v2.4.1.9

Summary of Significant Accounting Policies Deferred Charges (Details) (USD $) | 12 Months Ended
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Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Deferred Charges [Line Items] |  |  |  |
Payments for Commissions | $ 300,000 us-gaap_PaymentsForCommissions | $ 100,000 us-gaap_PaymentsForCommissions | $ 4,700,000 us-gaap_PaymentsForCommissions |
Contract Revenue Cost | 100,000 us-gaap_ContractRevenueCost | 100,000 us-gaap_ContractRevenueCost | 100,000 us-gaap_ContractRevenueCost |
Sales Commissions and Fees | 400,000 us-gaap_SalesCommissionsAndFees | 300,000 us-gaap_SalesCommissionsAndFees | 5,000,000 us-gaap_SalesCommissionsAndFees |
Amortization of Financing Costs | 1,303,000 us-gaap_AmortizationOfFinancingCosts | 1,303,000 us-gaap_AmortizationOfFinancingCosts | 1,303,000 us-gaap_AmortizationOfFinancingCosts |
Deferred Sales Commission Current [Member] |  |  |  |
Deferred Charges [Line Items] |  |  |  |
Other Deferred Costs, Net | 342,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredSalesCommissionCurrentMember | 290,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredSalesCommissionCurrentMember |  |
Deferred Contract Revenue Costs Current [Member] |  |  |  |
Deferred Charges [Line Items] |  |  |  |
Other Deferred Costs, Net | 79,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredContractRevenueCostsCurrentMember | 79,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredContractRevenueCostsCurrentMember |  |
Deferred Finance Costs Current [Member] |  |  |  |
Deferred Charges [Line Items] |  |  |  |
Deferred Finance Costs, Net | 1,303,000 us-gaap_DeferredFinanceCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredFinanceCostsCurrentMember | 1,303,000 us-gaap_DeferredFinanceCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredFinanceCostsCurrentMember |  |
Deferred Sales Commission Non-Current [Member] |  |  |  |
Deferred Charges [Line Items] |  |  |  |
Other Deferred Costs, Net | 495,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredSalesCommissionNonCurrentMember | 750,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredSalesCommissionNonCurrentMember |  |
Deferred Contract Revenue Costs Non-Current [Member] |  |  |  |
Deferred Charges [Line Items] |  |  |  |
Other Deferred Costs, Net | 79,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredContractRevenueCostsNonCurrentMember | 158,000 us-gaap_OtherDeferredCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredContractRevenueCostsNonCurrentMember |  |
Deferred Finance Costs Non-Current [Member] |  |  |  |
Deferred Charges [Line Items] |  |  |  |
Deferred Finance Costs, Net | 326,000 us-gaap_DeferredFinanceCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredFinanceCostsNonCurrentMember | 1,629,000 us-gaap_DeferredFinanceCostsNet / us-gaap_StatementScenarioAxis = idcc_DeferredFinanceCostsNonCurrentMember |  |
Convertible Debt [Member] | Equity [Member] |  |  |  |
Deferred Charges [Line Items] |  |  |  |
Payments of Debt Issuance Costs |  |  |  | $ 1,500,000 us-gaap_PaymentsOfDebtIssuanceCosts / us-gaap_BalanceSheetLocationAxis = us-gaap_EquityMember / us-gaap_LongtermDebtTypeAxis = us-gaap_ConvertibleDebtMember

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- Definition Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.8) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 8 -Article 9 + Details
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- Definition For an unclassified balance sheet, the carrying amount (net of accumulated amortization) as of the balance sheet date of capitalized costs associated with the issuance of debt instruments (for example, legal, accounting, underwriting, printing, and registration costs) that will be charged against earnings over the life of the debt instruments to which such costs pertain. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 + Details
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- Definition Net amount of other deferred costs capitalized at the end of the reporting period. Does not include deferred finance costs or deferred acquisition costs of insurance companies. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The amount of cash paid for commissions during the current period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3536-108585 + Details
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- Definition The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585 + Details
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- Definition Primarily represents commissions incurred in the period based upon the sale by commissioned employees or third parties of the entity's goods or services, and fees for sales assistance or product enhancements performed by third parties (such as a distributor or value added reseller). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.4) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
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