InterDigital (IDCC) 10-Q 4 Nov 21 2021 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2021	Nov. 02, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2021
Document Transition Report	false
Entity File Number	1-33579
Entity Registrant Name	INTERDIGITAL, INC.
Entity Incorporation, State or Country Code	PA
Entity Tax Identification Number	82-4936666
Entity Address, Address Line One	200 Bellevue Parkway
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Wilmington
Entity Address, State or Province	DE
Entity Address, Postal Zip Code	19809-3727
City Area Code	302
Local Phone Number	281-3600
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	IDCC
Security Exchange Name	NASDAQ
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 Common Stock, Shares Outstanding		30,677,998
Entity Central Index Key	0001405495
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 467,606	$ 473,474
Short-term investments	433,200	453,173
Accounts receivable, less allowances of $322 and $0	141,657	16,008
Prepaid and other current assets	80,304	59,894
Total current assets	1,122,767	1,002,549
PROPERTY AND EQUIPMENT, NET	14,182	16,630
PATENTS, NET	371,857	418,343
DEFERRED TAX ASSETS	94,850	80,380
OTHER NON-CURRENT ASSETS, NET	96,956	98,373
Total non-current assets	577,845	613,726
TOTAL ASSETS	1,700,612	1,616,275
CURRENT LIABILITIES:
Accounts payable	9,555	10,979
Accrued compensation and related expenses	33,838	32,413
Deferred revenue	325,375	219,935
Dividends payable	10,740	10,786
Other accrued expenses	38,521	21,649
Total current liabilities	418,029	295,762
LONG-TERM DEBT	421,420	367,992
LONG-TERM DEFERRED REVENUE	66,673	108,069
OTHER LONG-TERM LIABILITIES	59,173	47,886
TOTAL LIABILITIES	965,295	819,709
COMMITMENTS AND CONTINGENCIES
SHAREHOLDERS’ EQUITY:
Preferred Stock, $0.10 par value, 14,399 shares authorized, 0 shares issued and outstanding	0	0
Common Stock, $0.01 par value, 100,000 shares authorized, 71,616 and 71,389 shares issued and 30,689 and 30,816 shares outstanding	716	714
Additional paid-in capital	762,178	738,481
Retained earnings	1,364,378	1,413,969
Accumulated other comprehensive loss	(390)	(184)
TOTAL SHAREHOLDERS’ EQUITY	2,126,882	2,152,980
Treasury stock, 40,927 and 40,573 shares of common held at cost	1,402,611	1,379,611
Total InterDigital, Inc. shareholders’ equity	724,271	773,369
Noncontrolling interest	11,046	23,197
Total equity	735,317	796,566
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 1,700,612	$ 1,616,275

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
CURRENT ASSETS:
Accounts receivable, less allowances of $322 and $0	$ 322	$ 0
SHAREHOLDERS’ EQUITY:
Preferred stock, par value (in USD per share)	$ 0.10	$ 0.10
Preferred stock, shares authorized (in shares)	14,399,000	14,399,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	71,616,000	71,389,000
Common stock, shares outstanding (in shares)	30,689,000	30,816,000
Treasury stock, shares of common held at cost (in shares)	40,927,000	40,573,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
REVENUES	$ 143,496	$ 87,493	$ 313,594	$ 268,201
OPERATING EXPENSES:
Patent administration and licensing	56,150	40,364	133,694	119,167
Development	22,546	20,845	66,999	61,755
Selling, general and administrative	20,978	10,854	46,994	35,251
Restructuring activities	7,045	0	20,290	0
Total Operating expenses	106,719	72,063	267,977	216,173
Income from operations	36,777	15,430	45,617	52,028
INTEREST EXPENSE	(5,773)	(10,365)	(19,429)	(30,881)
OTHER (EXPENSE) INCOME, NET	(1,537)	3,994	2,226	13,806
Income before income taxes	29,467	9,059	28,414	34,953
INCOME TAX (PROVISION) BENEFIT	(4,253)	12,843	(6,039)	5,879
NET INCOME	25,214	21,902	22,375	40,832
Net loss attributable to noncontrolling interest	(1,014)	(1,882)	(11,042)	(5,319)
NET INCOME ATTRIBUTABLE TO INTERDIGITAL, INC.	$ 26,228	$ 23,784	$ 33,417	$ 46,151
NET INCOME PER COMMON SHARE — BASIC (in USD per share)	$ 0.85	$ 0.77	$ 1.09	$ 1.50
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING — BASIC (in shares)	30,737	30,804	30,792	30,762
NET INCOME PER COMMON SHARE — DILUTED (in USD per share)	$ 0.83	$ 0.76	$ 1.07	$ 1.49
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING — DILUTED (in shares)	31,431	31,119	31,272	31,029
Patent licensing royalties
REVENUES	$ 142,749	$ 85,222	$ 309,127	$ 259,404
Technology solutions
REVENUES	$ 747	$ 2,271	$ 4,467	$ 8,797

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income	$ 25,214	$ 21,902	$ 22,375	$ 40,832
Unrealized (loss) gain on investments, net of tax	(67)	(362)	(206)	82
Comprehensive income	25,147	21,540	22,169	40,914
Comprehensive loss attributable to noncontrolling interest	(1,014)	(1,882)	(11,042)	(5,319)
Total comprehensive income attributable to InterDigital, Inc.	$ 26,161	$ 23,422	$ 33,211	$ 46,233

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-In Capital	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss	Treasury Stock	Non-Controlling Interest
Beginning balance (in shares) at Dec. 31, 2019			71,268					40,567
Beginning balance at Dec. 31, 2019	$ 786,281		$ 712	$ 727,402	$ 1,412,779		$ (74)	$ (1,379,262)	$ 24,724
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	116				116
Net loss attributable to noncontrolling interest	(1,777)								(1,777)
Net change in unrealized loss on short-term investments	32						32
Dividends declared ($0.35 per share)	(10,763)			84	(10,847)
Exercise of common stock options (in shares)			27
Exercise of common stock options	778		$ 1	777
Issuance of common stock, net (in shares)			27
Issuance of common stock, net	(725)			(725)
Amortization of unearned compensation	2,003			2,003
Repurchase of common stock (in shares)								6
Repurchase of common stock	(349)							$ (349)
Ending balance (in shares) at Mar. 31, 2020			71,322					40,573
Ending balance at Mar. 31, 2020	775,596		$ 713	729,541	1,402,048		(42)	$ (1,379,611)	22,947
Beginning balance (in shares) at Dec. 31, 2019			71,268					40,567
Beginning balance at Dec. 31, 2019	786,281		$ 712	727,402	1,412,779		(74)	$ (1,379,262)	24,724
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	46,151
Net loss attributable to noncontrolling interest	(5,319)
Net change in unrealized loss on short-term investments	82
Ending balance (in shares) at Sep. 30, 2020			71,379					40,573
Ending balance at Sep. 30, 2020	802,676		$ 713	735,922	1,426,239		8	$ (1,379,611)	19,405
Beginning balance (in shares) at Mar. 31, 2020			71,322					40,573
Beginning balance at Mar. 31, 2020	775,596		$ 713	729,541	1,402,048		(42)	$ (1,379,611)	22,947
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	22,251				22,251
Net loss attributable to noncontrolling interest	(1,660)								(1,660)
Net change in unrealized loss on short-term investments	412						412
Dividends declared ($0.35 per share)	(10,781)			136	(10,917)
Exercise of common stock options (in shares)			19
Exercise of common stock options	1,014			1,014
Issuance of common stock, net (in shares)			36
Issuance of common stock, net	(755)			(755)
Amortization of unearned compensation	4,629			4,629
Ending balance (in shares) at Jun. 30, 2020			71,377					40,573
Ending balance at Jun. 30, 2020	790,706		$ 713	734,565	1,413,382		370	$ (1,379,611)	21,287
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	23,784				23,784
Net loss attributable to noncontrolling interest	(1,882)								(1,882)
Net change in unrealized loss on short-term investments	(362)						(362)
Dividends declared ($0.35 per share)	(10,782)			145	(10,927)
Issuance of common stock, net (in shares)			2
Issuance of common stock, net	(55)			(55)
Amortization of unearned compensation	1,267			1,267
Ending balance (in shares) at Sep. 30, 2020			71,379					40,573
Ending balance at Sep. 30, 2020	802,676		$ 713	735,922	1,426,239		8	$ (1,379,611)	19,405
Beginning balance (in shares) at Dec. 31, 2020			71,389					40,573
Beginning balance at Dec. 31, 2020	796,566	$ (50,184)	$ 714	738,481	1,413,969	$ (50,184)	(184)	$ (1,379,611)	23,197
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	5,571				5,571
Net loss attributable to noncontrolling interest	(1,613)								(1,613)
Noncontrolling interest distribution	(1,109)								(1,109)
Net change in unrealized loss on short-term investments	(70)						(70)
Dividends declared ($0.35 per share)	(10,766)			210	(10,976)
Exercise of common stock options (in shares)			32
Exercise of common stock options	737		$ 0	737
Issuance of common stock, net (in shares)			55
Issuance of common stock, net	(2,962)			(2,962)
Amortization of unearned compensation	2,153			2,153
Repurchase of common stock (in shares)								91
Repurchase of common stock	(5,750)							$ (5,750)
Ending balance (in shares) at Mar. 31, 2021			71,476					40,664
Ending balance at Mar. 31, 2021	732,573		$ 714	738,619	1,358,380		(254)	$ (1,385,361)	20,475
Beginning balance (in shares) at Dec. 31, 2020			71,389					40,573
Beginning balance at Dec. 31, 2020	796,566	$ (50,184)	$ 714	738,481	1,413,969	$ (50,184)	(184)	$ (1,379,611)	23,197
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	33,417
Net loss attributable to noncontrolling interest	(11,042)
Net change in unrealized loss on short-term investments	(206)
Ending balance (in shares) at Sep. 30, 2021			71,616					40,927
Ending balance at Sep. 30, 2021	735,317		$ 716	762,178	1,364,378		(390)	$ (1,402,611)	11,046
Beginning balance (in shares) at Mar. 31, 2021			71,476					40,664
Beginning balance at Mar. 31, 2021	732,573		$ 714	738,619	1,358,380		(254)	$ (1,385,361)	20,475
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	1,618				1,618
Net loss attributable to noncontrolling interest	(8,415)								(8,415)
Net change in unrealized loss on short-term investments	(69)						(69)
Dividends declared ($0.35 per share)	(10,767)			158	(10,925)
Exercise of common stock options (in shares)			71
Exercise of common stock options	3,632		$ 1	3,631
Issuance of common stock, net (in shares)			41
Issuance of common stock, net	(711)			(711)
Amortization of unearned compensation	3,775			3,775
Repurchase of common stock (in shares)								82
Repurchase of common stock	(5,391)							$ (5,391)
Ending balance (in shares) at Jun. 30, 2021			71,588					40,746
Ending balance at Jun. 30, 2021	716,245		$ 715	745,472	1,349,073		(323)	$ (1,390,752)	12,060
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income attributable to InterDigital, Inc.	26,228				26,228
Net loss attributable to noncontrolling interest	(1,014)								(1,014)
Net change in unrealized loss on short-term investments	(67)						(67)
Dividends declared ($0.35 per share)	(10,740)			183	(10,923)
Exercise of common stock options (in shares)			23
Exercise of common stock options	1,516		$ 1	1,515
Issuance of common stock, net (in shares)			5
Issuance of common stock, net	(74)			(74)
Amortization of unearned compensation	15,082			15,082
Repurchase of common stock (in shares)								181
Repurchase of common stock	(11,859)							$ (11,859)
Ending balance (in shares) at Sep. 30, 2021			71,616					40,927
Ending balance at Sep. 30, 2021	$ 735,317		$ 716	$ 762,178	$ 1,364,378		$ (390)	$ (1,402,611)	$ 11,046

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020
Statement of Stockholders' Equity [Abstract]
Dividends declared (in USD per share)	$ 0.35	$ 0.35	$ 0.35	$ 0.35	$ 0.35	$ 0.35
Accounting Standards Update [Extensible List]			Accounting Standards Update 2020-06
Unrealized (loss) gain on investments, net of tax	$ (67)	$ (69)	$ (70)	$ (362)	$ 412	$ 32
Repurchase of common stock	(11,859)	(5,391)	(5,750)			(349)
Amortization of unearned compensation	15,082	3,775	2,153	1,267	4,629	2,003
Exercise of common stock options	1,516	3,632	737		1,014	778
Issuance of common stock, net	(74)	(711)	(2,962)	(55)	(755)	(725)
Dividends declared ($0.35 per share)	(10,740)	(10,767)	(10,766)	(10,782)	(10,781)	(10,763)
Net income attributable to InterDigital, Inc.	26,228	1,618	5,571	23,784	22,251	116
Net loss attributable to noncontrolling interest	(1,014)	(8,415)	(1,613)	(1,882)	(1,660)	(1,777)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 735,317	$ 716,245	$ 732,573	$ 802,676	$ 790,706	$ 775,596

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 22,375	$ 40,832
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	58,971	61,027
Non-cash interest expense, net	5,240	13,202
Non-cash change in fair-value	(949)	(5,501)
Change in deferred revenue	64,044	53,066
Deferred income taxes	(14,416)	(5,518)
Share-based compensation	21,010	7,899
Patent impairment	11,000	0
Other	0	(63)
Increase in assets
Receivables	(125,649)	(10)
Deferred charges and other assets	(13,464)	(26,745)
Increase (decrease) in liabilities:
Accounts payable	2,266	(1,675)
Accrued compensation and other expenses	28,735	7,698
Net cash provided by operating activities	59,163	144,212
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of short-term investments	(498,151)	(187,707)
Sales of short-term investments	516,715	195,072
Purchases of property and equipment	(1,877)	(9,875)
Capitalized patent costs	(28,145)	(23,726)
Long-term investments	(1,091)	4,260
Net cash used in investing activities	(12,549)	(21,976)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from exercise of stock options	5,885	1,792
Payments on long-term debt	0	(94,909)
Repurchase of common stock	(23,000)	(349)
Non-controlling interest distribution	(1,109)	0
Taxes withheld upon restricted stock unit vestings	(3,747)	(1,535)
Dividends paid	(32,319)	(32,290)
Net cash used in financing activities	(54,290)	(127,291)
NET DECREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(7,676)	(5,055)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD	477,663	757,098
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD	$ 469,987	$ 752,043

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
BASIS OF PRESENTATION	BASIS OF PRESENTATION In the opinion of management, the accompanying unaudited, condensed consolidated financial statements contain all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the financial position of InterDigital, Inc. (individually and/or collectively with its subsidiaries referred to as “InterDigital,” the “Company,” “we,” “us” or “our,” unless otherwise indicated) as of September 30, 2021, the results of our operations for the three and nine months ended September 30, 2021 and 2020 and our cash flows for the nine months ended September 30, 2021 and 2020. The accompanying unaudited, condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and, accordingly, do not include all of the detailed schedules, information and notes necessary to state fairly the financial condition, results of operations and cash flows in conformity with United States generally accepted accounting principles (“GAAP”). The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP for year-end financial statements. Therefore, these financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020 (our “2020 Form 10-K”) as filed with the Securities and Exchange Commission (“SEC”) on February 18, 2021. Definitions of capitalized terms not defined herein appear within our 2020 Form 10-K. The results of operations for interim periods are not necessarily indicative of the results to be expected for the entire year. We have one reportable segment. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. InterDigital has analyzed the impact of the ongoing Coronavirus pandemic (“COVID-19”) on its financial statements as of September 30, 2021. InterDigital has determined that the changes to its significant judgments and estimates as a result of COVID-19 did not have a material impact on its financial statements. The potential impact of COVID-19 will continue to be analyzed going forward. Change in Accounting Policies There have been no material changes or updates to our existing accounting policies from the disclosures included in our 2020 Form 10-K, except as indicated below in " New Accounting Guidance ". Prior Periods' Financial Statement Revision In connection with the preparation of the condensed consolidated financial statements as of and for the three months ended June 30, 2021, it was identified that we incorrectly classified certain tax receivables, representing approximately 1.5% of total assets as of December 31, 2020, as other current assets instead of non-current in the presentation of our consolidated balance sheet. We assessed the materiality of this misstatement on prior periods’ financial statements in accordance with ASC Topic 250, Accounting Changes and Error Corrections, (“ASC 250”) and concluded it was not material to any prior annual or interim periods. In accordance with ASC 250, we have corrected our presentation of other current and non-current assets for prior periods presented in this Form 10-Q by revising the condensed consolidated financial statements and other consolidated financial information included herein. We will continue to present the prior periods on this revised basis to the extent we present such prior periods in future filings. Refer to Note 10, " Other Assets " for additional information on the revision. Reclassifications Certain reclassifications have been made to prior year amounts to conform to the current year presentation. Supplemental Cash Flow Information The following table presents additional supplemental cash flow information for the nine months ended September 30, 2021 and 2020 (in thousands): FOR THE NINE MONTHS ENDED SEPTEMBER 30, SUPPLEMENTAL CASH FLOW INFORMATION: 2021 2020 Interest paid $ 4,000 $ 4,712 Income taxes paid, including foreign withholding taxes 9,835 18,211 Non-cash investing and financing activities: Dividend payable 10,740 10,782 Non-cash acquisition of patents — 33,300 Accrued capitalized patent costs and property and equipment 3,690 (419) Unsettled repurchase of common stock 499 — New Accounting Guidance Accounting Standards Update: Simplifying the Accounting for Income Taxes In December 2019, the FASB issued ASU No. 2019-12, "Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes" ("ASU 2019-12"). The amendments in this ASU are intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020 with early adoption allowed. We adopted this guidance as of January 1, 2021 and the adoption did not have a material impact on our consolidated financial statements. Accounting Standards Update: Simplifying the Accounting for Convertible Instruments In August 2020, the FASB issued ASU No. 2020-06, “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity” (“ASU 2020-06”). The amendments in this ASU are intended to simplify accounting for convertible debt instruments and convertible preferred stock by removing certain accounting models which separate the embedded conversion features from the host contract. ASU 2020-06 also amends certain guidance in ASC 260 on the computation of earnings per share for convertible instruments and contracts on an entity’s own equity. ASU 2020-06 is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years, and early adoption is permitted for fiscal years beginning after December 15, 2020. This update permits the use of either the modified retrospective or fully retrospective methods of transition. We elected to early adopt this standard on a modified retrospective approach as of January 1, 2021. This adoption increased long-term debt by $50.2 million at January 1, 2021, which was comprised of $51.6 million of unamortized interest discount and was partially offset by a net increase of $1.4 million equity component of deferred financing costs. This was due to the standard no longer requiring bifurcation of the embedded conversion feature from the host contract on the 2024 Notes, as defined in Note 7, " Obligations ." This adoption also reduced non-cash interest expense starting in 2021 due to the removal of the accretion of the debt discount on the 2024 Notes. Lastly, the adoption requires the use of the if-converted method of calculating diluted earnings per share rather than the treasury stock method for convertible instruments and requires the inclusion of the potential effect of shares settled in cash or shares in the diluted earnings per share calculation. Due to the reduction in non-cash interest expense, this adoption increased both basic and diluted earnings per share by $0.09 in the three months ended September 30, 2021 and $0.26 in the nine months ended September 30, 2021. Accounting Standards Update: Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity Classified Written Call Options In May 2021, the FASB issued ASU No. 2021-04. The amendments in this ASU are intended to clarify and reduce diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options, including warrants, that remain equity classified after modification or exchange. ASU 2021-04 is effective for fiscal years beginning after December 15, 2021, with early adoption allowed. The Company is currently evaluating the anticipated impact of the adoption of ASU 2021-04 on its consolidated financial statements.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
REVENUE	REVENUE Disaggregated Revenue The following table presents the disaggregation of our revenue for the three and nine months ended September 30, 2021 and 2020 (in thousands): Three months ended September 30, 2021 2020 Increase/(Decrease) Variable patent royalty revenue $ 8,346 $ 7,377 $ 969 13 % Fixed-fee royalty revenue 84,295 77,338 6,957 9 % Current patent royalties a 92,641 84,715 7,926 9 % Non-current patent royalties b 50,108 507 49,601 9,783 % Total patent royalties 142,749 85,222 57,527 68 % Current technology solutions revenue a 747 2,271 (1,524) (67) % Total revenue $ 143,496 $ 87,493 $ 56,003 64 % Nine months ended September 30, 2021 2020 Increase/(Decrease) Variable patent royalty revenue $ 22,765 $ 17,920 $ 4,845 27 % Fixed-fee royalty revenue 222,887 221,023 1,864 1 % Current patent royalties a 245,652 238,943 6,709 3 % Non-current patent royalties b 63,475 20,461 43,014 210 % Total patent royalties 309,127 259,404 49,723 19 % Current technology solutions revenue a 4,467 8,797 (4,330) (49) % Total revenue $ 313,594 $ 268,201 $ 45,393 17 % a. Recurring revenues are comprised of current patent royalties, inclusive of dynamic fixed-fee royalty payments, and current technology solutions revenue. b. Non-recurring revenues are comprised of non-current patent royalties, which include past patent royalties and royalties from static agreements, as well as patent sales. During the nine months ended September 30, 2021, we recognized $186.9 million of revenue that had been included in deferred revenue as of the beginning of the period. As of September 30, 2021, we had contract assets of $20.5 million and $8.7 million included within " Accounts receivable " and " Other non-current assets, net " in the condensed consolidated balance sheet, respectively. As of December 31, 2020, we had contract assets of $9.7 million and $8.9 million included within " Accounts receivable " and " Other non-current assets, net " in the condensed consolidated balance sheet, respectively. Contracted Revenue Based on contracts signed and committed as of September 30, 2021, we expect to recognize the following revenue from dynamic fixed-fee royalty payments over the term of such contracts (in thousands): Revenue Remainder 2021 $ 89,541 2022 299,307 2023 104,469 2024 60,089 2025 and beyond 60,000 Total Revenue $ 613,406

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES In the nine months ended September 30, 2021 and 2020, the Company had an effective tax rate of 21.3% and (16.8)%, respectively. The effective tax rate in both periods was impacted by losses in certain jurisdictions where the Company presently has recorded a valuation allowance against the related tax benefit, as well as by the foreign-derived intangible income deduction and non-deductible compensation. Excluding this valuation allowance, our effective tax rate for the nine months ended September 30, 2021 and 2020 would have been 8.4% and (31.3)% respectively. During the nine months ended September 30, 2021 and 2020, the Company recorded a discrete net expense of $0.3 million and $18.2 million, respectively, primarily related to share-based compensation and the expected amendment of a prior year return to utilize a tax asset generated in the prior year. Due to the closing of the statute of limitations on certain tax years, the Company believes it is reasonably possible that it will have a reduction in the liability for unrecognized tax benefits of $1.1 million, excluding interest and penalties. The effective tax rate reported in any given year will continue to be influenced by a variety of factors, including timing differences between the recognition of book and tax revenue, the level of pre-tax income or loss, the foreign vs. domestic classification of the Company’s customers, and any discrete items that may occur.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
NET INCOME (LOSS) PER SHARE	NET INCOME PER SHARE Basic Earnings Per Share ("EPS") is calculated by dividing net income or loss available to common shareholders by the weighted-average number of common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if options or other securities with features that could result in the issuance of common stock were exercised or converted to common stock or resulting from the unvested outstanding RSUs. The following tables reconcile the numerator and the denominator of the basic and diluted net income per share computation (in thousands, except for per share data): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Net income applicable to InterDigital, Inc. $ 26,228 $ 23,784 $ 33,417 $ 46,151 Weighted-average shares outstanding: Basic 30,737 30,804 30,792 30,762 Dilutive effect of stock options, RSUs, convertible securities and warrants 694 315 480 267 Diluted 31,431 31,119 31,272 31,029 Earnings per share: Basic $ 0.85 $ 0.77 $ 1.09 $ 1.50 Dilutive effect of stock options, RSUs, convertible securities and warrants (0.02) (0.01) (0.02) (0.01) Diluted $ 0.83 $ 0.76 $ 1.07 $ 1.49 Shares of common stock issuable upon the exercise or conversion of certain securities have been excluded from our computation of EPS because the strike price or conversion rate, as applicable, of such securities was greater than the average market price of our common stock and, as a result, the effect of such exercise or conversion would have been anti-dilutive. Set forth below are the securities and the weighted average number of shares of common stock underlying such securities that were excluded from our computation of EPS for the periods presented (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Restricted stock units and stock options 441 156 289 154 Convertible securities (a) — 4,921 — 5,222 Warrants 4,921 5,319 4,921 5,931 Total 5,362 10,396 5,210 11,307 ______________________________ (a) As of December 31, 2020, we made the irrevocable election to settle all conversions of the 2024 Notes through combination settlements of cash and shares of our common stock, with a specified dollar amount of $1,000 per $1,000 principal amount of 2024 Notes and any remaining amounts in shares of our common stock. Convertible Notes and Warrants Refer to Note 7, " Obligations ," for information about the Company's convertible notes and warrants and related conversion and strike prices. During periods in which the average market price of the Company's common stock is above the applicable conversion price of the Company's convertible notes, or above the strike price of the Company's outstanding warrants, the impact of conversion or exercise, as applicable, would be dilutive and such dilutive effect is reflected in diluted EPS. As a result, in periods where the average market price of the Company's common stock is above the conversion price or strike price, as applicable, under the if-converted method, the Company calculates the number of shares issuable under the terms of the convertible notes and the warrants based on the average market price of the stock during the period, and includes that number in the total diluted shares outstanding for the period.

Litigation and Legal Proceeding

Litigation and Legal Proceedings	9 Months Ended
	Sep. 30, 2021
Litigation Settlement [Abstract]
LITIGATION AND LEGAL PROCEEDINGS	LITIGATION AND LEGAL PROCEEDINGS COURT PROCEEDINGS Lenovo UK Proceeding On August 27, 2019, the Company and certain of its subsidiaries filed a claim in the UK High Court against Lenovo Group Limited and certain of its subsidiaries. The claim, as amended, alleges infringement of five of the Company's patents relating to 3G and/or 4G/LTE standards: European Patent (U.K.) Nos. 2,363,008; 2,421,318; 2,485,558; 2,557,714; and 3,355,537. The UK High Court held case management conferences on October 6, 2020 and December 16, 2020, a disclosure hearing on January 19, 2021 and pre-trial review hearings for the first trial on January 28, 2021 and February 8, 2021. At those hearings, the UK High Court entered a schedule for the technical and non-technical FRAND proceedings. Two technical trials were scheduled for March 2021 and June 2021 and the non-technical FRAND trial is scheduled in January 2022. There are three additional technical trials scheduled for the remaining patents following the FRAND trial. The first and second technical trials were completed, and on July 29, 2021, the UK High Court issued its decision regarding the first technical trial finding European Patent (UK) No. 2 485 558 valid, infringed, and essential to Release 8 of LTE. The Company is awaiting the court’s decision regarding the merits of the second technical trial. District of Delaware Patent Proceeding On August 28, 2019, the Company and certain of its subsidiaries filed a complaint in the United States District Court for the District of Delaware (the "Delaware District Court") against Lenovo Holding Company, Inc. and certain of its subsidiaries alleging that Lenovo infringes eight of InterDigital's U.S. patents—U.S. Patent Nos. 8,085,665; 8,199,726; 8,427,954; 8,619,747; 8,675,612; 8,797,873; 9,203,580; and 9,456,449—by making, using, offering for sale, and/or selling Lenovo wireless devices with 3G and/or 4G LTE capabilities. As relief, InterDigital is seeking: (a) a declaration that InterDigital is not in breach of its relevant FRAND commitments with respect to Lenovo; (b) to the extent Lenovo does not agree to negotiate a worldwide patent license, does not agree to enter into binding international arbitration to set the terms of a FRAND license, and does not agree to be bound by the FRAND terms to be set by the UK High Court in the separately filed UK proceedings described above, an injunction prohibiting Lenovo from continued infringement; (c) damages, including enhanced damages for willful infringement and supplemental damages; and (d) attorneys’ fees and costs. On September 16, 2020, the Delaware District Court entered a schedule for the case, setting a patent jury trial. On March 8, 2021, the Delaware District Court held a claim construction hearing, and the court issued its order on May 10, 2021 construing various disputed terms. On March 24, 2021, the Delaware District Court consolidated the antitrust proceeding discussed below with this patent proceeding. Trial for the consolidated proceedings is scheduled for December 5, 2022. District of Delaware Antitrust Proceeding On April 9, 2020, Lenovo (United States) Inc. and Motorola Mobility LLC filed a complaint in the Delaware District Court against the Company and certain of its subsidiaries. The complaint alleges that the Company defendants have violated Sections 1 and 2 of the Sherman Act in connection with, among other things, their licensing of 3G and 4G standards essential patents ("SEPs"). The complaint further alleges that the Company defendants have violated their commitment to the ETSI with respect to the licensing of 3G and 4G SEPs on FRAND terms and conditions. The complaint seeks, among other things (i) rulings that the Company defendants have violated Sections 1 and 2 of the Sherman Act and are liable for breach of their ETSI FRAND commitments, (ii) a judgment that the plaintiffs are entitled to a license with respect to the Company's 3G and 4G SEPs on FRAND terms and conditions, and (iii) injunctions against any demand for allegedly excessive royalties or enforcement of the Company defendants' 3G and 4G U.S. SEPs against the plaintiffs or their customers via patent infringement proceedings. On June 22, 2020, the Company filed a motion to dismiss Lenovo's Sherman Act claims with prejudice, and to dismiss Lenovo's breach of contract claim with leave to re-file as a counterclaim in the Company's legal proceeding against Lenovo in the Delaware District Court discussed above. Oral argument on the Company's motion to dismiss was held on October 27, 2020. On March 24, 2021, the Delaware District Court ruled on the Company’s motion to dismiss. The Delaware District Court dismissed the Sherman Act Section 1 claim without prejudice, denied the motion to dismiss the Sherman Act Section 2 claim, and consolidated the Section 2 and breach of contract claims with Company’s patent proceeding against Lenovo in the Delaware District Court discussed above. China Proceeding On April 10, 2020, Lenovo (Beijing) Ltd. and certain of its affiliates filed a complaint against the Company and certain of its subsidiaries in the Beijing Intellectual Property Court (Beijing IP Court) seeking a determination of the FRAND royalty rates payable for the Company's Chinese 3G, 4G and 5G SEPs. On February 20, 2021, the Company filed an application challenging the jurisdiction of the Beijing IP Court to take up Lenovo’s complaint. The jurisdictional challenge remains pending. Xiaom i As a result of the license agreement between the Company and a subsidiary of Xiaomi Corporation ("Xiaomi"), the parties have ceased all activity in each of the disputes described below and will be taking timely action to formally withdraw all claims. China Proceeding On August 5, 2020, Xiaomi informed the Company that certain of its affiliates filed a complaint in the Wuhan Intermediate People's Court (the "Wuhan Court") seeking a determination of a global FRAND rate for a license to the Company's 3G and/or 4G/LTE SEPs. The Company was informed that the Wuhan Court held an ex parte hearing on or about September 23, 2020 and issued an order that enjoins the Company from seeking an injunction against Xiaomi and certain of its subsidiaries for infringement of certain of the Company's 3G and/or 4G/LTE SEPs on threat of a fine of up to one million yuan per day for violating that order. On September 30, 2020, the Company filed a response seeking reconsideration of the anti-suit injunction, which was denied. The Company challenged that decision at the Supreme People's Court of the People's Republic of China, but that challenge was also denied. The Wuhan Court held two evidentiary hearings in April and June 2021. On July 29, 2021, the Wuhan Court held the first of multiple substantive hearings during which the parties presented their respective claims, defenses and evidence. India Proceeding On July 29, 2020, the Company and certain of its subsidiaries filed two patent infringement actions in the Delhi High Court (the "Delhi High Court") against Xiaomi and certain of its subsidiaries. The first complaint alleges infringement of five of the Company's patents related to 3G and/or 4G/LTE standards: Indian Patent Nos. 262910; 295912; 298719; 313036; and 320182. The second complaint alleges infringement of three of the Company's patents related to H.265/HEVC standards: Indian Patent Nos. 242248; 299448; and 308108. On September 29, 2020, the Company filed an anti-anti-suit injunction application against Xiaomi in the Delhi High Court seeking to enjoin Xiaomi from enforcing the Wuhan Court's anti-suit injunction order described above. On October 9, 2020, the Delhi High Court granted the Company's motion and issued an ad interim injunction. On May 3, 2021, the interim anti-anti-suit injunction was made permanent for the duration of the Indian cellular case. On June 4, 2021, Xiaomi filed responses to the two complaints (cellular and H.265/HEVC), which included counterclaims seeking invalidation of the patents in the respective suits. The Company filed its replies on July 5, 2021. German Proceeding On October 30, 2020, the Company filed an anti-anti-suit injunction application against Xiaomi in the Munich District Court, seeking to enjoin Xiaomi from pursuing the Wuhan Court's anti-suit injunction order described above with respect to Germany. On November 11, 2020, the Munich District Court granted the Company's motion and issued an ex parte injunction restraining Xiaomi from enforcing the anti-suit injunction. Xiaomi opposed the injunction and requested a stay of enforcement. On January 28, 2021, the Munich District Court dismissed the request for stay of enforcement. On February 25, 2021 the Munich District Court confirmed its earlier ex parte anti-anti-suit injunction against Xiaomi. Xiaomi appealed the decision to the Higher Regional Court Munich. On April 27, 2021, the Company was informed that the Munich Regional Court commenced service of three patent infringement actions filed against Xiaomi and certain of its subsidiaries by a subsidiary of the Company. The complaints involve infringement of the Company's German 3G and/or 4G/LTE patents (Patent Nos. EP 2,421,318; EP 2,485,558; and EP 3,355,537). OTHER We are party to certain other disputes and legal actions in the ordinary course of business, including legal proceedings with licensees regarding the terms of their agreements and the negotiation thereof. We do not currently believe that these matters, even if adversely adjudicated or settled, would have a material adverse effect on our financial condition, results of operations or cash flows. None of the preceding matters have met the requirements for accrual or disclosure of a potential range as of September 30, 2021.

Cash, Concentration of Credit R

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
CASH, CONCENTRATION OF CREDIT RISK AND FAIR VALUE OF FINANCIAL INSTRUMENTS	CASH, CONCENTRATION OF CREDIT RISK AND FAIR VALUE OF FINANCIAL INSTRUMENTS Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash currently consists of money market and demand accounts. The following table provides a reconciliation of total cash, cash equivalents and restricted cash as of September 30, 2021, December 31, 2020 and September 30, 2020 to the captions within the condensed consolidated balance sheets and condensed consolidated statements of cash flows (in thousands): September 30, December 31, September 30, 2021 2020 2020 Cash and cash equivalents $ 467,606 $ 473,474 $ 746,561 Restricted cash included within prepaid and other current assets 1,300 3,108 4,401 Restricted cash included within other non-current assets 1,081 1,081 1,081 Total cash, cash equivalents and restricted cash $ 469,987 $ 477,663 $ 752,043 Concentration of Credit Risk and Fair Value of Financial Instruments Financial instruments that potentially subject us to concentration of credit risk consist primarily of cash equivalents, short-term investments, and accounts receivable. We place our cash equivalents and short-term investments only in highly rated financial instruments and in United States government instruments. Our accounts receivable and contract assets are derived principally from patent license and technology solutions agreements. As of September 30, 2021 two licensees comprised 93% and as of December 31, 2020 five licensees comprised 53%, respectively, of our net accounts receivable balance. We perform ongoing credit evaluations of our licensees, who generally include large, multinational, wireless telecommunications equipment manufacturers. We believe that the book values of our financial instruments approximate their fair values. Fair Value Measurements We use various valuation techniques and assumptions when measuring the fair value of our assets and liabilities. We utilize market data or assumptions that market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. This guidance established a hierarchy that prioritizes fair value measurements based on the types of input used for the various valuation techniques (market approach, income approach and cost approach). The levels of the hierarchy are described below: Level 1 Inputs — Level 1 includes financial instruments for which quoted market prices for identical instruments are available in active markets. Level 2 Inputs — Level 2 includes financial instruments for which there are inputs other than quoted prices included within Level 1 that are observable for the instrument such as quoted prices for similar instruments in active markets, quoted prices for identical or similar instruments in markets with insufficient volume or infrequent transactions (less active markets) or model-driven valuations in which significant inputs are observable or can be derived principally from, or corroborated by, observable market data, including market interest rate curves, referenced credit spreads and pre-payment rates. Level 3 Inputs — Level 3 includes financial instruments for which fair value is derived from valuation techniques including pricing models and discounted cash flow models in which one or more significant inputs are unobservable, including the Company’s own assumptions. The pricing models incorporate transaction details such as contractual terms, maturity and, in certain instances, timing and amount of future cash flows, as well as assumptions related to liquidity and credit valuation adjustments of marketplace participants. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of financial assets and financial liabilities and their placement within the fair value hierarchy. We use quoted market prices for similar assets to estimate the fair value of our Level 2 investments. Recurring Fair Value Measurements Our financial assets are generally included within short-term investments on our condensed consolidated balance sheets, unless otherwise indicated. Our financial assets and liabilities that are accounted for at fair value on a recurring basis are presented in the tables below as of September 30, 2021 and December 31, 2020 (in thousands): Fair Value as of September 30, 2021 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 469,987 $ — $ — $ 469,987 Commercial paper (b) — 254,688 — 254,688 U.S. government securities — 129,017 — 129,017 Corporate bonds, asset backed and other securities — 49,495 — 49,495 Total $ 469,987 $ 433,200 $ — $ 903,187 Fair Value as of December 31, 2020 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 397,522 $ — $ — $ 397,522 Commercial paper (b) — 285,242 — 285,242 U.S. government securities — 166,223 — 166,223 Corporate bonds, asset backed and other securities — 81,849 — 81,849 Total $ 397,522 $ 533,314 $ — $ 930,836 ______________________________ (a) Primarily included within cash and cash equivalents. (b) As of September 30, 2021 and December 31, 2020, $0.0 million and $80.1 million, respectively, of commercial paper was included within cash and cash equivalents. Non-Recurring Fair Value Measurements Investments in Other Entities During second quarter 2021, we recognized a $1.0 million unrealized gain resulting from observable price changes of one of our long-term strategic investments, which was included within “ Other (expense) income, net ” in the condensed consolidated statement of income. During first quarter 2020, we recognized a $5.5 million unrealized gain resulting from observable price changes of one of our long-term strategic investments, which was included within “ Other (expense) income, net ” in the condensed consolidated statement of income. Lease Assets During first quarter 2020, we recognized a $1.1 million impairment, comprised of $0.8 million of Property, Plant, and Equipment, and $0.3 million of Right of Use Asset related to the abandonment of one of our leased properties, which was included within “ Operating Expenses ” in the condensed consolidated statement of income. Patents During second quarter 2021, Convida approved a plan to sell certain patent assets, which were classified as held-for sale. This resulted in an impairment of $11.0 million and was included within restructuring activities as more fully discussed below. The patents held for sale are recorded at fair value on September 30, 2021 and are included within " Prepaid and other current assets " in the condensed consolidated balance sheet. Fair Value of Long-Term Debt 2024 Notes The principal amount, carrying value and related estimated fair value of the Company's senior convertible debt reported in the condensed consolidated balance sheets as of September 30, 2021 and December 31, 2020 was as follows (in thousands). The aggregate fair value of the principal amount of the senior convertible long-term debt is a Level 2 fair value measurement. September 30, 2021 December 31, 2020 Principal Carrying Fair Principal Carrying Fair Senior Convertible Long-Term Debt $ 400,000 $ 395,217 $ 432,000 $ 400,000 $ 343,821 $ 418,760 Technicolor Patent Acquisition Long-term Debt The carrying value and related estimated fair value of the Technicolor Patent Acquisition long-term debt reported in the condensed consolidated balance sheets as of September 30, 2021 and December 31, 2020 was as follows (in thousands). The aggregate fair value of the Technicolor Patent Acquisition long-term debt is a Level 3 fair value measurement. September 30, 2021 December 31, 2020 Carrying Fair Carrying Fair Technicolor Patent Acquisition Long-Term Debt $ 26,203 $ 33,192 $ 24,171 $ 27,016

Obligations

Obligations	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
OBLIGATIONS	OBLIGATIONS Technicolor Patent Acquisition Long-Term Debt On July 30, 2018, we completed our acquisition of the patent licensing business of Technicolor SA ("Technicolor"), a worldwide technology leader in the media and entertainment sector (the "Technicolor Patent Acquisition"). In conjunction with the Technicolor Patent Acquisition we assumed Technicolor’s rights and obligations under a joint licensing program with Sony Corporation ("Sony") relating to digital televisions and standalone computer display monitors, which commenced in 2015 and is referred to as the "Madison Arrangement." An affiliate of CPPIB Credit Investments Inc. ("CPPIB Credit"), a wholly owned subsidiary of Canada Pension Plan Investment Board, is a third-party investor in the Madison Arrangement. CPPIB Credit has made certain payments to Technicolor and Sony and has agreed to contribute cash to fund certain capital reserve obligations under the arrangement in exchange for a percentage of future revenues, specifically through September 11, 2030 in regard to the Technicolor patents. Upon our assumption of Technicolor’s rights and obligations under the Madison Arrangement, our relationship with CPPIB Credit meets the criteria in ASC 470-10-25 - Sales of Future Revenues or Various Other Measures of Income ("ASC 470"), which relates to cash received from an investor in exchange for a specified percentage or amount of revenue or other measure of income of a particular product line, business segment, trademark, patent, or contractual right for a defined period. Under this guidance, we recognized the fair value of our contingent obligation to CPPIB Credit, as of the acquisition date, as long-term debt in our condensed consolidated balance sheet. This initial fair value measurement was based on the perspective of a market participant and included significant unobservable inputs which are classified as Level 3 inputs within the fair value hierarchy. The fair value of the long-term debt as of September 30, 2021 and December 31, 2020 is disclosed within Note 6, " Cash, Concentration of Credit Risk and Fair Value of Financial Instruments. " Our repayment obligations are contingent upon future royalty revenues generated from the Madison Arrangement and there are no minimum or maximum payments under the arrangement. Under ASC 470, amounts recorded as debt are amortized under the interest method. At each reporting period, we will review the discounted expected future cash flows over the life of the obligation. The Company made an accounting policy election to utilize the catch-up method when there is a change in the estimated future cash flows, whereby we will adjust the carrying amount of the debt to the present value of the revised estimated future cash flows, discounted at the original effective interest rate, with a corresponding adjustment recognized as interest expense within “ Interest Expense ” in the condensed consolidated statements of income. The effective interest rate as of the acquisition date was approximately 14.5%. This rate represents the discount rate that equates the estimated future cash flows with the fair value of the debt as of the acquisition date, and is used to compute the amount of interest to be recognized each period based on the estimated life of the future revenue streams. During the three and nine months ended September 30, 2021, we recognized $0.4 million and $2.0 million, respectively, of interest expense related to this debt, compared to $0.8 million and $2.3 million during the three and nine months ended September 30, 2020, respectively. This was included within “ Interest Expense ” in the condensed consolidated statements of income. Any future payments made to CPPIB Credit, or additional proceeds received from CPPIB Credit, will decrease or increase the long-term debt balance accordingly. 2024 Notes, and Related Note Hedge and Warrant Transactions On June 3, 2019, we issued $400.0 million in aggregate principal amount of 2.00% Senior Convertible Notes due 2024 (the "2024 Notes"). The net proceeds from the issuance of the 2024 Notes, after deducting the initial purchasers' transaction fees and offering expenses, were approximately $391.6 million. The 2024 Notes (i) bear interest at a rate of 2.00% per year, payable in cash on June 1 and December 1 of each year, commencing on December 1, 2019, and (ii) mature on June 1, 2024, unless earlier converted or repurchased. The effective interest rate of the 2024 Notes is 2.02%. The 2024 Notes are convertible into cash, shares of our common stock or a combination thereof, at our election, at an initial conversion rate of 12.3018 shares of our common stock per $1,000 principal amount of 2024 Notes (which is equivalent to an initial conversion price of approximately $81.29 per share), as adjusted pursuant to the terms of the indenture governing the 2024 Notes (the "Indenture"). The conversion rate of the 2024 Notes, and thus the conversion price, may be adjusted in certain circumstances, including in connection with a conversion of the 2024 Notes made following certain fundamental changes and under other circumstances set forth in the Indenture. As of December 31, 2020, we made the irrevocable election to settle all conversions of the 2024 Notes through combination settlements of cash and shares of our common stock, with a specified dollar amount of $1,000 per $1,000 principal amount of 2024 Notes and any remaining amounts in shares of our common stock. The 2024 Notes are senior unsecured obligations of the Company and rank equally in right of payment with any of our current and any future senior unsecured indebtedness. The 2024 Notes are effectively subordinated to all of our future secured indebtedness to the extent of the value of the related collateral, and the 2024 Notes are structurally subordinated to indebtedness and other liabilities, including trade payables, of our subsidiaries. On May 29 and May 31, 2019, in connection with the offering of the 2024 Notes, we entered into convertible note hedge transactions (collectively, the "2024 Note Hedge Transactions") that cover, subject to customary anti-dilution adjustments, approximately 4.9 million shares of common stock, in the aggregate, at a strike price that initially corresponds to the initial conversion price of the 2024 Notes, subject to adjustment, and are exercisable upon any conversion of the 2024 Notes. On May 29 and May 31, 2019, we also entered into privately negotiated warrant transactions (collectively, the "2024 Warrant Transactions" and, together with the 2024 Note Hedge Transactions, the "2024 Call Spread Transactions"), whereby we sold warrants to acquire, subject to customary anti-dilution adjustments, approximately 4.9 million shares of common stock at an initial strike price of approximately $109.43 per share, subject to adjustment. There have been no material changes regarding the 2024 Notes and 2024 Call Spread Transactions from the disclosures included in Note 10, " Obligations " within the notes to the consolidated financial statements included in Part II, Item 8 of the 2020 Form 10-K. 2020 Notes On March 11, 2015, we issued $316.0 million in aggregate principal amount of 1.50% Senior Convertible Notes due 2020 (the "2020 Notes"). The 2020 Notes bore interest at a rate of 1.50% per year and matured on March 1, 2020. On the maturity date, the outstanding balance of $94.9 million under the 2020 Notes was repaid in full. The following table reflects the carrying value of our convertible notes long-term debt as of September 30, 2021 and December 31, 2020 (in thousands): September 30, 2021 December 31, 2020 Principal $ 400,000 $ 400,000 Less: Unamortized interest discount (a) — (51,567) Deferred financing costs (a) (4,783) (4,612) Net carrying amount of the 2024 Notes $ 395,217 $ 343,821 ______________________________ (a) Due to the adoption of ASU 2020-06 on January 1, 2021, the unamortized interest discount was reclassified back to the carrying value of the 2024 Notes. Refer to Note 1, " Basis of Presentation ", for further information regarding this adoption. The following table presents the amount of interest cost recognized, which is included within " Interest Expense" in our condensed consolidated statements of income, for the three and nine months ended September 30, 2021 and 2020 relating to the contractual interest coupon, accretion of the debt discount, and the amortization of deferred financing costs of the 2024 Notes and 2020 Notes (in thousands): Three months ended September 30, 2021 2020 2024 Notes 2024 Notes 2020 Notes Total Contractual coupon interest $ 2,000 $ 2,000 $ — $ 2,000 Accretion of debt discount (a) — 3,323 — 3,323 Amortization of deferred financing costs 411 297 — 297 Total $ 2,411 $ 5,620 $ — $ 5,620 Nine months ended September 30, 2021 2020 2024 Notes 2024 Notes 2020 Notes Total Contractual coupon interest $ 6,000 $ 6,000 $ 237 $ 6,237 Accretion of debt discount (a) — 9,800 669 10,469 Amortization of deferred financing costs 1,211 876 70 946 Total $ 7,211 $ 16,676 $ 976 $ 17,652 ______________________________ (a) Due to the adoption of ASU 2020-06, there is no longer accretion of the debt discount starting January 1, 2021. Refer to Note 1, " Basis of Presentation ", for further information regarding this adoption. Technicolor Contingent Consideration As part of the Technicolor Patent Acquisition, we entered into a revenue-sharing arrangement with Technicolor that created a contingent consideration liability. Under the revenue-sharing arrangement, Technicolor receives 42.5% of future cash receipts from new licensing efforts from the Madison Arrangement only, subject to certain conditions and hurdles. As of September 30, 2021, the contingent consideration liability from the revenue-sharing arrangement was deemed not probable and is therefore not reflected within the consolidated financial statements.

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
VARIABLE INTEREST ENTITIES	VARIABLE INTEREST ENTITIES As further discussed below, we are the primary beneficiary of three variable interest entities. As of September 30, 2021, the combined book values of the assets and liabilities associated with these variable interest entities included in our condensed consolidated balance sheet were $37.6 million and $2.9 million, respectively. Assets included $13.3 million of cash and cash equivalents, $6.4 million of accounts receivable and prepaid and other current assets, and $17.9 million of patents, net. As of December 31, 2020, the combined book values of the assets and liabilities associated with these variable interest entities included in our condensed consolidated balance sheet were $62.0 million and $5.8 million, respectively. Assets included $24.5 million of cash and cash equivalents, $2.3 million of accounts receivable and prepaid and other current assets, and $35.2 million of patents, net. Chordant On January 31, 2019, we launched the Company’s Chordant™ business as a standalone company. The spinout of the unit, which includes an affiliate of Sony as an investor along with the Company, gave Chordant added independence and flexibility in driving into its core operator and smart city markets. Chordant is a variable interest entity and we have determined that we are the primary beneficiary for accounting purposes and consolidate Chordant. For the three and nine months ended September 30, 2021, we have allocated approximately $0.0 million and $2.3 million, respectively, of Chordant's net loss to noncontrolling interests held by other parties, and for the three and nine months September 30, 2020, we allocated $0.4 million and $0.9 million, respectively, of Chordant's net loss to noncontrolling interests held by other parties. During second quarter 2021, Chordant began the process of ceasing operations. Convida Wireless Convida Wireless was launched in 2013 and most recently renewed in 2018 to combine Sony's consumer electronics expertise with our pioneering IoT expertise to drive IoT communications and connectivity. Based on the terms of the agreement, the parties contribute funding and resources for additional research and platform development, which we will perform. SCP IP Investment LLC, an affiliate of Stephens Inc., is a minority investor in Convida Wireless. Convida Wireless is a variable interest entity. Based on our provision of research and platform development services to Convida Wireless, we have determined that we remain the primary beneficiary for accounting purposes and will continue to consolidate Convida Wireless. For the three and nine months ended September 30, 2021, we allocated $1.0 million and $8.7 million, respectively, of Convida Wireless's net loss to noncontrolling interests held by other parties and for the three and nine months ended September 30, 2020, we allocated $1.5 million and $4.4 million, respectively. During second quarter 2021, Convida approved a plan to sell certain patent assets, which were classified as held-for sale. This resulted in an impairment of $11.0 million and was included within restructuring activities as more fully discussed below. The patents held for sale are recorded at fair value on September 30, 2021 and are included within " Prepaid and other current assets " in the condensed consolidated balance sheet. Signal Trust for Wireless Innovation During 2013, we announced the establishment of the Signal Trust for Wireless Innovation (the “Trust”), the goal of which was to monetize a patent portfolio primarily related to 3G cellular infrastructure. In response to a request from the Trust, in first quarter 2021 we provided our consent, as major beneficiary, to dissolve the Trust. The Trust has been accounted for as a variable interest entity. Based on the terms of the trust agreement, we determined that we are the primary beneficiary for accounting purposes and have included the Trust in our consolidated financial statements. Pending the dissolution of the Trust, we will continue to consolidate the Trust in our consolidated financial statements.

Other (Expense) Income, Net

Other (Expense) Income, Net	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
OTHER (EXPENSE) INCOME, NET	OTHER (EXPENSE) INCOME, NET The amounts included in " Other (expense) income, net " in the condensed consolidated statements of income for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Interest and investment income $ 385 $ 825 $ 1,384 $ 5,044 Other (1,922) 3,169 842 8,762 Other (expense) income, net $ (1,537) $ 3,994 $ 2,226 $ 13,806 Interest and investment income decreased in both the three and nine months ended September 30, 2021, due to reduced rates of return on our short-term investments. Other decreased in the three months ended September 30, 2021, compared to the three months ended September 30, 2020 primarily due to a foreign currency translation loss in the three months ended September 30, 2021, compared to a gain in three months ended September 30, 2020 arising from euro translation of our foreign subsidiaries. The decrease in other in the nine months ended September 30, 2021, compared to the nine months ended September 30, 2020 was primarily driven by a decrease in gains resulting from observable price changes of our long-term strategic investments, which were $5.5 million during the nine months ended September 30, 2020 and $1.0 million during the nine months ended September 30, 2021. This decrease was partially offset by a $1.9 million gain on a contract termination in first quarter 2021.

Other Assets

Other Assets	9 Months Ended
	Sep. 30, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
OTHER ASSETS	OTHER ASSETS The amounts included in " Prepaid and other current assets " in the consolidated balance sheet as of September 30, 2021 and December 31, 2020 were as follows (in thousands): As Reported As Revised (a) September 30, 2021 December 31, 2020 December 31, 2020 Tax receivables $ 49,734 $ 69,592 $ 45,262 Prepaid assets 8,520 10,899 10,899 Patents held for sale 6,228 — — Receivable from sale of long-term investments 3,016 — — Operating lease receivable 64 817 817 Other current assets 12,742 2,916 2,916 Total Prepaid and other current assets $ 80,304 $ 84,224 $ 59,894 The amounts included in " Other non-current assets, net " in the consolidated balance sheet as of September 30, 2021 and December 31, 2020 were as follows (in thousands): As Reported As Revised (a) September 30, 2021 December 31, 2020 December 31, 2020 Tax receivables $ 29,969 $ — $ 24,330 Goodwill 22,421 22,421 22,421 Right-of-use assets 18,871 22,456 22,456 Long-term investments 14,580 15,489 15,489 Other non-current assets 11,115 13,677 13,677 Total Other non-current assets, net $ 96,956 $ 74,043 $ 98,373 _____________________________ (a) As discussed in Note 1, we revised our prior period presentation of " Prepaid and other current assets " and " Other non-current assets, net ". This column represents the effect of the revision on the consolidated balance sheet.

Restructuring Activities

Restructuring Activities	9 Months Ended
	Sep. 30, 2021
Restructuring and Related Activities [Abstract]
RESTRUCTURING ACTIVITIES	RESTRUCTURING ACTIVITIES During second quarter 2021, the Company began the process of a strategic review and undertook certain actions in order to increase focus on core technologies and markets. On June 10, 2021, the Company announced that, as a result of a strategic review of its research and innovation priorities, it commenced the process of a collective economic layoff in which it proposed a reduction in force of 66 positions in its research and innovation unit, 60 of which are based in France. The Company launched an information-consultation process with respect to the contemplated reorganization with the works council of certain of its French subsidiaries, as required by French law. On September 28, 2021, the Company finalized an agreement with the representative trade unions of certain of its French subsidiaries to commence the reorganization of the research and innovation unit located in France as part of the reduction in force. This agreement was validated by the Regional Director of Economy, Employment, Labor and Solidarity on October 25, 2021. The majority of termination notices will be issued during the remainder of 2021. During June 2021, Chordant began the process of ceasing operations. The Company implemented a reduction in workforce action in second quarter 2021, consisting of 18 employees. Additionally, in June 2021, Convida approved a plan to sell certain patents. The proceeds from the sale of these patents will contribute to funding Convida's operations. These assets were evaluated as a separate asset group and reclassified as assets held for sale. Upon the reclassification, the patents to be sold are recorded at fair value, which resulted in the Company recognizing an $11.0 million impairment during the three months ended June 30, 2021. We determined the fair value based upon evaluation of market conditions. The patents held for sale are included within " Prepaid and other current assets " in the consolidated balance sheet. Restructuring charges are estimated based on information available at the time such charges are recorded. Due to the inherent uncertainty involved in estimating restructuring expenses, actual amounts incurred for such activities may differ from amounts initially estimated. The Company may also incur additional costs not currently contemplated due to events that may occur as a result of, or that are associated with, the reduction in force or other restructuring activities. The restructuring charges associated with the above activities totaling $7.0 million and $20.3 million in the three and nine months ended September 30, 2021, respectively, are presented net of any reimbursement arrangements and include $0.1 million and $1.2 million of outside services and other associated costs related to non-recurring consultant and legal fees in the three and nine months ended September 30, 2021. We expect additional charges to be recorded in fourth quarter 2021. As of September 30, 2021, the Company's restructuring liability was $17.8 million, of which $6.9 million was included in " Other accrued expenses " and $10.9 million was included in " Other long-term liabilities " on our condensed consolidated balance sheet. The following table presents the change in our restructuring liability during the period (in thousands): Balance as of March 31, 2021 $ — Accrual 12,285 Cash payments (628) Balance as of June 30, 2021 $ 11,657 Accrual 7,033 Cash payments (859) Balance as of September 30, 2021 $ 17,831 The restructuring expenses included in " Restructuring activities " in the condensed consolidated statements of income for the three and nine months ended September 30, 2021 were as follows (in thousands): Three months ended September 30, 2021 Nine months ended September 30, 2021 Patent impairment $ — $ 11,000 Severance and other benefits 6,998 18,084 Outside services and other associated costs 47 1,246 Reimbursement arrangements — (10,040) Total $ 7,045 $ 20,290

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	The accompanying unaudited, condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q and, accordingly, do not include all of the detailed schedules, information and notes necessary to state fairly the financial condition, results of operations and cash flows in conformity with United States generally accepted accounting principles (“GAAP”). The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP for year-end financial statements. Therefore, these financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020 (our “2020 Form 10-K”) as filed with the Securities and Exchange Commission (“SEC”) on February 18, 2021. Definitions of capitalized terms not defined herein appear within our 2020 Form 10-K. The results of operations for interim periods are not necessarily indicative of the results to be expected for the entire year. We have one reportable segment.
Estimates	The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.
Reclassifications	Certain reclassifications have been made to prior year amounts to conform to the current year presentation.
New Accounting Guidance	Accounting Standards Update: Simplifying the Accounting for Income Taxes In December 2019, the FASB issued ASU No. 2019-12, "Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes" ("ASU 2019-12"). The amendments in this ASU are intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020 with early adoption allowed. We adopted this guidance as of January 1, 2021 and the adoption did not have a material impact on our consolidated financial statements. Accounting Standards Update: Simplifying the Accounting for Convertible Instruments In August 2020, the FASB issued ASU No. 2020-06, “Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity” (“ASU 2020-06”). The amendments in this ASU are intended to simplify accounting for convertible debt instruments and convertible preferred stock by removing certain accounting models which separate the embedded conversion features from the host contract. ASU 2020-06 also amends certain guidance in ASC 260 on the computation of earnings per share for convertible instruments and contracts on an entity’s own equity. ASU 2020-06 is effective for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years, and early adoption is permitted for fiscal years beginning after December 15, 2020. This update permits the use of either the modified retrospective or fully retrospective methods of transition. We elected to early adopt this standard on a modified retrospective approach as of January 1, 2021. This adoption increased long-term debt by $50.2 million at January 1, 2021, which was comprised of $51.6 million of unamortized interest discount and was partially offset by a net increase of $1.4 million equity component of deferred financing costs. This was due to the standard no longer requiring bifurcation of the embedded conversion feature from the host contract on the 2024 Notes, as defined in Note 7, " Obligations ." This adoption also reduced non-cash interest expense starting in 2021 due to the removal of the accretion of the debt discount on the 2024 Notes. Lastly, the adoption requires the use of the if-converted method of calculating diluted earnings per share rather than the treasury stock method for convertible instruments and requires the inclusion of the potential effect of shares settled in cash or shares in the diluted earnings per share calculation. Due to the reduction in non-cash interest expense, this adoption increased both basic and diluted earnings per share by $0.09 in the three months ended September 30, 2021 and $0.26 in the nine months ended September 30, 2021. Accounting Standards Update: Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity Classified Written Call Options In May 2021, the FASB issued ASU No. 2021-04. The amendments in this ASU are intended to clarify and reduce diversity in an issuer’s accounting for modifications or exchanges of freestanding equity-classified written call options, including warrants, that remain equity classified after modification or exchange. ASU 2021-04 is effective for fiscal years beginning after December 15, 2021, with early adoption allowed. The Company is currently evaluating the anticipated impact of the adoption of ASU 2021-04 on its consolidated financial statements.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of supplemental cash flow information	The following table presents additional supplemental cash flow information for the nine months ended September 30, 2021 and 2020 (in thousands): FOR THE NINE MONTHS ENDED SEPTEMBER 30, SUPPLEMENTAL CASH FLOW INFORMATION: 2021 2020 Interest paid $ 4,000 $ 4,712 Income taxes paid, including foreign withholding taxes 9,835 18,211 Non-cash investing and financing activities: Dividend payable 10,740 10,782 Non-cash acquisition of patents — 33,300 Accrued capitalized patent costs and property and equipment 3,690 (419) Unsettled repurchase of common stock 499 —

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Schedule of disaggregation of revenue	The following table presents the disaggregation of our revenue for the three and nine months ended September 30, 2021 and 2020 (in thousands): Three months ended September 30, 2021 2020 Increase/(Decrease) Variable patent royalty revenue $ 8,346 $ 7,377 $ 969 13 % Fixed-fee royalty revenue 84,295 77,338 6,957 9 % Current patent royalties a 92,641 84,715 7,926 9 % Non-current patent royalties b 50,108 507 49,601 9,783 % Total patent royalties 142,749 85,222 57,527 68 % Current technology solutions revenue a 747 2,271 (1,524) (67) % Total revenue $ 143,496 $ 87,493 $ 56,003 64 % Nine months ended September 30, 2021 2020 Increase/(Decrease) Variable patent royalty revenue $ 22,765 $ 17,920 $ 4,845 27 % Fixed-fee royalty revenue 222,887 221,023 1,864 1 % Current patent royalties a 245,652 238,943 6,709 3 % Non-current patent royalties b 63,475 20,461 43,014 210 % Total patent royalties 309,127 259,404 49,723 19 % Current technology solutions revenue a 4,467 8,797 (4,330) (49) % Total revenue $ 313,594 $ 268,201 $ 45,393 17 % a. Recurring revenues are comprised of current patent royalties, inclusive of dynamic fixed-fee royalty payments, and current technology solutions revenue. b. Non-recurring revenues are comprised of non-current patent royalties, which include past patent royalties and royalties from static agreements, as well as patent sales.
Schedule of contracted revenue	Based on contracts signed and committed as of September 30, 2021, we expect to recognize the following revenue from dynamic fixed-fee royalty payments over the term of such contracts (in thousands): Revenue Remainder 2021 $ 89,541 2022 299,307 2023 104,469 2024 60,089 2025 and beyond 60,000 Total Revenue $ 613,406

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2021
Earnings Per Share [Abstract]
Schedule of numerator and the denominator of the basic and diluted	The following tables reconcile the numerator and the denominator of the basic and diluted net income per share computation (in thousands, except for per share data): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Net income applicable to InterDigital, Inc. $ 26,228 $ 23,784 $ 33,417 $ 46,151 Weighted-average shares outstanding: Basic 30,737 30,804 30,792 30,762 Dilutive effect of stock options, RSUs, convertible securities and warrants 694 315 480 267 Diluted 31,431 31,119 31,272 31,029 Earnings per share: Basic $ 0.85 $ 0.77 $ 1.09 $ 1.50 Dilutive effect of stock options, RSUs, convertible securities and warrants (0.02) (0.01) (0.02) (0.01) Diluted $ 0.83 $ 0.76 $ 1.07 $ 1.49
Schedule of excluded from our computation of EPS	Set forth below are the securities and the weighted average number of shares of common stock underlying such securities that were excluded from our computation of EPS for the periods presented (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Restricted stock units and stock options 441 156 289 154 Convertible securities (a) — 4,921 — 5,222 Warrants 4,921 5,319 4,921 5,931 Total 5,362 10,396 5,210 11,307 ______________________________ (a) As of December 31, 2020, we made the irrevocable election to settle all conversions of the 2024 Notes through combination settlements of cash and shares of our common stock, with a specified dollar amount of $1,000 per $1,000 principal amount of 2024 Notes and any remaining amounts in shares of our common stock.

Cash, Concentration of Credit_2

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2021
Fair Value Disclosures [Abstract]
Schedule of cash and cash equivalents	The following table provides a reconciliation of total cash, cash equivalents and restricted cash as of September 30, 2021, December 31, 2020 and September 30, 2020 to the captions within the condensed consolidated balance sheets and condensed consolidated statements of cash flows (in thousands): September 30, December 31, September 30, 2021 2020 2020 Cash and cash equivalents $ 467,606 $ 473,474 $ 746,561 Restricted cash included within prepaid and other current assets 1,300 3,108 4,401 Restricted cash included within other non-current assets 1,081 1,081 1,081 Total cash, cash equivalents and restricted cash $ 469,987 $ 477,663 $ 752,043
Schedule of restricted cash and cash equivalents	The following table provides a reconciliation of total cash, cash equivalents and restricted cash as of September 30, 2021, December 31, 2020 and September 30, 2020 to the captions within the condensed consolidated balance sheets and condensed consolidated statements of cash flows (in thousands): September 30, December 31, September 30, 2021 2020 2020 Cash and cash equivalents $ 467,606 $ 473,474 $ 746,561 Restricted cash included within prepaid and other current assets 1,300 3,108 4,401 Restricted cash included within other non-current assets 1,081 1,081 1,081 Total cash, cash equivalents and restricted cash $ 469,987 $ 477,663 $ 752,043
Schedule of fair value on a recurring basis	Our financial assets and liabilities that are accounted for at fair value on a recurring basis are presented in the tables below as of September 30, 2021 and December 31, 2020 (in thousands): Fair Value as of September 30, 2021 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 469,987 $ — $ — $ 469,987 Commercial paper (b) — 254,688 — 254,688 U.S. government securities — 129,017 — 129,017 Corporate bonds, asset backed and other securities — 49,495 — 49,495 Total $ 469,987 $ 433,200 $ — $ 903,187 Fair Value as of December 31, 2020 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 397,522 $ — $ — $ 397,522 Commercial paper (b) — 285,242 — 285,242 U.S. government securities — 166,223 — 166,223 Corporate bonds, asset backed and other securities — 81,849 — 81,849 Total $ 397,522 $ 533,314 $ — $ 930,836 ______________________________ (a) Primarily included within cash and cash equivalents. (b) As of September 30, 2021 and December 31, 2020, $0.0 million and $80.1 million, respectively, of commercial paper was included within cash and cash equivalents.
Schedule of aggregate fair value	The aggregate fair value of the principal amount of the senior convertible long-term debt is a Level 2 fair value measurement. September 30, 2021 December 31, 2020 Principal Carrying Fair Principal Carrying Fair Senior Convertible Long-Term Debt $ 400,000 $ 395,217 $ 432,000 $ 400,000 $ 343,821 $ 418,760 September 30, 2021 December 31, 2020 Carrying Fair Carrying Fair Technicolor Patent Acquisition Long-Term Debt $ 26,203 $ 33,192 $ 24,171 $ 27,016

Obligations (Tables)

Obligations (Tables)	9 Months Ended
	Sep. 30, 2021
Debt Disclosure [Abstract]
Schedule of carrying value of the 2024 Notes and 2020 Notes	The following table reflects the carrying value of our convertible notes long-term debt as of September 30, 2021 and December 31, 2020 (in thousands): September 30, 2021 December 31, 2020 Principal $ 400,000 $ 400,000 Less: Unamortized interest discount (a) — (51,567) Deferred financing costs (a) (4,783) (4,612) Net carrying amount of the 2024 Notes $ 395,217 $ 343,821 ______________________________ (a) Due to the adoption of ASU 2020-06 on January 1, 2021, the unamortized interest discount was reclassified back to the carrying value of the 2024 Notes. Refer to Note 1, " Basis of Presentation ", for further information regarding this adoption.
Schedule of accretion of the debt discount, and the amortization of financing costs	The following table presents the amount of interest cost recognized, which is included within " Interest Expense" in our condensed consolidated statements of income, for the three and nine months ended September 30, 2021 and 2020 relating to the contractual interest coupon, accretion of the debt discount, and the amortization of deferred financing costs of the 2024 Notes and 2020 Notes (in thousands): Three months ended September 30, 2021 2020 2024 Notes 2024 Notes 2020 Notes Total Contractual coupon interest $ 2,000 $ 2,000 $ — $ 2,000 Accretion of debt discount (a) — 3,323 — 3,323 Amortization of deferred financing costs 411 297 — 297 Total $ 2,411 $ 5,620 $ — $ 5,620 Nine months ended September 30, 2021 2020 2024 Notes 2024 Notes 2020 Notes Total Contractual coupon interest $ 6,000 $ 6,000 $ 237 $ 6,237 Accretion of debt discount (a) — 9,800 669 10,469 Amortization of deferred financing costs 1,211 876 70 946 Total $ 7,211 $ 16,676 $ 976 $ 17,652 ______________________________ (a) Due to the adoption of ASU 2020-06, there is no longer accretion of the debt discount starting January 1, 2021. Refer to Note 1, " Basis of Presentation ", for further information regarding this adoption.

Other (Expense) Income, Net (Ta

Other (Expense) Income, Net (Tables)	9 Months Ended
	Sep. 30, 2021
Other Income and Expenses [Abstract]
Schedule of other income expense, net	The amounts included in " Other (expense) income, net " in the condensed consolidated statements of income for the three and nine months ended September 30, 2021 and 2020 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2021 2020 2021 2020 Interest and investment income $ 385 $ 825 $ 1,384 $ 5,044 Other (1,922) 3,169 842 8,762 Other (expense) income, net $ (1,537) $ 3,994 $ 2,226 $ 13,806

Other Assets (Tables)

Other Assets (Tables)	9 Months Ended
	Sep. 30, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid and Other Current Assets	The amounts included in " Prepaid and other current assets " in the consolidated balance sheet as of September 30, 2021 and December 31, 2020 were as follows (in thousands): As Reported As Revised (a) September 30, 2021 December 31, 2020 December 31, 2020 Tax receivables $ 49,734 $ 69,592 $ 45,262 Prepaid assets 8,520 10,899 10,899 Patents held for sale 6,228 — — Receivable from sale of long-term investments 3,016 — — Operating lease receivable 64 817 817 Other current assets 12,742 2,916 2,916 Total Prepaid and other current assets $ 80,304 $ 84,224 $ 59,894
Schedule of Other Assets, Noncurrent	The amounts included in " Other non-current assets, net " in the consolidated balance sheet as of September 30, 2021 and December 31, 2020 were as follows (in thousands): As Reported As Revised (a) September 30, 2021 December 31, 2020 December 31, 2020 Tax receivables $ 29,969 $ — $ 24,330 Goodwill 22,421 22,421 22,421 Right-of-use assets 18,871 22,456 22,456 Long-term investments 14,580 15,489 15,489 Other non-current assets 11,115 13,677 13,677 Total Other non-current assets, net $ 96,956 $ 74,043 $ 98,373 _____________________________ (a) As discussed in Note 1, we revised our prior period presentation of " Prepaid and other current assets " and " Other non-current assets, net ". This column represents the effect of the revision on the consolidated balance sheet.

Restructuring Activities (Table

Restructuring Activities (Tables)	9 Months Ended
	Sep. 30, 2021
Restructuring and Related Activities [Abstract]
Schedule of Restructuring Reserve by Type of Cost	The following table presents the change in our restructuring liability during the period (in thousands): Balance as of March 31, 2021 $ — Accrual 12,285 Cash payments (628) Balance as of June 30, 2021 $ 11,657 Accrual 7,033 Cash payments (859) Balance as of September 30, 2021 $ 17,831 The restructuring expenses included in " Restructuring activities " in the condensed consolidated statements of income for the three and nine months ended September 30, 2021 were as follows (in thousands): Three months ended September 30, 2021 Nine months ended September 30, 2021 Patent impairment $ — $ 11,000 Severance and other benefits 6,998 18,084 Outside services and other associated costs 47 1,246 Reimbursement arrangements — (10,040) Total $ 7,045 $ 20,290

Basis of Presentation - Narrati

Basis of Presentation - Narrative (Details) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021USD ($)$ / shares	Sep. 30, 2020$ / shares	Sep. 30, 2021USD ($)segment$ / shares	Sep. 30, 2020$ / shares	Jan. 01, 2021USD ($)	Dec. 31, 2020USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments | segment			1
Error in accounting (as a percent)	1.50%		1.50%
Debt Instrument [Line Items]
Net income per common share: basic (in USD per share) | $ / shares	$ 0.85	$ 0.77	$ 1.09	$ 1.50
Accounting Standards Update 2020-06
Debt Instrument [Line Items]
Net income per common share: basic (in USD per share) | $ / shares	$ 0.09		$ 0.26
Senior Convertible Long-Term Debt
Debt Instrument [Line Items]
Unamortized discount	$ 0		$ 0			$ 51,567
Senior Convertible Long-Term Debt | Accounting Standards Update 2020-06
Debt Instrument [Line Items]
Long-term debt					$ (50,200)
Unamortized discount					51,600
Debt issuance costs equity component					$ 1,400

Basis of Presentation - Schedul

Basis of Presentation - Schedule of Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid	$ 4,000	$ 4,712
Income taxes paid, including foreign withholding taxes	9,835	18,211
Non-cash investing and financing activities:
Dividend payable	10,740	10,782	$ 10,786
Non-cash acquisition of patents	0	33,300
Accrued capitalized patent costs and property and equipment	3,690	(419)
Unsettled repurchase of common stock	$ 499	$ 0

Revenue - Disaggregated Revenue

Revenue - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Revenue	$ 143,496	$ 87,493	$ 313,594	$ 268,201
Increase/(decrease) in disaggregated revenue	$ 56,003		$ 45,393
Percentage increase/(decrease) in disaggregated revenue	64.00%		17.00%
Total patent royalties
Disaggregation of Revenue [Line Items]
Revenue	$ 142,749	85,222	$ 309,127	259,404
Increase/(decrease) in disaggregated revenue	$ 57,527		$ 49,723
Percentage increase/(decrease) in disaggregated revenue	68.00%		19.00%
Total patent royalties | Current revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 92,641	84,715	$ 245,652	238,943
Increase/(decrease) in disaggregated revenue	$ 7,926		$ 6,709
Percentage increase/(decrease) in disaggregated revenue	9.00%		3.00%
Total patent royalties | Non-current revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 50,108	507	$ 63,475	20,461
Increase/(decrease) in disaggregated revenue	$ 49,601		$ 43,014
Percentage increase/(decrease) in disaggregated revenue	9783.00%		210.00%
Technology solutions
Disaggregation of Revenue [Line Items]
Revenue	$ 747	2,271	$ 4,467	8,797
Increase/(decrease) in disaggregated revenue	$ (1,524)		$ (4,330)
Percentage increase/(decrease) in disaggregated revenue	(67.00%)		(49.00%)
Variable patent royalty revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 8,346	7,377	$ 22,765	17,920
Increase/(decrease) in disaggregated revenue	$ 969		$ 4,845
Percentage increase/(decrease) in disaggregated revenue	13.00%		27.00%
Fixed-fee royalty revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 84,295	$ 77,338	$ 222,887	$ 221,023
Increase/(decrease) in disaggregated revenue	$ 6,957		$ 1,864
Percentage increase/(decrease) in disaggregated revenue	9.00%		1.00%

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue recognized that had been included in deferred revenue as of the beginning of the period	$ 186.9
Contract assets, current	20.5	$ 9.7
Contract assets, non-current	$ 8.7	$ 8.9

Revenue - Remaining Performance

Revenue - Remaining Performance Obligation (Details) $ in Thousands	Sep. 30, 2021USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 89,541
Revenue, remaining performance obligation, expected timing of satisfaction, period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 299,307
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 104,469
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 60,089
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 60,000
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 613,406
Revenue, remaining performance obligation, expected timing of satisfaction, period

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Income Tax Contingency [Line Items]
Effective tax rate	21.30%	(16.80%)
Effective tax rate before valuation allowance is included (as percent)	8.40%	(31.30%)
Discrete tax expense (benefit)	$ 300	$ 18,200
Reasonably possible decrease in unrecognized tax benefits	1,100
Income taxes paid, including foreign withholding taxes	9,835	18,211
Foreign Country
Income Tax Contingency [Line Items]
Income taxes paid, including foreign withholding taxes	$ 8,900	$ 17,800

Net Income (Loss) Per Share - N

Net Income (Loss) Per Share - Numerator and Denominator of Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020
Earnings Per Share [Abstract]
Net income applicable to InterDigital, Inc.	$ 26,228	$ 1,618	$ 5,571	$ 23,784	$ 22,251	$ 116	$ 33,417	$ 46,151
Weighted-average shares outstanding:
Weighted-average shares outstanding: basic (in shares)	30,737			30,804			30,792	30,762
Dilutive effect of stock options, RSUs, convertible securities and warrants (in shares)	694			315			480	267
Weighted-average shares outstanding: diluted (in shares)	31,431			31,119			31,272	31,029
Earnings per share:
Net income per common share: basic (in USD per share)	$ 0.85			$ 0.77			$ 1.09	$ 1.50
Dilutive effect of stock options, RSUs, convertible securities and warrants (in USD per share)	0.02			0.01			0.02	0.01
Net income per common share: diluted (in USD per share)	$ 0.83			$ 0.76			$ 1.07	$ 1.49

Net Income (Loss) Per Share - A

Net Income (Loss) Per Share - Antidilutive Securities Excluded from Earnings Per Share (Details) - USD ($) shares in Thousands	Jun. 03, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		5,362	10,396	5,210	11,307
Convertible Notes 2024 | Senior Convertible Long-Term Debt
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Debt conversion converted instrument amount	$ 1,000					$ 1,000
Restricted stock units and stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		441	156	289	154
Convertible securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		0	4,921	0	5,222
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount (in shares)		4,921	5,319	4,921	5,931

Litigation and Legal Proceedi_2

Litigation and Legal Proceedings (Details)	Apr. 27, 2021patent	Aug. 05, 2020CNY (¥)	Jul. 29, 2020patent	Aug. 28, 2019patent	Aug. 27, 2019patent
Xiaomi
Loss Contingencies [Line Items]
Court fine per day | ¥		¥ 1,000,000
Pending Litigation | U.K. Proceedings
Loss Contingencies [Line Items]
Loss contingency, number of patents alleged infringement					5
Pending Litigation | District Of Delaware Proceedings
Loss Contingencies [Line Items]
Loss contingency, number of patents alleged infringement				8
Pending Litigation | India Proceedings
Loss Contingencies [Line Items]
Loss contingency, number of patents alleged infringement			2
Pending Litigation | India Proceedings One
Loss Contingencies [Line Items]
Loss contingency, number of patents alleged infringement			5
Pending Litigation | India Proceedings Two
Loss Contingencies [Line Items]
Loss contingency, number of patents alleged infringement			3
Pending Litigation | German Proceedings
Loss Contingencies [Line Items]
Loss contingency, number of patents alleged infringement	3

Cash, Concentration of Credit_3

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Cash and cash equivalents	$ 467,606	$ 473,474	$ 746,561
Restricted cash included within prepaid and other current assets	1,300	3,108	4,401
Restricted cash included within other non-current assets	1,081	1,081	1,081
Total cash, cash equivalents and restricted cash	$ 469,987	$ 477,663	$ 752,043	$ 757,098

Cash, Concentration of Credit_4

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments - Narrative (Details) $ in Thousands	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020	Mar. 31, 2021property
Concentration Risk [Line Items]
Unrealized gain		$ 1,000	$ 5,500
Lease asset impairment			1,100
Lease property, plant and equipment impairment			800
Lease right of use asset impairment			$ 300
Number of abandoned leased properties | property							1
Impairment of Patents held for sale	$ 0			$ 11,000	$ 0
Accounts Receivable | Licensee Concentration Risk | Five Largest Licensees
Concentration Risk [Line Items]
Accounts receivable percentage				93.00%		53.00%

Cash, Concentration of Credit_5

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments - Fair Value of Financial Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020	Sep. 30, 2020
Assets:
Total	$ 903,187	$ 930,836
Amount of commercial paper included in cash and cash equivalents	467,606	473,474	$ 746,561
U.S. government securities
Assets:
Securities	129,017	166,223
Corporate bonds, asset backed and other securities
Assets:
Securities	49,495	81,849
Money market and demand accounts
Assets:
Cash and cash equivalents	469,987	397,522
Commercial Paper
Assets:
Cash and cash equivalents	254,688	285,242
Amount of commercial paper included in cash and cash equivalents	0	80,100
Level 1
Assets:
Total	469,987	397,522
Level 1 | U.S. government securities
Assets:
Securities	0	0
Level 1 | Corporate bonds, asset backed and other securities
Assets:
Securities	0	0
Level 1 | Money market and demand accounts
Assets:
Cash and cash equivalents	469,987	397,522
Level 1 | Commercial Paper
Assets:
Cash and cash equivalents	0	0
Level 2
Assets:
Total	433,200	533,314
Level 2 | U.S. government securities
Assets:
Securities	129,017	166,223
Level 2 | Corporate bonds, asset backed and other securities
Assets:
Securities	49,495	81,849
Level 2 | Money market and demand accounts
Assets:
Cash and cash equivalents	0	0
Level 2 | Commercial Paper
Assets:
Cash and cash equivalents	254,688	285,242
Level 3
Assets:
Total	0	0
Level 3 | U.S. government securities
Assets:
Securities	0	0
Level 3 | Corporate bonds, asset backed and other securities
Assets:
Securities	0	0
Level 3 | Money market and demand accounts
Assets:
Cash and cash equivalents	0	0
Level 3 | Commercial Paper
Assets:
Cash and cash equivalents	$ 0	$ 0

Cash, Concentration of Credit_6

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments - Fair Value of Long-Term Debt (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Technicolor Patent Acquisition Long-Term Debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Carrying Value	$ 26,203,000	$ 24,171,000
Fair Value	33,192,000	27,016,000
Senior Convertible Long-Term Debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Principal	400,000,000	400,000,000
Carrying Value	395,217,000	343,821,000
Fair Value	$ 432,000,000	$ 418,760,000

Obligations - Technicolor Paten

Obligations - Technicolor Patent Acquisition Long-Term Debt (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Business Acquisition [Line Items]
Interest debt expense		$ 5,620		$ 17,652
Technicolor
Business Acquisition [Line Items]
Effective interest rate acquisition percentage	14.50%		14.50%
Interest debt expense	$ 400	$ 800	$ 2,000	$ 2,300

Obligations - 2024 and 2020 Sen

Obligations - 2024 and 2020 Senior Convertible Notes, and Related Note Hedge and Warrant Transactions (Details) $ / shares in Units, shares in Millions	Mar. 01, 2020USD ($)	Jun. 03, 2019USD ($)$ / shares	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)	May 31, 2019$ / sharesshares	Mar. 11, 2015USD ($)
Debt Instrument [Line Items]
Initial strike price (in USD per share) | $ / shares						$ 109.43
Payments on long-term debt			$ 0	$ 94,909,000
Convertible Notes 2020
Debt Instrument [Line Items]
Payments on long-term debt	$ 94,900,000
Convertible Debt | Convertible Notes 2024
Debt Instrument [Line Items]
Aggregate principal amount		$ 400,000,000
Debt instrument interest rate, stated percentage		2.00%
Transaction fees and offering expenses		$ 391,600,000
Debt instrument interest rate, effective percentage			2.02%
Initial conversion rate		12.3018
Debt conversion converted instrument amount		$ 1,000			$ 1,000
Initial conversion price (in USD per share) | $ / shares		$ 81.29
Convertible note hedge (in shares) | shares						4.9
Anti-dilution adjustments of common stock (in shares) | shares						4.9
Convertible Debt | Convertible Notes 2020
Debt Instrument [Line Items]
Aggregate principal amount							$ 316,000,000
Debt instrument interest rate, stated percentage							1.50%

Obligations - Carrying Value of

Obligations - Carrying Value of 2024 Notes and 2020 Notes (Details) - Convertible Debt - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Principal	$ 400,000,000	$ 400,000,000
Less:
Unamortized interest discount	0	(51,567,000)
Deferred financing costs	(4,783,000)	(4,612,000)
Net carrying amount of the 2024 Notes	$ 395,217,000	$ 343,821,000

Obligations - Accretion of Debt

Obligations - Accretion of Debt Discount and Amortization of Financing Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Debt Instrument [Line Items]
Contractual coupon interest		$ 2,000		$ 6,237
Accretion of debt discount(a)		3,323		10,469
Amortization of deferred financing costs		297		946
Total		5,620		17,652
Convertible Debt | Convertible Notes 2024
Debt Instrument [Line Items]
Contractual coupon interest	$ 2,000	2,000	$ 6,000	6,000
Accretion of debt discount(a)	0	3,323	0	9,800
Amortization of deferred financing costs	411	297	1,211	876
Total	$ 2,411	5,620	$ 7,211	16,676
Convertible Debt | Convertible Notes 2020
Debt Instrument [Line Items]
Contractual coupon interest		0		237
Accretion of debt discount(a)		0		669
Amortization of deferred financing costs		0		70
Total		$ 0		$ 976

Obligations - Additional Inform

Obligations - Additional Information (Details)	May 31, 2019
Technicolor
Business Acquisition [Line Items]
Receive future cash receipts percentage	42.50%

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)	Mar. 31, 2021USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)variable_interest_entity	Sep. 30, 2020USD ($)	Dec. 31, 2020USD ($)
Variable Interest Entity [Line Items]
Assets	$ 1,700,612						$ 1,700,612		$ 1,616,275
Liabilities	965,295						965,295		819,709
Cash and cash equivalents	467,606			$ 746,561			467,606	$ 746,561	473,474
Patents, net	371,857						371,857		418,343
Accounts receivable	141,657						141,657		16,008
Noncontrolling interests	(1,014)	$ (8,415)	$ (1,613)	(1,882)	$ (1,660)	$ (1,777)	(11,042)	(5,319)
Chordant
Variable Interest Entity [Line Items]
Noncontrolling interests	0			400			(2,300)	900
Convida
Variable Interest Entity [Line Items]
Noncontrolling interests	(1,000)			(8,700)			$ (1,000)	(8,700)
Other Parties
Variable Interest Entity [Line Items]
Noncontrolling interests				$ 1,500				$ 4,400
Primary Beneficiary
Variable Interest Entity [Line Items]
Number of variable interest entities | variable_interest_entity							3
Assets	37,600						$ 37,600		62,000
Liabilities	2,900						2,900		5,800
Cash and cash equivalents	13,300						13,300		24,500
Accounts receivable and prepaid assets	6,400						6,400
Patents, net	$ 17,900						$ 17,900		35,200
Accounts receivable									$ 2,300

Other (Expense) Income, Net - O

Other (Expense) Income, Net - Other Income, Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Other Income and Expenses [Abstract]
Interest and investment income	$ 385	$ 825	$ 1,384	$ 5,044
Other	(1,922)	3,169	842	8,762
Other (expense) income, net	$ (1,537)	$ 3,994	$ 2,226	$ 13,806

Other (Expense) Income, Net - N

Other (Expense) Income, Net - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Mar. 31, 2021	Sep. 30, 2021	Sep. 30, 2020
Other Income and Expenses [Abstract]
Gain from observable price changes in orderly transactions of a long-term strategic investment	$ 1.9	$ 1	$ 5.5

Other Assets - Prepaid and Othe

Other Assets - Prepaid and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Other Current Assets [Line Items]
Tax receivables	$ 49,734	$ 45,262
Prepaid assets	8,520	10,899
Patents held for sale	6,228	0
Receivable from sale of long-term investments	3,016	0
Operating lease receivable	64	817
Other current assets	12,742	2,916
Total Prepaid and other current assets	$ 80,304	59,894
As Reported
Other Current Assets [Line Items]
Tax receivables		69,592
Prepaid assets		10,899
Patents held for sale		0
Receivable from sale of long-term investments		0
Operating lease receivable		817
Other current assets		2,916
Total Prepaid and other current assets		$ 84,224

Other Assets - Other Non-Curren

Other Assets - Other Non-Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Other Non-Current Assets [Line Items]
Tax receivables	$ 29,969	$ 24,330
Goodwill	22,421	22,421
Right-of-use assets	18,871	22,456
Long-term investments	14,580	15,489
Other non-current assets	11,115	13,677
Other Assets, Noncurrent, Total	$ 96,956	98,373
As Reported
Other Non-Current Assets [Line Items]
Tax receivables		0
Goodwill		22,421
Right-of-use assets		22,456
Long-term investments		15,489
Other non-current assets		13,677
Other Assets, Noncurrent, Total		$ 74,043

Restructuring Activities - Narr

Restructuring Activities - Narrative (Details) $ in Thousands	3 Months Ended			7 Months Ended	9 Months Ended
	Sep. 30, 2021USD ($)	Jun. 30, 2021USD ($)employee	Sep. 30, 2020USD ($)	Dec. 31, 2021employee	Sep. 30, 2021USD ($)	Sep. 30, 2020USD ($)	Mar. 31, 2021USD ($)
Restructuring Cost and Reserve [Line Items]
Patent impairment	$ 0				$ 11,000	$ 0
Restructuring activities	7,045		$ 0		20,290	$ 0
Outside services and other associated costs	47				1,246
Restructuring Reserve	17,831	$ 11,657			17,831		$ 0
Restructuring reserve, current	6,900				6,900
Restructuring reserve, noncurrent	10,900				$ 10,900
Maximum
Restructuring Cost and Reserve [Line Items]
Outside services and other associated costs	$ 100
Chordant Cease of Operations
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | employee		18
Patents
Restructuring Cost and Reserve [Line Items]
Patent impairment		$ 11,000
Forecast | Economic Reduction in Force
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | employee				66
Forecast | FRANCE | Economic Reduction in Force
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated | employee				60

Restructuring Activities - Rest

Restructuring Activities - Restructuring Activity Included in Other Accrued Expenses (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2021	Jun. 30, 2021
Restructuring Reserve [Roll Forward]
Beginning balance	$ 11,657	$ 0
Accrual	7,033	12,285
Cash payments	(859)	(628)
Ending balance	$ 17,831	$ 11,657

Restructuring Activities - Re_2

Restructuring Activities - Restructuring Activity Included in Operating Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Restructuring and Related Activities [Abstract]
Patent impairment	$ 0		$ 11,000	$ 0
Severance and other benefits	6,998		18,084
Outside services and other associated costs	47		1,246
Reimbursement arrangements	0		(10,040)
Total	$ 7,045	$ 0	$ 20,290	$ 0