Earnings Per Common Share - Computation of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Income from continuing operations, net of tax	$ 4,887	$ 7,360	$ 12,394
Income (loss) from discontinued operations, net of tax	0	0	(4)
Net income	4,887	7,360	12,390
Dividends and undistributed earnings allocated to participating securities	(77)	(88)	(105)
Preferred stock dividends	(228)	(228)	(274)
Issuance cost for redeemed preferred stock	0	0	(46)
Net income available to common stockholders	$ 4,582	$ 7,044	$ 11,965
Total weighted-average basic common shares outstanding (in shares)	382,400	391,800	442,500
Effect of dilutive securities:
Stock options (in shares)	100	300	700
Other contingently issuable shares (in shares)	900	1,100	1,000
Total effect of dilutive securities (in shares)	1,000	1,400	1,700
Total weighted-average diluted common shares outstanding (in shares)	383,400	393,200	444,200
Basic earnings per common share:
Net income from continuing operations (in dollars per share)	$ 11.98	$ 17.98	$ 27.05
Income (loss) from discontinued operations (in dollars per share)	0.00	0.00	(0.01)
Net income per basic common share (in dollars per share)	11.98	17.98	27.04
Diluted earnings per common share:
Net income from continuing operations (in dollars per share)	11.95	17.91	26.95
Income (loss) from discontinued operations (in dollars per share)	0.00	0.00	(0.01)
Net income per diluted common share (in dollars per share)	$ 11.95	$ 17.91	$ 26.94
Award
Diluted earnings per common share:
Anti-dilutive options excluded from the computation of diluted earnings per share (in shares)	27	24	26
Stock options
Diluted earnings per common share:
Anti-dilutive options excluded from the computation of diluted earnings per share (in shares)	0	0	0