Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Receivables - allowance for credit losses	$ 30	$ 28
Aircraft fuel, spare, parts and supplies - obsolescence allowance	561	546
Intangibles - accumulated amortization	1,554	1,544
Allowance for credit losses on investments in affiliates and other	$ 619	$ 622
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common shares, authorized (in shares)	1,000,000,000	1,000,000,000
Common shares, outstanding (in shares)	326,728,861	323,810,825