Sales at market value EBP, Investment Sold, Plan Interest in Master Trust, Selling Price Entity tax identification number Entity Tax Identification Number Rollover EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Rollover Maximum Maximum [Member] Forfeited non-vested account balances applied to account expenses EBP, Forfeited Nonvested Account, Decrease from Administrative Expense Legal Entity [Axis] Legal Entity [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] EBP, Description of Plan [Table] EBP, Description of Plan [Table] Registered Investment Companies Total Mutual Fund [Member] Total Fully Corrected Under VFCP and PTE 2002-51 EBP, Schedule of Delinquent Participant Contribution, Corrected Multi-Asset/Other EBP, Other Investment [Member] Small/Mid-Cap Stocks Small/Mid-Cap Stocks [Member] Small/Mid-Cap Stocks EBP, Related Party and Party-in-Interest Transactions [Table] EBP, Related Party and Party-in-Interest Transactions [Table] Self-directed brokerage account EBP, Self-Directed Brokerage Account [Member] Total deductions EBP, Change in Net Asset Available for Benefit, Decrease Maximum borrowing amount, notes receivable from participant EBP, Note Receivable from Participant, Account, Maximum Borrowing, Amount FAIR VALUE MEASUREMENTS EBP, Investment, Fair Value and NAV [Text Block] Minimum borrowing amount, notes receivable from participant EBP, Note Receivable from Participant, Account, Minimum Borrowing, Amount EBP, Nonparticipant-Directed Investment [Abstract] Participant loans defaulted, reclassified to distributions EBP, Asset Held For Investment, Participant Loan, Default Reclassified To Distribution EBP, Asset Held For Investment, Participant Loan, Default Reclassified To Distribution Investments at fair value EBP, Investment, Excluding Plan Interest in Master Trust, Fair Value Level 1 Fair Value, Inputs, Level 1 [Member] EBP, Investment, Fair Value and NAV [Abstract] Participant loan, basis spread on variable rate EBP, Participant Loan, Basis Spread On Variable Rate EBP, Participant Loan, Basis Spread On Variable Rate International Stocks International Stocks [Member] International Stocks Participant contribution, pretax, compensation to eligible compensation, percentage EBP, Participant Contribution, Pretax, Compensation To Eligible Compensation, Percentage EBP, Participant Contribution, Pretax, Compensation To Eligible Compensation, Percentage Net increase in fair value of investments EBP, Change In Net Asset Available For Benefit, Increase From Gain On Investment EBP, Change In Net Asset Available For Benefit, Increase From Gain On Investment Statistical Measurement [Axis] Statistical Measurement [Axis] Additions EBP, Change in Net Asset Available for Benefit, Increase [Abstract] EBP, Statement of Change in Net Asset Available for Benefit [Table] EBP, Statement of Change in Net Asset Available for Benefit [Table] Payment of Benefits EBP, Payment to Participant [Policy Text Block] Amendment Flag Amendment Flag Basis of Accounting EBP, Basis of Accounting [Policy Text Block] EBP, Schedule of Asset Held for Investment [Table] EBP, Schedule of Asset Held for Investment [Table] EBP, Nonparticipant-Directed Investment [Line Items] EBP, Nonparticipant-Directed Investment [Line Items] EBP, Description of Plan and Accounting Change [Abstract] Schedule of Plan Assets at Fair Value EBP, Investment, Fair Value and NAV [Table Text Block] EBP, Contingency [Table] EBP, Contingency [Table] Less than 1 year EBP, Less Than One Year [Member] EBP, Less Than One Year Aggressive Bonds Aggressive Bonds [Member] Aggressive Bonds EBP, Contingency [Abstract] Other deductions EBP, Change In Net Asset Available For Benefit, Decrease From Other Deductions EBP, Change In Net Asset Available For Benefit, Decrease From Other Deductions Investments [Domain] Investments [Domain] Number of loans per participant EBP, Number Of Loans Per Participant EBP, Number Of Loans Per Participant EBP, Schedule of Delinquent Participant Contribution [Abstract] Use of Estimates EBP, Use of Estimate [Policy Text Block] Employer contribution vesting percentage EBP, Employer Contribution Vesting Percentage EBP, Employer Contribution Vesting Percentage Stable Pooled Fund EBP, Pooled Separate Account [Member] SCHEDULE H, LINE 4(i) - SCHEDULE OF ASSETS (HELD AT END OF YEAR) EBP, Schedule of Asset Held for Investment [Text Block] Cover [Abstract] INVESTMENTS EBP, Risk and Uncertainty [Text Block] Employer EBP, Change in Net Asset Available for Benefit, Increase from Employer Contribution, Cash EBP, Schedule of Delinquent Participant Contribution [Line Items] EBP, Schedule of Delinquent Participant Contribution [Line Items] Minimum Minimum [Member] Investment Type [Axis] Investment Type [Axis] Interest from notes receivable from participants EBP, Change in Net Asset Available for Benefit, Increase from Interest Income on Note Receivable from Participant Total contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution Participants EBP, Change in Net Asset Available for Benefit, Increase from Participant Contribution, Excluding Rollover EBP, Description of Plan [Line Items] EBP, Description of Plan [Line Items] Intermediate/Long-term Bonds Intermediate/Long Term Bonds [Member] Intermediate/Long Term Bonds EBP, Investment, Fair Value and NAV [Line Items] EBP, Investment, Fair Value and NAV [Line Items] DESCRIPTION OF THE PLAN EBP, Description of Plan [Text Block] Contributions Pending Correction in VFCP EBP, Schedule of Delinquent Participant Contribution, Pending Correction in VFCP EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Change in Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Statement of Net Asset Available for Benefit [Table] EBP, Schedule of Asset Held for Investment [Line Items] EBP, Schedule of Asset Held for Investment [Line Items] Contributions EBP, Contribution [Policy Text Block] Employer Stock Fund EBP, Employer, Common Stock [Member] EBP, Schedule of Asset Held for Investment [Abstract] At least 1, less than 2 years EBP, At Least One Year, Less Than Two [Member] EBP, At Least One Year, Less Than Two EBP, Nonparticipant-Directed Investment [Table] EBP, Nonparticipant-Directed Investment [Table] EBP, Accounting Policy [Table] EBP, Accounting Policy [Table] Total additions EBP, Change in Net Asset Available for Benefit, Increase Investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment [Abstract] Large-Cap Stocks Large Cap Stocks [Member] Large Cap Stocks Investment, Identifier [Axis] Investment, Identifier [Axis] Total assets held at end of year EBP, Asset Held for Investment Maximum term of notes receivable from participant EBP, Note Receivable From Participant, Maximum Borrowing Term EBP, Note Receivable From Participant, Maximum Borrowing Term Document Information [Line Items] Document Information [Line Items] EBP, Risk and Uncertainty [Line Items] EBP, Risk and Uncertainty [Line Items] At least 2, less than 3 years EBP, At Least Two Years, Less Than Three Years [Member] EBP, At Least Two Years, Less Than Three Years EBP, Risk and Uncertainty [Table] EBP, Risk and Uncertainty [Table] EBP, Vesting Tranche [Domain] EBP, Vesting Tranche [Domain] EBP, Vesting Tranche [Domain] EBP 001 EBP 001 [Member] EBP 001 Employer contribution, participant compensation matched, percentage EBP, Employer Contribution, Participant Compensation Matched, Percentage Number of hours, part-time employees EBP, Requisite Number Of Hours, Part Time Employees EBP, Requisite Number Of Hours, Part Time Employees EBP, Statement of Change in Net Asset Available for Benefit [Abstract] Level 2 Fair Value, Inputs, Level 2 [Member] Personal Choice Retirement Account Personal Choice Retirement Account [Member] Personal Choice Retirement Account Contributions Corrected outside VFCP EBP, Schedule of Delinquent Participant Contribution, Corrected Outside VFCP EBP, Tax Status [Table] EBP, Tax Status [Table] Net increase EBP, Change in Net Asset Available for Benefit, Increase (Decrease) RELATED PARTY AND PARTY-IN-INTEREST TRANSACTIONS EBP, Related Party and Party-in-Interest Transactions [Text Block] EBP, Related Party and Party-in-Interest Transactions [Abstract] EBP, Accounting Policy, Accounting Standard Update, and Change in Accounting Principle [Abstract] Contributions receivable EBP, Employer Contribution, Receivable Minimum age EBP, Participant Minimum Age EBP, Participant Minimum Age Payment of benefits EBP, Change in Net Asset Available for Benefit, Decrease from Payment to Participant Dividend income EBP, Change in Net Asset Available for Benefit, Increase from Dividend Income on Investment Current Value EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Current Value Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] EBP, Statement of Net Asset Available for Benefit [Abstract] EBP, Accounting Policy [Line Items] EBP, Accounting Policy [Line Items] EBP, Tax Status [Abstract] InterDigital Stock Fund EBP, Employer, Common Stock Fund [Member] Rollover contributions, vested, percentage EBP, Rollover Contributions, Vested, Percentage EBP, Rollover Contributions, Vested, Percentage Increase (decrease) in accrued expenses EBP, Increase (Decrease) in Accrued Expenses EBP, Increase (Decrease) in Accrued Expenses Cash EBP, Noninterest-Bearing Cash Requisite service period EBP, Requisite Service Period EBP, Requisite Service Period Notes receivable from participants EBP, Asset Held for Investment, Participant Loan, after Deemed Distribution Investment Valuation and Income Recognition EBP, Investment [Policy Text Block] Total Fair Value, Inputs, Level 1, Level 2, and Level 3 [Member] Document Type Document Type Entity Central Index Key Entity Central Index Key Participant loan, interest rate EBP, Asset Held for Investment, Participant Loan, Interest Rate Investments in common trusts Common Collective Trust [Member] EBP, Tax Status [Line Items] EBP, Tax Status [Line Items] EBP, Risk and Uncertainty [Abstract] EBP, Subsequent Event [Table] EBP, Subsequent Event [Table] Deductions EBP, Change in Net Asset Available for Benefit, Decrease [Abstract] Notes receivable from participants EBP, Note Receivable from Participant Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] PLAN EXPENSES EBP Plan Expenses [Text Block] EBP Plan Expenses SUMMARY OF ACCOUNTING POLICIES EBP, Summary of Accounting Policy [Text Block] Entity Registrant Name Entity Registrant Name Contributions into common stock EBP, Investment Acquired, Excluding Plan Interest in Master Trust, Cost EBP, Subsequent Event [Abstract] SUBSEQUENT EVENTS EBP, Subsequent Event [Text Block] SCHEDULE H, LINE 4(a) - SCHEDULE OF DELINQUENT PARTICIPANT CONTRIBUTIONS EBP, Schedule of Delinquent Participant Contribution [Text Block] EBP, Schedule of Delinquent Participant Contribution [Table] EBP, Schedule of Delinquent Participant Contribution [Table] TAX STATUS EBP, Tax Status [Text Block] 3 or more years EBP, Three Or More Years [Member] EBP, Three Or More Years Note receivable from participant, account, maximum borrowing, to total account, percentage EBP, Note Receivable from Participant, Account, Maximum Borrowing, to Total Account, Percentage NON-EXEMPT PARTY-IN-INTEREST TRANSACTIONS EBP, Contingency [Text Block] EBP, Subsequent Event [Line Items] EBP, Subsequent Event [Line Items] EBP, Contingency [Line Items] EBP, Contingency [Line Items] Document Information [Table] Document Information [Table] Schedule of Employer Contribution Vesting EBP, Schedule Of Employer Contribution Vesting [Table Text Block] EBP, Schedule Of Employer Contribution Vesting Notes Receivable from Participants EBP, Note Receivable from Participant [Policy Text Block] Total investment income EBP, Change in Net Asset Available for Benefit, Increase (Decrease) from Income (Loss) on Investment EBP, Vesting Tranche [Axis] EBP, Vesting Tranche [Axis] EBP, Vesting Tranche EBP, Related Party and Party-in-Interest Transactions [Line Items] EBP, Related Party and Party-in-Interest Transactions [Line Items] Level 3 Fair Value, Inputs, Level 3 [Member] Contributions Not Corrected EBP, Schedule of Delinquent Participant Contribution, Not Corrected Net assets available for benefits Net assets available for benefits - Beginning of year Net assets available for benefits - End of year EBP, Net Asset Available for Benefit Entity [Domain] Entity [Domain] Contributions EBP, Change in Net Asset Available for Benefit, Increase from Contribution [Abstract] Forfeited non-vested accounts EBP, Forfeited Nonvested Account Employer contribution, matching percentage EBP, Employer Contribution, Matching Percentage Fair Value Measured at Net Asset Value Per Share Fair Value Measured at Net Asset Value Per Share [Member] EBP, Investment, Fair Value and NAV [Table] EBP, Investment, Fair Value and NAV [Table] EBP, Statement of Net Asset Available for Benefit [Line Items] EBP, Statement of Net Asset Available for Benefit [Line Items]