v2.4.1.9
Document and Entity Information Document (USD $)
12 Months Ended
Dec. 31, 2014
Feb. 17, 2015
Jun. 30, 2014
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, 2013    
Document Fiscal Year Focus 2013    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   37,136,023dei_EntityCommonStockSharesOutstanding  
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 1,907,242,992dei_EntityPublicFloat