COMMITMENTS, CONTINGENCIES, AND GUARANTEES - Narrative (Details) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
|
Jun. 30, 2025
USD ($)
employee
|
Jun. 30, 2024
USD ($)
|
Jun. 30, 2025
USD ($)
employee
|
Jun. 30, 2024
USD ($)
|
|
| Commitments and Contingencies [Line Items] | ||||
| Special charges ratification payment | $ 561 | $ 0 | $ 561 | $ 0 |
| United Airlines, Inc. | ||||
| Commitments and Contingencies [Line Items] | ||||
| Number of employees | employee | 111,300 | 111,300 | ||
| 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 | $ 2,900 | $ 2,900 | ||
| Floating Rate Debt | ||||
| Commitments and Contingencies [Line Items] | ||||
| Long-term debt, carrying amount | 8,300 | $ 8,300 | ||
| 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 | $ 5,100 | $ 5,100 | ||