v2.4.0.6
Document and Entity Information (USD $)
12 Months Ended
Dec. 31, 2011
Feb. 23, 2012
Jun. 30, 2011
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, 2011    
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   45,100,011  
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 1,839,185,424