,046 ) $ (31,409 ) $ (4,200 ) $ (19,167 ) $ (19,987 ) $ (43,613 ) Net loss (1) $ (9,532 ) $ (17,331 ) $ (36,980 ) $ (26,576 ) $ (2,018 ) $ (104,893 ) $ (15,357 ) $ (35,689 ) Net loss per share — basic $ (0.09 ) $ (0.16 ) $ (0.33 ) $ (0.24 ) $ (0.02 ) $ (0.97 ) (0.14 ) $ (0.33 ) Net loss per share — diluted $ (0.09 ) $ (0.16 ) $ (0.33 ) $ (0.24 ) $ (0.02 ) $ (0.97 ) (0.14 ) $ (0.33 ) Shares used in per share calculations — basic (2) 111,883 111,315 110,875 109,692 108,826 107,897 107,737 109,358 Shares used in per share calculations — diluted (2) 111,883 111,315 110,875 109,692 108,826 107,897 107,737 109,358 ______________________________________ (1) The net loss for the quarter ended September 30, 2018 included a $91.3 million impact of an increase in our deferred tax asset valuation allowance. Refer to Note 19, “Income Taxes,” of Notes to Consolidated Financial Statements of this Form 10-K. (2) The quarterly financial information includes the impact of the accelerated share repurchase program as follows: 0.7 million shares in the quarter ended June 30, 2018 and 3.1 million shares repurchased in the quarter ended March 31, 2018. Refer to Note 15, “Stockholders’ Equity,” of Notes to Consolidated Financial Statements of this Form 10-K.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
Summary of Significant Accounting Policies (Policies)	Dec. 31, 2019
Accounting Policies [Abstract]
Financial Statement Presentation	Financial Statement Presentation The accompanying consolidated financial statements include the accounts of Rambus and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in the accompanying consolidated financial statements. Investments in entities with more than 20% ownership by Rambus and in which Rambus has the ability to significantly influence the operations of the investee (but not control) are accounted for using the equity method and are included in other assets.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ from those estimates.
Reclassifications	Reclassifications Certain prior year balances were reclassified to conform to the current year’s presentation. None of these reclassifications had an impact on reported net income or cash flows for any of the periods presented.
Revenue Recognition	Revenue Recognition The Company adopted the New Revenue Standard on January 1, 2018 and all the related amendments using the modified retrospective method. The Company recognized the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of accumulated deficit as of January 1, 2018. The comparative information for 2017 has not been recast and continues to be reported under the accounting standards in effect for that period. The Company recognizes revenue upon transfer of control of promised goods and services in an amount that reflects the consideration it expects to receive in exchange for those goods and services. Substantially all of the goods and services are distinct and are accounted for as separate performance obligations. Where an arrangement includes multiple performance obligations, the transaction price is allocated to these on a relative standalone selling price basis. The Company has established standalone selling prices for all of its offerings - specifically, the same pricing methodology is consistently applied to all licensing arrangements; all services offerings are priced within tightly controlled bands and all contracts that include support and maintenance state a renewal rate or price that is systematically enforced.
Cost of Revenue	Cost of Revenue Cost of revenue includes cost of professional services, materials, including cost of wafers processed by third-party foundries, cost associated with packaging and assembly, test and shipping, cost of personnel, including stock-based compensation, and equipment associated with manufacturing support, logistics and quality assurance, warranty cost, amortization of existing technology, write-down of inventories, amortization of production mask costs, overhead and an allocated portion of occupancy costs.
Leases	Leases The Company leases office space, domestically and internationally, under operating leases. The Company’s leases have remaining lease terms between one year and ten years . Operating leases are included in operating lease right-of-use (“ROU”) assets, operating lease liabilities, and long-term operating lease liabilities in the Company’s consolidated balance sheets. The Company does not have any finance leases. The Company determines if an arrangement is a lease, or contains a lease, at inception. The Company assesses all relevant facts and circumstances in making the determination of the existence of a lease. For leases with terms greater than 12 months, the Company records the related asset and obligation at the present value of lease payments over the term. Many of the Company’s leases include rental escalation clauses, renewal options and/or termination options that are factored into the determination of lease payments when appropriate. Leases with an initial term of 12 months or less are not recorded on the balance sheet, and the Company does not separate non-lease components from lease components. Operating lease costs are included in research and development and selling, general and administrative costs on the statement of operations.
Goodwill and Intangible Assets	Goodwill Goodwill represents the excess of the purchase price over the fair value of the net tangible and identifiable intangible assets acquired in each business combination. Goodwill is not subject to amortization, but is subject to at least an annual assessment for impairment. The Company performs its impairment analysis of goodwill on an annual basis during the fourth quarter of the year unless conditions arise that warrant a more frequent evaluation. When goodwill is assessed for impairment, the Company has the option to perform an assessment of qualitative factors of impairment (optional assessment) prior to necessitating a quantitative impairment test. Should the optional assessment be used for any given year, qualitative factors to consider for a reporting unit include: cost factors; financial performance; legal, regulatory, contractual, political, business, or other factors; entity specific factors; industry and market considerations; macroeconomic conditions; and other relevant events and factors affecting the reporting unit. If the Company determines in the qualitative assessment that it is more likely than not that the fair value of the reporting unit is less than its carrying value, a quantitative test is then performed. Otherwise, no further testing is required. For a reporting unit tested using a quantitative approach, the Company compares the fair value of the reporting unit with the carrying amount of the reporting unit, including goodwill. The fair value of the reporting unit is estimated using an income approach. Under the income approach, the Company measures fair value of the reporting unit based on a projected cash flow method using a discount rate determined by its management which is commensurate with the risk inherent in its current business model. The Company’s discounted cash flow projections are based on its annual financial forecasts developed internally by management for use in managing its business. If the fair value of the reporting unit exceeds its carrying value, goodwill is not impaired and no further testing is required. If the fair value of the reporting unit is less than the carrying value, then the amount of goodwill impairment will be the amount by which the reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The Company performed its annual goodwill impairment analysis as of December 31, 2019 and determined that there was no impairment of its goodwill. For the years ended December 31, 2018 and 2017, the Company did not recognize any goodwill impairment charges. Intangible Assets Intangible assets are comprised of existing technology, customer contracts and contractual relationships, and other definite-lived and indefinite-lived intangible assets. Identifiable intangible assets resulting from the acquisitions of entities accounted for using the purchase method of accounting are estimated by management based on the fair value of assets received. Identifiable definite-lived intangible assets are being amortized over the period of estimated benefit using the straight-line method and estimated useful lives ranging from six months to ten years . Acquired indefinite-lived intangible assets related to the Company’s in-process research and development (“IPR&D”) are capitalized and subject to impairment testing until completion or abandonment of the projects. Upon successful completion of each project, the Company makes a separate determination of the useful life of the acquired indefinite-lived intangible assets and the related amortization is recorded as an expense over the estimated useful life of the specific projects. Indefinite-lived intangible assets are subject to at least an annual assessment for impairment, applying a fair-value based test. Under the income approach, the Company measures fair value of the indefinite-lived intangible assets based on a projected cash flow method using a discount rate determined by its management which is commensurate with the risk inherent in its current business model. The Company’s discounted cash flow projections are based on its annual financial forecasts developed internally by management for use in managing its business. If the fair value of the indefinite-lived intangible assets exceeds its carrying value, the indefinite-lived intangible assets are not impaired and no further testing is required. If the implied fair value of the indefinite-lived intangible assets is less than the carrying value, the difference is recorded as an impairment loss.
Inventories	Inventories Inventories are stated at the lower of cost or net realizable value. Cost is computed using standard cost, which approximates actual cost, on a first-in, first-out basis. Inventories are reduced for write-downs based on periodic reviews for evidence of slow-moving or obsolete parts. The write-down is based on comparison between inventory on hand and estimated future sales for each specific product. Once written down, inventory write-downs are not reversed until the inventory is sold or scrapped. Inventory write-downs are also established when conditions indicate that the net realizable value is less than cost due to physical deterioration, obsolescence, changes in price level or other causes.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment include computer equipment, computer software, machinery, leasehold improvements, furniture and fixtures and buildings. Computer equipment, computer software, machinery, and furniture and fixtures are stated at cost and generally depreciated on a straight-line basis over an estimated useful life of three years , three years to five years , two years or seven years , and three years , respectively. The buildings were depreciated on a straight-line basis over an estimated useful life of approximately 39 years . Refer to Note 11, “Balance Sheet Details,” and Note 13, “Commitments and Contingencies,” for additional details. Leasehold improvements are amortized on a straight-line basis over the shorter of their estimated useful lives or the initial terms of the leases. Upon disposal, assets and related accumulated depreciation are removed from the accounts and the related gain or loss is included in the results from operations.
Intangible Assets Impairment	Definite-Lived and Indefinite-Lived Asset Impairment The Company evaluates definite-lived and indefinite-lived assets (including property, plant and equipment and intangible assets) for impairment whenever events or changes in circumstances indicate the carrying value of an asset group may not be recoverable. The carrying value is not recoverable if it exceeds the undiscounted cash flows resulting from the use of the asset group and its eventual disposition. The Company’s estimates of future cash flows attributable to its asset groups require significant judgment based on its historical and anticipated results and are subject to many factors. Factors that the Company considers important which could trigger an impairment review include significant negative industry or economic trends, significant loss of clients, and significant changes in the manner of its use of the acquired assets or the strategy for its overall business. When the Company determines that the carrying value of the asset groups may not be recoverable based upon the existence of one or more of the above indicators of impairment, the Company measures the potential impairment based on a projected discounted cash flow method using a discount rate determined by the Company to be commensurate with the risk inherent in the Company’s current business model. An impairment loss is recognized only if the carrying amount of the asset group is not recoverable and exceeds its fair value. The impairment charge is recorded to reduce the pre-impairment carrying amount of the assets based on the relative carrying amount of those assets, though not to reduce the carrying amount of an asset below its fair value. Different assumptions and judgments could materially affect the calculation of the fair value of the assets. During 2019 , 2018 and 2017, the Company did not recognize any impairment of its definite-lived and indefinite-lived assets.
Income Taxes	Income Taxes Income taxes are accounted for using an asset and liability approach, which requires the recognition of deferred tax assets and liabilities for expected future tax events that have been recognized differently in Rambus’ consolidated financial statements and tax returns. The measurement of current and deferred tax assets and liabilities is based on provisions of the enacted tax law and the effects of future changes in tax laws or rates are not anticipated. A valuation allowance is established when necessary to reduce deferred tax assets to amounts expected to be realized based on available evidence. In addition, the calculation of the Company’s tax liabilities involves dealing with uncertainties in the application of complex tax regulations. As a result, the Company reports a liability for unrecognized tax benefits resulting from uncertain tax positions taken or expected to be taken in its tax return. The Company considers many factors when evaluating and estimating its tax positions and tax benefits, which may require periodic adjustments and which may not accurately anticipate actual outcomes.
Stock-Based Compensation and Equity Incentive Plans	Stock-Based Compensation and Equity Incentive Plans The Company maintained stock plans covering a broad range of equity grants including stock options, nonvested equity stock and equity stock units and performance based instruments. In addition, the Company sponsors an Employee Stock Purchase Plan (“ESPP”), whereby eligible employees are entitled to purchase Common Stock semi-annually, by means of limited payroll deductions, at a 15% discount from the fair market value of the Common Stock as of specific dates. The Company determines compensation expense associated with restricted stock units based on the fair value of its common stock on the date of grant. The Company determines compensation expense associated with stock options based on the estimated grant date fair value method using the Black-Scholes Merton valuation model. The Company generally recognizes compensation expense using a straight-line amortization method over the respective vesting period for awards that are ultimately expected to vest. Stock-based compensation expense for 2019 , 2018 and 2017 has been reduced for estimated forfeitures. When estimating forfeitures, the Company considers voluntary termination behaviors as well as trends of actual option forfeitures.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash equivalents are highly liquid investments with original maturity of three months or less at the date of purchase. The Company maintains its cash balances with high quality financial institutions. Cash equivalents are invested in highly-rated and highly-liquid money market securities and certain U.S. government sponsored obligations.
Marketable Securities	Marketable Securities Available-for-sale securities are carried at fair value, based on quoted market prices, with the unrealized gains or losses reported, net of tax, in stockholders’ equity as part of accumulated other comprehensive income (loss). The amortized cost of debt securities is adjusted for amortization of premiums and accretion of discounts to maturity, both of which are included in interest and other income, net. Realized gains and losses are recorded on the specific identification method and are included in interest and other income, net. The Company reviews its investments in marketable securities for possible other than temporary impairments on a regular basis. If any loss on investment is believed to be a credit loss, a charge will be recognized in operations. In evaluating whether a credit loss on a debt security has occurred, the Company considers the following factors: 1) the Company’s intent to sell the security, 2) if the Company intends to hold the security, whether or not it is more likely than not that the Company will be required to sell the security before recovery of the security’s amortized cost basis and 3) even if the Company intends to hold the security, whether or not the Company expects the security to recover the entire amortized cost basis. Due to the high credit quality and short term nature of the Company’s investments, there have been no material credit losses recorded to date. The classification of funds between short-term and long-term is based on whether the securities are available for use in operations or other purposes.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying value of cash equivalents, accounts receivable and accounts payable approximate their fair values due to their relatively short maturities as of December 31, 2019 and 2018 . Marketable securities are comprised of available-for-sale securities that are reported at fair value with the related unrealized gains and losses included in accumulated other comprehensive income (loss), a component of stockholders’ equity, net of tax. Fair value of the marketable securities is determined based on quoted market prices. The fair value of the Company’s convertible notes fluctuates with interest rates and with the market price of the common stock, but does not affect the carrying value of the debt on the balance sheet.
Research and Development	Research and Development Costs incurred in research and development, which include engineering expenses, such as salaries and related benefits, stock-based compensation, depreciation, professional services and overhead expenses related to the general development of Rambus’ products, are expensed as incurred. Software development costs are capitalized beginning when a product’s technological feasibility has been established and ending when a product is available for general release to customers. Rambus has not capitalized any software development costs since the period between establishing technological feasibility and general customer release is relatively short and as such, these costs have not been material.
Computation of Earnings (Loss) Per Share	Computation of Earnings (Loss) Per Share Basic earnings (loss) per share is calculated by dividing the net income (loss) by the weighted average number of common shares outstanding during the period. Diluted earnings (loss) per share is calculated by dividing the earnings (loss) by the weighted average number of common shares and potentially dilutive securities outstanding during the period. Potentially dilutive common shares consist of incremental common shares issuable upon exercise of stock options, employee stock purchases, restricted stock and restricted stock units, and shares issuable upon the conversion of convertible notes. The dilutive effect of outstanding shares is reflected in diluted earnings per share by application of the treasury stock method. This method includes consideration of the amounts to be paid by the employees, the amount of excess tax benefits that would be recognized in equity if the instrument was exercised and the amount of unrecognized stock-based compensation related to future services. No potential dilutive common shares are included in the computation of any diluted per share amount when a net loss is reported.
Comprehensive Income (Loss)	Comprehensive Income (Loss) Comprehensive income (loss) is defined as the change in equity of a business enterprise during a period from transactions and other events and circumstances from non-owner sources, including foreign currency translation adjustments and unrealized gains and losses on marketable securities. Other comprehensive income (loss), net of tax, is presented in the consolidated statements of comprehensive income (loss).
Credit Concentration	Credit Concentration As of December 31, 2019 and 2018 , the Company’s cash, cash equivalents and marketable securities were invested with various financial institutions in the form of corporate notes, bonds and commercial paper, money market funds, U.S. Treasuries, U.S. Government Agencies, and municipal bonds and notes. The Company’s exposure to market risk for changes in interest rates relates primarily to its investment portfolio. The Company places its investments with high credit issuers and, by investment policy, attempts to limit the amount of credit exposure to any one issuer. As stated in the Company’s investment policy, it will ensure the safety and preservation of the Company’s invested funds by limiting default risk and market risk. The Company has no investments denominated in foreign country currencies and therefore is not subject to foreign exchange risk from these assets. The Company mitigates default risk by investing in high credit quality securities and by positioning its portfolio to respond appropriately to a significant reduction in a credit rating of any investment issuer or guarantor. The portfolio includes only marketable securities with active secondary or resale markets to enable portfolio liquidity. The Company’s note hedge transactions, entered into in connection with the 1.375% convertible senior notes due 2023 (the “2023 Notes”), expose the Company to credit risk to the extent that its counterparties may be unable to meet the terms of the transactions. The Company mitigates this risk by limiting its counterparties to major financial institutions. Refer to Note 12, “Convertible Notes” for further details. The Company’s accounts receivable are derived from revenue earned from customers located in the U.S. and internationally. Refer to Note 7, “Segments and Major Customers” for further details.
Foreign Currency Translation	Foreign Currency Translation and Re-Measurement The Company translates the assets and liabilities of its non-U.S. dollar functional currency subsidiaries into U.S. dollars using exchange rates in effect at the end of each period. Revenue and expenses for these subsidiaries are translated using rates that approximate those in effect during the period. Gains and losses from these translations are recognized in foreign currency translation included in Accumulated Other Comprehensive Gain (Loss) in the consolidated statements of stockholders’ equity. The Company’s subsidiaries that use the U.S. dollar as their functional currency re-measure monetary assets and liabilities at exchange rates in effect at the end of each period, and inventories, property and non-monetary assets and liabilities at historical rates. Additionally, foreign currency transaction gains and losses are included in interest income and other (income) expense, net, in the consolidated statements of operations and were not material in the periods presented. Subsequent to the divestiture of the Company’s Payments and Ticketing businesses, the U.S. dollar is primarily the functional currency of the Company’s foreign subsidiaries.
Business Combinations	Business Combinations The Company accounts for acquisitions of businesses using the purchase method of accounting, which requires the Company to recognize separately from goodwill the assets acquired and the liabilities assumed at their acquisition date fair values. While the Company uses its best estimates and assumptions to accurately value assets acquired and liabilities assumed at the acquisition date as well as contingent consideration, where applicable, the estimates are inherently uncertain and subject to refinement. As a result, during the measurement period, which may be up to one year from the acquisition date, the Company may record adjustments to the assets acquired and liabilities assumed with the corresponding offset to goodwill. Upon the conclusion of the measurement period or final determination of the values of assets acquired or liabilities assumed, whichever comes first, any subsequent adjustments are recorded to the consolidated statements of operations. Accounting for business combinations requires management to make significant estimates and assumptions, especially at the acquisition date including the Company’s estimates for intangible assets, contractual obligations assumed and pre-acquisition contingencies where applicable. Although, the Company believes the assumptions and estimates made in the past have been reasonable and appropriate, they are based in part on historical experience and information obtained from the management of the acquired companies and are inherently uncertain. Significant estimates and assumptions made by management in estimating the fair value of the existing technologies included revenue growth rates, operating expense margins, technology obsolescence rates and discount rates. Unanticipated events and circumstances may occur that may affect the accuracy or validity of such assumptions, estimates or actual results.
Litigation	Litigation Rambus may be involved in certain legal proceedings. Based upon consultation with outside counsel handling its defense in these matters and an analysis of potential results, if Rambus believes that a loss arising from such matters is probable and can be reasonably estimated, Rambus records the estimated liability in its consolidated financial statements. If only a range of estimated losses can be determined, Rambus records an amount within the range that, in its judgment, reflects the most likely outcome; if none of the estimates within that range is a better estimate than any other amount, Rambus records the low end of the range. Any such accrual would be charged to expense in the appropriate period. Rambus recognizes litigation expenses in the period in which the litigation services were provided.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
Revenue Recognition (Tables)	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Contract balances	The Company’s contract balances were as follows: As of (In thousands) December 31, 2019 December 31, 2018 Unbilled receivables $ 528,069 $ 673,616 Deferred revenue 11,947 19,566

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
Earnings (Loss) Per Share (Tables)	Dec. 31, 2019
Earnings Per Share [Abstract]
Computation of basic and diluted income (loss) per share	The following table sets forth the computation of basic and diluted income (loss) per share: For the Years Ended December 31, 2019 2018 2017 Net loss per share: Numerator: Net loss $ (90,419 ) $ (157,957 ) $ (22,862 ) Denominator: Weighted-average common shares outstanding - basic 110,948 108,450 110,198 Effect of potential dilutive common shares — — — Weighted-average common shares outstanding - diluted 110,948 108,450 110,198 Basic net loss per share $ (0.81 ) $ (1.46 ) $ (0.21 ) Diluted net loss per share $ (0.81 ) $ (1.46 ) $ (0.21 )

Intangible Assets and Goodwill

Intangible Assets and Goodwill (Tables)	12 Months Ended
Intangible Assets and Goodwill (Tables)	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of goodwill information by reportable units	The following tables present goodwill information for the years ended December 31, 2019 and December 31, 2018 : December 31, Additions to Goodwill (1) Divestiture of Goodwill (2) Effect of Exchange Rates (3) December 31, (In thousands) Total goodwill $ 207,178 $ 30,322 $ (54,494 ) $ 459 $ 183,465 ______________________________________ (1) In August 2019, the Company acquired Northwest Logic, Inc. (“Northwest Logic”), and in December 2019, the Company acquired the Secure Silicon IP and Protocols business from Verimatrix (the “Secure Silicon IP and Protocols business”), which resulted in the Company recognizing additional goodwill. Refer to Note 21, “Acquisitions,” for additional information. (2) Refer to Note 17, “Divestiture,” for additional information. (3) Effect of exchange rates relates to foreign currency translation adjustments for the period. As of December 31, 2019 Gross Carrying Amount Accumulated Impairment Losses Net Carrying Amount (In thousands) Total goodwill $ 205,235 $ (21,770 ) $ 183,465 December 31, Effect of Exchange Rates (1) December 31, (In thousands) Total goodwill $ 209,661 $ (2,483 ) $ 207,178 ______________________________________ (1) Effect of exchange rates relates to foreign currency translation adjustments for the period. As of December 31, 2018 Gross Carrying Amount Accumulated Impairment Losses Net Carrying Amount (In thousands) Total goodwill $ 228,948 $ (21,770 ) $ 207,178
Components of intangible assets	The components of the Company’s intangible assets as of December 31, 2019 and December 31, 2018 were as follows: As of December 31, 2019 Useful Life Gross Carrying Amount (1) (2) Accumulated Amortization (1) (2) Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 262,789 $ (213,354 ) $ 49,435 Customer contracts and contractual relationships 0.5 to 10 years 36,293 (33,428 ) 2,865 Non-compete agreements and trademarks 3 years 300 (300 ) — IPR&D Not applicable 2,600 — 2,600 Total intangible assets $ 301,982 $ (247,082 ) $ 54,900 _________________________________________ (1) In October 2019, the Company disposed of approximately $20.7 million of net intangible assets in connection with the sale of the legal entities comprising the Company’s Payments and Ticketing businesses. Refer to Note 17, “Divestiture,” for additional information. (2) In August 2019, the Company acquired Northwest Logic, and in December 2019, the Company acquired the Secure Silicon IP and Protocols business, which resulted in the Company recognizing additional intangible assets. Refer to Note 21, “Acquisitions,” for additional information. As of December 31, 2018 Useful Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount (In thousands) Existing technology 3 to 10 years $ 258,903 $ (213,824 ) $ 45,079 Customer contracts and contractual relationships 1 to 10 years 67,667 (54,410 ) 13,257 Non-compete agreements and trademarks 3 years 300 (300 ) — IPR&D Not applicable 1,600 — 1,600 Total intangible assets $ 328,470 $ (268,534 ) $ 59,936
Estimated future amortization expense of intangible assets	The estimated future amortization expense of intangible assets as of December 31, 2019 was as follows (amounts in thousands): Years Ending December 31: Amount 2020 $ 18,413 2021 14,411 2022 7,444 2023 6,740 2024 5,292 Thereafter — Total amortizable purchased intangible assets 52,300 IPR&D 2,600 Total intangible assets $ 54,900

Segments and Major Customers (T

Segments and Major Customers (Tables)	12 Months Ended
Segments and Major Customers (Tables)	Dec. 31, 2019
Concentration Risk
Revenue from external customer by geographic regions	Revenue from customers in the geographic regions based on the location of contracting parties is as follows: Years Ended December 31, 2019 2018 2017 (In thousands) USA $ 134,526 $ 129,567 $ 165,263 Taiwan 24,118 21,749 9,953 South Korea 3,583 13,421 115,811 Japan 11,877 23,222 23,378 Europe 10,262 15,668 22,597 Canada 3,554 4,960 4,373 Singapore 21,751 19,140 22,554 Asia-Other 14,356 3,474 29,167 Total $ 224,027 $ 231,201 $ 393,096
Accounts receivable
Concentration Risk
Schedule of customer accounts representing 10% or more than 10% of total revenue	Accounts receivable from the Company’s major customers representing 10% or more of total accounts receivable at December 31, 2019 and 2018 , respectively, was as follows: As of December 31, 2019 2018 Customer 1 19 % 39 % Customer 2 14 % * Customer 3 * 12 % _________________________________________ * Customer accounted for less than 10% of total accounts receivable in the period
Sales, net
Concentration Risk
Schedule of customer accounts representing 10% or more than 10% of total revenue	Revenue from the Company’s major customers representing 10% or more of total revenue for the years ended December 31, 2019 , 2018 and 2017 were as follows: Years Ended December 31, 2019 2018 2017 Customer A * * 17 % Customer B 10 % * 13 % Customer C * * 13 % Customer D 14 % 15 % * Customer E * 11 % *

Marketable Securities (Tables)

Marketable Securities (Tables)	12 Months Ended
Marketable Securities (Tables)	Dec. 31, 2019
Debt Securities, Available-for-sale [Abstract]
Cash equivalents and marketable securities classified as available-for-sale	Total cash, cash equivalents and marketable securities are summarized as follows: As of December 31, 2019 (Dollars in thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 10,065 $ 10,065 $ — $ — 1.48 % U.S. Government bonds and notes 39,086 39,087 — (1 ) 1.49 % Corporate notes, bonds, commercial paper and other 314,391 314,435 19 (63 ) 1.81 % Total cash equivalents and marketable securities 363,542 363,587 19 (64 ) Cash 44,122 44,122 — — Total cash, cash equivalents and marketable securities $ 407,664 $ 407,709 $ 19 $ (64 ) As of December 31, 2018 (Dollars in thousands) Fair Value Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Weighted Rate of Return Money market funds $ 10,080 $ 10,080 $ — $ — 2.23 % U.S. Government bonds and notes 32,630 32,634 — (4 ) 2.28 % Corporate notes, bonds, commercial paper and other 183,998 184,095 — (97 ) 2.37 % Total cash equivalents and marketable securities 226,708 226,809 — (101 ) Cash 51,056 51,056 — — Total cash, cash equivalents and marketable securities $ 277,764 $ 277,865 $ — $ (101 )
Available-for-sale securities reported at fair value	Available-for-sale securities are reported at fair value on the balance sheets and classified as follows: As of December 31, December 31, (Dollars in thousands) Cash equivalents $ 58,054 $ 64,868 Short term marketable securities 305,488 161,840 Total cash equivalents and marketable securities 363,542 226,708 Cash 44,122 51,056 Total cash, cash equivalents and marketable securities $ 407,664 $ 277,764
Estimated fair value of cash equivalents and marketable securities classified by date of contractual maturity and the length of time that the securities have been in a continuous unrealized loss position	The estimated fair value of cash equivalents and marketable securities classified by the length of time that the securities have been in a continuous unrealized loss position at December 31, 2019 and 2018 are as follows: Fair Value Gross Unrealized Loss December 31, December 31, December 31, December 31, (In thousands) Less than one year U.S. Government bonds and notes $ 14,112 $ 32,630 $ (1 ) $ (4 ) Corporate notes, bonds and commercial paper 250,822 183,998 (63 ) (97 ) Total Corporate notes, bonds, and commercial paper and U.S. Government bonds and notes $ 264,934 $ 216,628 $ (64 ) $ (101 )

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
Fair Value of Financial Instruments (Tables)	Dec. 31, 2019
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Summary of the valuation of cash equivalents and marketable securities by pricing levels	The following table presents the financial instruments that are carried at fair value and summarizes the valuation of its cash equivalents and marketable securities by the above pricing levels as of December 31, 2019 and 2018 : As of December 31, 2019 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 10,065 $ 10,065 $ — $ — U.S. Government bonds and notes 39,086 — 39,086 — Corporate notes, bonds, commercial paper and other 314,391 — 314,391 — Total available-for-sale securities $ 363,542 $ 10,065 $ 353,477 $ — As of December 31, 2018 Total Quoted Market Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) (In thousands) Money market funds $ 10,080 $ 10,080 $ — $ — U.S. Government bonds and notes 32,630 — 32,630 — Corporate notes, bonds, commercial paper and other 183,998 — 183,998 — Total available-for-sale securities $ 226,708 $ 10,080 $ 216,628 $ —
Financial instruments not carried at fair value but requiring fair value disclosure	The following table presents the financial instruments that are not carried at fair value but which require fair value disclosure as of December 31, 2019 and 2018 : As of December 31, 2019 As of December 31, 2018 (in thousands) Face Value Carrying Value Fair Value Face Value Carrying Value Fair Value 1.375% Convertible Senior Notes due 2023 $ 172,500 $ 148,788 $ 174,239 $ 172,500 $ 141,934 $ 150,075

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2019
Leases [Abstract]
Lessee, operating lease liabilities, maturities and undiscounted cash flows	The table below reconciles the undiscounted cash flows for the first five years and total of the remaining years to the operating lease liabilities recorded on the consolidated balance sheet as of December 31, 2019 (in thousands): Years ending December 31, Amount 2020 $ 7,926 2021 8,602 2022 7,381 2023 4,618 2024 3,977 Thereafter 23,314 Total minimum lease payments 55,818 Less: amount of lease payments representing interest (9,572 ) Present value of future minimum lease payments 46,246 Less: current obligations under leases (6,357 ) Long-term lease obligations $ 39,889

Balance Sheet Details (Tables)

Balance Sheet Details (Tables)	12 Months Ended
Balance Sheet Details (Tables)	Dec. 31, 2019
Balance Sheet Related Disclosures [Abstract]
Inventory Disclosure [Text Block]	Inventories consist of the following: As of December 31, 2019 2018 (In thousands) Raw materials $ 3,997 $ 2,583 Work in process 1,455 145 Finished goods 4,634 4,044 Total $ 10,086 $ 6,772
Components of property, plant and equipment, net	Property, plant and equipment, net is comprised of the following: As of December 31, 2019 2018 (In thousands) Building (1) $ — $ 40,320 Computer software 50,453 26,127 Computer equipment 36,761 37,223 Furniture and fixtures 16,136 16,286 Leasehold improvements 10,316 10,824 Machinery 10,446 9,097 Construction in progress 1,691 429 Property, plant and equipment, gross 125,803 140,306 Less accumulated depreciation and amortization (81,089 ) (83,278 ) Property, plant and equipment, net $ 44,714 $ 57,028 ______________________________________ (1) Refer to Note 3, “Recent Accounting Pronouncements” and Note 13, “Commitments and Contingencies,” for a discussion related to the Company’s facility leases due to the adoption of the New Leasing Standard on January 1, 2019.
Schedule of accumulated other comprehensive Income (Loss)	Accumulated other comprehensive gain (loss) is comprised of the following: As of December 31, 2019 2018 (In thousands) Foreign currency translation adjustments $ 105 $ (10,040 ) Unrealized loss on available-for-sale securities, net of tax (197 ) (251 ) Total $ (92 ) $ (10,291 )

Convertible Notes (Tables)

Convertible Notes (Tables)	12 Months Ended
Convertible Notes (Tables)	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of convertible notes	The Company’s convertible notes are shown in the following table: (Dollars in thousands) As of December 31, 2019 As of December 31, 2018 1.375% Convertible Senior Notes due 2023 $ 172,500 $ 172,500 Unamortized discount - 2023 Notes (22,163 ) (28,517 ) Unamortized debt issuance costs - 2023 Notes (1,549 ) (2,049 ) Total convertible notes $ 148,788 $ 141,934 Less current portion — — Total long-term convertible notes $ 148,788 $ 141,934
Schedule of interest expense on notes	Interest expense related to the notes for the years ended December 31, 2019 , 2018 and 2017 was as follows: Years Ended December 31, 2019 2018 2017 (in thousands) 2023 Notes coupon interest at a rate of 1.375% $ 2,372 $ 2,372 $ 290 2023 Notes amortization of discount and debt issuance cost at an additional effective interest rate of 4.9% 6,854 6,486 768 2018 Notes coupon interest at a rate of 1.125% — 377 1,488 2018 Notes amortization of discount and debt issuance cost at an additional effective interest rate of 5.5% — 2,756 6,810 Total interest expense on convertible notes $ 9,226 $ 11,991 $ 9,356

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Contractual Obligation, Fiscal Year Maturity Schedule [Table Text Block]	Additionally, the Company’s lease-related obligations as of December 31, 2018, as determined under the prior accounting standard, were as follows (in thousands): Total 2019 2020 2021 2022 2023 Lease-related obligations Imputed financing obligation (1) $ 8,081 $ 5,677 $ 2,404 $ — $ — $ — Leases 19,415 5,333 4,883 4,960 3,271 968 Total $ 27,496 $ 11,010 $ 7,287 $ 4,960 $ 3,271 $ 968 _________________________________________ (1) With respect to the imputed financing obligation, the main components of the difference between the amount reflected in the table above and the amount reflected on the consolidated balance sheet are the interest on the imputed financing obligation and the estimated common area expenses over the future periods. The amount includes the amended Ohio lease and the amended Sunnyvale lease.
Company's material contractual obligations	As of December 31, 2019 , the Company’s material contractual obligations were as follows (in thousands): Total 2020 2021 2022 2023 2024 Contractual obligations (1) (2) Other contractual obligations $ 468 $ 234 $ 234 $ — $ — $ — Software licenses (3) 31,530 13,525 11,977 6,028 — — Acquisition retention bonuses (4) 9,998 3,499 3,499 3,000 — — Convertible notes 172,500 — — — 172,500 — Interest payments related to convertible notes 8,308 2,372 2,372 2,372 1,192 — Total $ 222,804 $ 19,630 $ 18,082 $ 11,400 $ 173,692 $ — ______________________________________ (1) The above table does not reflect possible payments in connection with unrecognized tax benefits of approximately $24.6 million including $22.8 million recorded as a reduction of long-term deferred tax assets and $1.8 million in long-term income taxes payable, as of December 31, 2019 . As noted below in Note 19, “Income Taxes,” although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months , the Company cannot reasonably estimate the outcome at this time. (2) For the Company’s lease commitments as of December 31, 2019 , refer to Note 10, “Leases.” (3) The Company has commitments with various software vendors for agreements generally having terms longer than one year . (4) In connection with the acquisitions of Northwest Logic in August 2019 and the Secure Silicon IP and Protocols business in December 2019, the Company is obligated to pay retention bonuses to certain employees subject to certain eligibility and acceleration provisions including the condition of employment.

Equity Incentive Plans and St_2

Equity Incentive Plans and Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares available for grant under stock-based incentive plans	A summary of shares available for grant under the Company’s plans is as follows: Shares Available for Grant Total shares available for grant as of December 31, 2016 7,305,368 Stock options granted (558,426) Stock options forfeited 1,978,042 Nonvested equity stock and stock units granted (1) (2) (5,007,947) Nonvested equity stock and stock units forfeited (1) 1,334,110 Total shares available for grant as of December 31, 2017 5,051,147 Increase in shares approved for issuance 5,500,000 Stock options granted (711,479) Stock options forfeited 877,803 Nonvested equity stock and stock units granted (1) (3) (4,993,802) Nonvested equity stock and stock units forfeited (1) 4,350,377 Total shares available for grant as of December 31, 2018 10,074,046 Increase in shares approved for issuance (5) 400,000 Stock options granted (80,000) Stock options forfeited 426,960 Nonvested equity stock and stock units granted (1) (4) (7,261,845) Nonvested equity stock and stock units forfeited (1) 3,267,702 Total shares available for grant as of December 31, 2019 6,826,863 ______________________________________ (1) For purposes of determining the number of shares available for grant under the 2015 Plan against the maximum number of shares authorized, each restricted stock granted reduces the number of shares available for grant by 1.5 shares and each restricted stock forfeited increases shares available for grant by 1.5 shares. (2) Amount includes 0.4 million shares that had been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below. (3) Amount includes 0.5 million shares that have been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below. (4) Amount includes 1.0 million shares that have been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below. (5) Shares were reserved under the 2019 Inducement Plan adopted in the third quarter of 2019.
Schedule of stock option activity	The following table summarizes stock option activity under the Company’s equity incentive plans for the years ended December 31, 2019 , 2018 and 2017 and information regarding stock options outstanding, exercisable, and vested and expected to vest as of December 31, 2019 : Options Outstanding Weighted Average Remaining Contractual Term Number of Shares Weighted Average Exercise Price per Share Aggregate Intrinsic Value (Dollars in thousands, except per share amounts) Outstanding as of December 31, 2016 7,008,833 $ 9.34 Options granted 558,426 $ 12.95 Options exercised (1,278,856) $ 7.34 Options forfeited (1,978,042) $ 10.68 Outstanding as of December 31, 2017 4,310,361 $ 9.78 Options granted 711,479 $ 12.84 Options exercised (908,146) $ 6.70 Options forfeited (877,803) $ 13.73 Outstanding as of December 31, 2018 3,235,891 $ 10.25 Options granted 80,000 $ 13.25 Options exercised (1,249,785) $ 7.79 Options forfeited (426,960) $ 13.71 Outstanding as of December 31, 2019 1,639,146 $ 11.37 4.54 $ 4,631 Vested or expected to vest at December 31, 2019 1,627,218 $ 11.36 4.49 $ 4,621 Options exercisable at December 31, 2019 1,319,210 $ 11.01 3.63 $ 4,327
Weighted-average assumptions for Stock Option Plans	The following table presents the weighted-average assumptions used to estimate the fair value of stock options granted that contain only service conditions in the periods presented: Stock Option Plan for Years Ended December 31, 2019 2018 2017 Stock Option Plan Expected stock price volatility 33%-36% 24%-32% 24%-32% Risk free interest rate 1.4%-1.6% 2.6%-2.8% 1.8%-2.0% Expected term (in years) 5.1-5.2 5.8 5.3-5.4 Weighted-average fair value of stock options granted $4.36 $4.23 $4.09
Weighted-average assumptions for Employee Stock Purchase Plan	Employee Stock Purchase Plan for Years Ended December 31, 2019 2018 2017 Employee Stock Purchase Plan Expected stock price volatility 32% 27%-34% 25%-27% Risk free interest rate 1.6%-2.4% 2.05%-2.5% 0.98%-1.3% Expected term (in years) 0.5 0.5 0.5 Weighted-average fair value of purchase rights granted under the purchase plan $3.13 $2.59 $3.07
Activity related to nonvested equity stock and stock units	The following table reflects the activity related to nonvested equity stock and stock units for the three years ended December 31, 2019 : Nonvested Equity Stock and Stock Units Shares Weighted-Average Grant-Date Fair Value Nonvested at December 31, 2016 4,863,056 $ 12.33 Granted 3,075,396 $ 13.02 Vested (1,216,476) $ 12.15 Forfeited (860,627) $ 12.61 Nonvested at December 31, 2017 5,861,349 $ 12.68 Granted 2,978,558 $ 12.77 Vested (1,713,930) $ 12.39 Forfeited (2,266,842) $ 12.97 Nonvested at December 31, 2018 4,859,135 $ 12.71 Granted 4,233,701 $ 10.17 Vested (1,896,283) $ 12.40 Forfeited (1,907,070) $ 11.33 Nonvested at December 31, 2019 5,289,483 $ 11.27

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2019
Income Tax Expense (Benefit), Continuing Operations [Abstract]
Schedule of income before income tax	Income (loss) before taxes consisted of the following: Years Ended December 31, 2019 2018 2017 (In thousands) Domestic $ (81,316 ) $ (63,829 ) $ 46,031 Foreign (5,700 ) (6,799 ) (5,042 ) $ (87,016 ) $ (70,628 ) $ 40,989
Components of provision for (benefit from) income taxes	The provision for (benefit from) income taxes is comprised of: Years Ended December 31, 2019 2018 2017 (In thousands) Federal: Current $ 2,932 $ 5,451 $ 20,661 Deferred 2,016 82,726 43,678 State: Current 657 333 495 Deferred (1,198 ) 522 (43 ) Foreign: Current 1,708 1,592 1,101 Deferred (2,712 ) (3,295 ) (2,041 ) $ 3,403 $ 87,329 $ 63,851
Schedule of effective income tax rate reconciliation	The differences between Rambus’ effective tax rate and the U.S. federal statutory regular tax rate are as follows: Years Ended December 31, 2019 2018 2017 Expense at U.S. federal statutory rate 21.0 % 21.0 % 35.0 % Expense (benefit) at state statutory rate 0.9 (1.2 ) 0.7 Withholding tax (3.5 ) (7.7 ) 50.1 Foreign rate differential (1.1 ) (0.2 ) 2.8 Research and development (“R&D”) credit 1.2 2.2 (3.9 ) Executive compensation (1.2 ) (0.1 ) 1.8 Stock-based compensation (2.3 ) (2.8 ) 14.9 Foreign tax credit 3.4 7.7 (50.1 ) Foreign derived intangible income deduction 4.6 14.8 — Impact of corporate rate change on deferred taxes — — 50.6 Divestiture 4.8 — — Other (0.2 ) 0.7 1.4 Valuation allowance (31.5 ) (158.0 ) 52.5 (3.9 )% (123.6 )% 155.8 %
Components of the net deferred tax assets	The components of the net deferred tax assets (liabilities) are as follows: As of December 31, 2019 2018 (In thousands) Deferred tax assets: Depreciation and amortization $ 13,995 $ 13,085 Lease liabilities 10,734 — Other timing differences, accruals and reserves 9,522 8,272 Deferred equity compensation 4,456 6,236 Net operating loss carryovers 20,900 21,259 Tax credits 233,407 253,890 Total gross deferred tax assets 293,014 302,742 Deferred tax liabilities: Lease right-of-use assets (10,400) — Convertible debt (151) (207) Deferred revenue (94,763) (143,182 ) Total gross deferred tax liabilities (105,314) (143,389 ) Total net deferred tax assets 187,700 159,353 Valuation allowance (196,972 ) (173,878 ) Net deferred tax liabilities $ (9,272 ) $ (14,525 ) As of December 31, 2019 2018 (In thousands) Reported as: Non-current deferred tax assets $ 4,574 $ 4,435 Non-current deferred tax liabilities (13,846 ) (18,960 ) Net deferred tax liabilities $ (9,272 ) $ (14,525 )
Summary of valuation allowance	The following table presents the tax valuation allowance information for the years ended December 31, 2019 , 2018 and 2017 : Balance at Beginning of Period Charged (Credited) to Operations Charged to Other Account* Valuation Allowance Release Valuation Allowance Set up Balance at End of Period Tax Valuation Allowance Year ended December 31, 2017 $ 23,529 — 5,855 — 21,527 $ 50,911 Year ended December 31, 2018 $ 50,911 — 9,238 — 113,729 $ 173,878 Year ended December 31, 2019 $ 173,878 23,094 — — — $ 196,972 ______________________________________ * Amounts not charged to operations are charged to other comprehensive income or retained earnings.
Schedule of reconciliation of the beginning and ending amounts of unrecognized tax benefits	A reconciliation of the beginning and ending amounts of unrecognized income tax benefits for the years ended December 31, 2019 , 2018 and 2017 is as follows (amounts in thousands): Years Ended December 31, 2019 2018 2017 Balance at January 1 $ 23,482 $ 22,652 $ 21,925 Tax positions related to current year: Additions 16,485 1,032 1,083 Tax positions related to prior years: Additions 76,158 115 16 Reductions (472 ) (317 ) (372 ) Settlements — — — Balance at December 31 $ 115,653 $ 23,482 $ 22,652

Acquisitions (Tables)

Acquisitions (Tables)	12 Months Ended
Acquisitions (Tables)	Dec. 31, 2019
Northwest Logic
Business Acquisition [Line Items]
Schedule of recognized identified assets acquired and liabilities assumed	The total consideration from the business combination was allocated as of the Closing Date, including the retrospective adjustment made in the fourth quarter of 2019, as follows: Total (in thousands) Cash and cash equivalents $ 159 Accounts receivable 1,679 Prepaid expenses and other current assets 65 Identified intangible assets 8,800 Goodwill 13,477 Operating lease right-of-use asset 178 Other asset 9 Accounts payable (9 ) Operating lease liability (178 ) Other current liabilities (108 ) Deferred tax liability, net (2,133 ) Total $ 21,939
Schedule of finite-lived intangible assets acquired as part of business combination	The identified intangible assets assumed in the acquisition of Northwest Logic were recognized as follows based upon their estimated fair values as of the acquisition date: Total Estimated Weighted Average Useful Life (in thousands) (in years) Existing technology $ 8,100 5 Customer contracts and contractual relationships 400 2 Customer backlog 300 0.5 Total $ 8,800
Business acquisition, pro forma information	Additionally, the unaudited pro forma financial results do not include any anticipated synergies or other expected benefits from the acquisition (unaudited, in thousands, except per share amounts): Years Ended December 31, 2019 2018 Revenue $ 231,492 $ 241,049 Net loss $ (90,688 ) $ (160,742 ) Net loss per share - diluted $ (0.82 ) $ (1.48 )
Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Schedule of purchase consideration	The total adjusted purchase consideration for the acquisition of the Secure Silicon IP and Protocols business was $46.8 million , which consisted of the following: Total (in thousands) Cash consideration transferred at the Closing Date $ 45,000 Fair value of earn-out liability 1,800 Total adjusted purchase price $ 46,800
Schedule of recognized identified assets acquired and liabilities assumed	The total consideration from the acquisition was allocated as follows: Total (in thousands) Prepaid expenses and other current assets $ 267 Unbilled receivables 6,765 Operating lease right-of-use assets 852 Identified intangible assets 23,500 Goodwill 16,845 Deferred revenue (310 ) Operating lease liabilities (852 ) Other current liabilities (267 ) Total $ 46,800
Schedule of finite-lived intangible assets acquired as part of business combination	The identified intangible assets assumed in the acquisition of the Secure Silicon IP and Protocols business were recognized as follows based upon their estimated fair values as of the acquisition date: Total Estimated Weighted Average Useful Life (in thousands) (in years) Existing technology $ 21,600 3 to 5 years Customer contracts and contractual relationships 900 5 years IPR&D 1,000 Not applicable Total $ 23,500

CONSOLIDATED SUPPLEMENTARY FI_2

CONSOLIDATED SUPPLEMENTARY FINANCIAL DATA (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly statements of operations	RAMBUS INC. CONSOLIDATED SUPPLEMENTARY FINANCIAL DATA Quarterly Statements of Operations (Unaudited) Dec. 31, 2019 Sept. 30, 2019 June 30, 2019 March 31, 2019 Dec. 31, 2018 Sept. 30, 2018 June 30, 2018 March 31, 2018 (In thousands, except for per share amounts) Total revenue $ 59,947 $ 57,399 $ 58,297 $ 48,384 $ 68,563 $ 59,754 $ 56,458 $ 46,426 Total operating costs and expenses $ 73,158 $ 80,272 $ 95,343 $ 79,793 $ 72,763 $ 78,921 $ 76,445 $ 90,039 Operating loss $ (13,211 ) $ (22,873 ) $ (37,046 ) $ (31,409 ) $ (4,200 ) $ (19,167 ) $ (19,987 ) $ (43,613 ) Net loss (1) $ (9,532 ) $ (17,331 ) $ (36,980 ) $ (26,576 ) $ (2,018 ) $ (104,893 ) $ (15,357 ) $ (35,689 ) Net loss per share — basic $ (0.09 ) $ (0.16 ) $ (0.33 ) $ (0.24 ) $ (0.02 ) $ (0.97 ) (0.14 ) $ (0.33 ) Net loss per share — diluted $ (0.09 ) $ (0.16 ) $ (0.33 ) $ (0.24 ) $ (0.02 ) $ (0.97 ) (0.14 ) $ (0.33 ) Shares used in per share calculations — basic (2) 111,883 111,315 110,875 109,692 108,826 107,897 107,737 109,358 Shares used in per share calculations — diluted (2) 111,883 111,315 110,875 109,692 108,826 107,897 107,737 109,358 ______________________________________ (1) The net loss for the quarter ended September 30, 2018 included a $91.3 million impact of an increase in our deferred tax asset valuation allowance. Refer to Note 19, “Income Taxes,” of Notes to Consolidated Financial Statements of this Form 10-K. (2) The quarterly financial information includes the impact of the accelerated share repurchase program as follows: 0.7 million shares in the quarter ended June 30, 2018 and 3.1 million shares repurchased in the quarter ended March 31, 2018. Refer to Note 15, “Stockholders’ Equity,” of Notes to Consolidated Financial Statements of this Form 10-K.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details 2)	Dec. 31, 2019
Minimum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lessee, operating lease, term of contract	10 years

Summary of Significant Accoun_4

Summary of Significant Accounting Policies (Details 3)	12 Months Ended
Summary of Significant Accounting Policies (Details 3)	Dec. 31, 2019
Computer equipment
Property, plant and equipment
Property, plant and equipment, estimated useful life (in years)	3 years
Machinery
Property, plant and equipment
Property, plant and equipment, estimated useful life (in years)	7 years
Other Machinery and Equipment
Property, plant and equipment
Property, plant and equipment, estimated useful life (in years)	2 years
Furniture and fixtures
Property, plant and equipment
Property, plant and equipment, estimated useful life (in years)	3 years
Building
Property, plant and equipment
Property, plant and equipment, estimated useful life (in years)	39 years
Minimum \| Computer software
Property, plant and equipment
Property, plant and equipment, estimated useful life (in years)	3 years
Maximum \| Computer software
Property, plant and equipment
Property, plant and equipment, estimated useful life (in years)	5 years

Summary of Significant Accoun_5

Summary of Significant Accounting Policies (Details 4)	12 Months Ended
Summary of Significant Accounting Policies (Details 4)	Dec. 31, 2019	Dec. 31, 2018
Customer Concentration Risk
Equity Method Investment, Ownership Percentage	25.00%	27.70%
Stock-Based Compensation and Equity Incentive Plans
Discount from the fair market value (as a percent)	15.00%
Minimum
Intangible Assets
Intangible Assets, Finite-Lived, Policy	P6M
Maximum
Intangible Assets
Intangible Assets, Finite-Lived, Policy	P10Y

Recent Accounting Pronounceme_2

Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 37,020	$ 21,400	$ 0
Accumulated deficit	290,244	(4,500)	204,294
Operating lease, liability	46,246	23,900
Long-term imputed financing obligation	$ 0	37,600	36,297
Property, plant and equipment cost, capitalization amount		$ 32,000	$ 40,300

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
Revenue Recognition (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue from Contract with Customer, Including Assessed Tax	$ 59,947	$ 57,399	$ 58,297	$ 48,384	$ 68,563	$ 59,754	$ 56,458	$ 46,426	$ 224,027	$ 231,201	$ 393,096
Unbilled receivables	528,069				673,616				528,069	673,616
Deferred revenue	11,947				$ 19,566				11,947	19,566
Contract balances, revenue recognized									18,300	$ 20,500
Remaining performance obligations	$ 22,000								$ 22,000
Remaining performance obligations, expected timing of satisfaction period	2 years								2 years
Minimum
License agreement, term of agreement									1 year
Long-duration contracts, assumptions by product and guarantee, discount rate	3.00%								3.00%
Maximum
License agreement, term of agreement									7 years
Long-duration contracts, assumptions by product and guarantee, discount rate	6.00%								6.00%
Percentage of Completion [Member]
Revenue from Contract with Customer, Including Assessed Tax									$ 28,000

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended											12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Numerator:
Net income (loss)	$ (9,532)	$ (17,331)	$ (36,980)	$ (26,576)	$ (2,018)	$ (104,893)	[1]	$ (15,357)		$ (35,689)		$ (90,419)	$ (157,957)	$ (22,862)
Denominator:
Weighted-average common shares outstanding, Basic (in shares)	111,883	111,315	110,875	109,692	108,826	107,897		107,737	[2]	109,358	[2]	110,948	108,450	110,198
Effect of potential dilutive common shares												0	0	0
Denominator:
Weighted-average common shares outstanding, Diluted (in shares)	111,883	111,315	110,875	109,692	108,826	107,897		107,737	[2]	109,358	[2]	110,948	108,450	110,198
Earnings Per Share, Basic												$ (0.81)	$ (1.46)	$ (0.21)
Earnings Per Share, Diluted												$ (0.81)	$ (1.46)	$ (0.21)

[1]	The net loss for the quarter ended September 30, 2018 included a $91.3 million impact of an increase in our deferred tax asset valuation allowance. Refer to Note 19, “Income Taxes,” of Notes to Consolidated Financial Statements of this Form 10-K.
[2]	The quarterly financial information includes the impact of the accelerated share repurchase program as follows: 0.7 million shares in the quarter ended June 30, 2018 and 3.1 million shares repurchased in the quarter ended March 31, 2018. Refer to Note 15, “Stockholders’ Equity,” of Notes to Consolidated Financial Statements of this Form 10-K.

Earnings (Loss) Per Share (De_2

Earnings (Loss) Per Share (Details 2) - shares shares in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Anti-dilutive shares excluded from calculation of earnings per share
Anti-dilutive shares excluded from calculation of earnings per share	2.4	2.4	3.7
Options
Anti-dilutive shares excluded from calculation of earnings per share
Anti-dilutive shares excluded from calculation of earnings per share	1	1.6	1.5

Intangible Assets and Goodwil_2

Intangible Assets and Goodwill (Goodwill Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Gross Carrying Amount	$ 205,235	$ 228,948
Goodwill, Written off Related to Sale of Business Unit	54,494
Goodwill, Foreign Currency Translation Gain (Loss)	459	(2,483)
Goodwill, Impaired, Accumulated Impairment Loss	(21,770)	(21,770)
Net Carrying Amount	$ 183,465	$ 207,178	$ 209,661

Intangible Assets and Goodwil_3

Intangible Assets and Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill information for each reporting unit
Balance at the beginning of the period	$ 207,178	$ 209,661
Addition to goodwill	30,322
Goodwill, Written off Related to Sale of Business Unit	54,494
Goodwill, Foreign Currency Translation Gain (Loss)	459	(2,483)
Balance at the end of the period	$ 183,465	$ 207,178

Intangible Assets and Goodwil_4

Intangible Assets and Goodwill (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Components of intangible assets
Accumulated Amortization	$ (247,082)	$ (268,534)
Finite-lived intangible assets	52,300
Indefinite-lived Intangible Assets (Excluding Goodwill)	2,600
Intangible Assets, Gross (Excluding Goodwill)	301,982	328,470
Intangible assets, net	54,900	59,936
Amortization expense for intangible assets	$ 17,058	$ 29,341	$ 41,962
Minimum
Components of intangible assets
Useful life (in years)	6 months	1 year
Maximum
Components of intangible assets
Useful life (in years)	10 years	10 years
Existing technology
Components of intangible assets
Gross Carrying Amount	$ 262,789	$ 258,903
Accumulated Amortization	(213,354)	(213,824)
Finite-lived intangible assets	$ 49,435	$ 45,079
Existing technology \| Minimum
Components of intangible assets
Useful life (in years)	3 years	3 years
Existing technology \| Maximum
Components of intangible assets
Useful life (in years)	10 years	10 years
Customer contracts and contractual relationships
Components of intangible assets
Gross Carrying Amount	$ 36,293	$ 67,667
Accumulated Amortization	(33,428)	(54,410)
Finite-lived intangible assets	$ 2,865	$ 13,257
Customer contracts and contractual relationships \| Minimum
Components of intangible assets
Useful life (in years)	6 months	1 year
Customer contracts and contractual relationships \| Maximum
Components of intangible assets
Useful life (in years)	10 years	10 years
Non-competition agreements
Components of intangible assets
Gross Carrying Amount	$ 300	$ 300
Accumulated Amortization	(300)	(300)
Finite-lived intangible assets	$ 0	$ 0
Useful life (in years)	3 years	3 years
In-process research and development
Components of intangible assets
Indefinite-lived Intangible Assets (Excluding Goodwill)	$ 2,600	$ 1,600
Payments and Ticketing business
Components of intangible assets
Disposal Group, Including Discontinued Operation, Intangible Assets, Noncurrent	$ 20,700

Intangible Assets and Goodwil_5

Intangible Assets and Goodwill (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Purchased patents
Amortization of intangible assets	$ 17,058	$ 29,341	$ 41,962
Estimated future amortization expense of intangible assets
Next Twelve Months	18,413
Year Two	14,411
Year Three	7,444
Year Four	6,740
Year Five	5,292
Thereafter	0
Finite-lived intangible assets	52,300
Indefinite-lived Intangible Assets (Excluding Goodwill)	2,600
Intangible Assets, Net (Excluding Goodwill)	54,900	59,936
Customer contracts and contractual relationships
Estimated future amortization expense of intangible assets
Finite-lived intangible assets	2,865	13,257
Existing technology
Estimated future amortization expense of intangible assets
Finite-lived intangible assets	$ 49,435	$ 45,079
Non-competition agreements
Identified intangible assets assumed in the acquisitions
Useful life (in years)	3 years	3 years
Estimated future amortization expense of intangible assets
Finite-lived intangible assets	$ 0	$ 0
Minimum
Identified intangible assets assumed in the acquisitions
Useful life (in years)	6 months	1 year
Minimum \| Customer contracts and contractual relationships
Identified intangible assets assumed in the acquisitions
Useful life (in years)	6 months	1 year
Minimum \| Existing technology
Identified intangible assets assumed in the acquisitions
Useful life (in years)	3 years	3 years

Segments and Major Customers (D

Segments and Major Customers (Details 1) - Accounts receivable - Customer Concentration Risk	Dec. 31, 2019	Dec. 31, 2018
Customer 1 [Member]
Concentration Risk
Customer concentration risk	19.00%	39.00%
Customer 2 [Member]
Concentration Risk
Customer concentration risk	14.00%
Customer 3 [Member]
Concentration Risk
Customer concentration risk		12.00%

Segments and Major Customers _2

Segments and Major Customers (Details 2) - Sales, net - Customer Concentration Risk	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Customer A
Concentration Risk
Concentration risk as a percentage			17.00%
Customer B
Concentration Risk
Concentration risk as a percentage	10.00%		13.00%
Customer C
Concentration Risk
Concentration risk as a percentage			13.00%
Customer D [Member]
Concentration Risk
Concentration risk as a percentage	14.00%	15.00%
Customer E [Member]
Concentration Risk
Concentration risk as a percentage		11.00%

Segments and Major Customers _3

Segments and Major Customers (Details 3) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Major Customer Disclosure
Revenue	$ 59,947	$ 57,399	$ 58,297	$ 48,384	$ 68,563	$ 59,754	$ 56,458	$ 46,426	$ 224,027	$ 231,201	$ 393,096
Property, plant and equipment, net	44,714				57,028				44,714	57,028
South Korea
Major Customer Disclosure
Revenue									3,583	13,421	115,811
USA
Major Customer Disclosure
Revenue									134,526	129,567	165,263
Property, plant and equipment, net	40,300				50,400				40,300	50,400
TAIWAN, PROVINCE OF CHINA
Major Customer Disclosure
Revenue									24,118	21,749	9,953
Japan
Major Customer Disclosure
Revenue									11,877	23,222	23,378
Europe
Major Customer Disclosure
Revenue									10,262	15,668	22,597
Canada
Major Customer Disclosure
Revenue									3,554	4,960	4,373
SINGAPORE
Major Customer Disclosure
Revenue									21,751	19,140	22,554
Asia-Other
Major Customer Disclosure
Revenue									14,356	3,474	$ 29,167
India
Major Customer Disclosure
Property, plant and equipment, net	3,400				3,800				3,400	3,800
Other foreign locations
Major Customer Disclosure
Property, plant and equipment, net	$ 1,000				$ 2,800				$ 1,000	$ 2,800

Marketable Securities (Details)

Marketable Securities (Details) - USD ($) $ in Thousands	12 Months Ended
Marketable Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Cash equivalents and marketable securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 264,934	$ 216,628
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	$ (64)	$ (101)
Maximum maturity period of available-for-sale securities (in years)	3 years	3 years
Maximum remaining maturity period of available-for-sale securities (in years)	1 year	1 year
Fair Value	$ 363,542	$ 226,708
Amortized Cost	363,587	226,809
Cash Cash Equivalents And Short Term Investments Unrealized Gains	19	0
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses	(64)	(101)
Gross Unrealized Gains	19	0
Gross Unrealized Losses	64	101
Cash, fair value	44,122	51,056
Cash	44,122	51,056
Cash, cash equivalents and marketable securities
Fair Value	407,664	277,764
Amortized Cost	407,709	277,865
Money market funds
Cash equivalents and marketable securities
Fair Value	10,065	10,080
Amortized Cost	10,065	10,080
Cash Cash Equivalents And Short Term Investments Unrealized Gains	0	0
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses	$ 0	$ 0
Weighted Rate of Return (as a percent)	1.48%	2.23%
US Treasury and Government [Member]
Cash equivalents and marketable securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 14,112	$ 32,630
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(1)	(4)
Fair Value	39,086	32,630
Amortized Cost	39,087	32,634
Cash Cash Equivalents And Short Term Investments Unrealized Gains	0	0
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses	$ (1)	$ (4)
Weighted Rate of Return (as a percent)	1.49%	2.28%
Corporate notes, bonds and commercial paper
Cash equivalents and marketable securities
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 250,822	$ 183,998
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	(63)	(97)
Fair Value	314,391	183,998
Amortized Cost	314,435	184,095
Cash Cash Equivalents And Short Term Investments Unrealized Gains	19	0
CashCashEquivalentsAndShortTermInvestmentsUnrealizedLosses	$ (63)	$ (97)
Weighted Rate of Return (as a percent)	1.81%	2.37%
Short term marketable securities
Cash equivalents and marketable securities
Fair Value	$ 305,488	$ 161,840
Cash Equivalents [Member]
Cash equivalents and marketable securities
Fair Value	$ 58,054	$ 64,868

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	$ 363,542,000	$ 226,708,000
Equity Method Investments	$ 3,600,000	$ 3,300,000
Equity Method Investment, Ownership Percentage	25.00%	27.70%
Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	$ 10,065,000	$ 10,080,000
US Treasury and Government Short-term Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	39,086,000	32,630,000
Corporate notes, bonds and commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	314,391,000	183,998,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	363,542,000	226,708,000
Fair Value, Measurements, Recurring [Member] \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	10,065,000	10,080,000
Fair Value, Measurements, Recurring [Member] \| US Treasury and Government Short-term Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	39,086,000	32,630,000
Fair Value, Measurements, Recurring [Member] \| Corporate notes, bonds and commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	314,391,000	183,998,000
Fair Value, Measurements, Recurring [Member] \| Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	10,065,000	10,080,000
Fair Value, Measurements, Recurring [Member] \| Level 1 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	10,065,000	10,080,000
Fair Value, Measurements, Recurring [Member] \| Level 1 \| US Treasury and Government Short-term Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 1 \| Corporate notes, bonds and commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	353,477,000	216,628,000
Fair Value, Measurements, Recurring [Member] \| Level 2 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 2 \| US Treasury and Government Short-term Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	39,086,000	32,630,000
Fair Value, Measurements, Recurring [Member] \| Level 2 \| Corporate notes, bonds and commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	314,391,000	183,998,000
Fair Value, Measurements, Recurring [Member] \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 \| Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 \| US Treasury and Government Short-term Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	0	0
Fair Value, Measurements, Recurring [Member] \| Level 3 \| Corporate notes, bonds and commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total available-for-sale securities	$ 0	$ 0

Fair Value of Financial Instr_4

Fair Value of Financial Instruments (Details 2) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Carrying Value	$ 148,788	$ 141,934
1.375% convertible notes
Debt Instrument [Line Items]
Face value	172,500	172,500
Carrying Value	148,788	141,934
Fair Value	$ 174,239	$ 150,075

Leases Lease Arrangement (Detai

Leases Lease Arrangement (Details) - San Jose facility	Dec. 31, 2019USD ($)	Jul. 08, 2019USD ($)ft²
Lessee, Lease, Description [Line Items]
Total space under lease (in square feet) \| ft²		90,000
Lessee, operating lease, term of contract		128 months
Lessee, operating lease, variable rate, beginning of lease		$ 3.26
Lessee, operating lease, variable rate, end of lease		$ 4.38
Lessee, operating lease, renewal term		60 months
Lessee, operating lease, future lease payments	$ 41,000,000
Total reimbursement receivable under lease agreement	$ 8,900,000

Leases Operating Lease Maturiti

Leases Operating Lease Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Leases [Abstract]
Lessee, operating lease liabilities, due next twelve months	$ 7,926
Lessee, operating lease liabilities, due year two	8,602
Lessee, operating lease liabilities, due year three	7,381
Lessee, operating lease liabilities, due year four	4,618
Lessee, operating lease liabilities, due year five	3,977
Lessee, operating lease liabilities, due after year five	23,314
Lessee, operating lease liabilities, due	55,818
Lessee, operating lease liabilities, undiscounted excess amount	(9,572)
Operating lease, liability	$ 46,246	$ 23,900

Leases Additional Details (Deta

Leases Additional Details (Details) - USD ($) $ in Millions	12 Months Ended
Leases Additional Details (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Operating lease, weighted-average remaining lease term	7 years 10 months 24 days
Operating lease, weighted-average discount rate, percent	4.20%
Operating lease, cost	$ 9.6
Rent expense		$ 5.2	$ 4.4
Operating lease, payments	$ 10.4

Balance Sheet Details (Details)

Balance Sheet Details (Details) - USD ($) $ in Thousands	12 Months Ended
Balance Sheet Details (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, plant and equipment, net
Property, plant and equipment, gross	$ 125,803	$ 140,306
Less accumulated depreciation and amortization	(81,089)	(83,278)
Property, plant and equipment, net	44,714	57,028
Depreciation expense	15,200	10,700	$ 13,300
Building
Property, plant and equipment, net
Property, plant and equipment, gross	0	40,320
Computer software
Property, plant and equipment, net
Property, plant and equipment, gross	50,453	26,127
Computer equipment
Property, plant and equipment, net
Property, plant and equipment, gross	36,761	37,223
Furniture and fixtures
Property, plant and equipment, net
Property, plant and equipment, gross	16,136	16,286
Leasehold improvements
Property, plant and equipment, net
Property, plant and equipment, gross	10,316	10,824
Machinery
Property, plant and equipment, net
Property, plant and equipment, gross	10,446	9,097
Construction in progress
Property, plant and equipment, net
Property, plant and equipment, gross	$ 1,691	$ 429

Balance Sheet Details (Details

Balance Sheet Details (Details 2) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accumulated other comprehensive income (Loss)
Foreign currency translation adjustments, net of tax	$ 105	$ (10,040)
Unrealized gain (loss) on available-for-sale securities, net of tax	(197)	(251)
Total	$ (92)	$ (10,291)

Balance Sheet Details Balance S

Balance Sheet Details Balance Sheet Details (Details 3) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Inventory [Line Items]
Inventory, Raw Materials, Net of Reserves	$ 3,997	$ 2,583
Inventory, Work in Process, Net of Reserves	1,455	145
Inventory, Finished Goods, Net of Reserves	4,634	4,044
Inventories	$ 10,086	$ 6,772

Convertible Notes (Schedule of

Convertible Notes (Schedule of Notes) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Nov. 17, 2017	Aug. 16, 2013
Debt Instrument [Line Items]
Total convertible notes	$ 148,788	$ 141,934
Less current portion	0	0
Total long-term convertible notes	148,788	141,934
Convertible notes \| 1.375% convertible notes
Debt Instrument [Line Items]
Face value	172,500	172,500	$ 172,500
Unamortized discount	(22,163)	(28,517)
Unamortized Debt Issuance Expense	$ (1,549)	$ (2,049)
Convertible notes \| 1.125% Convertible Senior Notes due 2018
Debt Instrument [Line Items]
Face value				$ 138,000

Convertible Notes (Narrative) (

Convertible Notes (Narrative) (Details)	Nov. 17, 2017USD ($)D$ / shares	Aug. 16, 2013USD ($)D$ / shares	Dec. 31, 2018USD ($)shares	Dec. 31, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)shares	Dec. 31, 2017USD ($)	Nov. 14, 2017$ / shares
Debt Instrument [Line Items]
Derivative, Nonmonetary Notional Amount, Shares \| shares				9,100,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights \| shares				9,100,000
Class of Warrant or Right, Exercise Price of Warrants or Rights \| $ / shares				$ 23.30
Share Price \| $ / shares							$ 14.56
Proceeds from Issuance of Warrants				$ 0	$ 0	$ 23,173,000
Potential Incremental Common Shares Attributable To Dilutive Effect Of Conversion Of Debt Securities \| shares			9,100,000
Additional paid in capital			$ 1,226,588,000	1,261,142,000	1,226,588,000
Events of default
Payments for Hedge, Financing Activities				0	0	33,523,000
Convertible notes
Debt Instrument [Line Items]
Additional paid in capital			111,300,000	111,300,000	111,300,000
Convertible notes \| 1.375% convertible notes
Debt Instrument [Line Items]
Stock Price Premium							60.00%
Face value	$ 172,500,000		$ 172,500,000	$ 172,500,000	172,500,000
Liability Component, Principal amount	137,300,000
Equity Component, Principal amount	$ 35,200,000
Debt discount amortization period	5 years			3 years 1 month 6 days
Debt Issuance Cost, Convertible, Liability Component	$ 2,600,000
Debt Issuance Cost, Convertible, Equity Component	700,000
Debt Issuance Costs, Gross	$ 3,300,000
Conversion rate, number of shares to be issued per $1000 of principal (in shares)	52.8318
Principal amount of notes used as the denominator to determine number of shares converted into notes	$ 1,000
Initial conversion price of notes (in dollars per share) \| $ / shares	$ 18.93
Debt Instrument, Convertible, Threshold Trading Days	20
Debt Instrument, Convertible, Threshold Consecutive Trading Days \| D	30
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger	130.00%
Number of consecutive trading days before the five business days during the debt instrument measurement period	5 days
Denomination of the principal amount of notes used to calculate the percent of trading price during the debt instrument measurement period	$ 1,000
Maximum conversion price as a percentage of closing stock price	98.00%
Percentage of face amount of debt instrument redeemable at the company's option	100.00%
Events of default
Period of default in payment of interest (in days)	30 days
Period of default to comply with other agreements (in days)	60 days
Minimum percentage of aggregate outstanding principal required for default event with other agreements	25.00%
Minimum principal amount of debt nonpayment required for debt default to occur	$ 40,000,000
Period of nonpayment of principal amount required for debt default to occur (in days)	30 days
Minimum percentage of aggregate outstanding principal required for nonpayment of debt default to occur	25.00%
Minimum percentage of aggregate outstanding principal required for immediate payment declaration to occur	25.00%
Debt Instrument, Default Percent Of Principal And Accrued And Unpaid Interest	100.00%
Convertible notes \| 1.125% Convertible Senior Notes due 2018
Debt Instrument [Line Items]
Face value		$ 138,000,000
Liability Component, Principal amount		107,700,000
Equity Component, Principal amount		$ 30,300,000
Debt discount amortization period		5 years
Debt Issuance Cost, Convertible, Liability Component		$ 2,800,000
Debt Issuance Cost, Convertible, Equity Component		$ 800,000
Debt Instrument, Term		5 years
Debt Issuance Costs, Gross		$ 3,600,000
Conversion rate, number of shares to be issued per $1000 of principal (in shares)		82.8329
Principal amount of notes used as the denominator to determine number of shares converted into notes		$ 1,000
Initial conversion price of notes (in dollars per share) \| $ / shares		$ 12.07
Debt Instrument, Convertible, Threshold Trading Days		20
Debt Instrument, Convertible, Threshold Consecutive Trading Days \| D		30
Debt Instrument, Convertible, Threshold Percentage of Stock Price Trigger		130.00%
Number of business days immediately after any ten consecutive trading day period during the note measurement period		5 days
Number of consecutive trading days before the five business days during the debt instrument measurement period		5 days
Denomination of the principal amount of notes used to calculate the percent of trading price during the debt instrument measurement period		$ 1,000
Maximum conversion price as a percentage of closing stock price		98.00%
Percentage of face amount of debt instrument redeemable at the company's option		100.00%
Debt Instrument, Repurchase Amount						$ 56,800,000
Events of default
Period of default in payment of interest (in days)		30 days
Period of default to comply with other agreements (in days)		60 days
Minimum percentage of aggregate outstanding principal required for default event with other agreements		25.00%
Minimum principal amount of debt nonpayment required for debt default to occur		$ 40,000,000
Period of nonpayment of principal amount required for debt default to occur (in days)		30 days
Minimum percentage of aggregate outstanding principal required for nonpayment of debt default to occur		25.00%
Minimum percentage of aggregate outstanding principal required for immediate payment declaration to occur		25.00%
Convertible senior notes
Events of default
Repayments of Debt					$ 81,200,000
Debt Conversion, Converted Instrument, Shares Issued \| shares					423,873
Debt Instrument, Convertible, Beneficial Conversion Feature					$ 5,000,000
Convertible senior notes \| 1.375% convertible notes
Debt Instrument [Line Items]
Stated Interest rate (as a percent)	1.375%		1.375%	1.375%	1.375%	1.375%
Convertible senior notes \| 1.125% Convertible Senior Notes due 2018
Debt Instrument [Line Items]
Stated Interest rate (as a percent)		1.125%	1.125%		1.125%	1.125%

Convertible Notes (Interest Exp

Convertible Notes (Interest Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 17, 2017	Aug. 16, 2013
Interest expense related to notes
Amortization of Debt Issuance Costs and Discounts	$ 6,854	$ 9,243	$ 7,578
Additional paid in capital	$ 1,261,142	$ 1,226,588
Convertible senior notes \| 1.375% convertible notes
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.375%	1.375%	1.375%	1.375%
Convertible senior notes \| 1.125% Convertible Senior Notes due 2018
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage		1.125%	1.125%		1.125%
Convertible notes
Interest expense related to notes
Total interest expense on convertible notes	$ 9,226	$ 11,991	$ 9,356
Additional paid in capital	111,300	111,300
Convertible notes \| 1.375% convertible notes
Interest expense related to notes
Coupon interest	2,372	2,372	290
Amortization of Debt Issuance Costs and Discounts	$ 6,854	$ 6,486	$ 768
Debt Instrument, Interest Rate, Effective Percentage	4.90%	4.90%	4.90%
Debt Instrument, Face Amount	$ 172,500	$ 172,500		$ 172,500
Convertible notes \| 1.125% Convertible Senior Notes due 2018
Interest expense related to notes
Coupon interest	0	377	$ 1,488
Amortization of Debt Issuance Costs and Discounts	$ 0	$ 2,756	$ 6,810
Debt Instrument, Interest Rate, Effective Percentage		5.50%	5.50%
Debt Instrument, Face Amount					$ 138,000

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands

Nov. 17, 2017USD ($)

Aug. 16, 2013USD ($)

Dec. 15, 2009USD ($)ft²

Sep. 30, 2011

Dec. 31, 2019USD ($)

Dec. 31, 2018USD ($)

Dec. 31, 2017USD ($)

Dec. 31, 2013USD ($)

Jan. 01, 2019USD ($)

Jan. 31, 2013ft²

Sep. 29, 2012USD ($)

Nov. 04, 2011USD ($)ft²

Sep. 29, 2011ft²

Mar. 08, 2010ft²

Lease Commitments

Interest expense related to imputed financing obligation

$ 4,300

$ 4,400

Current and Long Term, Imputed Financing Obligation

37,600

Property, plant and equipment cost, capitalization amount

40,300

$ 32,000

Restructuring charges

$ 8,821

2,217

$ 0

Convertible notes | 1.125% Convertible Senior Notes due 2018

Lease Commitments

Face value

$ 138,000

Debt discount amortization period

5 years

Convertible notes | 1.375% convertible notes

Lease Commitments

Face value

$ 172,500

172,500

Unamortized discount

22,163

28,517

Unamortized Debt Issuance Expense

$ 1,549

$ 2,049

Debt discount amortization period

5 years

3 years 1 month 6 days

Facility closing

Lease Commitments

Restructuring charges

$ 2,000

Sunnyvale Facility, Original agreement

Lease Commitments

Number of options

Period for extension of lease (in months)

60 months

Operating Lease Commitment Termination Period

84 months

Total reimbursement receivable under lease agreement

$ 9,100

Total space under lease (in square feet) | ft²

125,000

Sunnyvale Facility, First Amended

Lease Commitments

Total reimbursement receivable under lease agreement

$ 1,700

Total space under lease (in square feet) | ft²

31,000

Sunnyvale Facility, Second Amended

Lease Commitments

Total reimbursement receivable under lease agreement

$ 1,500

Ohio Facility

Lease Commitments

Period for extension of lease (in months)

60 months

Total space under lease (in square feet) | ft²

51,000

Fogg-Brecksville Development Co., Original

Lease Commitments

Total space under lease (in square feet) | ft²

25,000

Commitments and Contingencies_3

Commitments and Contingencies (Details 2) - USD ($) $ in Thousands		Nov. 17, 2017	Aug. 16, 2013	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[1],[2]			$ 19,630
Contractual Obligation, Due in Second Year	[1],[2]			18,082
Contractual Obligation, Due in Third Year	[1],[2]			11,400
Contractual Obligation, Due in Fourth Year	[1],[2]			173,692
Contractual Obligation, Due in Fifth Year	[1],[2]			0
Contractual obligation	[1],[2]			$ 222,804
Terms of noncancellable license agreement, minimum (in years)				1 year
Rent expense					$ 5,200	$ 4,400
Property, plant and equipment cost, capitalization amount					40,300		$ 32,000
unrecognized tax benefit excluding foreign tax withholdings				$ 24,600
Other commitments
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[1],[2]			234
Contractual Obligation, Due in Second Year	[1],[2]			234
Contractual Obligation, Due in Third Year	[1],[2]			0
Contractual Obligation, Due in Fourth Year	[1],[2]			0
Contractual Obligation, Due in Fifth Year	[1],[2]			0
Contractual obligation	[1],[2]			468
Software licenses
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[1],[2],[3]			13,525
Contractual Obligation, Due in Second Year	[1],[2],[3]			11,977
Contractual Obligation, Due in Third Year	[1],[2],[3]			6,028
Contractual Obligation, Due in Fourth Year	[1],[2],[3]			0
Contractual Obligation, Due in Fifth Year	[1],[2],[3]			0
Contractual obligation	[1],[2],[3]			31,530
Retention bonus liability
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[1],[2],[4]			3,499
Contractual Obligation, Due in Second Year	[1],[2],[4]			3,499
Contractual Obligation, Due in Third Year	[1],[2],[4]			3,000
Contractual Obligation, Due in Fourth Year	[1],[2],[4]			0
Contractual Obligation, Due in Fifth Year	[1],[2],[4]			0
Contractual obligation	[1],[2],[4]			9,998
Convertible notes
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[1],[2]			0
Contractual Obligation, Due in Second Year	[1],[2]			0
Contractual Obligation, Due in Third Year	[1],[2]			0
Contractual Obligation, Due in Fourth Year	[1],[2]			172,500
Contractual Obligation, Due in Fifth Year	[1],[2]			0
Contractual obligation	[1],[2]			172,500
Interest payments related to convertible notes
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[1],[2]			2,372
Contractual Obligation, Due in Second Year	[1],[2]			2,372
Contractual Obligation, Due in Third Year	[1],[2]			2,372
Contractual Obligation, Due in Fourth Year	[1],[2]			1,192
Contractual Obligation, Due in Fifth Year	[1],[2]			0
Contractual obligation	[1],[2]			8,308
Imputed financing obligation
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[5]				5,677
Contractual Obligation, Due in Second Year	[5]				2,404
Contractual Obligation, Due in Third Year	[5]				0
Contractual Obligation, Due in Fourth Year	[5]				0
Contractual Obligation, Due in Fifth Year	[5]				0
Contractual obligation	[5]				8,081
Leases and other contractual obligations
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[5]				5,333
Contractual Obligation, Due in Second Year	[5]				4,883
Contractual Obligation, Due in Third Year	[5]				4,960
Contractual Obligation, Due in Fourth Year	[5]				3,271
Contractual Obligation, Due in Fifth Year	[5]				968
Contractual obligation	[5]				19,415
Convertible notes \| 1.125% Convertible Senior Notes due 2018
Contractual obligations
Face value			$ 138,000
Debt Instrument, Convertible, Remaining Discount Amortization Period			5 years
Convertible notes \| 1.375% convertible notes
Contractual obligations
Face value		$ 172,500		$ 172,500	172,500
Debt Instrument, Convertible, Remaining Discount Amortization Period		5 years		3 years 1 month 6 days
Leasing Arrangement [Member]
Contractual obligations
Contractual Obligation, Due in Next Fiscal Year	[5]				11,010
Contractual Obligation, Due in Second Year	[5]				7,287
Contractual Obligation, Due in Third Year	[5]				4,960
Contractual Obligation, Due in Fourth Year	[5]				3,271
Contractual Obligation, Due in Fifth Year	[5]				968
Contractual obligation	[5]				$ 27,496

[1]	For the Company’s lease commitments as of December 31, 2019 , refer to Note 10, “Leases.”
[2]	The above table does not reflect possible payments in connection with unrecognized tax benefits of approximately $24.6 million including $22.8 million recorded as a reduction of long-term deferred tax assets and $1.8 million in long-term income taxes payable, as of December 31, 2019 . As noted below in Note 19, “Income Taxes,” although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months , the Company cannot reasonably estimate the outcome at this time.
[3]	The Company has commitments with various software vendors for agreements generally having terms longer than one year .
[4]	In connection with the acquisitions of Northwest Logic in August 2019 and the Secure Silicon IP and Protocols business in December 2019, the Company is obligated to pay retention bonuses to certain employees subject to certain eligibility and acceleration provisions including the condition of employment.
[5]	With respect to the imputed financing obligation, the main components of the difference between the amount reflected in the table above and the amount reflected on the consolidated balance sheet are the interest on the imputed financing obligation and the estimated common area expenses over the future periods. The amount includes the amended Ohio lease and the amended Sunnyvale lease.

Equity Incentive Plans and St_3

Equity Incentive Plans and Stock-Based Compensation (Details) - shares	12 Months Ended
	Dec. 31, 2019		Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tenure of award (in years)	10 years
Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period (in months)	60 months
Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period (in months)	48 months
Stock Compensation Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	400,000	[1]	5,500,000
Restricted Stock and Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period (in months)	4 years
Director [Member] \| Restricted Stock and Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Requisite service period (in months)	1 year

[1]	Shares were reserved under the 2019 Inducement Plan adopted in the third quarter of 2019.

Equity Incentive Plans and St_4

Equity Incentive Plans and Stock-Based Compensation (Details 2) - shares		12 Months Ended
		Dec. 31, 2019		Dec. 31, 2018		Dec. 31, 2017
Stock Compensation Plan
Shares available for grant
Shares available, at the beginning of the year		10,074,046		5,051,147		7,305,368
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized		400,000	[1]	5,500,000
Stock options granted (in shares)		(80,000)		(711,479)		(558,426)
Options forfeited (in shares)		426,960		877,803		1,978,042
Nonvested equity stock and stock units granted (in shares)	[3]	(7,261,845)	[2]	(4,993,802)	[4]	(5,007,947)	[5]
Nonvested equity stock and stock units forfeited (in shares)	[3]	3,267,702		4,350,377		1,334,110
Shares available, at the end of the period		6,826,863		10,074,046		5,051,147
Conversion factor used to calculate the decrease in the number of shares available for grant resulting from the grant of restricted stock awards		1.5		1.5		1.5
Conversion factor used to calculate the increase in the number of shares available for grant resulting from the forfeiture of restricted stock awards		1.5		1.5		1.5
Potential additional performance stock units
Shares available for grant
Nonvested equity stock and stock units granted (in shares)		1,000,000		500,000		400,000

[1]	Shares were reserved under the 2019 Inducement Plan adopted in the third quarter of 2019.
[2]	Amount includes 1.0 million shares that have been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below.
[3]	For purposes of determining the number of shares available for grant under the 2015 Plan against the maximum number of shares authorized, each restricted stock granted reduces the number of shares available for grant by 1.5 shares and each restricted stock forfeited increases shares available for grant by 1.5 shares.
[4]	Amount includes 0.5 million shares that have been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below.
[5]	Amount includes 0.4 million shares that had been reserved for potential future issuance related to certain performance unit awards discussed under the section titled “Nonvested Equity Stock and Stock Units” below.

Equity Incentive Plans and St_5

Equity Incentive Plans and Stock-Based Compensation (Details 3) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Nov. 14, 2017
Aggregate Intrinsic Value
Share Price				$ 14.56
Options
Number of Shares
Outstanding, at the beginning of the period (in shares)	3,235,891	4,310,361	7,008,833
Options granted (in shares)	80,000	711,479	558,426
Options exercised (in shares)	(1,249,785)	(908,146)	(1,278,856)
Options forfeited (in shares)	(426,960)	(877,803)	(1,978,042)
Outstanding, at the end of the period (in shares)	1,639,146	3,235,891	4,310,361
Vested or expected to vest at the end of the period (in shares)	1,627,218
Options exercisable at the end of the period (in shares)	1,319,210
Weighted Average Exercise Price
Outstanding at the beginning of the year (in dollars per shares)	$ 10.25	$ 9.78	$ 9.34
Options granted (in dollars per share)	13.25	12.84	12.95
Options exercised (in dollars per share)	7.79	6.70	7.34
Options forfeited (in dollars per share)	13.71	13.73	10.68
Outstanding at the end of the period (in dollars per shares)	11.37	$ 10.25	$ 9.78
Vested or expected to vest at the end of the period (in dollars per share)	11.36
Options exercisable at the end of the period (in dollars per share)	$ 11.01
Weighted Average Remaining Contractual Term (in years)
Outstanding (in years)	4 years 6 months 14 days
Vested or expected to vest (in years)	4 years 5 months 26 days
Options exercisable (in years)	3 years 7 months 17 days
Aggregate Intrinsic Value
Outstanding	$ 4,631
Vested or expected to vest	4,621
Options exercisable	$ 4,327

Equity Incentive Plans and St_6

Equity Incentive Plans and Stock-Based Compensation (Details 4)	12 Months Ended
	Dec. 31, 2019USD ($)plan$ / sharesshares		Dec. 31, 2018USD ($)plan$ / sharesshares	Dec. 31, 2017USD ($)plan$ / sharesshares	Dec. 31, 2016shares
Stock-Based Compensation
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense \| $				$ 1,300,000
Stock Compensation Plan
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized	400,000	[1]	5,500,000
Shares available for issuance	6,826,863		10,074,046	5,051,147	7,305,368
Options granted (in shares)	80,000		711,479	558,426
Valuation assumptions
Dividend yield (as a percent)	0.00%		0.00%	0.00%
Share Based Compensation Arrangement by Share Based Payment Award, Equity Instruments, Other than Options Grants in Period Decrease in Available for Grant for Every Grant	1.5		1.5	1.5
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments, Other than Options, Forfeited in Period Increase in Available for Grant for Every Forfeiture	1.5		1.5	1.5
Options
Stock-Based Compensation
Options granted (in shares)	80,000		711,479	558,426
Estimated total grant date fair value \| $	$ 300,000		$ 3,000,000	$ 2,300,000
Stock-based compensation \| $	1,000,000		1,700,000	2,800,000
Unrecognized compensation cost net of expected forfeitures \| $	$ 2,000,000
Expected weighted-average period for recognition of compensation cost (in years)	2 years 3 months 18 days
Total fair value of options vested \| $	$ 6,700,000		$ 12,900,000	$ 17,300,000
Valuation assumptions
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	1,639,146		3,235,891	4,310,361	7,008,833
Expected stock price volatility rate minimum (as a percent)	33.00%		24.00%	24.00%
Expected stock price volatility rate maximum (as a percent)	36.00%		32.00%	32.00%
Risk free interest rate minimum (as a percent)	1.40%		2.60%	1.80%
Risk free interest rate maximum (as a percent)	1.60%		2.80%	2.00%
Expected term (in years)			5 years 9 months 18 days
Weighted average grant date fair value (in dollars per share) \| $ / shares	$ 4.36		$ 4.23	$ 4.09
Restricted Stock and Stock Units
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period	4 years
Stock-based compensation \| $	$ 23,900,000		$ 18,600,000	$ 22,900,000
Unrecognized compensation cost net of expected forfeitures \| $	$ 33,200,000
Expected weighted-average period for recognition of compensation cost (in years)	2 years 4 months 24 days
Total fair value of nonvested equity stock units at grant date \| $	$ 43,000,000		$ 38,100,000	$ 40,000,000
Valuation assumptions
Weighted-average fair value of purchase rights granted under the purchase plan (in dollars per share) \| $ / shares	$ 10.17		$ 12.77	$ 13.02
Nonvested equity stock and stock units
Nonvested at the beginning of the period (in shares)	4,859,135		5,861,349	4,863,056
Granted (in shares)	4,233,701		2,978,558	3,075,396
Vested (in shares)	(1,896,283)		(1,713,930)	(1,216,476)
Forfeited (in shares)	(1,907,070)		(2,266,842)	(860,627)
Nonvested at the end of the period (in shares)	5,289,483		4,859,135	5,861,349
Weighted-Average Grant-Date Fair Value
Nonvested at the beginning of the period (in dollars per share) \| $ / shares	$ 12.71		$ 12.68	$ 12.33
Granted (in dollars per share) \| $ / shares	10.17		12.77	13.02
Vested (in dollars per share) \| $ / shares	12.40		12.39	12.15
Forfeited (in dollars per share) \| $ / shares	11.33		12.97	12.61
Nonvested at the end of the period (in dollars per share) \| $ / shares	$ 11.27		$ 12.71	$ 12.68
Employee Stock Purchase Plan
Stock-Based Compensation
Number of employee stock purchase plans \| plan	1		1	1
Minimum number of hours of weekly employment in order to qualify for eligibility in the plan	20 hours		20 hours	20 hours
Minimum number of months of employment in a fiscal year in order to qualify for eligibility in the plan	5 months		5 months	5 months
Offering period (in months)	6 months		6 months	6 months
Percentage of the price at the beginning of the offering period or price at the end of each offering period to derive purchase price	85.00%		85.00%	85.00%
Maximum share value per employee in any calendar year \| $	$ 25,000		$ 25,000	$ 25,000
Shares issued under employee stock purchase plans	629,438		541,395	615,370
Weighted average price per share of shares issued (in dollars per share) \| $ / shares	$ 8.53		$ 9.99	$ 10.47
Shares available for issuance	1,665,440
Stock-based compensation \| $	$ 1,500,000		$ 1,400,000	$ 1,700,000
Unrecognized compensation cost net of expected forfeitures \| $	$ 700,000
Expected weighted-average period for recognition of compensation cost (in years)	4 months
Valuation assumptions
Expected stock price volatility rate minimum (as a percent)	32.00%		27.00%	25.00%
Expected stock price volatility rate maximum (as a percent)	32.00%		34.00%	27.00%
Risk free interest rate minimum (as a percent)	1.60%		2.05%	0.98%
Risk free interest rate maximum (as a percent)	2.40%		2.50%	1.30%
Expected term (in years)	6 months		6 months	6 months
Weighted-average fair value of purchase rights granted under the purchase plan (in dollars per share) \| $ / shares	$ 3.13		$ 2.59	$ 3.07
Weighted-Average Grant-Date Fair Value
Granted (in dollars per share) \| $ / shares	$ 3.13		$ 2.59	$ 3.07
Minimum
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	0.00%
Minimum \| Options
Valuation assumptions
Expected term (in years)	5 years 1 month 6 days			5 years 3 months 14 days
Maximum
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	200.00%
Maximum \| Options
Valuation assumptions
Expected term (in years)	5 years 2 months 12 days			5 years 4 months 24 days
Option One
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period	60 months
Option Two
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period	48 months

[1]	Shares were reserved under the 2019 Inducement Plan adopted in the third quarter of 2019.

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ in Millions	3 Months Ended				12 Months Ended
Stockholders' Equity (Details) - USD ($) $ in Millions	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2018	Dec. 31, 2019	Jan. 21, 2015
Class of Stock [Line Items]
Stock Repurchased and Retired During Period, Value		$ (40)		$ (40)	$ (37.5)
Number of shares authorized to be repurchased under the plan							20,000,000
UpfrontPaymentUnderAcceleratedStockRepurchaseProgram		$ 50		$ 50
Stock Repurchased and Retired During Period, Shares	(700,000)	(3,100,000)	(800,000)	(3,200,000)
UnsettledForwardContractIndexedtoIssuersStockClassifiedwithinStock		$ 10		$ 10
Remaining shares authorized to be repurchased						3,600,000

Benefit Plans (Details)

Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
Benefit Plans (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Retirement Benefits [Abstract]
Employee contribution limit per calendar year to 401 (k) Plan (as a percent of compensation)	60.00%
Employer match of employee contributions of first 6% of eligible compensation (as a percent)	50.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 2	$ 2.1	$ 2.3

Divestiture Divestiture (Additi

Divestiture Divestiture (Additional Information) (Details) - Payments and Ticketing business - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Oct. 21, 2019
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Divestiture, proceeds	$ 82.5	$ 75
Divestiture, working capital adjustments, net	7.5
Divestiture, working capital adjustments, due to buyer	1.1
Divestiture, transaction costs	$ 3.8

Restructuring Charges (Details)

Restructuring Charges (Details) $ in Thousands	12 Months Ended
Restructuring Charges (Details) $ in Thousands	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Jan. 30, 2018USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 8,821	$ 2,217	$ 0
2018 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring charges		1,200
Assets held-for-sale		$ 3,500
Restructuring and Related Cost, Positions Eliminated [Abstract]
Restructuring, number of positions eliminated		50
2018 Plan \| Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 2,200
2018 Plan \| Other \| Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges		2,000
2018 Plan \| Corporate \| Employee severance
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 200
2019 Plan
Restructuring Cost and Reserve [Line Items]
Restructuring accrual	5,000
Company estimate of the aggregate restructuring cost	$ 8,800
Restructuring and Related Cost, Positions Eliminated [Abstract]
Restructuring, number of positions eliminated	80
Minimum \| 2018 Plan
Restructuring Cost and Reserve [Line Items]
Company estimate of the aggregate restructuring cost				$ 2,000
Maximum \| 2018 Plan
Restructuring Cost and Reserve [Line Items]
Company estimate of the aggregate restructuring cost				$ 5,000

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation Allowance [Line Items]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	$ 0	$ 113,729	$ 21,527
Income before taxes
Domestic	(81,316)	(63,829)	46,031
Foreign	(5,700)	(6,799)	(5,042)
Income (loss) before income taxes	(87,016)	(70,628)	40,989
Federal:
Current	2,932	5,451	20,661
Deferred	2,016	82,726	43,678
State:
Current	657	333	495
Deferred	(1,198)	522	(43)
Foreign:
Current	1,708	1,592	1,101
Deferred	(2,712)	(3,295)	(2,041)
Provision for (benefit from) income taxes	$ 3,403	$ 87,329	$ 63,851
Effective income tax rate reconciliation
Expense (benefit) at U.S. federal statutory rate (as a percent)	21.00%	21.00%	35.00%
Expense (benefit) at state statutory rate (as a percent)	0.90%	(1.20%)	0.70%
Withholding tax (as a percent)	(3.50%)	(7.70%)	50.10%
Foreign rate differential (as a percent)	(1.10%)	(0.20%)	2.80%
Research and development ("R&D") credit (as a percent)	1.20%	2.20%	(3.90%)
Executive compensation (as a percent)	(1.20%)	(0.10%)	1.80%
Non-deductible stock-based compensation (as a percent)	(2.30%)	(2.80%)	14.90%
Foreign tax credit (as a percent)	3.40%	7.70%	(50.10%)
Foreigh derived intangible income deduction (as a percent)	4.60%	14.80%	0.00%
Impact of corporate rate change on deferred taxes (as a percent)	0.00%	0.00%	50.60%
Divestiture (as a percent)	4.80%	0.00%	0.00%
Other (as a percent)	(0.20%)	0.70%	1.40%
Valuation allowance (as a percent)	(31.50%)	(158.00%)	52.50%
Effective tax rate (as a percent)	(3.90%)	(123.60%)	155.80%
Components of net deferred tax assets
Depreciation and amortization	$ 13,995	$ 13,085
Lease liabilities	10,734	0
Other liabilities and reserves	9,522	8,272
Deferred equity compensation	4,456	6,236
Net operating loss carryovers	20,900	21,259
Tax credits	233,407	253,890
Total gross deferred tax assets	293,014	302,742
Lease right-of-use assets	(10,400)	0
Convertible debt	(151)	(207)
Deferred revenue	(94,763)	(143,182)
Deferred Tax Liabilities, Gross	(105,314)	(143,389)
Valuation allowance	(196,972)	(173,878)
Total net deferred tax assets	187,700	159,353
Net deferred tax assets reported as:
Non-current deferred tax assets	4,574	4,435
Non-current deferred tax liabilities	(13,846)	(18,960)
Net deferred tax liabilities	$ (9,272)	$ (14,525)

Income Taxes (Details 2)

Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details 2) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Income Tax Expense (Benefit)	$ 3,403	$ 87,329	$ 63,851
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	35.00%
Changes in Valuation and Qualifying Accounts
Charges Utilized	$ 0	$ (113,729)	$ (21,527)
Tax Valuation Allowance
Changes in Valuation and Qualifying Accounts
Balance at Beginning of Period	173,878	50,911	23,529
Charged (Credited) to Operations	23,094	0	0
Charged to Other Account	0	9,238	5,855
Charges Utilized	0	0	0
Balance at End of Period	$ 196,972	$ 173,878	$ 50,911

Income Taxes (Details 3)

Income Taxes (Details 3) - USD ($) $ in Thousands	12 Months Ended
Income Taxes (Details 3) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Tax credit and operating loss carryforwards
Deferred Tax Assets, Capital Loss Carryforwards	$ 26,400
Portion of unrecognized tax benefits, which if recognized, would be recorded as an income tax benefit	1,800	$ 2,100
Amount of potential unrecognized tax benefit	100
Reconciliation of the beginning and ending amounts of unrecognized income tax benefits
Balance at the beginning of the period	23,482	22,652	$ 21,925
Balance at the end of the period	115,653	23,482	22,652
Tax positions related to prior years:
Additions	76,158	115	16
Reductions	(472)	(317)	(372)
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	0	0	0
Tax positions related to current year:
Additions	16,485	$ 1,032	$ 1,083
Undistributed earnings	14,000
Deferred Tax Liabilities, Undistributed Foreign Earnings	$ 1,900
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	35.00%
Tax credit carryforwards, alternative minimum tax credit	$ 1,900
Foreign Tax Credit
Tax credit and operating loss carryforwards
Tax credit carryforwards	186,100
Foreign Tax Authority [Member]
Reconciliation of the beginning and ending amounts of unrecognized income tax benefits
Balance at the end of the period	91,000
Federal \| Research and Development
Tax credit and operating loss carryforwards
Tax credit carryforwards	40,600
Federal \| Foreign Tax Credit
Tax positions related to current year:
Tax credit carryforward, subject to expiration	29,100
State and local jurisdiction
Tax credit and operating loss carryforwards
Tax credit carryforwards, operating loss	36,400
State and local jurisdiction \| California Franchise Tax Board
Tax credit and operating loss carryforwards
Tax credit carryforwards, operating loss	202,700
State and local jurisdiction \| Research and Development
Tax credit and operating loss carryforwards
Tax credit carryforwards	31,500
Long-term deferred tax assets
Reconciliation of the beginning and ending amounts of unrecognized income tax benefits
Balance at the beginning of the period	21,400
Balance at the end of the period	22,800	$ 21,400
Long-term income taxes payable
Reconciliation of the beginning and ending amounts of unrecognized income tax benefits
Balance at the beginning of the period	2,100
Balance at the end of the period	$ 1,800	$ 2,100

Acquisitions Acquisition (Consi

Acquisitions Acquisition (Consideration Transferred) (Details) - USD ($) $ in Millions	Dec. 08, 2019	Aug. 23, 2019
Northwest Logic
Business Acquisition [Line Items]
Total consideration transferred		$ 21.9
Escrow deposit		$ 3
Escrow release term		24 months
Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Total consideration transferred	$ 46.8
Additional consideration subject to certain revenue targets, fair value	1.8
Maximum \| Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Total consideration	65
Additional consideration subject to certain revenue targets	20
Minimum \| Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Total consideration	$ 45

Acquisitions Acquisition (Purch

Acquisitions Acquisition (Purchase Price Allocation) (Details) - USD ($) $ in Thousands	Aug. 23, 2019	Dec. 31, 2019	Dec. 08, 2019	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill		$ 183,465		$ 207,178	$ 209,661
Northwest Logic
Business Acquisition [Line Items]
Preliminary purchase price allocation adjustment, goodwill	$ 2,100
Preliminary purchase price allocation adjustment, deferred tax liability	2,100
Cash and cash equivalents	159
Accounts receivable	1,679
Prepaid expenses and other current assets	65
Operating lease right-of-use assets	178
Identified intangible assets	8,800
Goodwill	13,477
Other asset	9
Accounts payable	(9)
Operating lease liability	(178)
Other current liabilities	(108)
Deferred tax liability, net	(2,133)
Recognized identifiable assets acquired and liabilities assumed, net	$ 21,939
Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Prepaid expenses and other current assets			$ 267
Unbilled receivables			6,765
Operating lease right-of-use assets			852
Identified intangible assets			23,500
Goodwill			16,845
Deferred revenue			(310)
Operating lease liability			(852)
Other current liabilities			(267)
Recognized identifiable assets acquired and liabilities assumed, net			$ 46,800

Acquisitions Acquisitions (Inta

Acquisitions Acquisitions (Intangible Assets Acquired as Part of Business Combination) (Details) - USD ($) $ in Thousands	Dec. 08, 2019	Aug. 23, 2019
Silicon IP and Business Protocols Business from Verimatrix
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed	$ 23,500
Indefinite-lived Intangible Assets Acquired	1,000
Silicon IP and Business Protocols Business from Verimatrix \| Existing technology
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed	21,600
Silicon IP and Business Protocols Business from Verimatrix \| Customer contracts and contractual relationships
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed	$ 900
Identified intangible assets assumed, weighted-average useful life	5 years
Northwest Logic
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed		$ 8,800
Northwest Logic \| Existing technology
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed		$ 8,100
Identified intangible assets assumed, weighted-average useful life		5 years
Northwest Logic \| Customer contracts and contractual relationships
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed		$ 400
Identified intangible assets assumed, weighted-average useful life		2 years
Northwest Logic \| Customer backlog
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed		$ 300
Identified intangible assets assumed, weighted-average useful life		6 months
Minimum \| Silicon IP and Business Protocols Business from Verimatrix \| Existing technology
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed, weighted-average useful life	3 years
Maximum \| Silicon IP and Business Protocols Business from Verimatrix \| Existing technology
Identified intangible assets assumed in the acquisitions
Identified intangible assets assumed, weighted-average useful life	5 years

Acquisitions Acquisitions (Pro

Acquisitions Acquisitions (Pro Forma Information) (Details) - Northwest Logic - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition, Pro Forma Information, Nonrecurring Adjustment [Line Items]
Pro forma financial information, revenue	$ 231,492	$ 241,049
Pro forma financial information, net income (loss)	$ (90,688)	$ (160,742)
Pro forma financial information, earnings per share, diluted	$ (0.82)	$ (1.48)

Acquisitions Acquisition (Addit

Acquisitions Acquisition (Additional Information) (Details) - USD ($) $ in Thousands		Dec. 08, 2019	Dec. 31, 2019	Dec. 31, 2018	Aug. 23, 2019
Business Acquisition [Line Items]
Contractual obligation	[1],[2]		$ 222,804
Northwest Logic
Business Acquisition [Line Items]
Acquisition-related costs			700
Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Acquisition-related costs		$ 3,100
Goodwill expected to be tax deductible		15,000
Retention bonus liability
Business Acquisition [Line Items]
Contractual obligation	[1],[2],[3]		9,998
Retention bonus liability \| Northwest Logic
Business Acquisition [Line Items]
Contractual obligation			3,000		$ 9,000
Retention bonus liability \| Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Contractual obligation		$ 1,000	$ 500
Minimum
Business Acquisition [Line Items]
Useful life (in years)			6 months	1 year
Minimum \| In-process research and development \| Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Useful life (in years)		3 years
Maximum
Business Acquisition [Line Items]
Useful life (in years)			10 years	10 years
Maximum \| In-process research and development \| Silicon IP and Business Protocols Business from Verimatrix
Business Acquisition [Line Items]
Useful life (in years)		5 years

[1]	For the Company’s lease commitments as of December 31, 2019 , refer to Note 10, “Leases.”
[2]	The above table does not reflect possible payments in connection with unrecognized tax benefits of approximately $24.6 million including $22.8 million recorded as a reduction of long-term deferred tax assets and $1.8 million in long-term income taxes payable, as of December 31, 2019 . As noted below in Note 19, “Income Taxes,” although it is possible that some of the unrecognized tax benefits could be settled within the next 12 months , the Company cannot reasonably estimate the outcome at this time.
[3]	In connection with the acquisitions of Northwest Logic in August 2019 and the Secure Silicon IP and Protocols business in December 2019, the Company is obligated to pay retention bonuses to certain employees subject to certain eligibility and acceleration provisions including the condition of employment.

CONSOLIDATED SUPPLEMENTARY FI_3

CONSOLIDATED SUPPLEMENTARY FINANCIAL DATA (Unaudited) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended											12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018		Jun. 30, 2018		Mar. 31, 2018		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 59,947	$ 57,399	$ 58,297	$ 48,384	$ 68,563	$ 59,754		$ 56,458		$ 46,426		$ 224,027	$ 231,201	$ 393,096
Operating costs and expenses:
Total operating costs and expenses	73,158	80,272	95,343	79,793	72,763	78,921		76,445		90,039		328,566	318,168	338,689
Operating income (loss)	(13,211)	(22,873)	(37,046)	(31,409)	(4,200)	(19,167)		(19,987)		(43,613)		(104,539)	(86,967)	54,407
Net Income (loss)	$ (9,532)	$ (17,331)	$ (36,980)	$ (26,576)	$ (2,018)	$ (104,893)	[1]	$ (15,357)		$ (35,689)		$ (90,419)	$ (157,957)	$ (22,862)
Net loss per share:
Net income (loss) per share - basic (in dollars per share)	$ (0.09)	$ (0.16)	$ (0.33)	$ (0.24)	$ (0.02)	$ (0.97)		$ (0.14)		$ (0.33)		$ (0.81)	$ (1.46)	$ (0.21)
Net income (loss) per share - diluted (in dollars per share)	$ (0.09)	$ (0.16)	$ (0.33)	$ (0.24)	$ (0.02)	$ (0.97)		$ (0.14)		$ (0.33)		$ (0.81)	$ (1.46)	$ (0.21)
Shares used in per share calculations:
Basic (in shares)	111,883	111,315	110,875	109,692	108,826	107,897		107,737	[2]	109,358	[2]	110,948	108,450	110,198
Diluted (in shares)	111,883	111,315	110,875	109,692	108,826	107,897		107,737	[2]	109,358	[2]	110,948	108,450	110,198

[1]	The net loss for the quarter ended September 30, 2018 included a $91.3 million impact of an increase in our deferred tax asset valuation allowance. Refer to Note 19, “Income Taxes,” of Notes to Consolidated Financial Statements of this Form 10-K.
[2]	The quarterly financial information includes the impact of the accelerated share repurchase program as follows: 0.7 million shares in the quarter ended June 30, 2018 and 3.1 million shares repurchased in the quarter ended March 31, 2018. Refer to Note 15, “Stockholders’ Equity,” of Notes to Consolidated Financial Statements of this Form 10-K.