COMMITMENTS, CONTINGENCIES, AND GUARANTEES - Narrative (Details) $ in Billions	3 Months Ended
Mar. 31, 2025 USD ($) employee
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Number of employees \| employee	109,200
Percentage of employees represented by various U.S. labor organizations	82.00%
Tax-Exempt Special Facilities Revenue Bonds
Commitments and Contingencies [Line Items]
Aggregate principal amount of guarantee	$ 2.9
Floating Rate Debt
Commitments and Contingencies [Line Items]
Long-term debt, carrying amount	$ 8.4
Remaining term of debt	12 years
Loans and Leases from Non-U.S. Entities
Commitments and Contingencies [Line Items]
Remaining term of debt	12 years
Aggregate balance	$ 5.2

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Commitments And Contingencies [Line Items]

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Years remaining on debt instruments.

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Percentage of employees represented by labor organizations

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Amount of contractual obligation, including, but not limited to, long-term debt, lease obligation, purchase obligation, and other commitments.

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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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