Earnings Per Common Share - Computation of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Income (loss) from continuing operations, net of tax	$ 7,360	$ 12,394	$ 2,717
Income (loss) from discontinued operations, net of tax	0	(4)	(3)
Net income	7,360	12,390	2,714
Dividends and undistributed earnings allocated to participating securities	(88)	(105)	(20)
Preferred stock dividends	(228)	(274)	(280)
Issuance cost for redeemed preferred stock	0	(46)	(39)
Net income available to common stockholders	$ 7,044	$ 11,965	$ 2,375
Total weighted-average basic common shares outstanding	391.8	442.5	457.8
Effect of dilutive securities:
Stock options	0.3	0.7	0.6
Other contingently issuable shares	1.1	1.0	0.5
Total effect of dilutive securities	1.4	1.7	1.1
Total weighted Average Number of Shares Outstanding, Diluted, Total	393.2	444.2	458.9
Basic earnings per common share:
Net income from continuing operations	$ 17.98	$ 27.05	$ 5.20
Income (loss) from discontinued operations	0.00	(0.01)	(0.01)
Net income per basic common share	17.98	27.04	5.19
Diluted earnings per common share:
Net income from continuing operations	17.91	26.95	5.19
Income (loss) from discontinued operations	0.00	(0.01)	(0.01)
Net income per diluted common share	$ 17.91	$ 26.94	$ 5.18