InterDigital (IDCC) 10-Q 31 Oct 19 2019 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 29, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
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		31,132,944
Entity Central Index Key	0001405495
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 735,886	$ 475,056
Short-term investments	211,737	470,724
Accounts receivable, less allowances of $537 and $693	23,355	35,032
Prepaid and other current assets	51,545	43,438
Total current assets	1,022,523	1,024,250
PROPERTY AND EQUIPMENT, NET	10,018	10,051
PATENTS, NET	448,957	454,567
DEFERRED TAX ASSETS	85,437	77,225
OTHER NON-CURRENT ASSETS	61,367	60,465
Total non-current assets	605,779	602,308
TOTAL ASSETS	1,628,302	1,626,558
CURRENT LIABILITIES:
Current portion of long-term debt	93,131	0
Accounts payable	12,713	19,367
Accrued compensation and related expenses	26,440	26,838
Deferred revenue	171,433	111,672
Taxes payable	193	1,508
Dividends payable	10,897	11,627
Other accrued expenses	19,492	8,383
Total current liabilities	334,299	179,395
LONG-TERM DEBT	346,397	317,377
LONG-TERM DEFERRED REVENUE	107,498	157,634
OTHER LONG-TERM LIABILITIES	36,809	34,139
TOTAL LIABILITIES	825,003	688,545
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, 71,267 and 71,134 shares issued and 31,133 and 33,529 shares outstanding	712	711
Additional paid-in capital	725,891	685,512
Retained earnings	1,409,870	1,435,970
Accumulated other comprehensive loss	(105)	(2,471)
TOTAL SHAREHOLDERS’ EQUITY	2,136,368	2,119,722
Treasury stock, 40,134 and 37,605 shares of common held at cost	1,354,262	1,182,993
Total InterDigital, Inc. shareholders’ equity	782,106	936,729
Noncontrolling interest	21,193	1,284
Total equity	803,299	938,013
TOTAL LIABILITIES AND SHAREHOLDERS’ EQUITY	$ 1,628,302	$ 1,626,558

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 537	$ 693
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)	71,267,000	71,134,000
Common stock, shares outstanding (in shares)	31,133,000	33,529,000
Preferred stock, par value (in usd per share)	$ 0.1	$ 0.1
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
Treasury stock, shares of common held at cost (in shares)	40,134,000	37,605,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
REVENUES	$ 72,523	$ 75,079	$ 216,763	$ 232,078
OPERATING EXPENSES:
Patent administration and licensing	34,772	32,077	108,196	85,480
Development	20,506	17,276	56,028	49,279
Selling, general and administrative	13,471	12,806	40,000	38,569
TOTAL OPERATING EXPENSES	68,749	62,159	204,224	173,328
Income from operations	3,774	12,920	12,539	58,750
INTEREST EXPENSE	(10,920)	(9,039)	(30,305)	(27,242)
OTHER INCOME (EXPENSE), NET	7,803	(4,914)	23,772	2,106
Income (loss) before income taxes	657	(1,033)	6,006	33,614
INCOME TAX BENEFIT (PROVISION)	178	21,143	(3,007)	25,001
NET INCOME	835	20,110	2,999	58,615
Net loss attributable to noncontrolling interest	(1,399)	(1,642)	(4,175)	(4,333)
NET INCOME ATTRIBUTABLE TO INTERDIGITAL, INC.	$ 2,234	$ 21,752	$ 7,174	$ 62,948
NET INCOME PER COMMON SHARE — BASIC (in usd per share)	$ 0.07	$ 0.63	$ 0.23	$ 1.81
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING — BASIC (in shares)	31,130	34,651	31,757	34,687
NET INCOME PER COMMON SHARE — DILUTED (in usd per share)	$ 0.07	$ 0.61	$ 0.22	$ 1.77
WEIGHTED AVERAGE NUMBER OF COMMON SHARES OUTSTANDING — DILUTED (in shares)	31,308	35,607	32,010	35,614
Patent licensing royalties
REVENUES	$ 68,049	$ 74,045	$ 207,994	$ 230,018
Technology solutions
REVENUES	3,724	1,034	7,794	2,060
Patent sales
REVENUES	$ 750	$ 0	$ 975	$ 0

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 835	$ 20,110	$ 2,999	$ 58,615
Unrealized gain (loss) on investments, net of tax	245	467	2,366	(904)
Comprehensive income	1,080	20,577	5,365	57,711
Comprehensive loss attributable to noncontrolling interest	(1,399)	(1,642)	(4,175)	(4,333)
Total comprehensive income attributable to InterDigital, Inc.	$ 2,479	$ 22,219	$ 9,540	$ 62,044

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Non-Controlling Interest
Ending balance (in shares) at Dec. 31, 2017		70,749				36,127
Ending balance at Dec. 31, 2017	$ 873,148	$ 707	$ 680,040	$ 1,257,632	$ (2,083)	$ (1,072,488)	$ 9,340
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	30,230			30,230
Net loss attributable to noncontrolling interest	(1,501)						(1,501)
Net change in unrealized gain (loss) on short-term investments	(1,747)				(1,747)
Dividends declared	(12,165)		115	(12,280)
Issuance of common stock, net (in shares)		208
Issuance of common stock, net	(8,277)	$ 2	(8,279)
Amortization of unearned compensation	816		816
Repurchase of common stock (in shares)						84
Repurchase of common stock	(6,024)					$ (6,024)
Ending balance (in shares) at Mar. 31, 2018		70,957				36,211
Ending balance at Mar. 31, 2018	1,035,732	$ 709	672,692	1,437,283	(4,279)	$ (1,078,512)	7,839
Beginning balance (in shares) at Dec. 31, 2017		70,749				36,127
Beginning balance at Dec. 31, 2017	873,148	$ 707	680,040	1,257,632	(2,083)	$ (1,072,488)	9,340
Ending balance (in shares) at Jun. 30, 2018		71,059				36,251
Ending balance at Jun. 30, 2018	1,036,224	$ 710	678,434	1,435,994	(3,903)	$ (1,081,660)	6,649
Beginning balance (in shares) at Dec. 31, 2017		70,749				36,127
Beginning balance at Dec. 31, 2017	873,148	$ 707	680,040	1,257,632	(2,083)	$ (1,072,488)	9,340
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	62,948
Net loss attributable to noncontrolling interest	(4,333)
Net change in unrealized gain (loss) on short-term investments	(904)
Ending balance (in shares) at Sep. 30, 2018		71,117				36,675
Ending balance at Sep. 30, 2018	1,015,049	$ 711	683,140	1,445,622	(3,436)	$ (1,115,995)	5,007
Beginning balance (in shares) at Dec. 31, 2017		70,749				36,127
Beginning balance at Dec. 31, 2017	873,148	$ 707	680,040	1,257,632	(2,083)	$ (1,072,488)	9,340
Ending balance (in shares) at Dec. 31, 2018		71,134				37,605
Ending balance at Dec. 31, 2018	938,013	$ 711	685,512	1,435,970	(2,471)	$ (1,182,993)	1,284
Beginning balance (in shares) at Mar. 31, 2018		70,957				36,211
Beginning balance at Mar. 31, 2018	1,035,732	$ 709	672,692	1,437,283	(4,279)	$ (1,078,512)	7,839
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	10,966			10,966
Net loss attributable to noncontrolling interest	(1,190)						(1,190)
Net change in unrealized gain (loss) on short-term investments	376				376
Dividends declared	(12,153)		102	(12,255)
Exercise of common stock options (in shares)		90
Exercise of common stock options	3,931	$ 1	3,930
Issuance of common stock, net (in shares)		12
Issuance of common stock, net	(111)		(111)
Amortization of unearned compensation	1,821		1,821
Repurchase of common stock (in shares)						40
Repurchase of common stock	(3,148)					$ (3,148)
Ending balance (in shares) at Jun. 30, 2018		71,059				36,251
Ending balance at Jun. 30, 2018	1,036,224	$ 710	678,434	1,435,994	(3,903)	$ (1,081,660)	6,649
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	21,752			21,752
Net loss attributable to noncontrolling interest	(1,642)						(1,642)
Net change in unrealized gain (loss) on short-term investments	467				467
Dividends declared	(11,997)		127	(12,124)
Exercise of common stock options (in shares)		56
Exercise of common stock options	2,432	$ 1	2,431
Issuance of common stock, net (in shares)		2
Issuance of common stock, net	(91)		(91)
Amortization of unearned compensation	2,239		2,239
Repurchase of common stock (in shares)						424
Repurchase of common stock	(34,335)					$ (34,335)
Ending balance (in shares) at Sep. 30, 2018		71,117				36,675
Ending balance at Sep. 30, 2018	1,015,049	$ 711	683,140	1,445,622	(3,436)	$ (1,115,995)	5,007
Ending balance (in shares) at Dec. 31, 2018		71,134				37,605
Ending balance at Dec. 31, 2018	938,013	$ 711	685,512	1,435,970	(2,471)	$ (1,182,993)	1,284
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	(2,803)			(2,803)
Proceeds from and increases in noncontrolling interests	12,834						12,834
Net loss attributable to noncontrolling interest	(1,411)						(1,411)
Net change in unrealized gain (loss) on short-term investments	1,045				1,045
Dividends declared	(11,180)		103	(11,283)
Exercise of common stock options	2		2
Issuance of common stock, net (in shares)		116
Issuance of common stock, net	(4,097)	$ 1	(4,098)
Amortization of unearned compensation	2,096		2,096
Repurchase of common stock (in shares)						1,585
Repurchase of common stock	(108,986)					$ (108,986)
Ending balance (in shares) at Mar. 31, 2019		71,250				39,190
Ending balance at Mar. 31, 2019	825,513	$ 712	683,615	1,421,884	(1,426)	$ (1,291,979)	12,707
Beginning balance (in shares) at Dec. 31, 2018		71,134				37,605
Beginning balance at Dec. 31, 2018	938,013	$ 711	685,512	1,435,970	(2,471)	$ (1,182,993)	1,284
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	7,174
Net loss attributable to noncontrolling interest	(4,175)
Net change in unrealized gain (loss) on short-term investments	2,366
Ending balance (in shares) at Sep. 30, 2019		71,267				40,134
Ending balance at Sep. 30, 2019	803,299	$ 712	725,891	1,409,870	(105)	$ (1,354,262)	21,193
Beginning balance (in shares) at Mar. 31, 2019		71,250				39,190
Beginning balance at Mar. 31, 2019	825,513	$ 712	683,615	1,421,884	(1,426)	$ (1,291,979)	12,707
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	7,743			7,743
Net loss attributable to noncontrolling interest							(1,365)
Net change in unrealized gain (loss) on short-term investments	1,076				1,076
Dividends declared	(10,895)		104	(10,999)
Issuance of common stock, net (in shares)		10
Issuance of common stock, net	(40)		(40)
Amortization of unearned compensation	2,116		2,116
Repurchase of common stock (in shares)						944
Repurchase of common stock	(62,283)					$ (62,283)
Equity component of debt, net of tax	56,917		56,917
Net convertible note hedge transactions, net of tax	(49,740)		(49,740)
Net warrant transactions	43,416		43,416
Deferred financing costs allocated to equity, net of tax	(1,569)		(1,569)
Reacquisition of equity component of debt due to prepayment, net of tax	(10,649)		(10,649)
Ending balance (in shares) at Jun. 30, 2019		71,260				40,134
Ending balance at Jun. 30, 2019	800,240	$ 712	724,170	1,418,628	(350)	$ (1,354,262)	11,342
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss (income) attributable to InterDigital, Inc.	2,234			2,234
Proceeds from and increases in noncontrolling interests	11,250						11,250
Net loss attributable to noncontrolling interest	(1,399)						(1,399)
Net change in unrealized gain (loss) on short-term investments	245				245
Dividends declared	(10,897)		95	(10,992)
Issuance of common stock, net (in shares)		7
Issuance of common stock, net	(179)		(179)
Amortization of unearned compensation	1,805		1,805
Ending balance (in shares) at Sep. 30, 2019		71,267				40,134
Ending balance at Sep. 30, 2019	$ 803,299	$ 712	$ 725,891	$ 1,409,870	$ (105)	$ (1,354,262)	$ 21,193

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Shareholders' Equity (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.35	$ 0.35	$ 0.35	$ 0.35	$ 0.35	$ 0.35

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 2,999	$ 58,615
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	56,907	47,024
Non-cash interest expense, net	13,586	10,684
Non-cash change in fair-value	710	0
Gain on asset acquisition and sale of business	(22,690)	0
Change in deferred revenue	875	9,822
Loss on extinguishment of debt	5,488	0
Deferred income taxes	(8,014)	(27,673)
Share-based compensation	6,017	4,875
Impairment of long-term investment	3,312	200
Loss on disposal of assets	119	8,176
Other	623	(2)
(Increase) decrease in assets:
Receivables	11,659	36,861
Deferred charges and other assets	(2,181)	(63,783)
Increase (decrease) in liabilities:
Accounts payable	(2,547)	5,640
Accrued compensation and other expenses	6,428	(5,618)
Accrued taxes payable and other tax contingencies	(1,315)	91,796
Net cash provided by operating activities	71,976	176,617
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of short-term investments	(92,270)	(142,562)
Sales of short-term investments	355,649	317,447
Purchases of property and equipment	(3,062)	(1,882)
Proceeds from sale of business	10,000	0
Capitalized patent costs	(26,123)	(23,845)
Acquisition of patents	0	(2,250)
Acquisition of business, net of cash acquired	0	(142,985)
Long-term investments	0	(6,686)
Net cash provided by (used in) investing activities	244,194	(2,763)
CASH FLOWS FROM FINANCING ACTIVITIES:
Net proceeds from exercise of stock options	2	6,362
Payments on long-term debt	(221,091)	0
Proceeds from issuance of convertible senior notes	400,000	0
Purchase of convertible bond hedge	(72,000)	0
Payment for warrant unwind	(4,184)	0
Prepayment penalty on long-term debt	(10,763)	0
Proceeds from hedge unwind	9,038	0
Proceeds from issuance of warrants	47,600	0
Payments of debt issuance costs	(8,375)	0
Proceeds from non-controlling interests	10,333	0
Dividends paid	(33,683)	(36,472)
Taxes withheld upon restricted stock unit vestings	(4,316)	(8,479)
Repurchase of common stock	(171,269)	(43,508)
Net cash used in financing activities	(58,708)	(82,097)
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	257,462	91,757
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, BEGINNING OF PERIOD	488,733	433,014
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, END OF PERIOD	$ 746,195	$ 524,771

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2019
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, 2019 , and the results of our operations for the three and nine months ended September 30, 2019 and 2018 and our cash flows for the nine months ended September 30, 2019 and 2018 . The accompanying unaudited, condensed consolidated financial statements have been prepared in accordance with the instructions for 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, 2018 (our “ 2018 Form 10-K ”) as filed with the Securities and Exchange Commission (“SEC”) on February 21, 2019. Definitions of capitalized terms not defined herein appear within our 2018 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. Change in Accounting Policies There have been no material changes or updates to our existing accounting policies from the disclosures included in our 2018 Form 10-K , except as indicated in Note 2, " Leases ". Reclassifications Certain reclassifications have been made to prior year amounts to conform to the current year presentation. Prior Periods Financial Statement Revision In connection with the preparation of the condensed consolidated financial statements for first quarter 2019, it was identified that we incorrectly attributed tax benefit to the net loss attributable to noncontrolling interest in our presentation of noncontrolling interest. 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 noncontrolling interest for all 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 12, " Revision to Noncontrolling Interest " for additional information on the revision. Supplemental Cash Flow Information The following table presents additional supplemental cash flow information for the nine months ended September 30, 2019 and 2018 (in thousands): FOR THE NINE MONTHS ENDED SEPTEMBER 30, SUPPLEMENTAL CASH FLOW INFORMATION: 2019 2018 Interest paid $ 3,930 $ 4,740 Income taxes paid, including foreign withholding taxes 16,483 24,459 Non-cash investing and financing activities: Dividend payable 10,897 11,996 Increases in noncontrolling interests 13,750 — Non-cash acquisition of patents 22,500 — Accrued capitalized patent costs and property and equipment 390 (1,513 ) New Accounting Guidance Accounting Standards Update: Leases In February 2016, the FASB issued ASU 2016-02, " Leases (Topic 842) " or ("ASC 842"), which outlines a comprehensive change to the lease accounting model and supersedes prior lease guidance. Refer to Note 2, " Leases ," for information regarding our adoption of this guidance effective January 1, 2019 and a discussion of the impact to information presented herein, as well as additional required disclosures under the new guidance. Accounting Standards Update: Improvements to Nonemployee Share-Based Payment Accounting In June 2018, the FASB issued ASU No. 2018-07, " Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ," which is intended to reduce cost and complexity and to improve financial reporting for share-based payments issued to nonemployees. The guidance is effective for fiscal years beginning after December 15, 2018 and early adoption is permitted. We adopted this guidance in first quarter 2019 and it did not have a material impact on our consolidated financial statements. Accounting Standards Update: Financial Instruments - Credit Losses In June 2016, the FASB issued ASU No. 2016-13, " Financial Instruments - Credit Losses ". This ASU introduces a new accounting model for recognizing credit losses on certain financial instruments and financial assets, including trade receivables, based upon an estimate of current expected credit losses, otherwise known as CECL. The new guidance requires the recognition of an allowance that reflects the current estimate of credit losses expected to be incurred over the life of the financial asset, based not only on historical experience and current conditions, but also on reasonable forecasts. Additionally, ASU No. 2016-13 made several changes to the available-for-sale impairment model. The guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. While we are still completing our accounting assessment, we do not expect this guidance to have a material impact on our consolidated financial statements. Accounting Standards Update: Cloud Computing Arrangements In August 2018, the FASB issued ASU No. 2018-15 “ Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract ”. The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. While we are still completing our accounting assessment, we do not expect this guidance to have a material impact on our consolidated financial statements. Accounting Standards Update: Collaborative Arrangements In November 2018, the FASB issued ASU No. 2018-18, " Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606 ". The amendments in this ASU provide guidance on how to assess whether certain transactions between collaborative arrangement participants should be accounted for within the revenue recognition standard. The amendments in this update are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted for entities who have previously adopted the new revenue recognition guidance. While we are still completing our accounting assessment, we do not expect this guidance to have a material impact on our consolidated financial statements.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
LEASES	LEASES In February 2016, the FASB issued ASC 842, which outlines a comprehensive change to the lease accounting model and supersedes prior lease guidance ("ASC 840"). The new guidance requires lessees to recognize lease liabilities and corresponding right-of-use assets for all leases with lease terms of greater than 12 months, and also changes the definition of a lease and expands the disclosure requirements of lease arrangements. The Company adopted this guidance on January 1, 2019 using the modified retrospective transition effective date method. As part of that adoption, we have elected the package of three practical expedients, which includes the following: an entity may elect not to reassess whether expired or existing contracts contain a lease under the revised definition of a lease; an entity may elect not to reassess the lease classification for expired or existing leases; and an entity may elect not to reassess whether previously capitalized initial direct costs would qualify for capitalization. The Company has elected not to utilize the hindsight expedient in determining the lease term, and to not record leases with an initial term of 12 months or less on our balance sheet. Additionally, the Company has elected to account for lease components and non-lease components as a single lease component for all asset classes. Lease expense is recognized over the expected term on a straight-line basis. The adoption did not have a material impact on the Company's condensed consolidated statements of income or cash flows. The Company enters into operating leases primarily for real estate to support research and development ("R&D") sites and general office space in North America, with additional locations in Europe and Asia. The Company does not currently have any finance leases. Certain of our leases include options to extend the lease at our discretion at the end of the lease term, or terminate the lease early subject to certain conditions and penalties. We do not include any renewal options in our lease terms for calculating our lease liabilities, as the renewal options allow us to maintain operational flexibility and we are not reasonably certain we will exercise these options. At the inception of an arrangement, the Company determines whether the arrangement is or contains a lease based on the specific facts and circumstances present. Operating lease liabilities and their corresponding right-of-use assets are recorded based on the present value of lease payments over the expected lease term. The interest rate implicit in lease contracts is typically not readily determinable, and, as such, the Company utilizes its incremental borrowing rate as the discount rate based on information available on the lease commencement date. Our incremental borrowing rate represents the rate we would incur to borrow on a collateralized basis over a similar term for an amount equal to the lease payments in a similar economic environment. We utilized the incremental borrowing rate as of January 1, 2019, our adoption date, for operating leases that commenced prior to that date. Upon our adoption of ASU 2016-02, the Company recorded the following operating lease right-of-use assets and operating lease liabilities as of January 1, 2019. Additionally, the table below includes the balances of operating lease right-of-use assets and operating lease liabilities as of September 30, 2019 (in thousands): Balance Sheet Classification January 1, 2019 September 30, 2019 Assets Operating lease right-of-use assets, net Other Non-current Assets $ 13,634 $ 16,587 Total Lease Assets $ 13,634 $ 16,587 Liabilities Operating lease liabilities - Current Other Accrued Expenses $ 3,519 $ 3,624 Operating lease liabilities - Noncurrent Other Long-Term Liabilities 13,652 15,867 Total Lease Liabilities $ 17,171 $ 19,491 The components of lease costs which were included within operating expenses in our condensed consolidated statements of income were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2019 2019 Operating lease cost $ 1,210 $ 3,325 Short-term lease cost 211 731 Variable lease cost 362 1,054 For the three and nine months ended September 30, 2019 , sublease income was insignificant. Cash paid for amounts included in the measurement of operating lease liabilities for the three and nine months ended September 30, 2019 was $1.4 million and $3.8 million , respectively, and was included in net cash provided by operating activities in our condensed consolidated statements of cash flows. Operating lease right-of-use assets obtained in exchange for operating lease obligations totaled $5.5 million during the three and nine months ended September 30, 2019 . As of September 30, 2019 , the weighted average remaining operating lease term was 5.6 years and the weighted average discount rate used to determine the operating lease liabilities was 6.2% . As of September 30, 2019 , the Company had an additional operating lease that had not yet commenced of approximately $10.0 million , which is set to commence in October 2019 and will have a lease term of approximately 10.8 years years. The maturities of our operating lease liabilities as of September 30, 2019 under ASC 842, excluding short-term leases with terms less than 12 months, were as follows (in thousands): Maturity of Operating Lease Liabilities September 30, 2019 Remainder 2019 $ 1,348 2020 4,440 2021 3,934 2022 3,965 2023 3,229 Thereafter 6,310 Total lease payments $ 23,226 Less: Imputed interest (3,735 ) Present value of lease liabilities $ 19,491 The undiscounted maturities of our operating leases as of December 31, 2018 under ASC 840, including short-term leases with terms less than 12 months, were as follows (in thousands): Maturity of Operating Leases December 31, 2018 2019 $ 5,362 2020 3,386 2021 2,883 2022 2,920 2023 2,184 Thereafter 5,582

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
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, 2019 and 2018 (in thousands): Three months ended September 30, 2019 2018 Increase/(Decrease) Variable patent royalty revenue $ 4,683 $ 13,645 $ (8,962 ) (66 )% Fixed-fee royalty revenue 63,736 60,272 3,464 6 % Current patent royalties a 68,419 73,917 (5,498 ) (7 )% Non-current patent royalties b (370 ) 128 (498 ) (389 )% Total patent royalties 68,049 74,045 (5,996 ) (8 )% Current technology solutions revenue a 3,724 1,034 2,690 260 % Patent sales b 750 — 750 — % Total revenue $ 72,523 $ 75,079 $ (2,556 ) (3 )% Nine months ended September 30, 2019 2018 Increase/(Decrease) Variable patent royalty revenue $ 22,557 $ 26,322 $ (3,765 ) (14 )% Fixed-fee royalty revenue 190,345 178,207 12,138 7 % Current patent royalties a 212,902 204,529 8,373 4 % Non-current patent royalties b (4,908 ) 25,489 (30,397 ) (119 )% Total patent royalties 207,994 230,018 (22,024 ) (10 )% Current technology solutions revenue a 7,794 2,060 5,734 278 % Patent sales b 975 — 975 — % Total revenue $ 216,763 $ 232,078 $ (15,315 ) (7 )% a. Recurring revenues are comprised of current patent royalties, inclusive of Dynamic Fixed-Fee Agreement royalties, and current technology solutions revenue. b. Non-recurring revenues are comprised of non-current patent royalties, which primarily include past patent royalties and royalties from static agreements, as well as patent sales. During first nine months 2019 , we recognized $120.3 million of revenue that had been included in deferred revenue as of the beginning of the period. As of September 30, 2019 , we had contract assets of $14.4 million and $1.3 million included within accounts receivable and other non-current assets, respectively. As of December 31, 2018, we had contract assets of $19.7 million and $5.5 million included within accounts receivable and other non-current assets, respectively. Contracted Revenue Based on contracts signed and committed as of September 30, 2019 , we expect to recognize the following revenue from Dynamic Fixed-Fee Agreement payments over the term of such contracts (in thousands): Revenue Remainder 2019 $ 63,736 2020 248,250 2021 178,583 2022 85,228 2023 —

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES In first nine months 2019 , based on the statutory federal tax rate net of discrete federal and state taxes, we had an effective tax rate of 50.1% . The effective tax rate for first nine months 2019 was impacted by losses in certain jurisdictions where the Company presently has recorded a valuation allowance against the related tax benefit. Excluding this valuation allowance, our first nine months 2019 effective tax rate would have been a benefit of 25.3% . In first nine months 2019 , the Company recorded net discrete tax expenses of $3.1 million related to the acquisition of the Research & Innovation ("R&I") unit of Technicolor SA, the extinguishment of long-term debt, the filing of amended federal income tax returns and the sale of our Hillcrest Laboratories, Inc. ("Hillcrest") product business. Refer to Note 7, " Business Combinations and Other Transaction s" and Note 9, " Long-Term Debt " for further discussion of these transactions. This is compared to an effective tax rate benefit of 74.4% based on the statutory federal tax rate net of discrete federal and state taxes during first nine months 2018 . During first nine months 2018 , we recorded discrete net benefits of $18.4 million related to share-based compensation, our sale of a commercial initiative and a benefit from the anticipated filing by the Company of amended tax returns in connection with the Competent Authority Proceeding (as defined in our 2018 Form 10-K). Excluding these discrete benefits, the effective tax rate would have been a benefit of 19.7% . On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the "Tax Reform Act") was signed into law. The Tax Reform Act imposes a 13.125% tax rate on income that qualifies as Foreign Derived Intangible Income ("FDII"). The reduction in benefit is primarily related to the differences in our FDII deduction between the periods. The difference in the FDII deduction between the periods was driven by the timing of income between book and tax mostly related to revenue recognition. On March 6, 2019, the IRS issued proposed regulations for FDII. The Company is currently evaluating the impact of the proposed regulations and will record the impact, if any, as applicable. 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. The Company further notes that its tax positions could be altered by pending IRS regulations that could clarify certain provisions of the Tax Reform Act. During first nine months 2019 and 2018 , we paid approximately $11.5 million and $16.5 million , respectively, of foreign source withholding tax. Additionally, as of September 30, 2019 and December 31, 2018, we included approximately $0.2 million and $1.5 million , respectively, of foreign source withholding tax within our taxes payable and deferred tax asset balances. These amounts are related to receivables from foreign licensees.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
NET INCOME (LOSS) PER SHARE	NET INCOME (LOSS) 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. The following tables reconcile the numerator and the denominator of the basic and diluted net income (loss) per share computation (in thousands, except for per share data): Three months ended September 30, 2019 2018 Basic Diluted Basic Diluted Numerator: Net income applicable to InterDigital, Inc. $ 2,234 $ 2,234 $ 21,752 $ 21,752 Denominator: Weighted-average shares outstanding: Basic 31,130 31,130 34,651 34,651 Dilutive effect of stock options, RSUs, convertible securities and warrants 178 956 Weighted-average shares outstanding: Diluted 31,308 35,607 Earnings Per Share: Net income per common share: Basic $ 0.07 $ 0.07 $ 0.63 $ 0.63 Dilutive effect of stock options, RSUs, convertible securities and warrants — (0.02 ) Net income per common share: Diluted $ 0.07 $ 0.61 Nine months ended September 30, 2019 2018 Basic Diluted Basic Diluted Numerator: Net income applicable to InterDigital, Inc. $ 7,174 $ 7,174 $ 62,948 $ 62,948 Denominator: Weighted-average shares outstanding: Basic 31,757 31,757 34,687 34,687 Dilutive effect of stock options, RSUs, convertible securities and warrants 253 927 Weighted-average shares outstanding: Diluted 32,010 35,614 Earnings Per Share: Net income per common share: Basic $ 0.23 $ 0.23 $ 1.81 $ 1.81 Dilutive effect of stock options, RSUs, convertible securities and warrants (0.01 ) (0.04 ) Net income per common share: Diluted $ 0.22 $ 1.77 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, 2019 2018 2019 2018 Restricted stock units and stock options 155 78 120 44 Convertible securities 6,260 — 5,236 — Warrants 6,260 4,405 5,236 4,404 Total 12,675 4,483 10,592 4,448 Convertible Notes and Warrants Refer to Note 9, " Long-Term Debt ," 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 our 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 treasury stock 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, 2019
Commitments and Contingencies Disclosure [Abstract]
LITIGATION AND LEGAL PROCEEDINGS	ITIGATION AND LEGAL PROCEEDINGS COURT PROCEEDINGS Huawei China On January 3, 2019, InterDigital was notified that a civil complaint was filed on January 2, 2019, by Huawei Technologies Co., Ltd. and certain of its subsidiaries against InterDigital, Inc. and certain of its subsidiaries in the Shenzhen Intermediate People’s Court. The complaint seeks a ruling that the InterDigital defendants have violated an obligation to license their patents that are essential to 3G, 4G and 5G wireless telecommunication standards on fair, reasonable and non-discriminatory (“FRAND”) terms and conditions. The complaint also seeks a determination of the terms for licensing all of the InterDigital defendants’ Chinese patents that are essential to 3G, 4G and 5G wireless telecommunication standards to the Huawei plaintiffs for the plaintiffs’ wireless terminal unit products made and/or sold in China from 2019 to 2023. On September 17, 2019, InterDigital filed a petition challenging the jurisdiction of the Shenzhen Intermediate People’s Court to hear the action. The court's decision regarding InterDigital's jurisdictional challenge is pending. InterDigital’s patent license agreement with Huawei expired on December 31, 2018. Lenovo U.K. Proceedings On August 27, 2019, InterDigital, Inc., and its wholly owned subsidiaries InterDigital Holdings, Inc., InterDigital Technology Corporation, and InterDigital Patent Holdings, Inc., filed a claim in the High Court of Justice, Business and Property Courts, Intellectual Property List (Chancery Division), Patents Court of England and Wales (the “High Court”), against Lenovo Group Limited, Lenovo (United States) Inc., Lenovo Technology (United Kingdom) Limited, Motorola Mobility LLC, and Motorola Mobility UK Limited (Claim No. HP-2019-000032). The claim alleges infringement of four of InterDigital’s patents relating to 3G and/or 4G/LTE standards: European Patent (U.K.) Nos. 2,363,008; 2,421,318; 2,485,558; and 2,557,714. In these proceedings, InterDigital is seeking a “FRAND injunction” of the type previously awarded by the High Court in Unwired Planet v. Huawei , preventing further infringement of InterDigital’s standards-essential patents where the court has settled the terms of a worldwide FRAND license and the defendant does not enter into a license on those terms, along with other relief concerning declarations, damages and costs. On October 3, 2019, Lenovo filed an application challenging the jurisdiction of the High Court to hear the action, as well as the order which permitted service outside of the United Kingdom with respect to the U.S. and Hong Kong defendants. The High Court's decision regarding these challenges is pending. District of Delaware Proceedings On August 28, 2019, InterDigital, Inc., and its wholly owned subsidiaries InterDigital Technology Corporation, IPR Licensing, Inc., InterDigital Communications, Inc., and InterDigital Holdings, Inc., filed a complaint in the United States District Court for the District of Delaware against Lenovo Holding Company, Inc., Lenovo (United States) Inc., and Motorola Mobility LLC, 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 High Court in the separately filed U.K. 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. ZTE USITC Proceedings and Related Delaware District Court Proceedings Information regarding legal proceedings that InterDigital filed against ZTE Corporation and ZTE (USA) Inc. (collectively, "ZTE") with the United States International Trade Commission ("USITC") and the Delaware District Court can be found in the description of legal proceedings contained in InterDigital's 2018 Form 10-K. With respect to the Delaware District Court proceeding related to the 2013 USITC Proceeding (337-TA-868), on January 23, 2019, InterDigital and ZTE filed a joint status report that informed the Delaware District Court of the Federal Circuit's decision regarding the '966 and '847 patents and that the PTAB proceedings regarding the '244 patent remained pending. The parties jointly requested that the case remain stayed so that the portion of the case related to damages potentially owed by ZTE as to the three patents-in-suit could be coordinated. The court granted that request on January 25, 2019. On October 18, 2019, InterDigital and ZTE entered into a Patent License Agreement pursuant to which the parties agreed that, upon the performance of certain obligations by ZTE, the parties will end all legal proceedings initiated by either party or otherwise pending between them. On October 25, 2019, ZTE filed an unopposed motion with the Federal Circuit to withdraw from the '244 patent PTAB remand appeal. InterDigital further expects that ZTE will withdraw from any other proceedings related to the Inter Parties Review of the '244 patent, though InterDigital has retained the right to continue to participate in such proceedings, including any remand or appeals. InterDigital expects that the Delaware District Court proceedings related to the 2011 USITC Proceeding (337-TA-800) and 2013 USITC Proceeding (337-TA-868) will be dismissed with prejudice by January 2020. REGULATORY PROCEEDING Investigation by National Development and Reform Commission of China (now State Administration for Market Regulation) On September 23, 2013, counsel for InterDigital was informed by China’s National Development and Reform Commission (“NDRC”) that the NDRC had initiated a formal investigation into whether InterDigital has violated China’s Anti-Monopoly Law (“AML”) with respect to practices related to the licensing of InterDigital’s standards-essential patents to Chinese companies. Companies found to violate the AML may be subject to a cease and desist order, fines and disgorgement of any illegal gains. On March 3, 2014, the Company submitted to NDRC, pursuant to a procedure set out in the AML, a formal application for suspension of the investigation that included proposed commitments by the Company. On May 22, 2014, NDRC formally suspended its investigation of the Company based on the commitments proposed by the Company. The Company’s commitments with respect to the licensing of its patent portfolio for wireless mobile standards to Chinese manufacturers of cellular terminal units (“Chinese Manufacturers”) are as follows: 1. Whenever InterDigital engages with a Chinese Manufacturer to license InterDigital’s patent portfolio for 2G, 3G and 4G wireless mobile standards, InterDigital will offer such Chinese Manufacturer the option of taking a worldwide portfolio license of only its standards-essential wireless patents, and comply with F/RAND principles when negotiating and entering into such licensing agreements with Chinese Manufacturers. 2. As part of its licensing offer, InterDigital will not require that a Chinese Manufacturer agree to a royalty-free, reciprocal cross-license of such Chinese Manufacturer's similarly categorized standards-essential wireless patents. 3. Prior to commencing any action against a Chinese Manufacturer in which InterDigital may seek exclusionary or injunctive relief for the infringement of any of its wireless standards-essential patents, InterDigital will offer such Chinese Manufacturer the option to enter into expedited binding arbitration under fair and reasonable procedures to resolve the royalty rate and other terms of a worldwide license under InterDigital's wireless standards-essential patents. If the Chinese Manufacturer accepts InterDigital's binding arbitration offer or otherwise enters into an agreement with InterDigital on a binding arbitration mechanism, InterDigital will, in accordance with the terms of the arbitration agreement and patent license agreement, refrain from seeking exclusionary or injunctive relief against such company. The commitments contained in item 3 above expired on May 22, 2019. With the consolidation of China’s anti-monopoly enforcement authorities into the State Administration for Market Regulation (“SAMR”) in April 2018, SAMR is now responsible for overseeing InterDigital’s commitments. OTHER We are party to certain other disputes and legal actions in the ordinary course of business, including arbitrations and 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, 2019 .

Business Combinations and Other

Business Combinations and Other Transactions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
BUSINESS COMBINATIONS AND OTHER TRANSACTIONS	BUSINESS COMBINATIONS AND OTHER TRANSACTIONS Acquisition of Technicolor's Patent Licensing Business On July 30, 2018, we completed our acquisition of the patent licensing business of Technicolor, a worldwide technology leader in the media and entertainment sector (the "Technicolor Acquisition"). The Technicolor Acquisition included the acquisition by InterDigital of approximately 18,000 patents and applications, across a broad range of technologies, including approximately 3,000 worldwide video coding patents and applications. Refer to our 2018 Form 10-K for further information on the Technicolor Acquisition. The Technicolor Acquisition met the definition of a business combination, and as such was accounted for using the acquisition method of accounting. We allocated the fair value of consideration transferred to identifiable assets acquired and liabilities assumed based on their estimated fair values as of the acquisition date. We recorded the excess of the fair value of consideration transferred over the net values of these assets and liabilities as goodwill. The amount of revenue and earnings that would have been included in the Company’s condensed consolidated statement of income for the three and nine months ended September 30, 2018 had the acquisition date been January 1, 2017 are reflected in the table below. These amounts have been calculated after applying the Company's accounting policies and adjusting the results to reflect additional interest expense as well as amortization that would have been charged assuming the fair value adjustments to amortizable intangible assets had been recorded as of January 1, 2017. In addition, pro forma adjustments have been made to reflect the impact of the transaction-related costs discussed below. These unaudited pro forma combined results of operations have been prepared for comparative purposes only, and they do not purport to be indicative of the results of operations that actually would have resulted had the acquisition occurred on the date indicated, or that may result in the future. The amounts in the table are unaudited (in thousands, except for per share data): Three Months Ended Nine Months Ended September 30, September 30, 2018 2018 Actual revenue $ 75,079 $ 232,078 Supplemental pro forma revenue 76,034 238,761 Actual earnings 21,752 62,948 Supplemental pro forma earnings 22,884 55,314 Actual diluted earnings per share 0.61 1.77 Supplemental pro forma diluted earnings per share 0.64 1.55 Acquisition of Technicolor's Research & Innovation Unit On May 31, 2019, we completed the acquisition of the Research & Innovation, or R&I, unit of Technicolor SA. The acquisition brought the Company’s research team to approximately 340 engineers in eight R&D offices worldwide, and expanded the Company’s research capabilities in video coding, Internet of Things ("IoT") and smart home, imaging sciences, augmented reality and virtual reality, and artificial intelligence and machine learning technologies. The R&I unit was the driving creative force behind the patent portfolio that was acquired in the Technicolor Acquisition discussed above. The acquisition of the R&I unit met the definition of an asset acquisition and was accounted for using the cost accumulation and allocation model. There was no cash consideration for the acquisition. As consideration for the acquisition, the jointly funded R&D collaboration that was entered into as part of the Technicolor Acquisition was terminated. Technicolor will continue to fund research to be performed by the R&I unit for certain limited projects for a specified time period, subject to renewal. The Company also assumed certain employee-related liabilities, including obligations for certain defined benefit post-retirement plans for the acquired R&I unit employees, which are further discussed below. Additionally, Technicolor agreed to reduce its rights under the revenue-sharing arrangement entered into as part of the Technicolor Acquisition, as further discussed below. The acquisition of the R&I unit resulted in a net gain of approximately $14.2 million in second quarter 2019, inclusive of the $20.5 million gain from the derecognition of the contingent consideration liability described below, all of which is included within “ Other Income (Expense), Net ” in the condensed consolidated statement of income. Contingent Consideration The original revenue-sharing arrangement between the Company and Technicolor created a contingent consideration liability upon closing of the Technicolor Acquisition in third quarter 2018. Refer to our 2018 Form 10-K for further information on the initial contingent consideration liability which was accounted for at fair value each reporting period. Under the amended revenue-sharing arrangement described above, Technicolor will now receive 42.5% of future cash receipts from new licensing efforts from the Madison Arrangement (as defined below) only, subject to certain conditions and hurdles, but will no longer receive revenue-sharing from other licensing efforts in the consumer electronics field outside of the Madison Arrangement. We determined that the initial contingent consideration liability from the Technicolor Acquisition was significantly modified in conjunction with the acquisition of the R&I unit, and, as such, the contingent consideration liability will now be accounted for under ASC 450 - Contingencies under the asset acquisition framework when the liability is deemed probable and estimable. Since the contingent consideration liability arising from the amended revenue-sharing arrangement was not probable and estimable as of the acquisition date, the carrying value of the previous contingent consideration liability was derecognized, which resulted in a $20.5 million gain during the nine months ended September 30, 2019 and is included within " Other Income (Expense), Net" in the condensed consolidated statement of income. Defined Benefit Plans In connection with the Technicolor Acquisition and the acquisition of the R&I unit, we assumed certain defined benefit plans which are accounted for in accordance with ASC 715 - Compensation - Retirement Benefits . These plans include a retirement lump sum indemnity plan and jubilee plan, both of which provide benefit payments to employees based upon years of service and compensation levels. As of September 30, 2019 , the combined accumulated projected benefit obligation related to these plans totaled $6.5 million . Service cost and interest cost for the combined plans totaled $0.1 million for the nine months ended September 30, 2019 . These plans are not required to be funded and were not funded as of September 30, 2019 . Madison Arrangement In conjunction with the Technicolor Acquisition, effective July 30, 2018, 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." We also assumed Technicolor's role as sole licensing agent for the Madison Arrangement. As licensing agent, we are responsible for making decisions regarding the prosecution and maintenance of the combined patent portfolio and the licensing and enforcement of the combined patent portfolio in the field of use of digital TVs and computer display monitors on an exclusive basis during the specified term in exchange for an agent fee. The Madison Arrangement falls under the scope of ASC 808, Collaborative Arrangements (“ASC 808”). Refer to our 2018 Form 10-K for further information on the Madison Arrangement. Long-term debt 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, 2019 and December 31, 2018 is disclosed within Note 8. 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, 2019 , we recognized $0.7 million and $2.0 million , respectively, of interest expense related to this debt, which 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. Restricted cash Under the Madison Arrangement, the parties reserve cash in bank accounts to fund our activities to manage the portfolios. These accounts are custodial accounts for which the funds are restricted for this purpose. Refer to Note 8, " Cash, Concentration of Credit Risk and Fair Value of Financial Instruments, " for a reconciliation of total cash, cash equivalents and restricted cash as of September 30, 2019 and December 31, 2018 to the captions within the condensed consolidated balance sheets. Commitments To receive consent from both Sony and CPPIB Credit to assume the rights and responsibilities of Technicolor under the Madison Arrangement, we committed to contributing cash to fund shortfalls in the Madison Arrangement, up to a maximum of $25.0 million , through 2020. A shortfall funding is only required in the scenario where the restricted cash is not sufficient to fund current obligations. In the event that we fund a shortfall, any surplus cash resulting from subsequent royalty receipts would be used to repay our shortfall funding plus 25% interest in advance of distributions of royalties to either Sony or CPPIB Credit, assuming they have not participated in the funding of the shortfall. As of September 30, 2019 , we have not contributed any shortfall funding. Transaction costs Transaction and integration related costs related to the above transactions for the three months ended September 30, 2019 and 2018 were $2.1 million and $5.4 million , respectively. Transaction and integration related costs related to the above transactions for the nine months ended September 30, 2019 and 2018 were $6.9 million and $9.2 million , respectively. The majority of these costs were recorded within “ Patent administration and licensing ” and “ Selling, general and administrative ” expenses in the condensed consolidated statements of income. Sale of Business On July 19, 2019, we completed the sale of our Hillcrest product business to a subsidiary of CEVA, Inc. In connection with the sale, we received initial proceeds of $10.0 million , with a customary portion of the purchase price placed in escrow to secure potential indemnification claims. As part of the transaction, we retained substantially all of the Hillcrest patent assets that we acquired in 2016. As a result of this transaction, we recorded an $8.5 million gain on sale which is included within “ Other Income (Expense), Net

Cash, Concentration of Credit R

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments	9 Months Ended
	Sep. 30, 2019
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, 2019 , December 31, 2018 and September 30, 2018 to the captions within the condensed consolidated balance sheets and condensed consolidated statements of cash flows (in thousands). The Company had no restricted cash balance prior to third quarter 2018. September 30, December 31, September 30, 2019 2018 2018 Cash and cash equivalents $ 735,886 $ 475,056 $ 508,829 Restricted cash included within prepaid and other current assets 9,229 13,677 15,942 Restricted cash included within other non-current assets 1,080 — — Total cash, cash equivalents and restricted cash $ 746,195 $ 488,733 $ 524,771 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, 2019 and December 31, 2018 , four and five licensees, respectively, comprised 54% and 76% of our net accounts receivable balance, respectively. 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, 2019 and December 31, 2018 (in thousands): Fair Value as of September 30, 2019 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 746,195 $ — $ — $ 746,195 Commercial paper (b) — — — — U.S. government securities — 113,541 — 113,541 Corporate bonds, asset backed and other securities — 98,196 — 98,196 Total $ 746,195 $ 211,737 $ — $ 957,932 Fair Value as of December 31, 2018 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 488,733 $ — $ — $ 488,733 Commercial paper (b) — 14,548 — 14,548 U.S. government securities — 289,576 — 289,576 Corporate bonds, asset backed and other securities — 166,600 — 166,600 Total $ 488,733 $ 470,724 $ — $ 959,457 Liabilities: Contingent consideration resulting from the Technicolor Acquisition $ — $ — $ 19,800 $ 19,800 Total $ — $ — $ 19,800 $ 19,800 ______________________________ (a) Primarily included within cash and cash equivalents. (b) As of September 30, 2019 and December 31, 2018, zero commercial paper was included within cash and cash equivalents. Level 3 Fair Value Measurements Contingent consideration As discussed in Note 7, " Business Combinations and Other Transactions ," we completed the Technicolor Acquisition during third quarter 2018. In conjunction with the Technicolor Acquisition, we initially recognized a contingent consideration liability which was measured at fair value on a recurring basis using significant unobservable inputs classified as Level 3 measurements within the fair value hierarchy. We utilized a Monte Carlo simulation model to determine the estimated fair value of the contingent consideration liability through first quarter 2019. A Monte Carlo simulation uses random numbers together with volatility assumptions to generate individual paths, or trials, for variables of interest governed by a Geometric Brownian Motion in a risk-neutral framework. During second quarter 2019, we completed the acquisition of the R&I unit of Technicolor SA. The transaction met the definition of an asset acquisition and was accounted for using the cost accumulation and allocation model. As discussed in Note 7, " Business Combinations and Other Transactions ," as part of this acquisition, Technicolor reduced its rights to the revenue-sharing arrangement that created the initial contingent consideration liability from the Technicolor Acquisition. We determined that the initial contingent consideration liability from the Technicolor Acquisition was significantly modified in conjunction with the acquisition of the R&I unit, and, as such, the contingent consideration liability will now be accounted for under ASC 450 - Contingencies under the asset acquisition framework when the liability is deemed probable and estimable. Since the contingent consideration liability arising from the amended revenue-sharing arrangement was not probable and estimable as of the acquisition date, the carrying value of the previous contingent consideration liability was derecognized, which resulted in a $20.5 million gain which was included within " Other Income (Expense), Net ” in the condensed consolidated statement of income for second quarter 2019. Therefore, effective as of the acquisition date of May 31, 2019, the contingent consideration liability was no longer a Level 3 fair value recurring measurement. The following table provides a reconciliation of the beginning and ending balances of our Level 3 fair value measurements from December 31, 2018 to September 30, 2019 , which includes the contingent consideration liability resulting from the Technicolor Acquisition discussed further above. The Level 3 contingent consideration liability was historically included within " Other long-term liabilities " in the condensed consolidated balance sheet prior to its derecognition in second quarter 2019. Level 3 Fair Value Measurements Contingent Consideration Liability Balance as of December 31, 2018 $ 19,800 Changes in fair value recognized in the condensed consolidated statements of income 710 Derecognition of contingent consideration liability as a Level 3 fair value measurement (20,510 ) Balance as of September 30, 2019 $ — Non-Recurring Fair Value Measurements Investments in Other Entities From time to time, we may make strategic investments in companies that have developed or are developing technologies that are complementary to our business. As disclosed in our 2018 Form 10-K, in conjunction with our adoption of ASU No. 2016-01, we made an accounting policy election for a measurement alternative for our equity investments that do not have readily determinable fair values, specifically related to our strategic investments in other entities. Under the alternative, our strategic investments in other entities without readily determinable fair values are measured at cost, less any impairment, plus or minus changes resulting from observable price changes in orderly transactions for an identical or similar investment of the same issuer, if any. Adjustments to the carrying value of those investments are considered non-recurring fair value measurements. During third quarter 2019, we recognized a $3.3 million loss resulting from the partial impairment of one of our long-term strategic investments, which was included within “ Other Income (Expense), Net ” in the condensed consolidated statement of income. Fair Value of Long-Term Debt 2024 and 2020 Senior Convertible 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, 2019 and December 31, 2018 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, 2019 December 31, 2018 Principal Amount Carrying Value Fair Value Principal Amount Carrying Fair Value Senior Convertible Long-Term Debt $ 494,909 $ 419,136 $ 488,432 $ 316,000 $ 298,951 $ 331,595 Technicolor Acquisition Long-term Debt As more fully disclosed in Note 7, " Business Combinations and Other Transactions ," we recognized long-term debt in conjunction with the Technicolor Acquisition. The carrying value and related estimated fair value of the Technicolor Acquisition long-term debt reported in the condensed consolidated balance sheets as of September 30, 2019 and December 31, 2018 was as follows (in thousands). The aggregate fair value of the Technicolor Acquisition long-term debt is a Level 3 fair value measurement. September 30, 2019 December 31, 2018 Carrying Value Fair Value Carrying Fair Value Technicolor Acquisition Long-Term Debt $ 20,393 $ 22,882 $ 18,428 $ 19,100

Long-Term Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
LONG-TERM DEBT	LONG-TERM DEBT Technicolor Acquisition Long-Term Debt Refer to Note 7, " Business Combinations and Other Transactions ," and Note 8, " Cash, Concentration of Credit Risk and Fair Value of Financial Instruments ," for information regarding the long-term debt recognized in conjunction with the Technicolor Acquisition. 2024 Senior Convertible 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 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 mature on June 1, 2024, unless earlier converted or repurchased. The 2024 Notes will be 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 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. It is our current intent and policy to settle all conversions of the 2024 Notes through combination settlements of cash and shares of 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 common stock. Prior to 5:00 p.m., New York City time, on the business day immediately preceding March 1, 2024, the 2024 Notes will be convertible only under certain circumstances as set forth in the Indenture, including on any date during any calendar quarter (and only during such calendar quarter) beginning after September 30, 2019 if the closing sale price of the common stock was more than 130% of the applicable conversion price (approximately $105.68 based on the current conversion price of the 2024 Notes) on each applicable trading day for at least 20 trading days (whether or not consecutive) in the period of the 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter. Commencing on March 1, 2024, the 2024 Notes will be convertible at any time prior to 5:00 p.m., New York City time, on the second scheduled trading day immediately preceding the maturity date of the 2024 Notes. The Company may not redeem the 2024 Notes prior to their maturity date. If a fundamental change (as defined in the Indenture) occurs, holders may require the Company to purchase all or a portion of their 2024 Notes for cash at a repurchase price equal to 100% of the principal amount of the 2024 Notes to be repurchased, plus any accrued and unpaid interest to, but excluding, the fundamental change repurchase date. The 2024 Notes are our senior unsecured obligations and rank equally in right of payment with any of our current and any future senior unsecured indebtedness, including our 1.50% senior convertible notes due 2020 (the “2020 Notes”) discussed below. 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. The aggregate cost of the 2024 Note Hedge Transactions was $72.0 million . 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. As consideration for the 2024 Warrant Transactions, we received aggregate proceeds of $47.6 million . The net cost of the 2024 Call Spread Transactions was $24.4 million . The net proceeds from the issuance of the 2024 Notes, after deducting fees and offering expenses, were used for the following: (i) $232.7 million was used to repurchase $221.1 million in aggregate principal amount of the 2020 Notes (as defined below) in privately negotiated transactions concurrently with the offering of the 2024 Notes (ii) $19.6 million was used to repurchase shares of common stock at $62.53 per share, the closing price of the stock on May 29, 2019; and (iii) $24.4 million, in addition to the proceeds from the 2024 Warrant Transactions discussed above, was used to fund the cost of the 2024 Call Spread Transactions. Accounting Treatment of the 2024 Notes and Related Convertible Note Hedge and Warrant Transactions The 2024 Call Spread Transactions were classified as equity. The Company bifurcated the proceeds from the offering of the 2024 Notes between liability and equity components. On the date of issuance, the liability and equity components were calculated to be approximately $328.0 million and $72.0 million , respectively. The initial $328.0 million liability component was determined based on the fair value of similar debt instruments excluding the conversion feature. The initial $72.0 million ( $56.9 million net of tax) equity component represents the difference between the fair value of the initial $328.0 million in debt and the $400.0 million gross proceeds. The related initial debt discount of $72.0 million is being amortized over the life of the 2024 Notes using the effective interest method. An effective interest rate of 6.25% was used to calculate the debt discount on the 2024 Notes. In connection with the above-noted transactions, the Company incurred approximately $8.4 million of directly related costs. The initial purchasers' transaction fees and related offering expenses were allocated to the liability and equity components in proportion to the allocation of proceeds and accounted for as debt and equity issuance costs, respectively. We allocated $6.4 million of debt issuance costs to the liability component, which were capitalized as deferred financing costs. These costs are being amortized as interest expense over the term of the debt using the effective interest method. The remaining $1.9 million of costs ( $1.6 million net of tax) allocated to the equity component were recorded as a reduction of the equity component. 2020 Senior Convertible Notes, and Related Note Hedge and Warrant Transactions On March 11, 2015, we issued $316.0 million in aggregate principal amount of 1.50% Senior Convertible Notes due 2020, referred to as the 2020 Notes. The 2020 Notes bear interest at a rate of 1.50% per year, payable in cash on March 1 and September 1 of each year, which commenced September 1, 2015, and mature on March 1, 2020, unless earlier converted or repurchased. In connection with the initial offering of the 2020 Notes, on March 5 and March 9, 2015, we entered into convertible note hedge transactions (the “2020 Note Hedge Transactions”) that initially covered approximately 4.4 million shares of common stock at a strike price that initially corresponded to the initial conversion price of the 2020 Notes and are exercisable upon any conversion of the 2020 Notes. On March 5 and March 9, 2015, we also entered into warrant transactions (collectively, the "2020 Warrant Transactions" and, together with the 2020 Note Hedge Transactions, the "2020 Call Spread Transactions") to initially acquire, subject to customary anti-dilution adjustments, approximately 4.4 million shares of common stock. The warrants become exercisable and expire in daily tranches over a three and a half month period starting in June 2020. Refer to the 2018 Form 10-K for further details on this transaction. As noted above, during second quarter 2019, the Company used $232.7 million from the offering of the 2024 Notes to repurchase $221.1 million in aggregate principal amount of the 2020 Notes in privately negotiated transactions concurrently with the offering of the 2024 Notes. As a result of the partial repurchase of the 2020 Notes, $94.9 million in aggregate principal amount of the 2020 Notes remain outstanding as of September 30, 2019 . Additionally, on May 29, 2019, in connection with the partial repurchase of the 2020 Notes, the Company entered into partial unwind agreements that amend the terms of the 2020 Note Hedge Transactions to reduce the number of options corresponding to the principal amount of the repurchased 2020 Notes. The unwind agreements also reduce the number of warrants exercisable under the 2020 Warrant Transactions. As a result of the partial unwind transactions, approximately 1.3 million shares of common stock in the aggregate were covered under each of the 2020 Note Hedge Transactions and the 2020 Warrant Transactions as of September 30, 2019 . As of September 30, 2019 , the warrants under the 2020 Warrant Transactions had a strike price of approximately $86.59 per share, as adjusted. Proceeds received from the unwind of the 2020 Note Hedge Transactions were $9.0 million , and consideration paid for the unwind of the 2020 Warrant Transactions was $4.2 million , resulting in net proceeds received of $4.9 million for the combined unwind transactions which was recorded to equity in second quarter 2019. We recognized a $5.5 million loss on extinguishment of debt during second quarter 2019 in connection with this repurchase, which was included within " Other Income (Expense), Net " in the condensed consolidated statement of income for the period. The loss on extinguishment represents the difference between the calculated fair value of the debt immediately prior to its derecognition and the carrying amount of the debt component, including any unamortized debt discount and issuance costs. The remaining consideration paid for the partial repurchase of the 2020 Notes was allocated to the reacquisition of the equity component, which equaled $13.0 million ( $10.6 million net of tax) and was recorded as a reduction of equity in second quarter 2019. The remaining unamortized debt discount and issuance costs of $3.3 million will continue to be amortized throughout the remaining life of the 2020 Notes, which are set to mature in March 2020. The remaining 2020 Notes will be convertible into cash, shares of our common stock or a combination thereof, at our election, at a current conversion rate of 14.1153 shares of common stock per $1,000 principal amount of 2020 Notes as of September 30, 2019 (which is equivalent to a conversion price of approximately $70.85 per share), as adjusted pursuant to the terms of the indenture governing the 2020 Notes (the "2020 Notes Indenture"). The conversion rate of the 2020 Notes, and thus the conversion price, may be adjusted in certain circumstances, including in connection with a conversion of the 2020 Notes made following certain fundamental changes and under other circumstances set forth in the 2020 Notes Indenture. It is our current intent and policy to settle all conversions of the 2020 Notes through combination settlements of cash and shares of common stock, with a specified dollar amount of $1,000 per $1,000 principal amount of 2020 Notes and any remaining amounts in shares of common stock. Prior to 5:00 p.m., New York City time, on the business day immediately preceding December 1, 2019, the 2020 Notes will be convertible only under certain circumstances as set forth in the 2020 Notes Indenture, including on any date during any calendar quarter (and only during such calendar quarter) if the closing sale price of our common stock was more than 130% of the applicable conversion price (approximately $92.11 based on the current conversion price of the 2020 Notes) on each applicable trading day for at least 20 trading days in the period of the 30 consecutive trading days ending on the last trading day of the immediately preceding calendar quarter. Commencing on December 1, 2019, the 2020 Notes will be convertible at any time prior to 5:00 p.m., New York City time, on the second scheduled trading day immediately preceding the maturity date of the 2020 Notes. The Company may not redeem the 2020 Notes prior to their maturity date. The following table reflects the carrying value of the 2024 Notes and 2020 Notes as of September 30, 2019 and December 31, 2018 (in thousands): September 30, 2019 December 31, 2018 2024 Notes 2020 Notes Total 2020 Notes Principal $ 400,000 $ 94,909 $ 494,909 $ 316,000 Less: Unamortized interest discount (67,857 ) (1,673 ) (69,530 ) (15,428 ) Deferred financing costs (6,069 ) (174 ) (6,243 ) (1,621 ) Net carrying amount of 2024 and 2020 Notes $ 326,074 $ 93,062 $ 419,136 $ 298,951 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, 2019 and September 30, 2018 relating to the contractual interest coupon, accretion of the debt discount, and the amortization of deferred financing costs (in thousands): Three months ended September 30, 2019 2018 2024 Notes 2020 Notes Total 2024 Notes 2020 Notes Total Contractual coupon interest $ 2,000 $ 356 $ 2,356 $ — $ 1,185 $ 1,185 Accretion of debt discount 3,088 1,004 4,092 — 3,124 3,124 Amortization of deferred financing costs 276 104 380 — 347 347 Total $ 5,364 $ 1,464 $ 6,828 $ — $ 4,656 $ 4,656 Nine months ended September 30, 2019 2018 2024 Notes 2020 Notes Total 2024 Notes 2020 Notes Total Contractual coupon interest $ 2,600 $ 2,468 $ 5,068 $ — $ 3,555 $ 3,555 Accretion of debt discount 4,189 6,739 10,928 — 9,252 9,252 Amortization of deferred financing costs 374 717 1,091 — 1,042 1,042 Total $ 7,163 $ 9,924 $ 17,087 $ — $ 13,849 $ 13,849

Variable Interest Entities

Variable Interest Entities	9 Months Ended
	Sep. 30, 2019
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, 2019 , the combined book values of the assets and liabilities associated with these variable interest entities included in our condensed consolidated balance sheet were $41.3 million and $3.8 million , respectively. Assets included $20.8 million of cash and cash equivalents, $1.5 million of accounts receivable and prepaid assets, $17.7 million of patents, net, and $1.3 million of other non-current assets. As of December 31, 2018 , the combined book values of the assets and liabilities associated with these variable interest entities included in our condensed consolidated balance sheet were $29.9 million and $6.1 million , respectively. Assets included $11.7 million of cash and cash equivalents, $1.3 million of accounts receivable, $14.4 million of patents, net, and $2.5 million of other non-current assets. Chordant On January 31, 2019, we launched the Company’s Chordant™ business as a standalone company. The spinout of the unit, which now includes an affiliate of Sony as an investor along with the Company, gives 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 will consolidate Chordant. For the three and nine months ended September 30, 2019 , we have allocated approximately $0.5 million and $1.2 million , respectively, of Chordant's net loss to noncontrolling interests held by other parties. 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 will 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, 2019 , we have allocated approximately $0.9 million and $3.0 million , respectively, of Convida Wireless's net loss to noncontrolling interests held by other parties. Signal Trust for Wireless Innovation During 2013, we announced the establishment of the Signal Trust for Wireless Innovation (the “Signal Trust”), the goal of which is to monetize a large InterDigital patent portfolio related to cellular infrastructure. The more than 500 patents and patent applications transferred from InterDigital to the Signal Trust focus primarily on 3G and LTE technologies, and were developed by InterDigital's engineers and researchers over more than a decade, with a number of the innovations contributing to the worldwide standards process. InterDigital is the primary beneficiary of the Signal Trust. The distributions from the Signal Trust will support continued research related to cellular wireless technologies. A small portion of the proceeds from the Signal Trust will be used to fund, through the Signal Foundation for Wireless Innovation, scholarly analysis of intellectual property rights and the technological, commercial and creative innovations they facilitate.

Other Income (Expense), Net

Other Income (Expense), Net	9 Months Ended
	Sep. 30, 2019
Other Income and Expenses [Abstract]
OTHER INCOME (EXPENSE), NET	OTHER INCOME (EXPENSE), NET The amounts included in " Other Income (Expense), Net " in the condensed consolidated statements of income for the three and nine months ended September 30, 2019 and 2018 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Interest and investment income $ 3,684 $ 3,740 $ 11,173 $ 11,013 Gain on asset acquisition and sale of business 8,515 — 22,690 — Loss on extinguishment of long-term debt — — (5,488 ) — Other (4,396 ) (8,654 ) (4,603 ) (8,907 ) Other income (expense), net $ 7,803 $ (4,914 ) $ 23,772 $ 2,106 Refer to Note 7, " Business Combinations and Other Transactions " for further information regarding the $14.2 million gain on asset acquisition and $8.5 million gain on sale of business and Note 9, " Long-term Debt" for further information on the $5.5 million loss on extinguishment of long-term debt recognized during the nine months ended September 30, 2019 . Additionally, refer to Note 8, " Cash, Concentration of Credit Risk and Fair Value of Financial Instruments, " for further information regarding the $3.3 million partial impairment of a strategic long-term investment during third quarter 2019 which is included in the " Other " caption in the table above. During the three and nine months ended September 30, 2018, we recognized an aggregate $8.4 million loss resulting from the sale of our entire ownership interest in one of our strategic long-term investments and the impairment of a separate strategic long-term investment. These items are also included in the " Other " caption in the table above.

Revision to Noncontrolling Inte

Revision to Noncontrolling Interest	9 Months Ended
	Sep. 30, 2019
Accounting Changes and Error Corrections [Abstract]
REVISION TO NONCONTROLLING INTEREST	REVISION TO NONCONTROLLING INTEREST As discussed in Note 1, " Basis of Presentation ," we revised our prior period presentation of noncontrolling interest. The following tables present the effect of the revision on the consolidated statements of income, statements of comprehensive income, balance sheets and statements of shareholders' equity (in thousands, except per share data). The correction of this error has no impact to the previously reported consolidated statements of cash flows for any periods. Statements of Income and Statements of Comprehensive Income Impact Year Ended December 31, December 31, December 31, 2016 2017 2018 Net loss attributable to noncontrolling interest - As Reported $3,521 $3,579 $4,393 Net loss attributable to noncontrolling interest - As Revised $5,261 $5,506 $5,556 Net income attributable to InterDigital, Inc. - As Reported $309,001 $174,293 $63,868 Net income attributable to InterDigital, Inc. - As Revised $310,741 $176,220 $65,031 Net income per common share, Basic - As Reported $8.95 $5.04 $1.85 Net income per common share, Basic - As Revised $9.00 $5.09 $1.89 Net income per common share, Diluted - As Reported $8.78 $4.87 $1.81 Net income per common share, Diluted - As Revised $8.83 $4.93 $1.84 Total comprehensive income attributable to InterDigital, Inc. - As Reported $308,665 $172,724 $63,929 Total comprehensive income attributable to InterDigital, Inc. - As Revised $310,405 $174,651 $65,092 Statements of Income and Statements of Comprehensive Income Impact Three Months Ended Six Months Ended Nine Months Ended March 31, June 30, September 30, December 31, June 30, September 30, 2017 2017 2017 2017 2017 2017 Net loss attributable to noncontrolling interest - As Reported $978 $955 $811 $835 $1,933 $2,744 Net loss attributable to noncontrolling interest - As Revised $1,483 $1,427 $1,226 $1,370 $2,910 $4,136 Net income attributable to InterDigital, Inc. - As Reported $33,756 $52,499 $35,536 $52,502 $86,255 $121,791 Net income attributable to InterDigital, Inc. - As Revised $34,261 $52,971 $35,951 $53,037 $87,232 $123,183 Net income per common share, Basic - As Reported $0.98 $1.51 $1.02 $1.52 $2.50 $3.52 Net income per common share, Basic - As Revised $1.00 $1.53 $1.04 $1.53 $2.53 $3.56 Net income per common share, Diluted - As Reported $0.93 $1.46 $1.00 $1.48 $2.39 $3.40 Net income per common share, Diluted - As Revised $0.95 $1.48 $1.02 $1.49 $2.42 $3.43 Total comprehensive income attributable to InterDigital, Inc. - As Reported $33,711 $52,457 $35,442 $51,114 $86,168 $121,610 Total comprehensive income attributable to InterDigital, Inc. - As Revised $34,216 $52,929 $35,857 $51,649 $87,145 $123,002 Statements of Income and Statements of Comprehensive Income Impact Three Months Ended Six Months Ended Nine Months Ended March 31, June 30, September 30, December 31, June 30, September 30, 2018 2018 2018 2018 2018 2018 Net loss attributable to noncontrolling interest - As Reported $1,196 $930 $1,297 $970 $2,126 $3,423 Net loss attributable to noncontrolling interest - As Revised $1,501 $1,190 $1,642 $1,223 $2,691 $4,333 Net income attributable to InterDigital, Inc. - As Reported $29,925 $10,706 $21,407 $1,830 $40,631 $62,038 Net income attributable to InterDigital, Inc. - As Revised $30,230 $10,966 $21,752 $2,083 $41,196 $62,948 Net income per common share, Basic - As Reported $0.86 $0.31 $0.62 $0.05 $1.17 $1.79 Net income per common share, Basic - As Revised $0.87 $0.32 $0.63 $0.06 $1.19 $1.81 Net income per common share, Diluted - As Reported $0.84 $0.30 $0.60 $0.05 $1.14 $1.74 Net income per common share, Diluted - As Revised $0.85 $0.31 $0.61 $0.06 $1.16 $1.77 Total comprehensive income attributable to InterDigital, Inc. - As Reported $28,178 $11,082 $21,874 $2,795 $39,260 $61,134 Total comprehensive income attributable to InterDigital, Inc. - As Revised $28,483 $11,342 $22,219 $3,048 $39,825 $62,044 Balance Sheets and Statements of Shareholders' Equity Impact December 31, December 31, March 31, June 30, September 30, December 31, 2016 2017 2018 2018 2018 2018 Retained earnings - As Reported $1,120,766 $1,249,091 $1,428,437 $1,426,888 $1,436,171 $1,426,266 Retained earnings - As Revised $1,127,380 $1,257,632 $1,437,283 $1,435,994 $1,445,622 $1,435,970 Total InterDigital, Inc. shareholders’ equity - As Reported $739,709 $855,267 $1,019,047 $1,020,469 $1,000,591 $927,025 Total InterDigital, Inc. shareholders’ equity - As Revised $746,323 $863,808 $1,027,893 $1,029,575 $1,010,042 $936,729 Noncontrolling interest - As Reported $14,659 $17,881 $16,685 $15,755 $14,458 $10,988 Noncontrolling interest - As Revised $8,045 $9,340 $7,839 $6,649 $5,007 $1,284 Total equity - As Reported $754,368 $873,148 $1,035,732 $1,036,224 $1,015,049 $938,013 Total equity - As Revised $754,368 $873,148 $1,035,732 $1,036,224 $1,015,049 $938,013

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reclassifications	Reclassifications Certain reclassifications have been made to prior year amounts to conform to the current year presentation.
New Accounting Guidance	New Accounting Guidance Accounting Standards Update: Leases In February 2016, the FASB issued ASU 2016-02, " Leases (Topic 842) " or ("ASC 842"), which outlines a comprehensive change to the lease accounting model and supersedes prior lease guidance. Refer to Note 2, " Leases ," for information regarding our adoption of this guidance effective January 1, 2019 and a discussion of the impact to information presented herein, as well as additional required disclosures under the new guidance. Accounting Standards Update: Improvements to Nonemployee Share-Based Payment Accounting In June 2018, the FASB issued ASU No. 2018-07, " Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting ," which is intended to reduce cost and complexity and to improve financial reporting for share-based payments issued to nonemployees. The guidance is effective for fiscal years beginning after December 15, 2018 and early adoption is permitted. We adopted this guidance in first quarter 2019 and it did not have a material impact on our consolidated financial statements. Accounting Standards Update: Financial Instruments - Credit Losses In June 2016, the FASB issued ASU No. 2016-13, " Financial Instruments - Credit Losses ". This ASU introduces a new accounting model for recognizing credit losses on certain financial instruments and financial assets, including trade receivables, based upon an estimate of current expected credit losses, otherwise known as CECL. The new guidance requires the recognition of an allowance that reflects the current estimate of credit losses expected to be incurred over the life of the financial asset, based not only on historical experience and current conditions, but also on reasonable forecasts. Additionally, ASU No. 2016-13 made several changes to the available-for-sale impairment model. The guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. While we are still completing our accounting assessment, we do not expect this guidance to have a material impact on our consolidated financial statements. Accounting Standards Update: Cloud Computing Arrangements In August 2018, the FASB issued ASU No. 2018-15 “ Intangibles – Goodwill and Other – Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement that is a Service Contract ”. The amendments in this ASU align the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The guidance is effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted. While we are still completing our accounting assessment, we do not expect this guidance to have a material impact on our consolidated financial statements. Accounting Standards Update: Collaborative Arrangements In November 2018, the FASB issued ASU No. 2018-18, " Collaborative Arrangements (Topic 808): Clarifying the Interaction Between Topic 808 and Topic 606 ". The amendments in this ASU provide guidance on how to assess whether certain transactions between collaborative arrangement participants should be accounted for within the revenue recognition standard. The amendments in this update are effective for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, and early adoption is permitted for entities who have previously adopted the new revenue recognition guidance. While we are still completing our accounting assessment, we do not expect this guidance to have a material impact on our consolidated financial statements.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019 and 2018 (in thousands): FOR THE NINE MONTHS ENDED SEPTEMBER 30, SUPPLEMENTAL CASH FLOW INFORMATION: 2019 2018 Interest paid $ 3,930 $ 4,740 Income taxes paid, including foreign withholding taxes 16,483 24,459 Non-cash investing and financing activities: Dividend payable 10,897 11,996 Increases in noncontrolling interests 13,750 — Non-cash acquisition of patents 22,500 — Accrued capitalized patent costs and property and equipment 390 (1,513 )

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Schedule of operating lease right-of-use assets and operating lease liabilities	Additionally, the table below includes the balances of operating lease right-of-use assets and operating lease liabilities as of September 30, 2019 (in thousands): Balance Sheet Classification January 1, 2019 September 30, 2019 Assets Operating lease right-of-use assets, net Other Non-current Assets $ 13,634 $ 16,587 Total Lease Assets $ 13,634 $ 16,587 Liabilities Operating lease liabilities - Current Other Accrued Expenses $ 3,519 $ 3,624 Operating lease liabilities - Noncurrent Other Long-Term Liabilities 13,652 15,867 Total Lease Liabilities $ 17,171 $ 19,491
Schedule of lease costs	The components of lease costs which were included within operating expenses in our condensed consolidated statements of income were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2019 2019 Operating lease cost $ 1,210 $ 3,325 Short-term lease cost 211 731 Variable lease cost 362 1,054
Schedule of maturities operating lease liabilities	The maturities of our operating lease liabilities as of September 30, 2019 under ASC 842, excluding short-term leases with terms less than 12 months, were as follows (in thousands): Maturity of Operating Lease Liabilities September 30, 2019 Remainder 2019 $ 1,348 2020 4,440 2021 3,934 2022 3,965 2023 3,229 Thereafter 6,310 Total lease payments $ 23,226 Less: Imputed interest (3,735 ) Present value of lease liabilities $ 19,491
Schedule of under ASC 840, including short-term leases with terms less than 12 months	The undiscounted maturities of our operating leases as of December 31, 2018 under ASC 840, including short-term leases with terms less than 12 months, were as follows (in thousands): Maturity of Operating Leases December 31, 2018 2019 $ 5,362 2020 3,386 2021 2,883 2022 2,920 2023 2,184 Thereafter 5,582

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019 and 2018 (in thousands): Three months ended September 30, 2019 2018 Increase/(Decrease) Variable patent royalty revenue $ 4,683 $ 13,645 $ (8,962 ) (66 )% Fixed-fee royalty revenue 63,736 60,272 3,464 6 % Current patent royalties a 68,419 73,917 (5,498 ) (7 )% Non-current patent royalties b (370 ) 128 (498 ) (389 )% Total patent royalties 68,049 74,045 (5,996 ) (8 )% Current technology solutions revenue a 3,724 1,034 2,690 260 % Patent sales b 750 — 750 — % Total revenue $ 72,523 $ 75,079 $ (2,556 ) (3 )% Nine months ended September 30, 2019 2018 Increase/(Decrease) Variable patent royalty revenue $ 22,557 $ 26,322 $ (3,765 ) (14 )% Fixed-fee royalty revenue 190,345 178,207 12,138 7 % Current patent royalties a 212,902 204,529 8,373 4 % Non-current patent royalties b (4,908 ) 25,489 (30,397 ) (119 )% Total patent royalties 207,994 230,018 (22,024 ) (10 )% Current technology solutions revenue a 7,794 2,060 5,734 278 % Patent sales b 975 — 975 — % Total revenue $ 216,763 $ 232,078 $ (15,315 ) (7 )% a. Recurring revenues are comprised of current patent royalties, inclusive of Dynamic Fixed-Fee Agreement royalties, and current technology solutions revenue. b. Non-recurring revenues are comprised of non-current patent royalties, which primarily 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, 2019 , we expect to recognize the following revenue from Dynamic Fixed-Fee Agreement payments over the term of such contracts (in thousands): Revenue Remainder 2019 $ 63,736 2020 248,250 2021 178,583 2022 85,228 2023 —

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2019
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 (loss) per share computation (in thousands, except for per share data): Three months ended September 30, 2019 2018 Basic Diluted Basic Diluted Numerator: Net income applicable to InterDigital, Inc. $ 2,234 $ 2,234 $ 21,752 $ 21,752 Denominator: Weighted-average shares outstanding: Basic 31,130 31,130 34,651 34,651 Dilutive effect of stock options, RSUs, convertible securities and warrants 178 956 Weighted-average shares outstanding: Diluted 31,308 35,607 Earnings Per Share: Net income per common share: Basic $ 0.07 $ 0.07 $ 0.63 $ 0.63 Dilutive effect of stock options, RSUs, convertible securities and warrants — (0.02 ) Net income per common share: Diluted $ 0.07 $ 0.61 Nine months ended September 30, 2019 2018 Basic Diluted Basic Diluted Numerator: Net income applicable to InterDigital, Inc. $ 7,174 $ 7,174 $ 62,948 $ 62,948 Denominator: Weighted-average shares outstanding: Basic 31,757 31,757 34,687 34,687 Dilutive effect of stock options, RSUs, convertible securities and warrants 253 927 Weighted-average shares outstanding: Diluted 32,010 35,614 Earnings Per Share: Net income per common share: Basic $ 0.23 $ 0.23 $ 1.81 $ 1.81 Dilutive effect of stock options, RSUs, convertible securities and warrants (0.01 ) (0.04 ) Net income per common share: Diluted $ 0.22 $ 1.77
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, 2019 2018 2019 2018 Restricted stock units and stock options 155 78 120 44 Convertible securities 6,260 — 5,236 — Warrants 6,260 4,405 5,236 4,404 Total 12,675 4,483 10,592 4,448

Business Combinations and Oth_2

Business Combinations and Other Transactions (Tables)	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Schedule of pro forma information	The amounts in the table are unaudited (in thousands, except for per share data): Three Months Ended Nine Months Ended September 30, September 30, 2018 2018 Actual revenue $ 75,079 $ 232,078 Supplemental pro forma revenue 76,034 238,761 Actual earnings 21,752 62,948 Supplemental pro forma earnings 22,884 55,314 Actual diluted earnings per share 0.61 1.77 Supplemental pro forma diluted earnings per share 0.64 1.55

Cash, Concentration of Credit_2

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments (Tables)	9 Months Ended
	Sep. 30, 2019
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, 2019 , December 31, 2018 and September 30, 2018 to the captions within the condensed consolidated balance sheets and condensed consolidated statements of cash flows (in thousands). The Company had no restricted cash balance prior to third quarter 2018. September 30, December 31, September 30, 2019 2018 2018 Cash and cash equivalents $ 735,886 $ 475,056 $ 508,829 Restricted cash included within prepaid and other current assets 9,229 13,677 15,942 Restricted cash included within other non-current assets 1,080 — — Total cash, cash equivalents and restricted cash $ 746,195 $ 488,733 $ 524,771
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, 2019 , December 31, 2018 and September 30, 2018 to the captions within the condensed consolidated balance sheets and condensed consolidated statements of cash flows (in thousands). The Company had no restricted cash balance prior to third quarter 2018. September 30, December 31, September 30, 2019 2018 2018 Cash and cash equivalents $ 735,886 $ 475,056 $ 508,829 Restricted cash included within prepaid and other current assets 9,229 13,677 15,942 Restricted cash included within other non-current assets 1,080 — — Total cash, cash equivalents and restricted cash $ 746,195 $ 488,733 $ 524,771
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, 2019 and December 31, 2018 (in thousands): Fair Value as of September 30, 2019 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 746,195 $ — $ — $ 746,195 Commercial paper (b) — — — — U.S. government securities — 113,541 — 113,541 Corporate bonds, asset backed and other securities — 98,196 — 98,196 Total $ 746,195 $ 211,737 $ — $ 957,932 Fair Value as of December 31, 2018 Level 1 Level 2 Level 3 Total Assets: Money market and demand accounts (a) $ 488,733 $ — $ — $ 488,733 Commercial paper (b) — 14,548 — 14,548 U.S. government securities — 289,576 — 289,576 Corporate bonds, asset backed and other securities — 166,600 — 166,600 Total $ 488,733 $ 470,724 $ — $ 959,457 Liabilities: Contingent consideration resulting from the Technicolor Acquisition $ — $ — $ 19,800 $ 19,800 Total $ — $ — $ 19,800 $ 19,800 ______________________________ (a) Primarily included within cash and cash equivalents. (b) As of September 30, 2019 and December 31, 2018, zero commercial paper was included within cash and cash equivalents.
Schedule of contingent consideration liability	The Level 3 contingent consideration liability was historically included within " Other long-term liabilities " in the condensed consolidated balance sheet prior to its derecognition in second quarter 2019. Level 3 Fair Value Measurements Contingent Consideration Liability Balance as of December 31, 2018 $ 19,800 Changes in fair value recognized in the condensed consolidated statements of income 710 Derecognition of contingent consideration liability as a Level 3 fair value measurement (20,510 ) Balance as of September 30, 2019 $ —
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, 2019 December 31, 2018 Principal Amount Carrying Value Fair Value Principal Amount Carrying Fair Value Senior Convertible Long-Term Debt $ 494,909 $ 419,136 $ 488,432 $ 316,000 $ 298,951 $ 331,595 September 30, 2019 December 31, 2018 Carrying Value Fair Value Carrying Fair Value Technicolor Acquisition Long-Term Debt $ 20,393 $ 22,882 $ 18,428 $ 19,100

Long-Term Debt (Tables)

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of carrying value of the 2024 Notes and 2020 Notes	The following table reflects the carrying value of the 2024 Notes and 2020 Notes as of September 30, 2019 and December 31, 2018 (in thousands): September 30, 2019 December 31, 2018 2024 Notes 2020 Notes Total 2020 Notes Principal $ 400,000 $ 94,909 $ 494,909 $ 316,000 Less: Unamortized interest discount (67,857 ) (1,673 ) (69,530 ) (15,428 ) Deferred financing costs (6,069 ) (174 ) (6,243 ) (1,621 ) Net carrying amount of 2024 and 2020 Notes $ 326,074 $ 93,062 $ 419,136 $ 298,951
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, 2019 and September 30, 2018 relating to the contractual interest coupon, accretion of the debt discount, and the amortization of deferred financing costs (in thousands): Three months ended September 30, 2019 2018 2024 Notes 2020 Notes Total 2024 Notes 2020 Notes Total Contractual coupon interest $ 2,000 $ 356 $ 2,356 $ — $ 1,185 $ 1,185 Accretion of debt discount 3,088 1,004 4,092 — 3,124 3,124 Amortization of deferred financing costs 276 104 380 — 347 347 Total $ 5,364 $ 1,464 $ 6,828 $ — $ 4,656 $ 4,656 Nine months ended September 30, 2019 2018 2024 Notes 2020 Notes Total 2024 Notes 2020 Notes Total Contractual coupon interest $ 2,600 $ 2,468 $ 5,068 $ — $ 3,555 $ 3,555 Accretion of debt discount 4,189 6,739 10,928 — 9,252 9,252 Amortization of deferred financing costs 374 717 1,091 — 1,042 1,042 Total $ 7,163 $ 9,924 $ 17,087 $ — $ 13,849 $ 13,849

Other Income (Expense), Net (Ta

Other Income (Expense), Net (Tables)	9 Months Ended
	Sep. 30, 2019
Other Income and Expenses [Abstract]
Schedule of other income expense, net	The amounts included in " Other Income (Expense), Net " in the condensed consolidated statements of income for the three and nine months ended September 30, 2019 and 2018 were as follows (in thousands): Three months ended September 30, Nine months ended September 30, 2019 2018 2019 2018 Interest and investment income $ 3,684 $ 3,740 $ 11,173 $ 11,013 Gain on asset acquisition and sale of business 8,515 — 22,690 — Loss on extinguishment of long-term debt — — (5,488 ) — Other (4,396 ) (8,654 ) (4,603 ) (8,907 ) Other income (expense), net $ 7,803 $ (4,914 ) $ 23,772 $ 2,106

Revision to Noncontrolling In_2

Revision to Noncontrolling Interest (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Changes and Error Corrections [Abstract]
Effect of the revision on the financial statements	The following tables present the effect of the revision on the consolidated statements of income, statements of comprehensive income, balance sheets and statements of shareholders' equity (in thousands, except per share data). The correction of this error has no impact to the previously reported consolidated statements of cash flows for any periods. Statements of Income and Statements of Comprehensive Income Impact Year Ended December 31, December 31, December 31, 2016 2017 2018 Net loss attributable to noncontrolling interest - As Reported $3,521 $3,579 $4,393 Net loss attributable to noncontrolling interest - As Revised $5,261 $5,506 $5,556 Net income attributable to InterDigital, Inc. - As Reported $309,001 $174,293 $63,868 Net income attributable to InterDigital, Inc. - As Revised $310,741 $176,220 $65,031 Net income per common share, Basic - As Reported $8.95 $5.04 $1.85 Net income per common share, Basic - As Revised $9.00 $5.09 $1.89 Net income per common share, Diluted - As Reported $8.78 $4.87 $1.81 Net income per common share, Diluted - As Revised $8.83 $4.93 $1.84 Total comprehensive income attributable to InterDigital, Inc. - As Reported $308,665 $172,724 $63,929 Total comprehensive income attributable to InterDigital, Inc. - As Revised $310,405 $174,651 $65,092 Statements of Income and Statements of Comprehensive Income Impact Three Months Ended Six Months Ended Nine Months Ended March 31, June 30, September 30, December 31, June 30, September 30, 2017 2017 2017 2017 2017 2017 Net loss attributable to noncontrolling interest - As Reported $978 $955 $811 $835 $1,933 $2,744 Net loss attributable to noncontrolling interest - As Revised $1,483 $1,427 $1,226 $1,370 $2,910 $4,136 Net income attributable to InterDigital, Inc. - As Reported $33,756 $52,499 $35,536 $52,502 $86,255 $121,791 Net income attributable to InterDigital, Inc. - As Revised $34,261 $52,971 $35,951 $53,037 $87,232 $123,183 Net income per common share, Basic - As Reported $0.98 $1.51 $1.02 $1.52 $2.50 $3.52 Net income per common share, Basic - As Revised $1.00 $1.53 $1.04 $1.53 $2.53 $3.56 Net income per common share, Diluted - As Reported $0.93 $1.46 $1.00 $1.48 $2.39 $3.40 Net income per common share, Diluted - As Revised $0.95 $1.48 $1.02 $1.49 $2.42 $3.43 Total comprehensive income attributable to InterDigital, Inc. - As Reported $33,711 $52,457 $35,442 $51,114 $86,168 $121,610 Total comprehensive income attributable to InterDigital, Inc. - As Revised $34,216 $52,929 $35,857 $51,649 $87,145 $123,002 Statements of Income and Statements of Comprehensive Income Impact Three Months Ended Six Months Ended Nine Months Ended March 31, June 30, September 30, December 31, June 30, September 30, 2018 2018 2018 2018 2018 2018 Net loss attributable to noncontrolling interest - As Reported $1,196 $930 $1,297 $970 $2,126 $3,423 Net loss attributable to noncontrolling interest - As Revised $1,501 $1,190 $1,642 $1,223 $2,691 $4,333 Net income attributable to InterDigital, Inc. - As Reported $29,925 $10,706 $21,407 $1,830 $40,631 $62,038 Net income attributable to InterDigital, Inc. - As Revised $30,230 $10,966 $21,752 $2,083 $41,196 $62,948 Net income per common share, Basic - As Reported $0.86 $0.31 $0.62 $0.05 $1.17 $1.79 Net income per common share, Basic - As Revised $0.87 $0.32 $0.63 $0.06 $1.19 $1.81 Net income per common share, Diluted - As Reported $0.84 $0.30 $0.60 $0.05 $1.14 $1.74 Net income per common share, Diluted - As Revised $0.85 $0.31 $0.61 $0.06 $1.16 $1.77 Total comprehensive income attributable to InterDigital, Inc. - As Reported $28,178 $11,082 $21,874 $2,795 $39,260 $61,134 Total comprehensive income attributable to InterDigital, Inc. - As Revised $28,483 $11,342 $22,219 $3,048 $39,825 $62,044 Balance Sheets and Statements of Shareholders' Equity Impact December 31, December 31, March 31, June 30, September 30, December 31, 2016 2017 2018 2018 2018 2018 Retained earnings - As Reported $1,120,766 $1,249,091 $1,428,437 $1,426,888 $1,436,171 $1,426,266 Retained earnings - As Revised $1,127,380 $1,257,632 $1,437,283 $1,435,994 $1,445,622 $1,435,970 Total InterDigital, Inc. shareholders’ equity - As Reported $739,709 $855,267 $1,019,047 $1,020,469 $1,000,591 $927,025 Total InterDigital, Inc. shareholders’ equity - As Revised $746,323 $863,808 $1,027,893 $1,029,575 $1,010,042 $936,729 Noncontrolling interest - As Reported $14,659 $17,881 $16,685 $15,755 $14,458 $10,988 Noncontrolling interest - As Revised $8,045 $9,340 $7,839 $6,649 $5,007 $1,284 Total equity - As Reported $754,368 $873,148 $1,035,732 $1,036,224 $1,015,049 $938,013 Total equity - As Revised $754,368 $873,148 $1,035,732 $1,036,224 $1,015,049 $938,013

Basis of Presentation (Details)

Basis of Presentation (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)segment	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments | segment	1
SUPPLEMENTAL CASH FLOW INFORMATION:
Interest paid	$ 3,930	$ 4,740
Income taxes paid, including foreign withholding taxes	16,483	24,459
Non-cash investing and financing activities:
Dividend payable	10,897	11,996	$ 11,627
Increases in noncontrolling interests	13,750	0
Non-cash acquisition of patents	22,500	0
Accrued capitalized patent costs and property and equipment	$ 390	$ (1,513)

Leases - Operating Lease Right-

Leases - Operating Lease Right-of-use Assets and Operating Lease Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Assets
Operating lease right-of-use assets, net	$ 16,587	$ 13,634
Total Lease Assets	16,587	13,634
Liabilities
Operating lease liabilities - Current	3,624	3,519
Operating lease liabilities - Noncurrent	15,867	13,652
Total Lease Liabilities	$ 19,491	$ 17,171

Leases - Schedule of Lease Cost

Leases - Schedule of Lease Costs (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 1,210	$ 3,325
Short-term lease cost	211	731
Variable lease cost	$ 362	$ 1,054

Leases - Schedule of Other Info

Leases - Schedule of Other Information Related to Leases (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)
Leases [Abstract]
Measurement of operating lease liabilities	$ 1.4	$ 3.8
Operating lease right-of-use assets	$ 5.5	$ 5.5
Weighted average remaining operating lease term	5 years 7 months 6 days	5 years 7 months 6 days
Operating lease liabilities percentage	6.20%	6.20%
Additional operating lease that had not yet commenced	$ 10	$ 10
Lease term	10 years 9 months 18 days	10 years 9 months 18 days

Leases - Schedule of Future Min

Leases - Schedule of Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Maturity of Operating Lease Liabilities
Remainder 2019	$ 1,348
2020	4,440
2021	3,934
2022	3,965
2023	3,229
Thereafter	6,310
Total lease payments	23,226
Less: Imputed interest	(3,735)
Present value of lease liabilities	$ 19,491	$ 17,171
Maturity of Operating Leases
2019			$ 5,362
2020			3,386
2021			2,883
2022			2,920
2023			2,184
Thereafter			$ 5,582

Revenue - Disaggregated Revenue

Revenue - Disaggregated Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Revenue	$ 72,523	$ 75,079	$ 216,763	$ 232,078
Increase/(Decrease) in Disaggregated Revenue	$ (2,556)		$ (15,315)
Percentage Increase/(Decrease) in Disaggregated Revenue	(3.00%)		(7.00%)
Revenue recognized that had been included in deferred revenue as of the beginning of the period			$ 120,300
Contract assets, current	$ 14,400		14,400		$ 19,700
Contract assets, non-current	1,300		1,300		$ 5,500
Total patent royalties
Disaggregation of Revenue [Line Items]
Revenue	68,049	74,045	207,994	230,018
Increase/(Decrease) in Disaggregated Revenue	$ (5,996)		$ (22,024)
Percentage Increase/(Decrease) in Disaggregated Revenue	(8.00%)		(10.00%)
Current patent royalties
Disaggregation of Revenue [Line Items]
Revenue	$ 68,419	73,917	$ 212,902	204,529
Increase/(Decrease) in Disaggregated Revenue	$ (5,498)		$ 8,373
Percentage Increase/(Decrease) in Disaggregated Revenue	(7.00%)		4.00%
Variable patent royalty revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 4,683	13,645	$ 22,557	26,322
Increase/(Decrease) in Disaggregated Revenue	$ (8,962)		$ (3,765)
Percentage Increase/(Decrease) in Disaggregated Revenue	(66.00%)		(14.00%)
Fixed-fee royalty revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 63,736	60,272	$ 190,345	178,207
Increase/(Decrease) in Disaggregated Revenue	$ 3,464		$ 12,138
Percentage Increase/(Decrease) in Disaggregated Revenue	6.00%		7.00%
Non-current patent royalties
Disaggregation of Revenue [Line Items]
Revenue	$ (370)	128	$ (4,908)	25,489
Increase/(Decrease) in Disaggregated Revenue	$ (498)		$ (30,397)
Percentage Increase/(Decrease) in Disaggregated Revenue	(389.00%)		(119.00%)
Current technology solutions revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 3,724	1,034	$ 7,794	2,060
Increase/(Decrease) in Disaggregated Revenue	$ 2,690		$ 5,734
Percentage Increase/(Decrease) in Disaggregated Revenue	260.00%		278.00%
Patent sales
Disaggregation of Revenue [Line Items]
Revenue	$ 750	$ 0	$ 975	$ 0
Increase/(Decrease) in Disaggregated Revenue	$ 750		$ 975
Percentage Increase/(Decrease) in Disaggregated Revenue	0.00%		0.00%

Revenue - Remaining Performance

Revenue - Remaining Performance Obligation (Details) $ in Thousands	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 63,736
Revenue, remaining performance obligation, expected timing of satisfaction, period	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 248,250
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 178,583
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year
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	$ 85,228
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	$ 0
Revenue, remaining performance obligation, expected timing of satisfaction, period	1 year

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Income Tax Contingency [Line Items]
Effective tax rate (benefit) expense			50.10%	(74.40%)
Estimated annual effective tax benefit rate			25.30%	19.70%
Discrete tax expense			$ 3,100
Discrete net benefits	$ 178	$ 21,143	(3,007)	$ 25,001
Income taxes paid, including foreign withholding taxes			16,483	24,459
Taxes payable	$ 193		193		$ 1,508
Share-based Payment Arrangement
Income Tax Contingency [Line Items]
Discrete net benefits				18,400
Foreign Country
Income Tax Contingency [Line Items]
Income taxes paid, including foreign withholding taxes			$ 11,500	$ 16,500

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, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income applicable to InterDigital, Inc.	$ 2,234	$ 7,743	$ (2,803)	$ 21,752	$ 10,966	$ 30,230	$ 7,174	$ 62,948
Denominator:
Weighted-average shares outstanding: Basic (in shares)	31,130			34,651			31,757	34,687
Dilutive effect of stock options, RSUs, convertible securities and warrants (in shares)	178			956			253	927
Weighted-average shares outstanding: Diluted (in shares)	31,308			35,607			32,010	35,614
Earnings Per Share:
Net income per common share: Basic (in usd per share)	$ 0.07			$ 0.63			$ 0.23	$ 1.81
Dilutive effect of stock options, RSUs, convertible securities and warrants (in usd per share)	0			(0.02)			(0.01)	(0.04)
Net income per common share: Diluted (in usd per share)	$ 0.07			$ 0.61			$ 0.22	$ 1.77

Net Income (Loss) Per Share - A

Net Income (Loss) Per Share - Antidilutive Securities Excluded from Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	12,675	4,483	10,592	4,448
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	155	78	120	44
Convertible securities
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	6,260	0	5,236	0
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount	6,260	4,405	5,236	4,404

Litigation and Legal Proceedi_2

Litigation and Legal Proceedings (Details) - Pending Litigation - patent	Aug. 28, 2019	Aug. 27, 2019	Jan. 23, 2019
U.K. Proceedings
Loss Contingencies [Line Items]
Number of claim alleges infringement		4
District Of Delaware Proceedings
Loss Contingencies [Line Items]
Number of claim alleges infringement	8
ZTE USITC Proceedings and Related Delaware District Court Proceedings
Loss Contingencies [Line Items]
Number of patents-in-suit			3

Business Combinations and Oth_3

Business Combinations and Other Transactions - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Business Acquisition [Line Items]
Actual revenue	$ 72,523			$ 75,079			$ 216,763	$ 232,078
Actual earnings	$ 2,234	$ 7,743	$ (2,803)	$ 21,752	$ 10,966	$ 30,230	$ 7,174	$ 62,948
Actual diluted earnings per share (in usd per share)	$ 0.07			$ 0.61			$ 0.22	$ 1.77
Technicolor
Business Acquisition [Line Items]
Supplemental pro forma revenue				$ 76,034				$ 238,761
Supplemental pro forma earnings				$ 22,884				$ 55,314
Actual diluted earnings per share (in usd per share)								$ 1.77
Supplemental pro forma diluted earnings per share (in usd per share)				$ 0.64				$ 1.55

Business Combinations and Oth_4

Business Combinations and Other Transactions - Narrative (Details) patent_and_application in Thousands, coding_patent_and_application in Thousands	Jul. 19, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	May 31, 2019engineeroffice	Jul. 30, 2018coding_patent_and_application	Jul. 30, 2018patent_and_application
Business Acquisition [Line Items]
Gain on asset acquisition			$ 14,200,000		$ 14,200,000
Interest expense debt		$ 6,828,000		$ 4,656,000	17,087,000	$ 13,849,000
Proceeds from sale of business	$ 10,000,000				10,000,000	0
Gain on sale of business		8,500,000			8,500,000
Technicolor
Business Acquisition [Line Items]
Number of patents and applications								3	18
Number of engineers | engineer							340
Number of R&D offices worldwide | office							8
Gain on derecognition of contingent consideration liability			$ 20,500,000		20,500,000
Receive future cash receipts percentage							42.50%
Combined accumulated projected benefit obligation		$ 6,500,000			6,500,000
Service cost and interest cost					$ 100,000
Effective interest rate acquisition percentage		14.50%			14.50%
Interest expense debt		$ 700,000			$ 2,000,000
Transaction and integration related costs		2,100,000		$ 5,400,000	6,900,000	$ 9,200,000
Technicolor | Shortfalls funding
Business Acquisition [Line Items]
Shortfalls funding amount		$ 25,000,000			$ 25,000,000
Shortfall funding plus percentage					25.00%

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, 2019	Dec. 31, 2018	Sep. 30, 2018
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 735,886	$ 475,056	$ 508,829
Restricted cash included within prepaid and other current assets	9,229	13,677	15,942
Restricted cash included within other non-current assets	1,080	0	0
Total cash, cash equivalents and restricted cash	746,195	488,733	$ 524,771
Money market and demand accounts
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total cash, cash equivalents and restricted cash	$ 746,195	$ 488,733

Cash, Concentration of Credit_4

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Impairment of long-term strategic investments	$ 3,300		$ 3,312	$ 200
Accounts Receivable | Licensee Concentration Risk | Four Largest Licensees
Concentration Risk [Line Items]
Accounts receivable percentage			54.00%
Accounts Receivable | Licensee Concentration Risk | Five Largest Licensees
Concentration Risk [Line Items]
Accounts receivable percentage					76.00%
Technicolor
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability		$ 20,500	$ 20,500

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, 2019	Dec. 31, 2018	Sep. 30, 2018
Assets:
Money market and demand accounts	$ 746,195	$ 488,733	$ 524,771
Commercial paper	0	14,548
Total	957,932	959,457
Liabilities:
Contingent consideration resulting from the Technicolor Acquisition		19,800
Total		19,800
Money market and demand accounts
Assets:
Money market and demand accounts	746,195	488,733
U.S. government securities
Assets:
Securities	113,541	289,576
Corporate bonds, asset backed and other securities
Assets:
Securities	98,196	166,600
Level 1
Assets:
Commercial paper	0	0
Total	746,195	488,733
Liabilities:
Contingent consideration resulting from the Technicolor Acquisition		0
Total		0
Level 1 | Money market and demand accounts
Assets:
Money market and demand accounts	746,195	488,733
Level 1 | U.S. government securities
Assets:
Securities	0	0
Level 1 | Corporate bonds, asset backed and other securities
Assets:
Securities	0	0
Level 2
Assets:
Commercial paper	0	14,548
Total	211,737	470,724
Liabilities:
Contingent consideration resulting from the Technicolor Acquisition		0
Total		0
Level 2 | Money market and demand accounts
Assets:
Money market and demand accounts	0	0
Level 2 | U.S. government securities
Assets:
Securities	113,541	289,576
Level 2 | Corporate bonds, asset backed and other securities
Assets:
Securities	98,196	166,600
Level 3
Assets:
Commercial paper	0	0
Total	0	0
Liabilities:
Total		19,800
Level 3 | Money market and demand accounts
Assets:
Money market and demand accounts	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

Cash, Concentration of Credit_6

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments - Contingent Consideration Liability (Details) - Level 3 $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of December 31, 2018	$ 19,800
Changes in fair value recognized in the condensed consolidated statements of income	710
Derecognition of contingent consideration liability as a Level 3 fair value measurement	(20,510)
Balance as of September 30, 2019	$ 0

Cash, Concentration of Credit_7

Cash, Concentration of Credit Risk and Fair Value of Financial Instruments - Fair Value of Long-Term Debt (Details) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Technicolor Acquisition Long-Term Debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Carrying Value	$ 20,393,000	$ 18,428,000
Fair Value	22,882,000	19,100,000
Senior Convertible Long-Term Debt
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Principal Amount	494,909,000	316,000,000
Carrying Value	419,136,000	298,951,000
Fair Value	$ 488,432,000	$ 331,595,000

Long-Term Debt - 2024 and 2020

Long-Term Debt - 2024 and 2020 Senior Convertible Notes, and Related Note Hedge and Warrant Transactions (Details) $ / shares in Units, shares in Millions	Jun. 03, 2019USD ($)day$ / shares	May 31, 2019USD ($)$ / sharesshares	May 31, 2019USD ($)$ / sharesshares	Sep. 30, 2019USD ($)$ / shares	Jun. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)day$ / sharesshares	Sep. 30, 2018USD ($)	May 29, 2019USD ($)$ / shares	Dec. 31, 2018USD ($)	Mar. 11, 2015USD ($)	Mar. 09, 2015shares
Debt Instrument [Line Items]
Convertible note hedge		$ 72,000,000	$ 72,000,000
Initial strike price (in usd per share) | $ / shares		$ 109.43	$ 109.43
Aggregate proceeds warrant amount			$ 47,600,000				$ 47,600,000	$ 0
Call spread transactions		$ 24,400,000	24,400,000
Use of proceeds repayment of long term debt		232,700,000	$ 232,700,000		$ 232,700,000
Payments on long-term debt		$ 221,100,000			221,100,000		$ 221,091,000	0
Use of proceeds repurchases of common stock									$ 19,600,000
Closing price (in usd per share) | $ / shares									$ 62.53
Unwind transactions (in shares) | shares							1.3
Proceeds from hedge unwind					9,000,000		$ 9,038,000	0
Payment for warrant unwind					4,200,000		4,184,000	0
Proceeds for combined unwind transactions, net					4,900,000
Loss on extinguishment of debt				$ 0		$ 0	5,488,000	$ 0
Debt equity component before tax					13,000,000
Debt equity component net of tax					10,649,000
Convertible Notes 2020
Debt Instrument [Line Items]
Unamortized debt discount and issuance costs					$ 3,300,000
Convertible Debt
Debt Instrument [Line Items]
Aggregate principal amount				494,909,000			494,909,000			$ 316,000,000
Net of tax debt issuance cost				6,243,000			6,243,000
Convertible Debt | Convertible Notes 2024
Debt Instrument [Line Items]
Aggregate principal amount	$ 400,000,000			400,000,000			400,000,000
Debt instrument interest rate, stated percentage	2.00%
Transaction fees and offering expenses	$ 391,600,000
Initial conversion rate	12.3018
Debt conversion converted instrument amount	$ 1,000						1,000
Initial conversion price (in usd per share) | $ / shares	$ 81.29
Conversion price percentage	130.00%
Stock price trigger (in usd per share) | $ / shares	$ 105.68
Convertible threshold trading days | day	20
Convertible threshold consecutive trading days | day	30
Repurchase price percentage	100.00%
Convertible note hedge (in shares) | shares		4.9	4.9
Anti-dilution adjustments of common stock (in shares) | shares		4.9	4.9
Debt instrument carrying amount of liability component	$ 328,000,000
Debt instrument carrying amount of equity component	72,000,000
Equity component of the 2020 Notes, net of tax	$ 56,900,000
Effective interest rate	6.25%
Debt issuance directly related costs	$ 8,400,000
Debt issuance costs	6,400,000
Debt issuance costs equity component	1,900,000
Net of tax debt issuance cost	$ 1,600,000			6,069,000			6,069,000
Convertible Debt | Convertible Notes 2020
Debt Instrument [Line Items]
Aggregate principal amount				$ 94,909,000			$ 94,909,000			316,000,000	$ 316,000,000
Debt instrument interest rate, stated percentage	1.50%										1.50%
Initial conversion rate							14.1153
Debt conversion converted instrument amount							$ 1,000
Initial conversion price (in usd per share) | $ / shares				$ 70.85			$ 70.85
Conversion price percentage							130.00%
Stock price trigger (in usd per share) | $ / shares							$ 92.11
Convertible threshold trading days | day							20
Convertible threshold consecutive trading days | day							30
Convertible note hedge (in shares) | shares												4.4
Anti-dilution adjustments of common stock (in shares) | shares												4.4
Initial strike price (in usd per share) | $ / shares				$ 86.59			$ 86.59
Net of tax debt issuance cost				$ 174,000			$ 174,000			$ 1,621,000
Debt outstanding				$ 94,900,000			$ 94,900,000

Long-Term Debt - Carrying Value

Long-Term Debt - Carrying Value of 2024 Notes and 2020 Notes (Details) - Convertible Debt - USD ($)	Sep. 30, 2019	Jun. 03, 2019	Dec. 31, 2018	Mar. 11, 2015
Debt Instrument [Line Items]
Principal	$ 494,909,000		$ 316,000,000
Unamortized interest discount	(69,530,000)
Deferred financing costs	(6,243,000)
Net carrying amount of 2024 and 2020 Notes	419,136,000		298,951,000
Convertible Notes 2024
Debt Instrument [Line Items]
Principal	400,000,000	$ 400,000,000
Unamortized interest discount	(67,857,000)
Deferred financing costs	(6,069,000)	$ (1,600,000)
Net carrying amount of 2024 and 2020 Notes	326,074,000
Convertible Notes 2020
Debt Instrument [Line Items]
Principal	94,909,000		316,000,000	$ 316,000,000
Unamortized interest discount	(1,673,000)		(15,428,000)
Deferred financing costs	(174,000)		(1,621,000)
Net carrying amount of 2024 and 2020 Notes	$ 93,062,000		$ 298,951,000

Long-Term Debt - Accretion of D

Long-Term Debt - Accretion of Debt Discount and Amortization of Financing Costs (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Instrument [Line Items]
Contractual coupon interest	$ 2,356	$ 1,185	$ 5,068	$ 3,555
Accretion of debt discount	4,092	3,124	10,928	9,252
Amortization of deferred financing costs	380	347	1,091	1,042
Total	6,828	4,656	17,087	13,849
Convertible Debt | Convertible Notes 2024
Debt Instrument [Line Items]
Contractual coupon interest	2,000	0	2,600	0
Accretion of debt discount	3,088	0	4,189	0
Amortization of deferred financing costs	276	0	374	0
Total	5,364	0	7,163	0
Convertible Debt | Convertible Notes 2020
Debt Instrument [Line Items]
Contractual coupon interest	356	1,185	2,468	3,555
Accretion of debt discount	1,004	3,124	6,739	9,252
Amortization of deferred financing costs	104	347	717	1,042
Total	$ 1,464	$ 4,656	$ 9,924	$ 13,849

Variable Interest Entities (Det

Variable Interest Entities (Details) $ in Thousands	3 Months Ended					9 Months Ended
	Sep. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Sep. 30, 2018USD ($)	Jun. 30, 2018USD ($)	Mar. 31, 2018USD ($)	Sep. 30, 2019USD ($)variable_interest_entity	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2013patent
Variable Interest Entity [Line Items]
Variable interest entities assets	$ 41,300					$ 41,300		$ 29,900
Variable interest entities liabilities	3,800					3,800		6,100
Noncontrolling interests	(1,399)	$ (1,411)	$ (1,642)	$ (1,190)	$ (1,501)	(4,175)	$ (4,333)
Cash and Cash Equivalents
Variable Interest Entity [Line Items]
Variable interest entities assets	20,800					20,800		11,700
Accounts Receivable
Variable Interest Entity [Line Items]
Variable interest entities assets	1,500					1,500		1,300
Patents
Variable Interest Entity [Line Items]
Variable interest entities assets	17,700					17,700		14,400
Other Noncurrent Assets
Variable Interest Entity [Line Items]
Variable interest entities assets	1,300					1,300		$ 2,500
Chordant
Variable Interest Entity [Line Items]
Noncontrolling interests	500					1,200
Convida
Variable Interest Entity [Line Items]
Noncontrolling interests	$ 900					$ 3,000
Primary Beneficiary
Variable Interest Entity [Line Items]
Number of variable interest entities | variable_interest_entity						3
Number of patents (more than) | patent									500

Other Income (Expense), Net - O

Other Income (Expense), Net - Other Income (Expense), Net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Income and Expenses [Abstract]
Interest and investment income	$ 3,684	$ 3,740	$ 11,173	$ 11,013
Gain on asset acquisition and sale of business	8,515	0	22,690	0
Loss on extinguishment of long-term debt	0	0	(5,488)	0
Other	(4,396)	(8,654)	(4,603)	(8,907)
Other income (expense), net	$ 7,803	$ (4,914)	$ 23,772	$ 2,106

Other Income (Expense), Net - N

Other Income (Expense), Net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other Income and Expenses [Abstract]
Gain on asset acquisition		$ 14,200		$ 14,200
Gain on sale of business	$ 8,500			8,500
Loss on extinguishment of debt	$ 0		$ 0	$ 5,488	$ 0
Loss resulting from sale of entire ownership interest in strategic long-term investments			$ 8,400		$ 8,400

Revision to Noncontrolling In_3

Revision to Noncontrolling Interest (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended											6 Months Ended		9 Months Ended			12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Jun. 30, 2018	Jun. 30, 2017	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss attributable to noncontrolling interest	$ (1,399)		$ (1,411)		$ (1,642)	$ (1,190)	$ (1,501)							$ (4,175)	$ (4,333)
Net income applicable to InterDigital, Inc.	$ 2,234	$ 7,743	(2,803)		$ 21,752	10,966	30,230							$ 7,174	$ 62,948
Net income per common share, Basic (in usd per share)	$ 0.07				$ 0.63									$ 0.23	$ 1.81
Net income per common share, Diluted (in usd per share)	$ 0.07				$ 0.61									$ 0.22	$ 1.77
Total comprehensive income attributable to InterDigital, Inc.	$ 2,479				$ 22,219									$ 9,540	$ 62,044
Retained earnings	1,409,870			$ 1,435,970										1,409,870			$ 1,435,970
Total InterDigital, Inc. shareholders’ equity	782,106			936,729										782,106			936,729
Noncontrolling interest	21,193			1,284										21,193			1,284
Total equity	$ 803,299	$ 800,240	$ 825,513	938,013	1,015,049	1,036,224	1,035,732	$ 873,148				$ 1,036,224		$ 803,299	1,015,049		938,013	$ 873,148
As Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss attributable to noncontrolling interest				970	1,297	930	1,196	835	$ 811	$ 955	$ 978	2,126	$ 1,933		3,423	$ 2,744	4,393	3,579	$ 3,521
Net income applicable to InterDigital, Inc.				$ 1,830	$ 21,407	$ 10,706	$ 29,925	$ 52,502	$ 35,536	$ 52,499	$ 33,756	$ 40,631	$ 86,255		$ 62,038	$ 121,791	$ 63,868	$ 174,293	$ 309,001
Net income per common share, Basic (in usd per share)				$ 0.05	$ 0.62	$ 0.31	$ 0.86	$ 1.52	$ 1.02	$ 1.51	$ 0.98	$ 1.17	$ 2.50		$ 1.79	$ 3.52	$ 1.85	$ 5.04	$ 8.95
Net income per common share, Diluted (in usd per share)				$ 0.05	$ 0.60	$ 0.30	$ 0.84	$ 1.48	$ 1	$ 1.46	$ 0.93	$ 1.14	$ 2.39		$ 1.74	$ 3.40	$ 1.81	$ 4.87	$ 8.78
Total comprehensive income attributable to InterDigital, Inc.				$ 2,795	$ 21,874	$ 11,082	$ 28,178	$ 51,114	$ 35,442	$ 52,457	$ 33,711	$ 39,260	$ 86,168		$ 61,134	$ 121,610	$ 63,929	$ 172,724	$ 308,665
Retained earnings				1,426,266	1,436,171	1,426,888	1,428,437	1,249,091				1,426,888			1,436,171		1,426,266	1,249,091	1,120,766
Total InterDigital, Inc. shareholders’ equity				927,025	1,000,591	1,020,469	1,019,047	855,267				1,020,469			1,000,591		927,025	855,267	739,709
Noncontrolling interest				10,988	14,458	15,755	16,685	17,881				15,755			14,458		10,988	17,881	14,659
Total equity				938,013	1,015,049	1,036,224	1,035,732	873,148				1,036,224			1,015,049		938,013	873,148	754,368
As Revised
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net loss attributable to noncontrolling interest				1,223	1,642	1,190	1,501	1,370	1,226	1,427	1,483	2,691	2,910		4,333	4,136	5,556	5,506	5,261
Net income applicable to InterDigital, Inc.				$ 2,083	$ 21,752	$ 10,966	$ 30,230	$ 53,037	$ 35,951	$ 52,971	$ 34,261	$ 41,196	$ 87,232		$ 62,948	$ 123,183	$ 65,031	$ 176,220	$ 310,741
Net income per common share, Basic (in usd per share)				$ 0.06	$ 0.63	$ 0.32	$ 0.87	$ 1.53	$ 1.04	$ 1.53	$ 1	$ 1.19	$ 2.53		$ 1.81	$ 3.56	$ 1.89	$ 5.09	$ 9
Net income per common share, Diluted (in usd per share)				$ 0.06	$ 0.61	$ 0.31	$ 0.85	$ 1.49	$ 1.02	$ 1.48	$ 0.95	$ 1.16	$ 2.42		$ 1.77	$ 3.43	$ 1.84	$ 4.93	$ 8.83
Total comprehensive income attributable to InterDigital, Inc.				$ 3,048	$ 22,219	$ 11,342	$ 28,483	$ 51,649	$ 35,857	$ 52,929	$ 34,216	$ 39,825	$ 87,145		$ 62,044	$ 123,002	$ 65,092	$ 174,651	$ 310,405
Retained earnings				1,435,970	1,445,622	1,435,994	1,437,283	1,257,632				1,435,994			1,445,622		1,435,970	1,257,632	1,127,380
Total InterDigital, Inc. shareholders’ equity				936,729	1,010,042	1,029,575	1,027,893	863,808				1,029,575			1,010,042		936,729	863,808	746,323
Noncontrolling interest				1,284	5,007	6,649	7,839	9,340				6,649			5,007		1,284	9,340	8,045
Total equity				$ 938,013	$ 1,015,049	$ 1,036,224	$ 1,035,732	$ 873,148				$ 1,036,224			$ 1,015,049		$ 938,013	$ 873,148	$ 754,368

Uncategorized Items - idcc-q393

Label	Element	Value
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 161,252,000
AOCI Attributable to Parent [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	(449,000)
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 161,701,000