v2.4.1.9
Litigation and Legal Proceedings (Details) (USD $)
9 Months Ended 12 Months Ended
Sep. 30, 2014
Dec. 31, 2014
China, Yuan Renminbi | Huawei [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value $ 20,000,000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_CNY
/ us-gaap_MajorCustomersAxis
= idcc_HuaweiDomain
 
China, Yuan Renminbi | ZTE [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value   20,000,000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_CNY
/ us-gaap_MajorCustomersAxis
= idcc_ZTEDomain
China, Yuan Renminbi | Arima China [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value   120,000,000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_CNY
/ us-gaap_MajorCustomersAxis
= idcc_ArimaChinaDomain
United States of America, Dollars | Huawei [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value 3,200,000.000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_USD
/ us-gaap_MajorCustomersAxis
= idcc_HuaweiDomain
 
United States of America, Dollars | ZTE [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value   3,300,000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_USD
/ us-gaap_MajorCustomersAxis
= idcc_ZTEDomain
United States of America, Dollars | Arima [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value   3,150,000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_USD
/ us-gaap_MajorCustomersAxis
= idcc_ArimaDomain
United States of America, Dollars | Arima China [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value   19,500,000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_USD
/ us-gaap_MajorCustomersAxis
= idcc_ArimaChinaDomain
Taiwan, New Dollars | Arima [Domain]    
Loss Contingencies [Line Items]    
Loss Contingency, Damages Sought, Value   $ 100,000,000us-gaap_LossContingencyDamagesSoughtValue
/ us-gaap_CurrencyAxis
= currency_TWD
/ us-gaap_MajorCustomersAxis
= idcc_ArimaDomain