Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Cargo revenue Cargo and Freight [Member] Investments Investment, Policy [Policy Text Block] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Miles earned Frequent Flyer Mileage, Miles Awarded In Period Frequent flyer mileage miles awarded in period. Estimated Future Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] 2030 Unrecorded Unconditional Purchase Obligation, to be Paid, Year Five Award Timing Predetermined Award Timing Predetermined [Flag] Aircraft Fuel, Spare Parts and Supplies Aircraft Fuel Spare Parts And Supplies [Policy Text Block] Aircraft Fuel Spare Parts And Supplies Weighted-average remaining lease term - other financial liabilities Other Financial Liabilities, Weighted ​Average ​Remaining ​Lease ​Term Other Financial Liabilities, Weighted ​Average ​Remaining ​Lease ​Term Indefinite-lived Intangible Assets [Axis] Indefinite-Lived Intangible Assets [Axis] Entity File Number Entity File Number Additional Capital Invested Additional Paid-in Capital [Member] Third-Party Business Third Party Business [Policy Text Block] Third Party Business Policy Tabular List, Table Tabular List [Table Text Block]  Percent of Total Defined Benefit Plan, Plan Assets, Target Allocation, Percentage Frequent flyer deferred revenue Contract With Customer, Liability, Current, Frequent Flyer Contract With Customer, Liability, Current, Frequent Flyer Recently Issued Accounting Standards New Accounting Pronouncements, Policy [Policy Text Block] Purchases of short-term and other investments Payments to Acquire Short-Term Investments Secured Overnight Financing Rate (SOFR) Secured Overnight Financing Rate (SOFR) [Member] Schedule of Carrying Values and Estimated Fair Values of Financial Instruments Fair Value, by Balance Sheet Grouping [Table Text Block] Net Operating Loss Carryforward, By Expiration [Axis] Net Operating Loss Carryforward, By Expiration [Axis] Net Operating Loss Carryforward, By Expiration [Axis] Underlying debt and interest Guarantor Obligations, Maximum Exposure, Undiscounted Employee stock awards Share-Based Payment Arrangement [Member] Measurement Basis Measurement Basis [Axis] Adjustment to Compensation: Adjustment to Compensation [Axis] Named Executive Officers, Footnote Named Executive Officers, Footnote [Text Block] REVENUE RECOGNITION Revenue from Contract with Customer [Text Block] Defined Benefit Plan, Plan Assets, Category [Table] Defined Benefit Plan, Plan Assets, Category [Table] Reconciliation of Cash, Cash Equivalents and Restricted Cash Schedule of Cash and Cash Equivalents [Table Text Block] Total nonoperating special charges and unrealized (gains) losses on investments, net Special Charges And Unrealized Losses (Gains) On Financial Instruments, Non-Operating, Before Tax Special Charges And Losses On Financial Instruments, Nonoperating, Before Tax Total Current Current Income Tax Expense (Benefit) Adjustment to Compensation, Amount Adjustment to Compensation Amount Less: unamortized debt discount, premiums and debt issuance costs Debt Instrument, Unamortized Discount (Premium) and Debt Issuance Costs, Net Pension Benefits Pension Pension Plan [Member] US Federal Federal Income Tax Expense (Benefit), Continuing Operations Stock options Stock Options Share-Based Payment Arrangement, Option [Member] After 2030 Contractual Obligation, to be Paid, after Year Five Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Cash and Cash Equivalents and Restricted Cash Cash and Cash Equivalents, Policy [Policy Text Block] Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Percent Effective Income Tax Rate Reconciliation, Percent [Abstract] Actual return (loss) on plan assets: Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchase, Sale, and Settlement [Abstract] Rate to which the cost trend rate is assumed to decline (ultimate trend rate in 2035) Defined Benefit Plan, Ultimate Health Care Cost Trend Rate Antidilutive Securities [Axis] Antidilutive Securities [Axis] Total stockholders' equity Beginning balance Ending balance Equity, Attributable to Parent Other comprehensive income (loss), net of tax: Other Comprehensive Income (Loss), Net of Tax [Abstract] Insider Trading Policies and Procedures [Line Items] Operating Property and Equipment, Net Property, Plant and Equipment [Table Text Block] Common shares, authorized (in shares) Common Stock, Shares Authorized Surety Bonds Surety Bond [Member] Cash Paid During the Period for: Cash Paid Refunded During Period For [Abstract] Cash Paid Refunded During Period For [Abstract] LIABILITIES AND STOCKHOLDERS' EQUITY Liabilities and Equity [Abstract] State State State and Local Jurisdiction [Member] Cover [Abstract] Cover [Abstract] Cash and cash equivalents Cash and Cash Equivalents, Fair Value Disclosure Portion at Fair Value Measurement Portion at Fair Value Measurement [Member] Maximum Maximum [Member] Multi-employer plan contributions Multiemployer Plan, Pension, Significant, Plan Contribution Rate of compensation increase Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase Surcharge imposed Multiemployer Plan, Pension, Significant, Surcharge [Fixed List] Non-PEO NEO Average Total Compensation Amount Non-PEO NEO Average Total Compensation Amount Debt Instrument [Line Items] Debt Instrument [Line Items] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table] Summary of RSU and Restricted Stock Activity Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block] Aircraft fuel Fuel Costs Adjustment to Non-PEO NEO Compensation Footnote Adjustment to Non-PEO NEO Compensation Footnote [Text Block] Retirement Benefits [Abstract] Retirement Benefits [Abstract] Forgone Recovery due to Disqualification of Tax Benefits, Amount Forgone Recovery due to Disqualification of Tax Benefits, Amount Debt Instrument, Redemption, Period One Debt Instrument, Redemption, Period One [Member] Non-Rule 10b5-1 Arrangement Terminated Non-Rule 10b5-1 Arrangement Terminated [Flag] Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Entity Shell Company Entity Shell Company Schedule of Long-term Debt Instruments [Table] Schedule of Long-Term Debt Instruments [Table] Proceeds from sale of property and equipment Proceeds from Sale of Property, Plant, and Equipment Proceeds from issuance of debt Proceeds from Issuance of Debt Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Schedule of Income Tax Payments, Net of Refunds Supplemental Cash Flow Information Related to Leases Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Award Timing MNPI Considered Award Timing MNPI Considered [Flag] Operating And Financing Leases, Lease Not Yet Commenced Operating And Financing Leases, Lease Not Yet Commenced [Member] Operating And Financing Leases, Lease Not Yet Commenced Prior service credit Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, Prior Service Cost (Credit), before Tax Current maturities of operating leases Less: current maturities of lease obligations Operating Lease, Liability, Current Interest on finance lease liabilities Finance Lease, Interest Expense Computer software Software and Software Development Costs [Member] Document Fiscal Period Focus Document Fiscal Period Focus Rate of compensation increase Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase Receivables Receivable [Policy Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] Proceeds from issuance of debt and other financial liabilities, net of discounts and fees Proceeds From Issuance Of Long-Term Debt, Net Proceeds From Issuance Of Long-Term Debt, Net Award Timing Method Award Timing Method [Text Block] Total operating and nonoperating special charges and unrealized (gains) losses on investments, net Special Charges (Credits) And Losses On Financial Instruments, Operating And Nonoperating, Before Tax Special Charges (Credits) And Losses On Financial Instruments, Operating And Nonoperating, Before Tax Award Type Award Type [Axis] Investment, Name [Domain] Investment, Name [Domain] Share-Based Compensation Share-Based Payment Arrangement [Policy Text Block] Trading Symbol Trading Symbol 2029 Lessee, Operating Lease, Liability, to be Paid, Year Four Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Information about Goodwill and Other Intangible Assets Schedule of Intangible Assets and Goodwill [Table Text Block] Stock issued for share-based awards, net of shares withheld for tax (in shares) Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture Entity Address, City or Town Entity Address, City or Town Increase in frequent flyer deferred revenue Increase (Decrease) In Contract With Customer, Liability, Frequent Flyer Increase (Decrease) In Contract With Customer, Liability, Frequent Flyer Weighted-average discount rate - finance leases Finance Lease, Weighted Average Discount Rate, Percent Total deferred tax assets Deferred Tax Assets, Net of Valuation Allowance Non-PEO NEO Average Compensation Actually Paid Amount Non-PEO NEO Average Compensation Actually Paid Amount RSUs Restricted Stock Units (RSUs) [Member] Compensation Actually Paid vs. Other Measure Compensation Actually Paid vs. Other Measure [Text Block] Entity Emerging Growth Company Entity Emerging Growth Company 2028 Long-Term Debt, Maturity, Year Three Total accumulated other comprehensive gain/income Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax Weighted-average remaining lease term - finance leases Finance Lease, Weighted Average Remaining Lease Term 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] 2026 Defined Benefit Plan, Expected Future Benefit Payment, Year One Gross  Carrying Amount Indefinite-Lived Intangible Assets (Excluding Goodwill) PSP Notes Payroll Support Program Notes [Member] Payroll Support Program (PSP) Note [Member] (Gains) losses on sale of assets and other special charges Net gains on sale of assets and other special charges Gain (Loss) On Sale Of Other Assets And Other Miscellaneous Charges Amount of gain (loss) on sale of other assets and other miscellaneous charges. Imputed interest Finance Lease, Liability, Undiscounted Excess Amount Common shares, outstanding (in shares) Beginning balance (in shares) Ending balance (in shares) Common Stock, Shares, Outstanding Notes Unsecured Notes [Member] Unsecured Notes Assumptions used to determine benefit obligations Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Benefit Obligation [Abstract] Frequent flyer database Frequent Flyer Database [Member] Frequent Flyer Database [Member] Schedule of Operating Revenue by Components and Geographic Region Disaggregation of Revenue [Table Text Block] Stock issued for share-based awards, net of shares withheld for tax Shares Issued, Value, Share-Based Payment Arrangement, After Forfeiture, Net Of Adjustments To Additional Paid In Capital Shares Issued, Value, Share-Based Payment Arrangement, After Forfeiture, Net Of Adjustments To Additional Paid In Capital Noncurrent asset Assets for Plan Benefits, Defined Benefit Plan Net Operating Loss Carryforward, By Expiration [Domain] Net Operating Loss Carryforward, By Expiration [Domain] [Domain] for Net Operating Loss Carryforward, By Expiration [Axis] Current: Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Proceeds from exercise of stock options Stock Issued During Period, Value, Stock Options Exercised 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] Contingent liabilities based on participation Guarantor Obligations, Current Carrying Value Imputed interest Contractual Obligation, Imputed Interest Contractual Obligation, Imputed Interest Change in projected benefit obligation: Defined Benefit Plan, Change in Benefit Obligation [Roll Forward] Prepaid expenses and other Prepaid Expense and Other Assets, Current Awards Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Restatement Determination Date Restatement Determination Date Total Income Tax Expense Income tax expense Income Tax Expense (Benefit) Basis spread on variable rate Debt Instrument, Basis Spread on Variable Rate Debt instrument, remaining terms Debt Instrument, Remaining Terms Years remaining on debt instruments. Document Information [Line Items] Document Information [Line Items] Pension Adjustments Service Cost Pension Adjustments Service Cost [Member] Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Aircraft, spare engines and related rotable parts Aircraft And Related Rotable Parts [Member] Aircraft And Related Rotable Parts [Member] Total operating property and equipment Property, Plant and Equipment, Gross Value of shares repurchased, including commissions and tax Treasury Stock, Value, Acquired, Cost Method, Including Commissions And Taxes Treasury Stock, Value, Acquired, Cost Method, Including Commissions And Taxes Accumulated Benefit Obligation and Projected Benefit Obligation in Excess of Plan Assets Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Table Text Block] Expense for defined contribution plans Defined Contribution Plan, Employer Discretionary Contribution Amount Compensation Actually Paid vs. Company Selected Measure Compensation Actually Paid vs. Company Selected Measure [Text Block] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Table] Federal Income Tax Paid, Federal, after Refund Received 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 percentage of principal amount Debt Instrument, Redemption Price, Percentage Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Amount Accumulated benefit obligation Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Accumulated Benefit Obligation Outstanding (in shares) Outstanding (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number Dilutive effect of stock Warrants (in shares) Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Legacy Republic Legacy Republic Airways Holdings Inc. [Member] New Merged Entity Between Mesa Air Group, Inc. And Republic Airways Holdings Inc. Net cash provided by operating activities Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Amounts recognized in the consolidated balance sheets consist of: Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract] Investments in affiliates and other, net Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss, Noncurrent Term of debt Debt Instrument, Term Tax credits without an expiration date Deferred Tax Assets, Tax Credit Carryforwards, Not Subject To Expiration Deferred Tax Assets, Tax Credit Carryforwards, Not Subject To Expiration Junior preferred stock par value per share (in dollars per share) Preferred Stock, Par or Stated Value Per Share Estimated Useful Life (in years) Property, Plant and Equipment, Useful Life Building improvements Building Improvements [Member] Schedule of Multiemployer Plans [Table] Multiemployer Plan [Table] Subsequent Event Subsequent Event [Member] Equity Valuation Assumption Difference, Footnote Equity Valuation Assumption Difference, Footnote [Text Block] PEO Total Compensation Amount PEO Total Compensation Amount Long-term Debt, Type [Axis] Long-Term Debt, Type [Axis] Depreciation expense Depreciation 2029 Finance Lease, Liability, to be Paid, Year Four Mesa Airlines Mesa Airlines Inc. [Member] Mesa Airlines Inc. Equity Components [Axis] Equity Components [Axis] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Sublease income Sublease Income Non-Rule 10b5-1 Arrangement Adopted Non-Rule 10b5-1 Arrangement Adopted [Flag] Advertising Advertising Cost [Policy Text Block] Contractual Obligation, Fiscal Year Maturity Schedule of Estimated Future Payments of Contractual Obligation Contractual Obligation, Fiscal Year Maturity [Table Text Block] Entity Address, State or Province Entity Address, State or Province Financing cash flows for finance leases Finance Lease, Principal Payments Profit sharing and payroll tax expense Defined Benefit Plan Profit Sharing And Payroll Tax Expense Defined Benefit Plan Profit Sharing And Payroll Tax Expense Antidilutive Security, Excluded EPS Calculation [Table] Antidilutive Security, Excluded EPS Calculation [Table] 2029 Defined Benefit Plan, Expected Future Benefit Payment, Year Four Total current liabilities Liabilities, Current Domestic (U.S. and Canada) Domestic Destination [Member] Aircraft maintenance materials and outside repairs Aircraft Maintenance, Materials, and Repairs Individual: Individual [Axis] Capacity Purchase Agreements Capacity Purchase Agreements [Member] Capacity Purchase Agreements Azul Azul Linhas Aereas Brasileiras S.A. [Member] Azul Linhas Aereas Brasileiras S.A. Fair Value [Table] Fair Value [Table] Fair Value [Table] Income Tax Jurisdiction [Domain] Income Tax Jurisdiction [Domain] Document Annual Report Document Annual Report Movement in Deferred Revenue [Roll Forward] Movement In Contract With Customer Liability [Roll Forward] Movement In Contract With Customer Liability [Roll Forward] Forgone Recovery, Explanation of Impracticability Forgone Recovery, Explanation of Impracticability [Text Block] Payments of long-term debt, finance leases and other financial liabilities Voluntarily prepayment of outstanding principal balance of debt Repayments of Long-Term Debt Entity Interactive Data Current Entity Interactive Data Current Funded status—Net amount recognized Defined Benefit Plan, Funded (Unfunded) Status of Plan Deferred revenue Deferred Tax Assets, Deferred Income Revenue Recognition Revenue from Contract with Customer [Policy Text Block] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] Current maturities of long-term debt, finance leases, and other financial liabilities Long-Term Debt and Lease Obligation, Current Federal and state net operating loss ("NOL") carryforwards Deferred Tax Assets, Operating Loss Carryforwards Held at year end Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Still Held Long-Lived Tangible Asset [Axis] Long-Lived Tangible Asset [Axis] Class of Warrant or Right [Table] Class of Warrant or Right [Table] Sold during the year Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Actual Return (Loss) on Plan Assets Sold Ownership [Domain] Ownership [Domain] 2027 Finance Lease, Liability, to be Paid, Year Two Balance, before tax Balance, before tax AOCI before Tax, Attributable to Parent 2027 Defined Benefit Plan, Expected Future Benefit Payment, Year Two Summary of Unearned Compensation and Weighted-Average Remaining Period to Recognize Costs Share-Based Payment Arrangement, Nonvested Award, Cost [Table Text Block] Operating lease liabilities Deferred Tax Asset, Leasing Arrangements Deferred Tax Asset, Leasing Arrangements Award payout percentage Share-Based Compensation Arrangement By Share-Based Payment Award, Payout Percentage Share-Based Compensation Arrangement By Share-Based Payment Award, Payout Percentage Entity Central Index Key Entity Central Index Key Other property and equipment Property, Plant and Equipment, Other, Gross PEO Name PEO Name Schedule of Contractual Principal Payments Schedule of Maturities of Long-Term Debt [Table Text Block] 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, Balance Sheet Grouping, Financial Statement Captions [Line Items] Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] Outstanding Aggregate Erroneous Compensation Amount Outstanding Aggregate Erroneous Compensation Amount Tax-Exempt Special Facilities Revenue Bonds Tax Exempt Bonds [Member] Tax Exempt Bonds [Member] US State and Local State and Local Income Tax Expense (Benefit), Continuing Operations Defined Benefit Plan [Table] Defined Benefit Plan [Table] Commitments and Contingencies [Table] Commitments and Contingencies [Table] Commitments And Contingencies [Table] Exercise price of warrants (in dollars per share) Class of Warrant or Right, Exercise Price of Warrants or Rights Increase in prepaids and other assets Increase (Decrease) in Prepaid Expense and Other Assets Exercise Price Award Exercise Price Entity Filer Category Entity Filer Category Class of Stock [Domain] Class of Stock [Domain] Benefits paid Defined Benefit Plan, Benefit Obligation, Benefits Paid Income tax provision at statutory rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Subsequent Event Type [Axis] Subsequent Event Type [Axis] Foreign Foreign Income Tax Expense (Benefit), Continuing Operations Long-term debt, net Long-Term Debt, Excluding Current Maturities Expiration period for advance ticket sales Ticket Revenue, Performance Obligation, Term Ticket Revenue, Performance Obligation, Term Projected amortization expense in 2028 Finite-Lived Intangible Asset, Expected Amortization, Year Three Chase and Other Partner Agreements Chase And Other Partner Agreements [Member] Chase And Other Partner Agreements [Member] Deferred income tax asset (liability): Deferred Tax Assets, Net [Abstract] Gross  Carrying Amount Finite-Lived Intangible Assets, Gross 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] Entity Address, Address Line One Entity Address, Address Line One Other Market Rates Other Market Rates [Member] Other Market Rates Accumulated Other Comprehensive Income (Loss) Accumulated Other Comprehensive Income (Loss) AOCI Attributable to Parent [Member] Share issued for settlement of Warrants (in shares) Number of shares issued in settlement of warrants exercised (in shares) Stock Issued During Period, Shares, Conversion of Convertible Securities Ownership [Axis] Ownership [Axis] PSP1 Note Payroll Support Program Notes, 1 [Member] Payroll Support Program (PSP) Note [Member] Amortization of prior service (credits) cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Special charges Total operating special charges Restructuring, Settlement and Impairment Provisions Fair Value as of Grant Date Award Grant Date Fair Value Less: current maturities of lease obligations Other Financial Liabilities, Current Other Financial Liabilities, Current NOL carryforwards Operating Loss Carryforwards Number of aircraft subject to finance leases Number Of Aircraft Subject To Finance Leases Number Of Aircraft Subject To Finance Leases Summary of Long-Term Debt Schedule of Long-Term Debt Instruments [Table Text Block] Salaries and related costs Labor and Related Expense Nonoperating debt extinguishment and modification fees Charges related to the repayment in full of the outstanding principal balance of debt Debt Extinguishment and Modification Fees, Non-Operating Debt Extinguishment and Modification Fees, Non-Operating Dilutive effect of employee stock awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements Awards granted (in shares) Granted (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period Other financial liabilities Other Financial Liabilities, Noncurrent Other Financial Liabilities, Noncurrent Total operating expense Costs and Expenses Forfeited (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period Unearned Compensation Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount Investment interests received in exchange for loans, goods and services Other Significant Noncash Transaction, Value of Consideration Received Deferred income tax expense Deferred Income Taxes and Tax Credits Fair Value 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] 2027 Lessee, Operating Lease, Liability, to be Paid, Year Two MileagePlus Senior Secured Notes Mileage Plus Senior Secured Notes [Member] Mileage Plus Senior Secured Notes Pacific Pacific Destination [Member] Adjustment To PEO Compensation, Footnote Adjustment To PEO Compensation, Footnote [Text Block] Title Trading Arrangement, Individual Title Peer Group Total Shareholder Return Amount Peer Group Total Shareholder Return Amount 2028 Defined Benefit Plan, Expected Future Benefit Payment, Year Three Latin America Latin America Destination [Member] Weighted-average interest rate - other financial liabilities Other Financial Liabilities, Weighted Average Discount Rate, Percent Other Financial Liabilities, Weighted Average Discount Rate, Percent Non-PEO NEO Non-PEO NEO [Member] Operating lease right-of-use asset Deferred Tax Liabilities, Leasing Arrangements Accumulated Other Comprehensive Income (Loss) [Line Items] Accumulated Other Comprehensive Income (Loss) [Line Items] Other Other Intangible Assets [Member] Award Type [Domain] Award Type [Domain] 2026 Lessee, Operating Lease, Liability, to be Paid, Year One Equity Awards Adjustments Equity Awards Adjustments [Member] Alternatives Alternatives Alternative [Member] Alternative [Member] Deferred Income Tax Assets And Liabilities [Line Items] Deferred Income Tax Assets And Liabilities [Line Items] Deferred Income Tax Assets And Liabilities [Line Items] Advertising expense Advertising Expense Pension Benefits Adjustments, Footnote Pension Benefits Adjustments, Footnote [Text Block] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Compensation Amount Outstanding Recovery Compensation Amount After 2030 Unrecorded Unconditional Purchase Obligation, to be Paid, after Year Five Deferred: Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] IAM National Pension Plan International Association Of Machinists National Pension Plan [Member] International Association of Machinists National Pension Plan [Member] Certificates of deposit placed through an account registry service ("CDARS") Certificates of Deposit [Member] Recovery of Erroneously Awarded Compensation Disclosure [Line Items] Fair Value Estimate of Fair Value Measurement [Member] Revenue recognized Contract with Customer, Liability, Revenue Recognized Increase (decrease) in advance ticket sales Increase (Decrease) In Contract With Customer, Liability, Advance Ticket Sales Increase (Decrease) in Contract with Customer, Liability, Advance Ticket Sales Retirement Plan Type [Domain] Retirement Plan Type [Domain] MNPI Disclosure Timed for Compensation Value MNPI Disclosure Timed for Compensation Value [Flag] Airline Destination [Axis] Airline Destination [Axis] Equity interests exchanged for commitment to facilitate merger transaction Equity Ownership, Excluding Consolidated Entity and Equity Method Investee, Percentage 2029 Notes 4.875% Notes Due 2029 [Member] 4.875% Notes Due 2029 Operating revenue: Revenues [Abstract] Documents Incorporated by Reference Documents Incorporated by Reference [Text Block] Schedule Of Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items] Schedule Of Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items] Schedule Of Defined Benefit Plans And Defined Contribution Plans Disclosures [Line Items] Accumulated other comprehensive income Accumulated Other Comprehensive Income (Loss), Net of Tax Long-term debt, finance leases, and other financial liabilities Long-Term Debt and Lease Obligation 2026 Long-Term Debt, Maturity, Year One Financial Instruments [Domain] Financial Instruments [Domain] Total deferred tax liabilities Deferred Tax Liabilities, Gross 2030 Long-Term Debt, Maturity, Year Five Aggregate Pension Adjustments Service Cost Aggregate Pension Adjustments Service Cost [Member] Tax credit expiration period Tax Credit Carryforward, Expiration Period Tax Credit Carryforward, Expiration Period Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Minimum Minimum [Member] Additional contribution as a percentage of the hourly contribution rate Multiemployer Plan, Additional Contribution Rate In Excess Of The Hourly Contribution Rate Multiemployer Plan, Additional Contribution Rate In Excess Of The Hourly Contribution Rate Company Selected Measure Name Company Selected Measure Name Uncertain Income Tax Positions Income Tax Uncertainties, Policy [Policy Text Block] Mainline Aircraft Mainline [Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Aggregate Available Trading Arrangement, Securities Aggregate Available Amount Accounts payable Liabilities due Accounts Payable, Current Operating cash flows for operating leases Operating Lease, Payments Stock Appreciation Rights (SARs) Stock Appreciation Rights (SARs) [Member] Foreign Current Foreign Tax Expense (Benefit) COMMITMENTS, CONTINGENCIES AND GUARANTEES Commitments and Contingencies Disclosure [Text Block] Diluted weighted-average shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Segments Segment Reporting, Policy [Policy Text Block] Non-GAAP Measure Description Non-GAAP Measure Description [Text Block] Entity Small Business Entity Small Business Carrying value of computer software Capitalized Computer Software, Gross Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Other operating expenses Other Cost and Expense, Operating Junior preferred stock outstanding (in shares) Preferred Stock, Shares Outstanding US State and Local Current State and Local Tax Expense (Benefit) DEBT Long-Term Debt [Text Block] Document Transition Report Document Transition Report Minimum lease payments Finance Lease, Liability, to be Paid Underlying Securities Award Underlying Securities Amount Equity Component [Domain] Equity Component [Domain] Document Period End Date Document Period End Date INCOME TAXES Income Tax Disclosure [Text Block] Total Aggregate balance Contractual Obligation Non-Aircraft Non-Aircraft [Member] Non-Aircraft [Member] Awards Close in Time to MNPI Disclosures, Table Awards Close in Time to MNPI Disclosures [Table Text Block] Average price per share of shares repurchased (in dollars per share) Shares Acquired, Average Cost Per Share Guatemala GUATEMALA Document Type Document Type Level 3 Fair Value, Inputs, Level 3 [Member] EARNINGS PER SHARE Earnings Per Share [Text Block] Name Outstanding Recovery, Individual Name Advance Ticket Sales Passenger, Advance Ticket Sales [Member] Advance Ticket Sales [Member] Pension and Other Postretirement Plan Assets Schedule of Defined Benefit Plans Disclosures [Table Text Block] Product and Service [Axis] Product and Service [Axis] Total operating revenue Revenue Revenue from Contract with Customer, Excluding Assessed Tax Revenue From Contract With Customer [Table] Revenue From Contract With Customer [Table] Revenue From Contract With Customer [Table] [Table] Total current assets Assets, Current Statistical Measurement [Axis] Statistical Measurement [Axis] Aggregate value of outstanding shares authorized for purchase under share repurchase program Share Repurchase Program, Authorized, Amount Aggregate limit value of outstanding shares authorized for purchase in fiscal year under share repurchase program Share Repurchase Program, Authorized, Fiscal Year Limit Amount Share Repurchase Program, Authorized, Fiscal Year Limit Amount Aggregate Erroneous Compensation Amount Aggregate Erroneous Compensation Amount Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Summary Of Significant Accounting Policies [Line Items] Peer Group Issuers, Footnote Peer Group Issuers, Footnote [Text Block] Earnings available to common stockholders Net Income (Loss) Available to Common Stockholders, Basic Investments and other Other Comprehensive Income, Investments And Other, Net Of Tax Other Comprehensive Income, Investments And Other, Net Of Tax Fair Value [Line Items] Fair Value [Line Items] Fair Value [Line Items] Guarantor Obligations, Nature [Domain] Guarantor Obligations, Nature [Domain] Tax effected amount of NOLs Operating Loss Carryforwards, Tax Effected Amount Operating Loss Carryforwards, Tax Effected Amount Level 1 Fair Value, Inputs, Level 1 [Member] Number of days used to compute performance period average closing price of restricted stock units Determination Period Average Closing Price The time period over which the stock closing prices are averaged to arrive at a per-share valuation for equity based awards such as Restricted Stock Units, Performance Share and other equity based awards. Deferred Taxes AOCI Attributable To Parent, Tax [Roll Forward] AOCI Attributable To Parent, Tax [Roll Forward] Earnings per share, diluted (in dollars per share) Earnings Per Share, Diluted Investing and Financing Activities Not Affecting Cash: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]     Total AOCI Attributable to Parent, Net of Tax [Roll Forward] Time-Vested RSUs Time-Vested Restricted Stock Units (RSUs) [Member] Time-Vested Restricted Stock Units (RSUs) [Member] Assumptions Used for Benefit Plans Defined Benefit Plan, Assumptions [Table Text Block] NOL and tax credit carryforwards, valuation allowance Operating Loss Carryforwards And Tax Credit Carryforwards, Valuation Allowance Operating Loss Carryforwards And Tax Credit Carryforwards, Valuation Allowance State Income Tax Paid, State and Local, after Refund Received Loans And Leases From Non-U.S. Entities Loans And Leases From Non-U.S. Entities [Member] Loans And Leases From Non U.S Entities [Member] Frequent flyer deferred revenue Contract With Customer, Liability, Noncurrent, Frequent Flyer Contract With Customer, Liability, Noncurrent, Frequent Flyer Auditor Location Auditor Location Equity interests received for commitment to facilitate merger transaction (in shares) Equity Ownership, Excluding Consolidated Entity And Equity Method Investee, Shares Equity Ownership, Excluding Consolidated Entity And Equity Method Investee, Shares Short-term investments Debt Securities, Available-for-Sale, Current Actuarial (gain) loss Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss) Federal Domestic Tax Jurisdiction [Member] Participant contributions Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant Other Stockholders' Equity, Other Imputed interest Lessee, Operating Lease, Liability, Undiscounted Excess Amount Republic Republic Airways Holdings, Inc. [Member] Republic Airways Holdings, Inc. [Member] Income taxes Income taxes Income Taxes Paid, Net Projected amortization expense in 2027 Finite-Lived Intangible Asset, Expected Amortization, Year Two Long term debt Debt recorded Long-Term Debt, Gross Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer Accrued salaries and benefits Employee-related Liabilities, Current Minimum lease payments Lessee, Operating Lease, Liability, to be Paid Expiration Date Trading Arrangement Expiration Date Additional Information Related to Leases Lessee, Operating And Finance Leases, Weighted-Average Assumptions [Table Text Block] Lessee, Operating And Finance Leases, Weighted-Average Assumptions [Table Text Block] Increase in other liabilities Increase (Decrease) in Other Operating Liabilities Projected amortization expense in 2030 Finite-Lived Intangible Asset, Expected Amortization, Year Five Gains on various aircraft sale-leaseback transactions Gain (Loss) On Aircraft Sale-Leaseback Transactions Gain (Loss) On Aircraft Sale-Leaseback Transactions Lease terms of additional leases that have not yet commenced (up to) Lessee, Operating And Finance Lease, Not Yet Commenced, Term Of Contract Lessee, Operating And Finance Lease, Not Yet Commenced, Term Of Contract Other fixed-income securities Fixed Income Securities [Member] Other investments Other Investments [Member] Operating property and equipment, net Total operating property and equipment, net Property, Plant and Equipment, Net 2026 2026 Unrecorded Unconditional Purchase Obligation, to be Paid, Year One Compensation Actually Paid vs. Net Income Compensation Actually Paid vs. Net Income [Text Block] Entity Current Reporting Status Entity Current Reporting Status Awards Close in Time to MNPI Disclosures Awards Close in Time to MNPI Disclosures [Table] Operating leases converted to finance leases Operating Leases Converted To Finance Leases Operating Leases Converted To Finance Leases Income tax provision at statutory rate Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount Financial Instrument [Axis] Financial Instrument [Axis] Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] Executive Category: Executive Category [Axis] State income tax provision, net of federal income tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Less: current maturities of lease obligations Finance Lease, Liability, Current Accumulated benefit obligation Defined Benefit Plan, Accumulated Benefit Obligation Current Fiscal Year End Date Current Fiscal Year End Date Health care cost trend rate assumed for next year Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year Changes in operating assets and liabilities - Increase (Decrease) in Other Operating Assets and Liabilities, Net [Abstract] Other Investments Other Equity Investments [Member] Other Investments Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Weighted- Average Grant Price Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] India INDIA Restricted cash - current Restricted Cash, Current, Fair Value Disclosure Restricted Cash, Current, Fair Value Disclosure Equity Awards Adjustments, Excluding Value Reported in Compensation Table Equity Awards Adjustments, Excluding Value Reported in the Compensation Table [Member] Percentage of employees represented by various U.S. labor organizations Percentage Of Employees Represented By Labor Organizations Percentage of employees represented by labor organizations Receivables, net Receivables, Net, Current Schedule of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Advance ticket sales Contract With Customer, Liability, Current, Advance Ticket Sales Contract With Customer, Liability, Current, Advance Ticket Sales Unrecognized tax benefits Unrecognized Tax Benefits Number of aircraft operated Number of Aircraft Operated Potentially dilutive securities (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Amount of leases that have not yet commenced Total Unrecorded Unconditional Purchase Obligation Fair Value, by Balance Sheet Grouping [Table] Fair Value, by Balance Sheet Grouping [Table] 2027 Long-Term Debt, Maturity, Year Two Tradenames and logos Tradenames And Logos [Member] Tradenames And Logos [Member] Revenue From Contract With Customer [Line Items] Revenue From Contract With Customer [Line Items] [Line Items] for Revenue From Contract With Customer [Table] [Table] LEASES Lessee, Operating Leases [Text Block] Net cash used in financing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Measure: Measure [Axis] 2027 Unrecorded Unconditional Purchase Obligation, to be Paid, Year Two Hubs Hubs [Member] Hubs [Member] Long-Lived Tangible Asset [Domain] Long-Lived Tangible Asset [Domain] Value of authorized shares yet to be purchased under share repurchase program Share Repurchase Program, Remaining Authorized, Amount Subscribed equity investments in connection with reorganization process Equity Securities, Restructuring Agreement, Committed Investment Amount Equity Securities, Restructuring Agreement, Maximum Investment Pay vs Performance Disclosure, Table Pay vs Performance [Table Text Block] Amounts recognized in accumulated other comprehensive income consist of: Defined Benefit Plan, Amounts Recognized in Other Comprehensive Income (Loss) [Abstract] Forgone Recovery due to Violation of Home Country Law, Amount Forgone Recovery due to Violation of Home Country Law, Amount Entity Tax Identification Number Entity Tax Identification Number 2028 Contractual Obligation, to be Paid, Year Three Schedule Of Defined Benefit Plans And Defined Contribution Plans Disclosures [Table] Schedule Of Defined Benefit Plans And Defined Contribution Plans Disclosures [Table] Schedule Of Defined Benefit Plans And Defined Contribution Plans Disclosures Common shares, issued (in shares) Common Stock, Shares, Issued Deferred Income Tax Assets And Liabilities [Table] Deferred Income Tax Assets And Liabilities [Table] Deferred Income Tax Assets And Liabilities [Table] Performance-Based RSUs Performance-Based Restricted Stock Units (RSUs) [Member] Performance-Based Restricted Stock Units (RSUs) [Member] Weighted-average remaining lease term - operating leases Operating Lease, Weighted Average Remaining Lease Term 2029 Long-Term Debt, Maturity, Year Four CommuteAir CommuteAir LLC [Member] CommuteAir LLC UAL and United UAL And United [Member] UAL And United [Member] Entity Public Float Entity Public Float Interest expense Interest Expense, Nonoperating Trading Arrangement: Trading Arrangement [Axis] 2026 and 2029 Notes Secured Notes Due 2026 And 2029 [Member] Secured Notes Due 2026 And 2029 Total Shareholder Return Amount Total Shareholder Return Amount Income Taxes [Line Items] Income Taxes [Line Items] Income Taxes [Line Items] Net actuarial gain Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax Operating and non-operating special charges, non-cash portion Restructuring Costs and Asset Impairment Charges Security Exchange Name Security Exchange Name Foreign Income Tax Paid, Foreign, after Refund Received Passenger, Ancillary Fees Passenger, Ancillary Fees [Member] Passenger - Ancillary Fees [Member] 2027 Contractual Obligation, to be Paid, Year Two Total noncurrent liabilities Liabilities, Noncurrent Purchase commitments Capital Addition Purchase Commitments [Member] Other Defined Benefit Plan, Plan Assets, Increase (Decrease) For Other Change Defined benefit plan other changes plan assets Nontaxable or nondeductible items Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount Defined Benefit Plan, Plan Assets, Category [Domain] Defined Benefit Plan, Plan Assets, Category [Domain] Maintenance and Repairs Maintenance Cost, Policy [Policy Text Block] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-Lived Intangible Assets, Major Class Name [Domain] Other Other Liabilities, Current Participant contributions Defined Benefit Plan, Plan Assets, Contributions by Plan Participant Asset Class [Domain] Asset Class [Domain] Discount rate Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate Noncurrent liability Liability, Defined Benefit Plan, Noncurrent Statement [Line Items] Statement [Line Items] Rule 10b5-1 Arrangement Adopted Rule 10b5-1 Arrangement Adopted [Flag] Cash and cash equivalents Cash and Cash Equivalent Common Stock Common Stock [Member] Vested (in shares) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period NOL expiration period Operating Loss Carryforwards, Expiration Period Operating Loss Carryforwards, Expiration Period Intangibles Assets Goodwill and Intangible Assets, Intangible Assets, Policy [Policy Text Block] Finance Leases Finance Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Net increase (decrease) in cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Unrealized gains (losses) on investments, net Unrealized (gains) losses on investments Unrealized Gain (Loss) on Investments BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES Significant Accounting Policies [Text Block] Statistical Measurement [Domain] Statistical Measurement [Domain] After 2030 Lessee, Operating Lease, Liability, to be Paid, after Year Five Equipment Notes Equipment Notes [Member] Equipment Notes Funded percentage Defined Benefit Plan, Funded Percentage Asset Class Asset Class [Axis] Long-Lived Asset Impairments Impairment or Disposal of Long-Lived Assets, Policy [Policy Text Block] Leases [Abstract] Leases [Abstract] Frequent Flyer Accounting Frequent Flier Program, Policy [Policy Text Block] Increase in accounts payable Increase (Decrease) in Accounts Payable Multiemployer Plan Name [Axis] Retirement Plan Name [Axis] Summary of Purchase Commitments Unrecorded Unconditional Purchase Obligations Disclosure [Table Text Block] Contributions Multiemployer Plan, Employer Contribution, Cost Trading Arrangements, by Individual Trading Arrangements, by Individual [Table] Earnings per share, basic (in dollars per share) Earnings Per Share, Basic Term of sale-leaseback transactions Sale Leaseback Transaction, Lease Term SPECIAL CHARGES (CREDITS) Business Combination, Integration, Restructuring, and Other Related Costs [Text Block] Common stock reserved for future issuance (in shares) Common Stock, Capital Shares Reserved for Future Issuance Regional capacity purchase Airline, Capacity Purchase Arrangements Finite-lived intangible assets Finite-Lived Intangible Assets, Gross [Abstract] Fair value of plan assets Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Plan Assets Discount rate Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate Total other comprehensive income (loss), net of tax Other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Debt Instrument, Redemption, Period [Axis] Debt Instrument, Redemption, Period [Axis] Other Defined Benefit Plan, Other Cost (Credit) 2028 Finance Lease, Liability, to be Paid, Year Three Employee benefits, including pension, postretirement and medical Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits Award Timing MNPI Disclosure Award Timing MNPI Disclosure [Text Block] Changes in value OCI, before Reclassifications, Net of Tax, Attributable to Parent Compensation cost Share-Based Payment Arrangement, Expense Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Summary Of Significant Accounting Policies [Table] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other unsecured debt Other Unsecured Debt [Member] Other Unsecured Debt Current assets: Assets, Current [Abstract] Total liabilities and stockholders' equity Liabilities and Equity Other Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Other Change Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Pension and Other Postretirement Liabilities Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member] Amounts reclassified to earnings Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent Other Deferred Tax Assets, Other Accounting Policies [Abstract] Accounting Policies [Abstract] Summary of Scheduled Future Minimum Lease Payments under Operating Leases Lessee, Operating Lease, Liability, to be Paid, Maturity [Table Text Block] Treasury Stock Treasury Stock, Common [Member] Fair value of RSUs and restricted stock vested in period Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value Pay vs Performance Disclosure [Line Items] Cash Collateralized Letters of Credit Collateralized Debt Obligations [Member] Present value of minimum lease payments Operating Lease, Liability U.S. government and agency notes US Government Agencies Debt Securities [Member] Other charges Special Charges, Other Charges Gain (Loss) On Other Charges Amortization of finance lease assets Finance Lease, Right-of-Use Asset, Amortization Airline Destination [Domain] Airline Destination [Domain] Other Other Liabilities, Noncurrent Debt Instrument, Redemption, Period [Domain] Debt Instrument, Redemption, Period [Domain] Less: current portion of long-term debt Long-Term Debt, Current Maturities Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Company Selected Measure Amount Company Selected Measure Amount 2028 Lessee, Operating Lease, Liability, to be Paid, Year Three Employer contributions Defined Benefit Plan, Plan Assets, Contributions by Employer Total comprehensive income, net Comprehensive Income (Loss), Net of Tax, Attributable to Parent 2030 Contractual Obligation, to be Paid, Year Five Name Measure Name Secured Debt Secured Debt [Member] Deferred income taxes Deferred Income Tax Liabilities, Net Expected return on plan assets Expected Long-Term Rate of Return Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets Unsecured Unsecured Debt [Member] Carrying Amount Total Long term debt Long-Term Debt Term for frequent flyer mileage sales to partners Mileage Plus Partner Agreement, Term Frequent flyer mileage program expiration period. Legal Entity [Axis] Legal Entity [Axis] Total assets Assets Projected amortization expense in 2026 Finite-Lived Intangible Asset, Expected Amortization, Year One Vested (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Landing fees and other rent Landing Fees and Other Rentals Share issued for settlement of Warrants Stock Issued During Period, Value, Conversion Of Convertible Securities, Net Of Adjustments To Additional Paid In Capital Stock Issued During Period, Value, Conversion Of Convertible Securities, Net Of Adjustments To Additional Paid In Capital Operating Activities: Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract] Number of call options to purchase regional jet aircraft Number Of Call Options To Purchase Regional Jet Aircraft Number Of Call Options To Purchase Regional Jet Aircraft Aircraft Purchase Financing Equipment Notes, Aircraft Purchase Financing [Member] Equipment Notes, Aircraft Purchase Financing Percentage of principal amount bearing fixed interest rate Debt Instrument, Issue Price, Percentage Of Principal Debt Instrument, Issue Price, Percentage Of Principal Projected amortization expense in 2029 Finite-Lived Intangible Asset, Expected Amortization, Year Four 2026 Finance Lease, Liability, to be Paid, Year One Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Preferred Stock Purchase Rights Stock Warrants Warrant [Member] Right-of-use assets acquired or modified through operating leases Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Level 2 Fair Value, Inputs, Level 2 [Member] Document Financial Statement Error Correction [Flag] Document Financial Statement Error Correction [Flag] State income tax provision, net of federal income tax benefit Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount Equity method investments Equity Method Investments Insider Trading Policies and Procedures Not Adopted Insider Trading Policies and Procedures Not Adopted [Text Block] Operating Leases Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract] Related Party Related Party [Member] Change in plan assets: Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Schedule of Components of Income Tax Provision Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Property and Equipment Property, Plant and Equipment, Policy [Policy Text Block] Document Information [Table] Document Information [Table] PEO PEO [Member] Proceeds from sale of short-term and other investments Proceeds from Sale, Maturity and Collection of Investments Interest income Investment Income, Interest Intangible assets Deferred Tax Liabilities, Intangible Assets Number of employees Entity Number of Employees Income Tax Paid, by Individual Jurisdiction [Line Items] Income Tax Paid, by Individual Jurisdiction [Line Items] Unrecorded Unconditional Purchase Obligation [Line Items] Unrecorded Unconditional Purchase Obligation [Line Items] Plan length Multiemployer Plan, Rehabilitation Plan Term Multiemployer Plan, Rehabilitation Plan Term Change in valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Amount Depreciation Deferred Tax Liabilities, Property, Plant and Equipment Retained Earnings Retained Earnings [Member] Income Tax Jurisdiction [Axis] Income Tax Jurisdiction [Axis] Share-based Payment Arrangement [Abstract] Share-Based Payment Arrangement [Abstract] Cash, cash equivalents and restricted cash at beginning of year Cash, cash equivalents and restricted cash at end of year Total cash, cash equivalents and restricted cash Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Income Statement [Abstract] Income Statement [Abstract] Defined Benefit Plan Assets Measured at Fair Value Using Unobservable Inputs Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block] Changes in value OCI, before Reclassifications, before Tax, Attributable to Parent Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Product and Service [Domain] Product and Service [Domain] Restatement does not require Recovery Restatement Does Not Require Recovery [Text Block] Income Tax Paid, by Individual Jurisdiction [Table] Income Tax Paid, by Individual Jurisdiction [Table] Payable to parent Payable to Shareholders or Affiliates for Issuance of Capital Stock Payable to Shareholders or Affiliates for Issuance of Capital Stock City Area Code City Area Code Award Timing, How MNPI Considered Award Timing, How MNPI Considered [Text Block] Defined Benefit Plan, Plan Assets, Category [Line Items] Defined Benefit Plan, Plan Assets, Category [Line Items] Class of Warrant or Right [Line Items] Class of Warrant or Right [Line Items] Schedule of Roll Forward of Frequent Flyer Deferred Revenue Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block] Net deferred tax liability Deferred Tax Liabilities, Net Investing Activities: Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Pay vs Performance Disclosure Pay vs Performance Disclosure [Table] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Unrecorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Amortization of unrecognized actuarial (gain) loss Defined Benefit Plan, Amortization of Gain (Loss) Total lease cost Lease, Cost Goodwill Goodwill Components of Lease Cost Lease, Cost [Table Text Block] Interest expense carryforward Deferred Tax Asset, Interest Carryforward US Federal Deferred Federal Income Tax Expense (Benefit) Auditor Name Auditor Name Flight equipment Flight Equipment, Gross Pension and Other Postretirement Defined Benefit Plan, Expected Future Benefit Payment [Abstract] Equity Awards - RSUs Restricted Stock Units (RSUs) - Equity Awards [Member] Restricted Stock Units (RSUs) - Equity Awards [Member] Other Performance Measure, Amount Other Performance Measure, Amount Reconciliation of Cash, Cash Equivalents and Restricted Cash Restrictions on Cash and Cash Equivalents [Table Text Block] Fair Value Measurements Fair Value Measurement, Policy [Policy Text Block] Related and Nonrelated Parties [Domain] Related and Nonrelated Parties [Domain] Frequent Flyer Frequent Flyer Program [Member] Frequent Flyer Program [Member] Amount Income Tax Expense (Benefit), Effective Income Tax Rate Reconciliation, Amount [Abstract] Interest capitalized Interest Costs Capitalized Adjustment Benefits paid Defined Benefit Plan, Plan Assets, Benefits Paid LEASES Lessee, Finance Leases [Text Block] Additional capital invested Additional Paid in Capital, Common Stock Entity [Domain] Entity [Domain] Net cash used in investing activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation 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] Interest Interest Paid, Excluding Capitalized Interest, Operating Activity Document Fiscal Year Focus Document Fiscal Year Focus Basis of Presentation Basis of Accounting, Policy [Policy Text Block] Operating lease right-of-use assets Operating Lease, Right-of-Use Asset Number of aircraft leases under various sale-leaseback transactions Sale-Leaseback Transaction, Number Of Aircraft Leases Sale-Leaseback Transaction, Number Of Aircraft Leases Income tax expense Effective Income Tax Rate Reconciliation, Percent Operating lease cost Operating Lease, Cost Carrying Amount Reported Value Measurement [Member] Weighted-Average Remaining Period (in years) Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition 2029 Net Operating Loss Carry Forward Expiration Year 2029 [Member] Net Operating Loss Carry Forward Expiration Year 2029 [Member] Less: Valuation allowance Deferred Tax Assets, Valuation Allowance Equity [Abstract] Equity [Abstract] Buildings Building [Member] 2028 Unrecorded Unconditional Purchase Obligation, to be Paid, Year Three Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Amounts Recognized in Consolidated Balance Sheet and Accumulated Other Comprehensive Income (Loss) Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Fair value of plan assets at beginning of year Fair value of plan assets at end of year Fair value of plan assets Defined Benefit Plan, Plan Assets, Amount US Federal Current Federal Tax Expense (Benefit) Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Other property and equipment Other Capitalized Property Plant and Equipment [Member] Components Of Net Periodic Benefit Cost Schedule of Net Benefit Costs [Table Text Block] Compensation Actually Paid vs. Total Shareholder Return Compensation Actually Paid vs. Total Shareholder Return [Text Block] ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) ("AOCI") Comprehensive Income (Loss) Note [Text Block] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] United Airlines, Inc. United Air Lines Inc [Member] United Airlines, Inc. [Member] Amortization expense Amortization of Intangible Assets Leases Lessee, Leases [Policy Text Block] Restricted cash in Prepaid expenses and other Restricted Cash and Cash Equivalent, Current PSP3 Note Payroll Support Program Notes, 3 [Member] Payroll Support Program Notes, 3 Impact of UAL share repurchase Stock Repurchased During Period, Value Schedule of Components of Accumulated Other Comprehensive Income (Loss), Net of Tax Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Capital expenditures, net of flight equipment purchase deposit returns Payments to Acquire Productive Assets Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization Expenses related to CPAs Costs and Expenses, Related Party Revolving Credit Facility Revolving Credit Facility [Member] Present value of minimum lease payments Finance Lease, Liability Arrangement Duration Trading Arrangement Duration PSP2 Note Payroll Support Program Notes, 2 [Member] Payroll Support Program Notes, 2 Local Phone Number Local Phone Number Additional 402(v) Disclosure Additional 402(v) Disclosure [Text Block] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Collaborative Arrangement and Arrangement Other than Collaborative [Domain] Other, net Payment for (Proceeds from) Other Investing Activity Other operating activities Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Other Item After 2030 Long-Term Debt, Maturity, after Year Five SHARE-BASED COMPENSATION PLANS Share-Based Payment Arrangement [Text Block] Airport slots Airport Slots And Gates Indefinite Lived [Member] Airport Slots And Gates [Member] China route authority China Route Authority [Member] China Route Authority ASSETS Assets [Abstract] Credit Facility [Axis] Credit Facility [Axis] Underlying Security Market Price Change Underlying Security Market Price Change, Percent Debt Instrument [Axis] Debt Instrument [Axis] Total operating and nonoperating special charges and unrealized (gains) losses on investments, net of income taxes Special Charges (Credits), Net of Income Tax Benefit Total special items in the period. Forfeited (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value FAIR VALUE MEASUREMENTS, INVESTMENTS AND NOTES RECEIVABLE Fair Value Disclosures [Text Block] PENSION, POSTRETIREMENT AND OTHER EMPLOYEE BENEFIT PLANS Retirement Benefits [Text Block] Credit Facility [Domain] Credit Facility [Domain] Stockholders' equity: Equity, Attributable to Parent [Abstract] Award vesting percentage Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage Repurchases of common stock Value of shares repurchased Treasury Stock, Value, Acquired, Cost Method Aircraft fuel, spare parts and supplies, net Airline Related Inventory, Net Interest rate Debt Instrument, Interest Rate, Stated Percentage Investment, Name [Axis] Investment, Name [Axis] Future commitments under CPAs Airline Capacity Purchase Arrangements [Member] Long-term obligations under operating leases Long-term lease obligations Operating Lease, Liability, Noncurrent Entity Voluntary Filers Entity Voluntary Filers Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Unconditional Purchase Obligation, Category of Goods or Services Acquired [Domain] Entity Registrant Name Entity Registrant Name Multiemployer Plan Name [Domain] Retirement Plan Name [Domain] Stock Price or TSR Estimation Method Stock Price or TSR Estimation Method [Text Block] Special Purpose Airport Facilities Revenue Bonds Municipal Bonds [Member] Net periodic benefit cost (credit) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Debt Instrument, Redemption, Period Two Debt Instrument, Redemption, Period Two [Member] All other state State and Local Tax Jurisdiction, Other [Member] Cash paid for amounts included in the measurement of lease liabilities: Cash Flow, Leases, Lessee [Abstract] Cash Flow, Leases, Lessee [Abstract] Carrying value of other investment Equity Securities without Readily Determinable Fair Value, Amount Number of operating segments Number of Operating Segments Variable and short-term lease cost Variable And Short-Term Lease, Cost Variable And Short-Term Lease, Cost Related and Nonrelated Parties [Axis] Related and Nonrelated Parties [Axis] Interest cost Defined Benefit Plan, Interest Cost Granted (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Unrecorded Unconditional Purchase Obligation [Table] Unrecorded Unconditional Purchase Obligation [Table] Alliances Alliances [Member] Alliances [Member] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Collaborative Arrangement and Arrangement Other than Collaborative [Axis] Restatement Determination Date: Restatement Determination Date [Axis] Multiemployer Plans [Line Items] Multiemployer Plan [Line Items] Accumulated Other Comprehensive Income (Loss) [Table] Accumulated Other Comprehensive Income (Loss) [Table] Schedule of Components of Special Charges (Credits) Restructuring and Related Costs [Table Text Block] Total income tax expense: Income Tax Expense (Benefit), Continuing Operations [Abstract] Other, net Proceeds from (Payment for) Other Financing Activity Name Trading Arrangement, Individual Name Commitment payment Long-Term Purchase Commitment, Amount Indebtedness incurred Debt Instrument, Face Amount Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Assumptions used to determine net expense Defined Benefit Plan, Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost [Abstract] Name Awards Close in Time to MNPI Disclosures, Individual Name Outstanding (in dollars per share) Outstanding (in dollars per share) Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Aggregate Erroneous Compensation Not Yet Determined Aggregate Erroneous Compensation Not Yet Determined [Text Block] Term of operating leases Lessee, Operating And Finance Leases, Term Of Contract Lessee, Operating And Finance Leases, Term Of Contract ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Employer contribution percentage Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay Stock-settled share-based compensation APIC, Share-Based Payment Arrangement, Increase for Cost Recognition Summary of Scheduled Future Minimum Lease Payments Under Finance Leases Finance Lease, Liability, to be Paid, Maturity [Table Text Block] Fixed-income securities Fixed Income Funds [Member] Changes in value Other Comprehensive Income (Loss) before Reclassifications, Tax Foreign Foreign Tax Jurisdiction [Member] Auditor Firm ID Auditor Firm ID Total noncurrent assets Assets, Noncurrent Undrawn and available amount under revolving credit facility Line of Credit Facility, Remaining Borrowing Capacity Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Projected benefit obligation at beginning of year Projected benefit obligation at end of year Defined Benefit Plan, Benefit Obligation Regional Aircraft Regional Carrier [Member] Amortization of debt discount and debt issuance costs Amortization of Debt Issuance Costs and Discounts Number of shares purchased as a result of warrants exercised (in shares) Class of Warrant or Right, Number of Securities Called by Warrants or Rights Noncurrent assets: Assets, Noncurrent [Abstract] Income Taxes [Table] Income Taxes [Table] Income Taxes [Table] Investments and Other AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-Sale, Parent [Member] Less—Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Income tax benefit, net of valuation allowance Income Tax Expense (Benefit) Special Charges Income tax expense (benefit) special charges. Senior Notes Senior Notes [Member] Preferred stock Preferred Stock, Value, Issued Number of aircraft subject to operating leases Number Of Aircraft Subject To Operating Leases Number Of Aircraft Subject To Operating Leases All Executive Categories All Executive Categories [Member] Schedule of Temporary Differences and Carryforwards Giving Rise to Deferred Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Common stock at par, $0.01 par value; authorized 1,000,000,000 shares; outstanding 323,470,682 and 327,899,771 shares at December 31, 2025 and 2024, respectively Common stock at par, $0.01 par value; authorized 1,000 shares; issued and outstanding 1,000 shares at December 31, 2025 and 2024 Common Stock, Value, Issued Short-term investments Short-Term Investments Commitments and Contingencies Commitments and Contingencies Nonoperating unrealized (gains) losses on investments, net Gain (Loss) On Financial Instruments, Non-Operating Gain (Loss) On Financial Instruments, Non-Operating Assets Measured at NAV Fair Value Measured at Net Asset Value Per Share [Member] Ownership stake Equity Method Investment, Ownership Percentage City Of Houston, Texas City Of Houston, Texas [Member] City Of Houston, Texas Expenses related to ratification payment Labor contract ratification bonuses Special charge in connection with a proposed labor contract ratification payment Labor Contract Ratification Bonus Labor Contract Ratification Bonus PEO Actually Paid Compensation Amount PEO Actually Paid Compensation Amount Period over which miles are expected to be redeemed Revenue, Performance Obligation, Description of Timing Capital loss carryforwards, valuation allowance Capital Loss Carryforwards, Valuation Allowance Capital Loss Carryforwards, Valuation Allowance Revenue from Contract with Customer [Abstract] Pension and postretirement benefit liability Liability, Retirement and Postemployment Benefits Projected benefit obligation Defined Benefit Plan, Pension Plan with Accumulated Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation MileagePlus Senior Secured Notes MileagePlus Senior Secured Notes Due 2027 [Member] MileagePlus Senior Secured Notes Due 2027 Employee benefit plans Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax California CALIFORNIA 2030 Defined Benefit Plan, Expected Future Benefit Payment, Year Five Continuous employment period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period All Individuals All Individuals [Member] Long-term Debt, Type [Domain] Long-Term Debt, Type [Domain] Available for sale investment maturity term (less than) Available for Sale Investment Maturity Term Available for Sale Investment Maturity Term Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] (Increase) decrease in receivables Increase (Decrease) in Receivables Purchase deposits for flight equipment Deposits on Flight Equipment Name Forgone Recovery, Individual Name 2029 Unrecorded Unconditional Purchase Obligation, to be Paid, Year Four Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested Year-over-Year Change in Fair Value of Equity Awards Granted in Prior Years That are Outstanding and Unvested [Member] Liability Awards - RSUs Restricted Stock Units (RSUs) - Liability Awards [Member] Restricted Stock Units (RSUs) - Liability Awards [Member] Decrease in intercompany payable Increase (Decrease) in Due to Affiliates Before Tax AOCI Attributable To Parent, Before Tax [Roll Forward] AOCI Attributable To Parent, Before Tax [Roll Forward] Minimum ratio of appraised value of collateral for credit agreement Debt Instrument, Covenant, Collateral Appraised Value To Outstanding Secured Debt Ratio, Minimum Debt Instrument, Covenant, Collateral Appraised Value To Outstanding Secured Debt Ratio, Minimum Atlantic Atlantic Destination [Member] Equity securities Equity securities Defined Benefit Plan, Equity Securities [Member] Deposit administration fund Deposit Administration Fund [Member] Deposit Administration Fund [Member] Erroneous Compensation Analysis Erroneous Compensation Analysis [Text Block] Intangible Asset, Finite-Lived [Table] Intangible Asset, Finite-Lived [Table] Balance, deferred taxes Balance, deferred taxes AOCI Tax, Attributable to Parent Lessee, Lease, Description [Line Items] Lessee, Lease, Description [Line Items] Rule 10b5-1 Arrangement Terminated Rule 10b5-1 Arrangement Terminated [Flag] 2031 Notes 5.375% Notes Due 2031 [Member] 5.375% Notes Due 2031 Restricted cash - non-current Restricted Cash, Noncurrent, Fair Value Disclosure Restricted Cash Fair Value Disclosure Erroneously Awarded Compensation Recovery Erroneously Awarded Compensation Recovery [Table] Title of 12(b) Security Title of 12(b) Security Lessee, Lease, Description [Table] Lessee, Lease, Description [Table] Floating Rate Debt Floating Rate Debt [Member] Floating Rate Debt [Member] Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward] Earnings Per Share [Abstract] Earnings Per Share [Abstract] 2030 Lessee, Operating Lease, Liability, to be Paid, Year Five Total nonoperating expense, net Nonoperating Income (Expense) Recorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Recorded Unconditional Purchase Obligation by Category of Item Purchased [Axis] Number of defined benefit pension plans Number Of Defined Benefit Pension Plans Number Of Defined Benefit Pension Plans 2026 Contractual Obligation, to be Paid, Year One Tax credits Tax Credit Carryforward, Amount Purchases, sales, issuances and settlements (net) Defined Benefit Plan, Plan Assets Level 3 Reconciliation, Increase (Decrease) for Purchase, Sale, and Settlement Equity securities Equity Securities, FV-NI, Noncurrent Repurchase of common stock (in shares) Number of shares repurchased (in shares) Treasury Stock, Shares, Acquired After 2030 Finance Lease, Liability, to be Paid, after Year Five Award Timing Disclosures [Line Items] Service cost Defined Benefit Plan, Service Cost COMMON STOCKHOLDERS' EQUITY AND PREFERRED SECURITIES Equity [Text Block] US State and Local Deferred State and Local Income Tax Expense (Benefit) Carrying amount of loan receivable Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss Allowance for obsolescence Airline Related Inventory, Valuation Reserves Illinois ILLINOIS Net income Net income Net Income (Loss) Attributable to Parent Schedule of Income Tax Provision Differed from Amounts Computed at the Statutory Federal Income Tax Rate Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Award vesting period Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period Other, net Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Expiration period for refundable tickets Refundable Tickets, Expiration Period Refundable Tickets, Expiration Period Preferred stock authorized to issue (in shares) Preferred Stock, Shares Authorized Repurchases of common stock Payments for Repurchase of Common Stock Adoption Date Trading Arrangement Adoption Date (Receivable from) Payable to Related Parties, Net Receivables from Stockholder [Member] Non-travel miles redeemed Non-Travel Miles Redemption, Frequent Flyer Deferred Revenue Non-travel miles redemption, frequent flyer deferred revenue. Operating income Operating Income (Loss) Payment related to share-based liabilities Share-Based Payment Arrangement, Cash Used to Settle Award Retained earnings Retained Earnings (Accumulated Deficit) Reconciliation of the Change in Benefit Obligation and Plan Assets and Funded Status Schedule of Net Funded Status [Table Text Block] Commitments and Contingencies [Line Items] Commitments and Contingencies [Line Items] Commitments And Contingencies [Line Items] Information Related to Share-Based Compensation Plan Cost Share-Based Payment Arrangement, Cost by Plan [Table Text Block] Ticket Taxes Ticket Taxes, Policy [Policy Text Block] Ticket Taxes, Policy Liabilities related to share based payments Deferred Compensation Share-Based Arrangements, Liability, Current and Noncurrent Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested Year-end Fair Value of Equity Awards Granted in Covered Year that are Outstanding and Unvested [Member] Passenger revenue Passenger [Member] Class of Stock [Axis] Class of Stock [Axis] Subsequent Event Type [Domain] Subsequent Event Type [Domain] Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table Aggregate Grant Date Fair Value of Equity Award Amounts Reported in Summary Compensation Table [Member] Mesa Mesa Air Group, Inc. [Member] Mesa Air Group, Inc. 2029 Contractual Obligation, to be Paid, Year Four Retirement Plan Type [Axis] Retirement Plan Type [Axis] Miscellaneous, net Other Nonoperating Income (Expense) Statement [Table] Statement [Table] SFRB Special Facilities Revenue Bonds [Member] Special Facilities Revenue Bonds Actual return on plan assets Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss) Deferred income tax Total Deferred Deferred Income Tax Expense (Benefit) Adjustments to reconcile net income to net cash provided by (used in) operating activities - Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract] Financing Activities: Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Nontaxable or nondeductible items Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent All other foreign Foreign Tax Jurisdiction, Other [Member] Variable Rate [Domain] Variable Rate [Domain] Balance at January 1 Balance at December 31 Contract with Customer, Liability Long-term lease obligations Finance Lease, Liability, Noncurrent Property and equipment acquired through the issuance or modification of debt, finance leases and other financial liabilities Noncash Or Part Noncash Acquisition, Fixed Assets Acquired, Net Of Vendor Credits Noncash Or Part Noncash Acquisition, Fixed Assets Acquired, Net Of Vendor Credits All Adjustments to Compensation All Adjustments to Compensation [Member] Amendment Flag Amendment Flag Other financial liabilities Deferred Tax Assets, Other Financial Liability Deferred Tax Assets, Other Financial Liability Other Postretirement Benefits Other Postretirement Other Postretirement Benefits Plan [Member] Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Stock held in treasury, at cost Treasury Stock, Common, Value Termination Date Trading Arrangement Termination Date Insider Trading Policies and Procedures Adopted Insider Trading Policies and Procedures Adopted [Flag] Weighted-average discount rate - operating leases Operating Lease, Weighted Average Discount Rate, Percent Unrestricted liquidity required for credit agreement Debt Instrument, Covenant, Unrestricted Liquidity Amount, Minimum Debt Instrument, Covenant, Unrestricted Liquidity Amount, Minimum Basic weighted-average shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Distribution expenses Selling Expense Indefinite-lived intangible assets Indefinite-Lived Intangible Assets (Excluding Goodwill) [Abstract] Obsolescence expense Inventory Write-down Schedule of Computation of Basic and Diluted Earnings Per Share Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Restricted cash in Investments in affiliates and other, net Restricted Cash and Cash Equivalent, Noncurrent Debt Disclosure [Abstract] Debt Disclosure [Abstract] Nonoperating income (expense): Nonoperating Income (Expense) [Abstract] Defined Benefit Plan, Plan Assets, Category [Axis] Defined Benefit Plan, Plan Assets, Category [Axis] Operating expense: Costs and Expenses [Abstract] Amounts reclassified to earnings Reclassification from AOCI, Current Period, Tax Labor Costs Labor Costs [Policy Text Block] Labor Costs Policy Amounts reclassified to earnings Reclassification from AOCI, Current Period, before Tax, Attributable to Parent Restructuring and Related Activities [Abstract] Restructuring and Related Activities [Abstract] Forgone Recovery due to Expense of Enforcement, Amount Forgone Recovery due to Expense of Enforcement, Amount Recorded Unconditional Purchase Obligation, Category [Domain] Recorded Unconditional Purchase Obligation, Category [Domain] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items] Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Participation in the IAM National Pension Plan Multiemployer Plan [Table Text Block] Years 2031 – 2035 Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years Audit Information [Abstract] Audit Information Use of Estimates Use of Estimates, Policy [Policy Text Block] Guarantor Obligations, Nature [Axis] Guarantor Obligations, Nature [Axis] Term Loan Facility Term Loan Facility [Member] Term Loan Facility Due Operating cash flows for finance leases Finance Lease, Interest Payment on Liability Current liability Liability, Defined Benefit Plan, Current Fund United Airlines Ventures Sustainable Flight Fund [Member] United Airlines Ventures Sustainable Flight Fund [Member] Aircraft rent Aircraft Rental Insider Trading Arrangements [Line Items] 2024 Term Loans Term Loan Due 2024 [Member] Term Loan Due 2024 Travel miles redeemed Travel Miles Redemption, Frequent Flyer Deferred Revenue Travel miles redemption, frequent flyer deferred revenue. Other operating revenue Product and Service, Other [Member] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] 2030 Finance Lease, Liability, to be Paid, Year Five Pension Adjustments Prior Service Cost Pension Adjustments Prior Service Cost [Member] Redemption of aggregate principal amount of outstanding debt Debt Instrument, Repurchased Face Amount Material Terms of Trading Arrangement Material Terms of Trading Arrangement [Text Block] Indirect Guarantee of Indebtedness Indirect Guarantee of Indebtedness [Member] NOLs without an expiration date Deferred Tax Assets, Operating Loss Carryforwards, Not Subject to Expiration Anticipated employer contributions Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Variable Rate [Axis] Variable Rate [Axis] Other Secured Debt Other Secured Debt [Member] Other Secured Debt Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Non-NEOs Non-NEOs [Member] Corporate debt Corporate Debt Corporate Debt Securities [Member] Total liability Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position Aircraft seats Aircraft Seats [Member] Aircraft Seats [Member]