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Percentage of employees represented by labor organizations

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Commitments and Contingencies - Narrative (Details) employee in Thousands, $ in Millions		6 Months Ended
	Apr. 17, 2024	Jun. 30, 2024 USD ($) employee aircraft	Jul. 31, 2024 aircraft	Jul. 18, 2024 USD ($)
Commitments and Contingencies [Line Items]
Additional leases		$ 13,300
United Airlines, Inc.
Commitments and Contingencies [Line Items]
Number of employees \| employee		106
Percentage of employees represented by various U.S. labor organizations		82.00%
Proposed extension period for technician labor contracts	4 years
Tax-Exempt Special Facilities Revenue Bonds
Commitments and Contingencies [Line Items]
Aggregate principal amount of guarantee		$ 1,900
Aircraft Mortgage Debt
Commitments and Contingencies [Line Items]
Aggregate principal amount of guarantee		70
Floating Rate Debt
Commitments and Contingencies [Line Items]
Long-term debt		$ 10,300
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		$ 7,200
Subsequent Event
Commitments and Contingencies [Line Items]
Additional leases				$ 3,700
Lease terms of additional leases				12 years
A321neo
Commitments and Contingencies [Line Items]
Number of aircrafts with expected deliveries in 2026 and 2027 \| aircraft		40
A321neo \| Subsequent Event
Commitments and Contingencies [Line Items]
Number of aircraft entered into lease agreements \| aircraft			35