v2.4.1.9
Income Taxes (Details) (USD $)
12 Months Ended 108 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2014
Income Tax Contingency [Line Items]        
Additions $ 95,000us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions $ 0us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions $ 0us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions  
Excess Tax Benefit from Share-based Compensation, Operating Activities 1,176,000us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities 0us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities 0us-gaap_ExcessTaxBenefitFromShareBasedCompensationOperatingActivities  
Excess Tax Benefit from Share-based Compensation, Financing Activities 0us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities 815,000us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities 898,000us-gaap_ExcessTaxBenefitFromShareBasedCompensationFinancingActivities  
Adjustments to Additional Paid in Capital, Income Tax Benefit from Share-based Compensation (2,738,000)us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation (2,458,000)us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation (4,387,000)us-gaap_AdjustmentsToAdditionalPaidInCapitalTaxEffectFromShareBasedCompensation  
Federal 49,049,000us-gaap_CurrentFederalTaxExpenseBenefit (6,093,000)us-gaap_CurrentFederalTaxExpenseBenefit 93,441,000us-gaap_CurrentFederalTaxExpenseBenefit  
State 2,499,000us-gaap_CurrentStateAndLocalTaxExpenseBenefit 225,000us-gaap_CurrentStateAndLocalTaxExpenseBenefit 44,000us-gaap_CurrentStateAndLocalTaxExpenseBenefit  
Foreign source withholding tax 70,703,000us-gaap_CurrentForeignTaxExpenseBenefit 23,269,000us-gaap_CurrentForeignTaxExpenseBenefit 4,173,000us-gaap_CurrentForeignTaxExpenseBenefit  
Current Income Tax Expense (Benefit) 122,251,000us-gaap_CurrentIncomeTaxExpenseBenefit 17,401,000us-gaap_CurrentIncomeTaxExpenseBenefit 97,658,000us-gaap_CurrentIncomeTaxExpenseBenefit  
Federal (121,937,000)us-gaap_DeferredFederalIncomeTaxExpenseBenefit (18,727,000)us-gaap_DeferredFederalIncomeTaxExpenseBenefit 22,209,000us-gaap_DeferredFederalIncomeTaxExpenseBenefit  
State (437,000)us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit 2,614,000us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit (4,494,000)us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit  
Foreign source withholding tax 52,231,000us-gaap_DeferredForeignIncomeTaxExpenseBenefit 24,548,000us-gaap_DeferredForeignIncomeTaxExpenseBenefit 21,457,000us-gaap_DeferredForeignIncomeTaxExpenseBenefit  
Deferred income taxes (70,143,000)us-gaap_DeferredIncomeTaxExpenseBenefit 8,435,000us-gaap_DeferredIncomeTaxExpenseBenefit 39,172,000us-gaap_DeferredIncomeTaxExpenseBenefit  
Income Tax Expense (Benefit) 34.00%us-gaap_EffectiveIncomeTaxRateContinuingOperations 41.90%us-gaap_EffectiveIncomeTaxRateContinuingOperations 33.60%us-gaap_EffectiveIncomeTaxRateContinuingOperations  
Net operating losses 168,960,000us-gaap_OperatingIncomeLoss 84,756,000us-gaap_OperatingIncomeLoss 419,030,000us-gaap_OperatingIncomeLoss  
Deferred Tax Assets, Operating Loss Carryforwards 71,841,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwards 70,602,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwards   71,841,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwards
Deferred revenue, net 73,273,000us-gaap_DeferredTaxAssetsDeferredIncome 12,809,000us-gaap_DeferredTaxAssetsDeferredIncome   73,273,000us-gaap_DeferredTaxAssetsDeferredIncome
Stock compensation 12,318,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost 8,694,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost   12,318,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
Patent amortization 18,337,000idcc_DeferredTaxAssetAmortizationOfIntangibles 16,424,000idcc_DeferredTaxAssetAmortizationOfIntangibles   18,337,000idcc_DeferredTaxAssetAmortizationOfIntangibles
Deferred Tax Asset Depreciation 1,139,000idcc_DeferredTaxAssetDepreciation 1,464,000idcc_DeferredTaxAssetDepreciation   1,139,000idcc_DeferredTaxAssetDepreciation
Deferred Tax Asset OTTI 10,164,000idcc_DeferredTaxAssetOTTI 10,116,000idcc_DeferredTaxAssetOTTI   10,164,000idcc_DeferredTaxAssetOTTI
Other accrued liabilities 1,069,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities 1,088,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities   1,069,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
Other employee benefits 9,452,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits 5,014,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits   9,452,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
Deferred Tax Assets Net Before Deducting Valuation Allowance 197,593,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance 126,211,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance   197,593,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
Less: valuation allowance 71,731,000us-gaap_DeferredTaxAssetsValuationAllowance 70,492,000us-gaap_DeferredTaxAssetsValuationAllowance   71,731,000us-gaap_DeferredTaxAssetsValuationAllowance
Net deferred tax asset 125,862,000us-gaap_DeferredTaxAssetsNet 55,719,000us-gaap_DeferredTaxAssetsNet   125,862,000us-gaap_DeferredTaxAssetsNet
Tax at U.S. statutory rate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate 35.00%us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate  
State 0.10%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes 4.10%us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes (1.10%)us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes  
Change in federal and state valuation allowance 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance 0.40%us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance (0.50%)us-gaap_EffectiveIncomeTaxRateReconciliationChangeInDeferredTaxAssetsValuationAllowance  
Adjustment to tax credits (4.70%)us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationTaxCredits  
Adjustments to uncertain tax positions 0.90%us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationTaxContingencies  
Permanent differences 1.50%us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent 3.50%us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent 0.10%us-gaap_EffectiveIncomeTaxRateReconciliationOtherReconcilingItemsPercent  
Settlement with taxing authorities 1.10%us-gaap_EffectiveIncomeTaxRateReconciliationTaxSettlements 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationTaxSettlements 0.00%us-gaap_EffectiveIncomeTaxRateReconciliationTaxSettlements  
Other 0.10%us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments (1.10%)us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments 0.10%us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments  
Unrecognized Tax Benefits   0us-gaap_UnrecognizedTaxBenefits 0us-gaap_UnrecognizedTaxBenefits  
Deferred Tax Assets, Tax Credit Carryforwards, Research 700,000us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch     700,000us-gaap_DeferredTaxAssetsTaxCreditCarryforwardsResearch
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities  
Unrecognized Tax Benefits, Increases Resulting from Prior Period Tax Positions 1,266,000us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions  
Foreign Income Tax Expense (Benefit), Continuing Operations 5,700,000us-gaap_ForeignIncomeTaxExpenseBenefitContinuingOperations      
Liability for Uncertain Tax Positions, Noncurrent Balance as of December 31, 2010 0us-gaap_LiabilityForUncertainTaxPositionsNoncurrent 0us-gaap_LiabilityForUncertainTaxPositionsNoncurrent 0us-gaap_LiabilityForUncertainTaxPositionsNoncurrent  
Unrecognized Tax Benefits, Period Increase (Decrease) 700,000us-gaap_UnrecognizedTaxBenefitsPeriodIncreaseDecrease      
Reductions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromCurrentPeriodTaxPositions  
Unrecognized Tax Benefits, Decreases Resulting from Prior Period Tax Positions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions  
Settlements 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities 0us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities  
Lapses in statues of limitations 0us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations 0us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations 0us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations  
Liability for Uncertain Tax Positions, Noncurrent Balance as of December 31, 2011 1,361,000us-gaap_LiabilityForUncertainTaxPositionsNoncurrent 0us-gaap_LiabilityForUncertainTaxPositionsNoncurrent 0us-gaap_LiabilityForUncertainTaxPositionsNoncurrent 1,361,000us-gaap_LiabilityForUncertainTaxPositionsNoncurrent
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued 100,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued 0us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued 0us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued 100,000us-gaap_UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued
Income taxes paid, including foreign witholding taxes 114,876,000us-gaap_IncomeTaxesPaid 24,961,000us-gaap_IncomeTaxesPaid 116,871,000us-gaap_IncomeTaxesPaid  
Taxes Payable 0us-gaap_TaxesPayableCurrentAndNoncurrent 7,056,000us-gaap_TaxesPayableCurrentAndNoncurrent   0us-gaap_TaxesPayableCurrentAndNoncurrent
Federal        
Income Tax Contingency [Line Items]        
Deferred Tax Assets, Operating Loss Carryforwards, Domestic 0us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
0us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  0us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsDomestic
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Deferred revenue, net 50,575,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
8,564,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  50,575,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Stock compensation 10,567,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
7,606,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  10,567,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Patent amortization 18,337,000idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
16,424,000idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  18,337,000idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Deferred Tax Asset Depreciation 1,110,000idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
1,295,000idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  1,110,000idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Deferred Tax Asset OTTI 10,010,000idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
9,815,000idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  10,010,000idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Other accrued liabilities 1,097,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
1,044,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  1,097,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Other employee benefits 8,784,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
4,497,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  8,784,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Deferred Tax Assets Net Before Deducting Valuation Allowance 100,480,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
49,245,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  100,480,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Less: valuation allowance 0us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
0us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  0us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
Net deferred tax asset 100,480,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
49,245,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
  100,480,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_DomesticCountryMember
State        
Income Tax Contingency [Line Items]        
Deferred Tax Assets, Operating Loss Carryforwards, State and Local 71,837,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
70,602,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  71,837,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Deferred revenue, net 41,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
56,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  41,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Stock compensation 1,751,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
1,088,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  1,751,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Patent amortization 0idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
0idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  0idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Deferred Tax Asset Depreciation 29,000idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
169,000idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  29,000idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Deferred Tax Asset OTTI 154,000idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
301,000idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  154,000idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Other accrued liabilities (28,000)us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
44,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  (28,000)us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Other employee benefits 668,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
517,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  668,000us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Deferred Tax Assets Net Before Deducting Valuation Allowance 74,452,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
72,777,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  74,452,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Less: valuation allowance 71,731,000us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
70,492,000us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  71,731,000us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Net deferred tax asset 2,721,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
2,285,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  2,721,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
Unrecognized Tax Benefits 12,200,000us-gaap_UnrecognizedTaxBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
12,200,000us-gaap_UnrecognizedTaxBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
  12,200,000us-gaap_UnrecognizedTaxBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_StateAndLocalJurisdictionMember
New York State Division of Taxation and Finance [Member]        
Income Tax Contingency [Line Items]        
Tax Adjustments, Settlements, and Unusual Provisions 2,500,000us-gaap_TaxAdjustmentsSettlementsAndUnusualProvisions
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_NewYorkStateDivisionOfTaxationAndFinanceMember
     
Foreign        
Income Tax Contingency [Line Items]        
Deferred Tax Assets, Operating Loss Carryforwards, Foreign 4,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  4,000us-gaap_DeferredTaxAssetsOperatingLossCarryforwardsForeign
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Deferred revenue, net 22,657,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
4,189,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  22,657,000us-gaap_DeferredTaxAssetsDeferredIncome
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Stock compensation 0us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  0us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Patent amortization 0idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  0idcc_DeferredTaxAssetAmortizationOfIntangibles
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Deferred Tax Asset Depreciation 0idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  0idcc_DeferredTaxAssetDepreciation
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Deferred Tax Asset OTTI 0idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  0idcc_DeferredTaxAssetOTTI
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Other accrued liabilities 0us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  0us-gaap_DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Other employee benefits 0us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  0us-gaap_DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsEmployeeBenefits
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Deferred Tax Assets Net Before Deducting Valuation Allowance 22,661,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
4,189,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  22,661,000idcc_DeferredTaxAssetsNetBeforeDeductingValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Less: valuation allowance 0us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
0us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  0us-gaap_DeferredTaxAssetsValuationAllowance
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Net deferred tax asset 22,661,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
4,189,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
  22,661,000us-gaap_DeferredTaxAssetsNet
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
Income taxes paid, including foreign witholding taxes $ 70,700,000us-gaap_IncomeTaxesPaid
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
$ 23,300,000us-gaap_IncomeTaxesPaid
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
$ 3,600,000us-gaap_IncomeTaxesPaid
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember
$ 239,800,000us-gaap_IncomeTaxesPaid
/ us-gaap_IncomeTaxAuthorityAxis
= us-gaap_ForeignCountryMember