Earnings Per Common Share - Computations of Basic Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income available to common shareholders:
Net income	$ 2,588	$ 2,741	$ 1,992
Less: Preferred stock dividends	(134)	(100)	(97)
Net income available to common equity	2,454	2,641	1,895
Less: Income attributable to unvested stock-based compensation awards	(5)	(5)	(4)
Net income available to common shareholders	$ 2,449	$ 2,636	$ 1,891
Weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards	166,806	166,662	163,489
Unvested stock awards (in shares)	(327)	(301)	(315)
Weighted-average shares outstanding (in shares)	166,479	166,361	163,174
Basic earnings per common share (in USD per share)	$ 14.71	$ 15.85	$ 11.59