Patents and other Patents And Other [Member] Patents And Other Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization 4.125% Superpriority Senior Secured Notes Due 2029 4.125% Superpriority Senior Secured Notes Due 2029 [Member] 4.125% Superpriority Senior Secured Notes Due 2029 Statistical Measurement [Domain] Statistical Measurement [Domain] Capitalized Contract Cost [Axis] Capitalized Contract Cost [Axis] Number of subsidiaries Number Of Subsidiary Number Of Subsidiary Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Property, plant and equipment, accumulated depreciation Disposal Group, Including Discontinued Operation, Property, Plant and Equipment Restricted cash included in Other current assets, net Restricted Cash, Current Award Timing Predetermined Award Timing Predetermined [Flag] Long-term debt, weighted average interest rate Long-Term Debt, Weighted Average Interest Rate, at Point in Time Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis] Judicial Ruling Judicial Ruling [Member] Entity File Number Entity File Number Tabular List, Table Tabular List [Table Text Block] Other Financial Information Additional Financial Information Disclosure [Text Block] 10.000% Secured Notes due 2032 10.000% Secured Notes Due 2032 [Member] 10.000% Secured Notes Due 2032 Recently Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Large Enterprise Large Enterprise [Member] Large Enterprise Accounts payable Increase (Decrease) in Accounts Payable SOFR Secured Overnight Financing Rate (SOFR) [Member] Schedule of Carrying Amounts and Estimated Fair Values of Financial Assets and Liabilities Fair Value, by Balance Sheet Grouping [Table Text Block] Schedule of Balance Sheet Components at Fair Value as of Transaction Close Date Disposal Groups, Including Discontinued Operations [Table Text Block] Deferred revenue Deferred Revenue, Noncurrent Type of Restructuring [Domain] Type of Restructuring [Domain] Guaranteed amount Guarantor Obligations, Maximum Exposure, Undiscounted 2030 Long-Term Debt And Lease Obligation, Maturity, Year Four Long-Term Debt And Lease Obligation, Maturity, Year Four Shares withheld to satisfy tax withholdings Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation Unionized Employees Concentration Risk Unionized Employees Concentration Risk [Member] Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Measurement Basis [Axis] Measurement Basis [Axis] Federal Funds Rate Fed Funds Effective Rate Overnight Index Swap Rate [Member] Deferred revenue Disposal Group, Including Discontinued Operation, Deferred Revenue BASIC (in dollars per share) Basic loss per common share (in dollars per share) Earnings Per Share, Basic Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] Other Other Assets, Miscellaneous, Current Revenue Recognition Revenue from Contract with Customer [Text Block] 2028 Long-Term Debt And Lease Obligation, Maturity, Year Two Long-Term Debt And Lease Obligation, Maturity, Year Two Schedule of Segment Information Schedule of Segment Reporting Information, by Segment [Table Text Block] Capitalized Contract Cost [Roll Forward] Capitalized Contract Cost [Roll Forward] Capitalized Contract Cost [Roll Forward] Remaining performance obligation Revenue, Remaining Performance Obligation, Amount Net assets Disposal Group, Including Discontinued Operation, Assets Capitalized Contract Cost [Domain] Capitalized Contract Cost [Domain] Adjustment to Compensation, Amount Adjustment to Compensation Amount Concentration risk (as a percent) Concentration Risk, Percentage Combined Pension Plan Pension Plans Pension Plan [Member] Basis of Presentation Consolidation, Policy [Policy Text Block] Stock-based compensation Share-Based Payment Arrangement, Noncash Expense Employee Stock Option Share-Based Payment Arrangement, Option [Member] Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] 4.125% Superpriority Senior Secured Notes Due 2030 4.125% Superpriority Senior Secured Notes Due 2030 [Member] 4.125% Superpriority Senior Secured Notes Due 2030 Proceeds from sale of property, plant and equipment, and other assets Proceeds from Sale of Productive Assets Accounts and Financing Receivables [Table] Accounts and Financing Receivables [Table] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Total stockholders' deficit Balance at beginning of period Balance at end of period Equity, Attributable to Parent Other comprehensive income (loss) before reclassifications OCI, before Reclassifications, Net of Tax, Attributable to Parent Insider Trading Policies and Procedures [Line Items] Stock-based compensation Share-Based Payment Arrangement, Expense Common stock, shares authorized (in shares) Common Stock, Shares Authorized 6.875% Senior Notes due 2028 6.875% Senior Notes Due 2028 [Member] 6.875% Senior Notes Due 2028 Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] CURRENT ASSETS Assets, Current [Abstract] TOTAL LIABILITIES AND STOCKHOLDERS' DEFICIT Liabilities and Equity Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Defined Benefit Plan Defined Benefit Plan Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Concentration Risk Benchmark [Axis] Concentration Risk Benchmark [Axis] LIABILITIES AND STOCKHOLDERS' DEFICIT Liabilities and Equity [Abstract] Term Loan Medium-Term Note [Member] Reclassifications out of accumulated other comprehensive income loss by component Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items] Cover [Abstract] Cover [Abstract] Amounts reclassified from accumulated other comprehensive loss Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Portion at fair value measurement Portion at Fair Value Measurement [Member] Divestiture Disposal Groups, Including Discontinued Operations, Disclosure [Text Block] Maximum Maximum [Member] Acquisition Costs Contract Acquisition Costs [Member] Incremental costs incurred in obtaining a contract with a customer, which are recognized (i.e., amortized) over the term of the initial contract and anticipated renewal contracts to which the costs relate. Level 3 Collateral Guarantors Level 3 Collateral Guarantors [Member] Level 3 Collateral Guarantors Change in net actuarial loss, tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Intangible assets, net Net Carrying Amount Finite-Lived Intangible Assets, Net Punitive Damages Punitive Damages [Member] Punitive Damages Concentration Risk Type [Domain] Concentration Risk Type [Domain] Restricted stock Restricted Stock [Member] Wholesale Wholesale [Member] Wholesale [Member] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Long-term Debt and Credit Facilities Debt Instrument [Line Items] Labor Union Contracts Concentration Risk Disclosure [Text Block] Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Pay vs Performance Disclosure [Line Items] 8.500% Senior Notes due 2036 8.500% Senior Notes due 2036 [Member] 8.500% Senior Notes due 2036 Retirement Benefits [Abstract] Retirement Benefits [Abstract] First Lien Notes First Lien Notes [Member] First Lien Notes Foreign currency translation adjustment, net of $— and $— tax Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction INCOME (LOSS) BEFORE INCOME TAXES Total before tax Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company 2031 and thereafter Long-Term Debt And Lease Obligation, Maturity, Year Five And Thereafter Long-Term Debt And Lease Obligation, Maturity, Year Five And Thereafter Other liabilities Other Liabilities, Noncurrent Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Change in deferred revenue Increase (Decrease) in Deferred Revenue Loss Contingency Nature [Axis] Loss Contingency Nature [Axis] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Operating Segments Operating Segments [Member] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount Contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Award Timing MNPI Considered Award Timing MNPI Considered [Flag] 4.500% Second Lien Notes due 2030 4.500% Second Lien Notes Due 2030 [Member] 4.500% Second Lien Notes Due 2030 COMPREHENSIVE LOSS Comprehensive Income (Loss), Net of Tax, Attributable to Parent Reclassification out of Accumulated Other Comprehensive Income [Table] Reclassification out of Accumulated Other Comprehensive Income [Table] Schedule of Components of Other Current Assets, Net Schedule of Other Current Assets [Table Text Block] Disposal Group Name [Domain] Disposal Group Name [Domain] Name Measure Name Balance as of beginning of the period Balance as of end of the period Restructuring Reserve Prepaid Expenses and Other Current Assets [Abstract] Prepaid Expense and Other Assets, Current [Abstract] Letter of Credit Letter of Credit [Member] Current operating lease liabilities Operating Lease, Liability, Current Mass Market Customers Mass Market Customers [Member] Mass Market Customers Deferred income taxes, net Deferred Income Tax Liabilities, Net Document Fiscal Period Focus Document Fiscal Period Focus Voice and Other Voice And Other [Member] Voice And Other Term Loan B-1 Term Loan B-1 [Member] Term Loan B-1 Accrued income and other taxes Increase (Decrease) in Accrued Taxes Payable Award Timing Method Award Timing Method [Text Block] Litigation Case [Domain] Litigation Case [Domain] Award Type Award Type [Axis] Contract liabilities Contract with Customer, Liability, Noncurrent Foreign Currency Translation Adjustment and Other Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Legal Entity [Axis] Legal Entity [Axis] TOTAL ASSETS Assets Trading Symbol Trading Symbol Indemnifications related to the sale of the Latin American business Disposal Group, Including Discontinued Operation, Fair Value of Indemnification Disposal Group, Including Discontinued Operation, Fair Value of Indemnification Term Loan B-4 Term Loan B-4 [Member] Term Loan B-4 Entity Address, City or Town Entity Address, City or Town OPERATING ACTIVITIES Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Superpriority Notes Superpriority Notes Due on Various Dates [Member] Superpriority Notes Due on Various Dates Intangible Assets Intangible Assets Disclosure [Text Block] Concentration Risk Type [Axis] Concentration Risk Type [Axis] Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Loss contingency, damages awarded, value Loss Contingency, Damages Awarded, Value Entity Emerging Growth Company Entity Emerging Growth Company Capitalized Contract Cost [Table] Capitalized Contract Cost [Table] Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Beginning of period balance End of period balance Capitalized Contract Cost, Net Retirement benefits Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits Total other assets Intangible Assets Net Including Other Assets, Noncurrent Aggregate carrying amount, as of the balance sheet date, of finite-lived intangible assets, indefinite-lived intangible assets, goodwill and other noncurrent assets not separately disclosed in the balance sheet. Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year Change in Fair Value as of Vesting Date of Prior Year Equity Awards Vested in Covered Year [Member] Fair Value Inputs, Level 2 Fair Value, Inputs, Level 2 [Member] Unamortized debt issuance costs Debt Issuance Costs, Net Restructuring reserve Restructuring Reserve [Roll Forward] Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Business Combination [Domain] Business Combination [Domain] Pre-tax gain on the disposal Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Provision for uncollectible accounts Accounts Receivable, Credit Loss Expense (Reversal) Items related to employee benefit plans: Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax and Reclassification Adjustment, Attributable to Parent [Abstract] Current portion of deferred revenue Disposal Group, Including Discontinued Operation, Deferred Revenue, Current Document Information [Table] Document Information [Table] PEO PEO [Member] Interest coverage ratio Debt Instrument, Covenant, Interest Coverage Ratio Debt Instrument, Covenant, Interest Coverage Ratio First Lien Notes Due 2033 First Lien Notes Due 2033 [Member] First Lien Notes Due 2033 Severance Employee Severance [Member] Supplemental noncash information regarding financing activities: Noncash Investing and Financing Items [Abstract] One Month SOFR Rate One Month SOFR [Member] One Month SOFR Changes in current assets and liabilities: Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract] Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year Dividends or Other Earnings Paid on Equity Awards not Otherwise Reflected in Total Compensation for Covered Year [Member] Change in net prior service cost, net of $2 and $— tax Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax ACCUMULATED DEFICIT Retained Earnings [Member] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Cash, cash equivalents and restricted cash at beginning of period Cash, cash equivalents and restricted cash at end of period Total Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Income tax expense (benefit) Income Tax Expense (Benefit) Basis spread (as a percent) Debt Instrument, Basis Spread on Variable Rate Income and other taxes Taxes Payable, Current Statutory Damages Statutory Damages [Member] Statutory Damages Document Information [Line Items] Document Information [Line Items] Preferred stock-non-redeemable, shares issued (in shares) Preferred Stock, Shares Issued Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Term Loan B-2 Term Loan B-2 [Member] Term Loan B-2 Product and Service [Domain] Product and Service [Domain] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Schedule of Capitalized Contract Cost Capitalized Contract Cost [Table Text Block] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Superpriority Term Loan B-1 Superpriority Term Loan B-1 [Member] Superpriority Term Loan B-1 Discontinued Operations and Disposal Groups [Abstract] Discontinued Operations and Disposal Groups [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Change in net actuarial loss, net of $(8) and $(7) tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Severance Restructuring and Related Activities Disclosure [Text Block] Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Accumulated depreciation Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization City Area Code City Area Code Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] All Trading Arrangements All Trading Arrangements [Member] Equity Awards Adjustments, Footnote Equity Awards Adjustments, Footnote [Text Block] Total Shareholder Return Vs Peer Group Total Shareholder Return Vs Peer Group [Text Block] Redemption price (as a percent) Debt Instrument, Redemption Price, Percentage Additional depreciation and amortization if held for sale criteria is not met Disposal Group, Including Discontinued Operations, Held-For-Sale Criteria Not Met, Depreciation And Amortization Disposal Group, Including Discontinued Operations, Held-For-Sale Criteria Not Met, Depreciation And Amortization Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Schedule of Contract with Customer, Asset and Liability Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] INVESTING ACTIVITIES Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Disposed of by sale Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] Preferred stock-non-redeemable, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Recognition of actuarial gain (loss) Defined Benefit Plan, Amortization of Gain (Loss) Subsequent Event Subsequent Event [Member] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] Estimate of possible loss Loss Contingency, Estimate of Possible Loss PEO Total Compensation Amount PEO Total Compensation Amount Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Allowance Contract with Customer, Receivable, Allowance for Credit Loss 2026 (remaining nine months) Long-Term Debt And Lease Obligation, Maturity, Remainder Of Fiscal Year Long-Term Debt And Lease Obligation, Maturity, Remainder Of Fiscal Year Weighted-average number of shares: Weighted Average Number of Shares Outstanding, Basic [Abstract] Senior Notes Maturing 2028-2042 Senior Notes Maturing 2028-2042 [Member] Senior Notes Maturing 2028-2042 Loss (numerator) Net Income (Loss) Available to Common Stockholders, Diluted [Abstract] Headcount costs Headcount Costs Headcount Costs Equity Components [Axis] Equity Components [Axis] Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Concentration Risk [Table] Concentration Risk [Table] OPERATING EXPENSES Operating expenses Operating Costs and Expenses [Abstract] Number of reportable segments Number of Reportable Segments FCPA Litigation FCPA Litigation [Member] FCPA Litigation Unamortized premiums (discounts), net Debt Instrument, Unamortized Discount (Premium), Net Senior Notes Maturing 2028-2036 Senior Notes Maturing 2028-2036 [Member] Senior Notes Maturing 2028-2036 Background Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block] Costs incurred Capitalized Contract Cost, Incurred Capitalized Contract Cost, Incurred Supplemental cash flow information: Supplemental Cash Flow Information [Abstract] Revenue from External Customer [Line Items] Revenue from External Customer [Line Items] Restructuring Cost and Reserve [Line Items] Restructuring Cost and Reserve [Line Items] Other Performance Measure, Amount Other Performance Measure, Amount Entity Address, State or Province Entity Address, State or Province 4.875% Second Lien Notes due 2029 4.875% Second Lien Notes Due 2029 [Member] 4.875% Second Lien Notes Due 2029 Alkira, Inc. Alkira, Inc. [Member] Alkira, Inc. Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Security, Excluded EPS Calculation [Table] Total current liabilities Liabilities, Current Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Litigation Status [Axis] Litigation Status [Axis] Individual: Individual [Axis] Superpriority Term Loan B-2 Superpriority Term Loan B-2 [Member] Superpriority Term Loan B-2 Other current assets and liabilities, net Increase (Decrease) in Other Current Assets and Liabilities, Net Other current assets, net Total other current assets, net Other Assets, Current Entity [Domain] Entity [Domain] Net cash provided by (used in) investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Remaining performance obligation, satisfaction period Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table Aggregate Change in Present Value of Accumulated Benefit for All Pension Plans Reported in Summary Compensation Table [Member] Net gain on sale of business Net gain on sale of business Gain (Loss) on Disposition of Business Interest paid (net of capitalized interest of $39 and $37) Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Payments of long-term debt Repayments of Long-Term Debt Entity Interactive Data Current Entity Interactive Data Current DEFERRED CREDITS AND OTHER LIABILITIES Deferred Revenue, Noncurrent [Abstract] Capitalized software Computer Software, Intangible Asset [Member] Carrying Amount Reported Value Measurement [Member] Loss Contingency, Nature [Domain] Loss Contingency, Nature [Domain] Segment Information Segment Reporting Disclosure [Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Current maturities of long-term debt Less current maturities Long-Term Debt and Lease Obligation, Current Total long-term debt Debt and Lease Obligation Increase (Decrease) in Stockholders' Equity Increase (Decrease) in Stockholders' Equity [Roll Forward] Latin American Tax Litigation and Claims Latin American Tax Litigation and Claims [Member] Latin American Tax Litigation and Claims Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Workforce Subject to Collective Bargaining Arrangements Expiring within One Year Workforce Subject to Collective-Bargaining Arrangements Expiring within One Year [Member] Schedule of Components of Net Periodic Pension Benefit Expense and Post-retirement Benefit Expense Schedule of Net Benefit Costs [Table Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] Senior Notes Maturing 2028-2031 Senior Notes Maturing 2028 - 2031 [Member] Senior Notes Maturing 2028 - 2031 Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Weighted Average Weighted Average [Member] Amortization expense Amortization of Intangible Assets Selling, general and administrative Selling, General and Administrative Expense Schedule of the Entity's Accumulated Other Comprehensive Loss by Component Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Capital expenditures Payments to Acquire Productive Assets Depreciation and amortization Depreciation, Depletion and Amortization Mid-Market Enterprise Mid-Market Enterprise [Member] Mid-Market Enterprise Other assets, net Other Assets, Noncurrent Customer [Domain] Customer [Domain] Interest Interest Payable, Current Entity Central Index Key Entity Central Index Key Settlement charges Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement PEO Name PEO Name Legacy Legacy [Member] Legacy Schedule of Maturities of Long-Term Debt Schedule of Maturities of Long-Term Debt [Table Text Block] OPERATING REVENUE Total Revenue Revenues Revenues Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year Prior Year End Fair Value of Equity Awards Granted in Any Prior Year that Fail to Meet Applicable Vesting Conditions During Covered Year [Member] Fair value disclosure Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Curtailment gain (loss) Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Curtailment Schedule of Debt Repurchases Schedule Of Debt Repurchases [Table Text Block] Schedule Of Debt Repurchases Shares issuable under convertible securities (in shares) Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Revolving Credit Facility Revolving Credit Facility [Member] Defined Benefit Plan [Table] Defined Benefit Plan [Table] Arrangement Duration Trading Arrangement Duration Schedule of Segment Reporting Information, by Segment [Table] Schedule of Segment Reporting Information, by Segment [Table] Segments [Axis] Segments [Axis] Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Local Phone Number Local Phone Number Class of Stock [Domain] Class of Stock [Domain] Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Other, net Payment for (Proceeds from) Other Investing Activity Other, net Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item Subsequent Event Type [Axis] Subsequent Event Type [Axis] Cash consideration of planned divestiture Disposal Group, Including Discontinued Operation, Consideration Proceeds from sale of business Payments for (Proceeds from) Businesses and Interest in Affiliates ASSETS Assets [Abstract] Fiscal Quarter Ending After December 31, 2024 Fiscal Quarter Ending After December 31, 2024 [Member] Fiscal Quarter Ending After December 31, 2024 Credit Facility [Axis] Credit Facility [Axis] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Components of net periodic (benefit) expense Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract] Debt Instrument [Axis] Debt Instrument [Axis] Fair Value of Financial Instruments Fair Value Disclosures [Text Block] Employee Benefits Retirement Benefits [Text Block] Net loss on early retirement of debt (Note 5) Net loss on early retirement of debt Gain (Loss) on Extinguishment of Debt Credit Facility [Domain] Credit Facility [Domain] Gross Carrying Amount Finite-Lived Intangible Assets, Gross STOCKHOLDERS' DEFICIT Equity, Attributable to Parent [Abstract] Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year Vesting Date Fair Value of Equity Awards Granted and Vested in Covered Year [Member] Number of states in which the business is conducted Number of States in which Entity Operates Entity Address, Address Line One Entity Address, Address Line One Old Notes - 6.75% Notes Due 2057 Old Notes - 6.75% Notes Due 2057 [Member] Old Notes - 6.75% Notes Due 2057 Number of people killed in fire Loss Contingency, Number Of People Killed Loss Contingency, Number Of People Killed ACCUMULATED OTHER COMPREHENSIVE LOSS Total AOCI Attributable to Parent [Member] Stated interest rate (as a percent) Debt Instrument, Interest Rate, Stated Percentage Accounts receivable, allowance Accounts Receivable, Allowance for Credit Loss, Current Schedule of Revenue from External Customers by Products and Services Revenue from External Customers by Products and Services [Table Text Block] Customer receivables, less allowance Contract with Customer, Receivable, after Allowance for Credit Loss Term Loan A Term Loan A [Member] Represents Term Loan A , which is a credit facility included in the Credit Agreement. Recognition of prior service credit Recognition of prior service costs (credits) Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] Fair Value as of Grant Date Award Grant Date Fair Value Entity Registrant Name Entity Registrant Name Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Net periodic post-retirement benefit expense Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Held for sale Disposal Group, Held-for-Sale, Not Discontinued Operations [Member] Foreign currency translation adjustment, tax Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax, Portion Attributable to Parent New Notes - 6.500% Notes Due 2056 New Notes - 6.500% Notes Due 2056 [Member] New Notes - 6.500% Notes Due 2056 Total liabilities Disposal Group, Including Discontinued Operation, Liabilities Schedule of Long-term Debt Including Unamortized Discounts and Premiums Schedule of Long-Term Debt Instruments [Table Text Block] Shares issuable under incentive compensation plans (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Total operating expenses Costs and Expenses Document Quarterly Report Document Quarterly Report Maximum total net leverage ratio Debt Instrument, Covenant, Leverage Ratio, Maximum Debt Instrument, Covenant, Leverage Ratio, Maximum allowed Percentage of Operating revenue Operating Lease, Lease Income, Percent Of Operating Revenue Operating Lease, Lease Income, Percent Of Operating Revenue Strategic Strategic [Member] Strategic Deferred income taxes Deferred Income Taxes and Tax Credits Long-term debt, excluding finance lease and other obligations Long-Term Debt, Fair Value Schedule of Fair Value Measurement Inputs and Valuation Techniques Fair Value Measurement Inputs and Valuation Techniques [Table Text Block] Changed Peer Group, Footnote Changed Peer Group, Footnote [Text Block] Number of operating segments Number of Operating Segments Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Level 3 Communications, LLC Level 3 Communications, LLC [Member] Level 3 Communications, LLC Interest cost Defined Benefit Plan, Interest Cost Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount Other current liabilities Disposal Group, Including Discontinued Operation, Other Liabilities, Current Schedule of Intangible Assets, Net Schedule of Finite-Lived Intangible Assets [Table Text Block] Restatement Determination Date: Restatement Determination Date [Axis] Cash consideration Payments to Acquire Businesses, Gross Non-PEO NEO Non-PEO NEO [Member] Letters of credit outstanding Letters of Credit Outstanding, Amount Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Issuance of term loans as part of refinancings (Note 5) Notes Issued Other, net Proceeds from (Payment for) Other Financing Activity Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss) [Line Items] Name Trading Arrangement, Individual Name Materials, supplies and inventory Materials, Supplies, and Other All Award Types Award Type [Domain] Prior service credit Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member] Incentive compensation plans or convertible securities Share-Based Payment Arrangement Or Convertible Securities [Member] Share-Based Payment Arrangement Or Convertible Securities Series A Revolving Credit Facility Series A Revolving Credit Facility [Member] Series A Revolving Credit Facility Equity Awards Adjustments Equity Awards Adjustments [Member] Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Employee Benefits Defined Benefit Plan Disclosure [Line Items] Compensation Amount Outstanding Recovery Compensation Amount Debt instrument, face amount Debt Instrument, Face Amount Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Fiscal Quarter Ending After December 31, 2025 Fiscal Quarter Ending After December 31, 2025 [Member] Fiscal Quarter Ending After December 31, 2025 Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Estimate of Fair Value Measurement [Member] Revenue recognized Contract with Customer, Liability, Revenue Recognized Second Lien Notes Second Lien Notes Maturing 2029-2031 [Member] Second Lien Notes Maturing 2029-2031 Number of patents allegedly infringed Loss Contingency, Patents Allegedly Infringed, Number Retirement Plan Type [Domain] Retirement Plan Type [Domain] Preferred Stock Preferred Stock [Member] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Name Awards Close in Time to MNPI Disclosures, Individual Name Payments, net Payments for Restructuring Restricted cash included in Other assets, net Restricted Cash, Noncurrent Restructuring Type [Axis] Restructuring Type [Axis] Penalties Sought by Washington Attorneys General Office Penalties Sought By Washington Attorneys General Office [Member] Penalties Sought By Washington Attorneys General Office Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax LONG-TERM DEBT Long-term debt, excluding current maturities Long-Term Debt and Lease Obligation Other current assets, net Disposal Group, Including Discontinued Operation, Other Assets, Current Litigation Case [Axis] Litigation Case [Axis] Segments [Domain] Segments [Domain] Potential future cost obligations Disposal Group, Including Discontinued Operation, Potential Future Cost Obligations Disposal Group, Including Discontinued Operation, Potential Future Cost Obligations Total Number of Employees Number of Employees, Total [Member] Loss contingency, damages sought, value Loss Contingency, Damages Sought, Value Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Fair Value, Measurements, Fair Value Hierarchy [Domain] Fair Value Hierarchy and NAV [Domain] Public Sector Public Sector [Member] Public Sector Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Minimum Minimum Minimum [Member] OTHER ASSETS Assets, Noncurrent [Abstract] Other net assets Disposal Group, Including Discontinued Operation, Other Assets Mass Market Mass Market Segment [Member] Mass Market Segment Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Company Selected Measure Name Company Selected Measure Name Level 3 Financing, Inc. Level 3 Financing, Inc. [Member] An subsidiary of CenturyLink, Inc. 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Violation Of Washington Regulations And Laws Filed By Staff Of W U T C First Lien Notes Due 2034 First Lien Notes Due 2034 [Member] First Lien Notes Due 2034 Property, plant and equipment, net of accumulated depreciation of $24,042 and $23,744 Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Contract costs Capitalized Contract Cost, Net, Current Number of indentures Debt Instrument, Number Of Indentures Debt Instrument, Number Of Indentures Available borrowing capacity Line of Credit Facility, Current Borrowing Capacity Change in contract costs held for sale Capitalized Contract Cost, Change In Contract Costs Held For Sale Capitalized Contract Cost, Change In Contract Costs Held For Sale NET LOSS NET LOSS Net loss Net of tax Net Income (Loss) Attributable to Parent Subsequent Event [Table] Subsequent Event [Table] Schedule of Operating Lease Revenue Operating Lease, Lease Income [Table Text Block] Expiration Date 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Enforcement, Amount Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares issued (in shares) Common Stock, Shares, Issued Income tax receivable Income Taxes Receivable, Current Qwest Capital Funding, Inc. Qwest Capital Funding Inc [Member] Represents details pertaining to Qwest Capital Funding, Inc., a wholly owned subsidiary of Qwest Communications International. Inc.. Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Other Broadband Other Broadband [Member] Other Broadband Litigation settlement amount Litigation Settlement, Amount Awarded to Other Party Interest expense Interest Expense, Nonoperating Trading Arrangement: Trading Arrangement [Axis] Total Shareholder Return Amount Total Shareholder Return Amount Uncommitted Letter of Credit Facility Uncommitted Letter of Credit Facility [Member] Uncommitted Letter of Credit Facility [Member] Operating lease revenue Operating Lease, Lease Income Loss Contingencies Loss Contingencies [Line Items] Subsequent Event Subsequent Events [Text Block] Insider Trading Arrangements [Line Items] Reportable Segment Reportable Segment [Member] Reportable Segment Security Exchange Name Security Exchange Name Qwest Corporation Qwest Corporation [Member] Represents Qwest Corporation, a wholly-owned subsidiary of Qwest Communications International Inc. 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