Earnings (Loss) Per Common Share - Computation of Basic and Diluted (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Basic EPS:
Net income (loss)	$ (149)	$ 717	$ (312)	$ (545)	$ 1,338	$ 10	$ 256	$ 803
Weighted average common shares outstanding (in thousands) (in shares)	657,424			654,119			656,745	653,241
Basic EPS (in dollars per share)	$ (0.23)			$ (0.83)			$ 0.39	$ 1.23
Diluted EPS:
Net income (loss)	$ (149)	$ 717	$ (312)	$ (545)	$ 1,338	$ 10	$ 256	$ 803
Interest expense on 6.50% convertible senior notes	0			0			0	33
Net income (loss) for purposes of computing diluted EPS	$ (149)			$ (545)			$ 256	$ 836
Share computation for diluted EPS (in thousands):
Basic weighted average common shares outstanding (in shares)	657,424			654,119			656,745	653,241
Dilutive effect of stock awards (in shares)	0			0			888	1,677
Dilutive effect of certain PSP Warrants and Treasury Loan Warrants (in shares)	0			0			1,142	3,310
Assumed conversion of 6.50% convertible senior notes (in shares)	0			0			0	61,728
Diluted weighted average common shares outstanding (in shares)	657,424			654,119			658,775	719,956
Diluted EPS (in dollars per share)	$ (0.23)			$ (0.83)			$ 0.39	$ 1.16
6.50% Senior Notes | Senior Notes
Diluted EPS:
Interest rate	6.50%						6.50%