v2.4.1.9

Selected Quarterly Results (Details) (USD $) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
Effect of Fourth Quarter Events [Line Items] |  |  |  |  |  |  |  |  |  |  |
Restructuring Charges |  |  |  |  |  |  |  | $ 1,500,000 us-gaap_RestructuringCharges | $ 0 us-gaap_RestructuringCharges | $ 1,544,000 us-gaap_RestructuringCharges | $ 12,536,000 us-gaap_RestructuringCharges
Other than Temporary Impairment Losses, Investments |  |  |  |  | 15,000,000 us-gaap_ImpairmentOfInvestments |  |  | 6,700,000 us-gaap_ImpairmentOfInvestments | 559,000 us-gaap_ImpairmentOfInvestments | 21,720,000 us-gaap_ImpairmentOfInvestments | 0 us-gaap_ImpairmentOfInvestments
Sales Revenue, Goods, Net |  |  |  |  |  |  |  |  | 1,999,000 us-gaap_SalesRevenueGoodsNet | 0 us-gaap_SalesRevenueGoodsNet | 384,000,000 us-gaap_SalesRevenueGoodsNet
Revenues | 86,121,000 us-gaap_Revenues | 77,622,000 us-gaap_Revenues | 194,234,000 us-gaap_Revenues | 57,844,000 us-gaap_Revenues | 99,683,000 us-gaap_Revenues | 110,623,000 us-gaap_Revenues | 67,692,000 us-gaap_Revenues | 47,363,000 us-gaap_Revenues | 415,821,000 us-gaap_Revenues | 325,361,000 us-gaap_Revenues | 663,063,000 us-gaap_Revenues
NET INCOME | 13,790,000 us-gaap_NetIncomeLoss | 13,512,000 us-gaap_NetIncomeLoss | 78,901,000 us-gaap_NetIncomeLoss | (1,861,000)us-gaap_NetIncomeLoss | 14,536,000 us-gaap_NetIncomeLoss | 26,660,000 us-gaap_NetIncomeLoss | 9,238,000 us-gaap_NetIncomeLoss | (12,269,000)us-gaap_NetIncomeLoss | 101,420,000 us-gaap_NetIncomeLoss | 35,683,000 us-gaap_NetIncomeLoss | 271,804,000 us-gaap_NetIncomeLoss
NET INCOME PER COMMON SHARE — BASIC | $ 0.37 us-gaap_EarningsPerShareBasic | $ 0.34 us-gaap_EarningsPerShareBasic | $ 1.95 us-gaap_EarningsPerShareBasic | $ (0.05)us-gaap_EarningsPerShareBasic | $ 0.35 us-gaap_EarningsPerShareBasic | $ 0.65 us-gaap_EarningsPerShareBasic | $ 0.22 us-gaap_EarningsPerShareBasic | $ (0.30)us-gaap_EarningsPerShareBasic | $ 2.65 us-gaap_EarningsPerShareBasic | $ 0.93 us-gaap_EarningsPerShareBasic | $ 6.31 us-gaap_EarningsPerShareBasic
NET INCOME PER COMMON SHARE — DILUTED | $ 0.36 us-gaap_EarningsPerShareDiluted | $ 0.34 us-gaap_EarningsPerShareDiluted | $ 1.93 us-gaap_EarningsPerShareDiluted | $ (0.05)us-gaap_EarningsPerShareDiluted | $ 0.35 us-gaap_EarningsPerShareDiluted | $ 0.64 us-gaap_EarningsPerShareDiluted | $ 0.22 us-gaap_EarningsPerShareDiluted | $ (0.30)us-gaap_EarningsPerShareDiluted | $ 2.62 us-gaap_EarningsPerShareDiluted | $ 0.92 us-gaap_EarningsPerShareDiluted | $ 6.26 us-gaap_EarningsPerShareDiluted
Past Infringement [Member] |  |  |  |  |  |  |  |  |  |  |
Effect of Fourth Quarter Events [Line Items] |  |  |  |  |  |  |  |  |  |  |
Royalty Revenue |  |  | 119,900,000 us-gaap_RoyaltyRevenue / idcc_RoyaltyRevenueAxis = idcc_PastInfringementMember |  |  |  |  |  |  |  |
Litigation Settlement, Amount |  |  |  |  | 36,400,000 us-gaap_LitigationSettlementAmount / idcc_RoyaltyRevenueAxis = idcc_PastInfringementMember |  |  |  |  |  |
Pegatron [Member] | Past Infringement [Member] |  |  |  |  |  |  |  |  |  |  |
Effect of Fourth Quarter Events [Line Items] |  |  |  |  |  |  |  |  |  |  |
Litigation Settlement, Amount |  |  |  |  |  |  | 23,500,000 us-gaap_LitigationSettlementAmount / us-gaap_MajorCustomersAxis = idcc_PegatronMember / idcc_RoyaltyRevenueAxis = idcc_PastInfringementMember |  |  | 71,400,000 us-gaap_LitigationSettlementAmount / us-gaap_MajorCustomersAxis = idcc_PegatronMember / idcc_RoyaltyRevenueAxis = idcc_PastInfringementMember |
Technology Solutions Customer [Member] | Past Infringement [Member] |  |  |  |  |  |  |  |  |  |  |
Effect of Fourth Quarter Events [Line Items] |  |  |  |  |  |  |  |  |  |  |
Litigation Settlement, Amount |  |  |  |  |  | $ 51,600,000 us-gaap_LitigationSettlementAmount / us-gaap_MajorCustomersAxis = idcc_TechnologySolutionsCustomerMember / idcc_RoyaltyRevenueAxis = idcc_PastInfringementMember |  |  |  | $ 53,300,000 us-gaap_LitigationSettlementAmount / us-gaap_MajorCustomersAxis = idcc_TechnologySolutionsCustomerMember / idcc_RoyaltyRevenueAxis = idcc_PastInfringementMember |

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