Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 16, 2016	Jun. 30, 2015
Entity Information [Line Items]
Entity Registrant Name	INTERDIGITAL, INC.
Entity Central Index Key	0001405495
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		34,996,183
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 2,026,553,956