Earnings Per Common Share - Computation of Basic and Diluted Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income	$ 1,280	$ 960
Dividends and undistributed earnings allocated to participating securities	(23)	(16)
Preferred stock dividends	(57)	(57)
Net income available to common stockholders	$ 1,200	$ 887
Total weighted-average basic common shares outstanding (in shares)	382,200	382,600
Effect of dilutive securities:
Stock options (in shares)	200	100
Other contingently issuable shares (in shares)	1,000	1,100
Total effect of dilutive securities (in shares)	1,200	1,200
Total weighted-average diluted common shares outstanding (in shares)	383,400	383,800
Basic earnings per common share:
Net income per basic common share (in dollars per share)	$ 3.14	$ 2.32
Diluted earnings per common share:
Net income per diluted common share (in dollars per share)	$ 3.13	$ 2.31
Award
Diluted earnings per common share:
Anti-dilutive options excluded from the computation of diluted earnings per share (in shares)	128	40
Stock options
Diluted earnings per common share:
Anti-dilutive options excluded from the computation of diluted earnings per share (in shares)	0	0