Significant Accounting Policies (Notes)	6 Months Ended
Jun. 30, 2013
Basis of Presentation [Abstract]
Basis of Presentation and Significant Accounting Policies [Text Block]	BASIS OF PRESENTATION: In the opinion of management, the accompanying unaudited, condensed consolidated financial statements contain all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the financial position of InterDigital, Inc. (individually and/or collectively with its subsidiaries referred to as “InterDigital,” the “Company,” “we,” “us” or “our,” unless otherwise indicated) as of June 30, 2013, and the results of our operations for the three and six months ended June 30, 2013 and 2012 and our cash flows for the six months June 30, 2013 and 2012. The accompanying unaudited, condensed consolidated financial statements have been prepared in accordance with the instructions for Form 10-Q and, accordingly, do not include all of the detailed schedules, information and notes necessary to state fairly the financial condition, results of operations and cash flows in conformity with generally accepted accounting principles (“GAAP”). The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP for year-end financial statements. Therefore, these financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012 (our “2012 Form 10-K”) as filed with the Securities and Exchange Commission (“SEC”) on February 26, 2013. The results of operations for interim periods are not necessarily indicative of the results to be expected for the entire year. We have one reportable segment. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates. Change in Accounting Policies There have been no material changes or updates in our existing accounting policies from the disclosures included in our 2012 Form 10-K. New Accounting Guidance Accounting Standards Updates: Presentation of Comprehensive Income In June 2011, the FASB issued authoritative guidance requiring most entities to present items of net income and other comprehensive income either in one continuous statement, referred to as the statement of comprehensive income, or in two separate, but consecutive, statements of net income and other comprehensive income. The option to present items of other comprehensive income in the statement of changes in equity was eliminated. This guidance is effective for interim and annual periods beginning after December 15, 2011. We adopted this guidance effective January 1, 2012. We have chosen to present items of net income and other comprehensive income in two separate but consecutive statements. On December 23, 2011, the FASB issued an amendment to the new standard on comprehensive income to defer the requirement to measure and present reclassification adjustments from accumulated other comprehensive income to net income by income statement line item in net income and also in other comprehensive income. The deferred requirement would have called for the measurement and presentation in net income of items previously recognized in other comprehensive income. In February 2013, the FASB issued final guidance on the presentation of reclassifications out of other comprehensive income. The amendments require an entity to provide information about the amounts reclassified out of other comprehensive income by component. In addition, an entity is required to present, either on the face of the income statement or in a footnote, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, only if the amount reclassified is required by GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under GAAP to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures required under GAAP that provide detail about those amounts. This amendment is effective for interim and fiscal years beginning after December 15, 2012. The amended standard will not impact the Company's financial position or results of operations.

BASIS OF PRESENTATION:

In the opinion of management, the accompanying unaudited, condensed consolidated financial statements contain all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the financial position of InterDigital, Inc. (individually and/or collectively with its subsidiaries referred to as “InterDigital,” the “Company,” “we,” “us” or “our,” unless otherwise indicated) as of June 30, 2013, and the results of our operations for the three and six months ended June 30, 2013 and 2012 and our cash flows for the six months June 30, 2013 and 2012. The accompanying unaudited, condensed consolidated financial statements have been prepared in accordance with the instructions for Form 10-Q and, accordingly, do not include all of the detailed schedules, information and notes necessary to state fairly the financial condition, results of operations and cash flows in conformity with generally accepted accounting principles (“GAAP”). The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP for year-end financial statements. Therefore, these financial statements should be read in conjunction with the financial statements and notes thereto contained in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2012 (our “2012 Form 10-K”) as filed with the Securities and Exchange Commission (“SEC”) on February 26, 2013. The results of operations for interim periods are not necessarily indicative of the results to be expected for the entire year. We have one reportable segment.

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities as of the date of the financial statements, as well as the reported amounts of revenues and expenses during the reporting period. Actual results could differ from these estimates.

Change in Accounting Policies

There have been no material changes or updates in our existing accounting policies from the disclosures included in our 2012 Form 10-K.

New Accounting Guidance

Accounting Standards Updates: Presentation of Comprehensive Income

In June 2011, the FASB issued authoritative guidance requiring most entities to present items of net income and other comprehensive income either in one continuous statement, referred to as the statement of comprehensive income, or in two separate, but consecutive, statements of net income and other comprehensive income. The option to present items of other comprehensive income in the statement of changes in equity was eliminated. This guidance is effective for interim and annual periods beginning after December 15, 2011. We adopted this guidance effective January 1, 2012. We have chosen to present items of net income and other comprehensive income in two separate but consecutive statements.

On December 23, 2011, the FASB issued an amendment to the new standard on comprehensive income to defer the requirement to measure and present reclassification adjustments from accumulated other comprehensive income to net income by income statement line item in net income and also in other comprehensive income. The deferred requirement would have called for the measurement and presentation in net income of items previously recognized in other comprehensive income.

In February 2013, the FASB issued final guidance on the presentation of reclassifications out of other comprehensive income. The amendments require an entity to provide information about the amounts reclassified out of other comprehensive income by component. In addition, an entity is required to present, either on the face of the income statement or in a footnote, significant amounts reclassified out of accumulated other comprehensive income by the respective line items of net income, only if the amount reclassified is required by GAAP to be reclassified to net income in its entirety in the same reporting period. For other amounts that are not required under GAAP to be reclassified in their entirety to net income, an entity is required to cross-reference to other disclosures required under GAAP that provide detail about those amounts. This amendment is effective for interim and fiscal years beginning after December 15, 2012. The amended standard will not impact the Company's financial position or results of operations.