Contractual interest rate for funds borrowed, under the debt agreement.

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Debt - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Debt - Narrative (Details) - USD ($) $ in Millions	Jun. 30, 2022	Jun. 30, 2022	Jun. 30, 2021
Debt Instrument [Line Items]
Unamortized debt discount	$ 447	$ 447
Proceeds from issuance of debt, net of discounts and fees		$ 212	$ 11,116
Secured Debt
Debt Instrument [Line Items]
Proceeds from issuance of debt, net of discounts and fees	$ 220
Stated interest rate	4.00%	4.00%
United Airlines, Inc.
Debt Instrument [Line Items]
Proceeds from issuance of debt, net of discounts and fees		$ 212	$ 11,116
Revolving Credit Facility \| United Airlines, Inc. \| Secured Debt
Debt Instrument [Line Items]
Available under revolving credit facility	$ 1,750	$ 1,750