Consolidated Statement of Comprehensive Income (Loss) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income (loss)	$ 539	$ 977	$ (3,074)
Unrealized gain (loss) on defined benefit plan items, net of deferred taxes of $24, $25, and ($15)	80	84	(48)
Other, net of deferred taxes of $—, ($13), and $7	0	(47)	25
OTHER COMPREHENSIVE INCOME (LOSS)	(44)	513	(44)
COMPREHENSIVE INCOME (LOSS)	495	1,490	(3,118)
Fuel derivative contracts
Unrealized gain (loss) on derivatives, net of tax	(143)	469	4
Interest rate derivatives
Unrealized gain (loss) on derivatives, net of tax	$ 19	$ 7	$ (25)