v2.4.1.9

Summary of Significant Accounting Policies Compensation Programs (Details) | 12 Months Ended
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Dec. 31, 2014
Minimum [Member] |
Forfeiture Rate [Line Items] |
Forfeiture Rate | 0.00%idcc_Sharebasedcompensationarrangementbysharebasedpaymentawardfairvalueassumptionsforfeiturerateptions / us-gaap_RangeAxis = us-gaap_MinimumMember
Maximum [Member] |
Forfeiture Rate [Line Items] |
Forfeiture Rate | 25.00%idcc_Sharebasedcompensationarrangementbysharebasedpaymentawardfairvalueassumptionsforfeiturerateptions / us-gaap_RangeAxis = us-gaap_MaximumMember

X
- Details
Name: | idcc_ForfeitureRateLineItems
Namespace Prefix: | idcc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the rate at which stock options are expected to be forfeited by employees subsequent to their vest dates. + References No definition available. + Details
Name: | idcc_Sharebasedcompensationarrangementbysharebasedpaymentawardfairvalueassumptionsforfeiturerateptions
Namespace Prefix: | idcc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |