Earnings Per Common Share - Computations of Diluted Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net income available to common equity	$ 506	$ 677
Less: Income attributable to unvested stock-based compensation awards	(1)	(1)
Net income available to common shareholders	$ 505	$ 676
Adjusted weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards	166,738	168,010
Less: Unvested stock-based compensation awards	(278)	(278)
Plus: Incremental shares from assumed conversion of stock-based compensation awards	624	678
Adjusted weighted-average shares outstanding	167,084	168,410
Diluted earnings per common share	$ 3.02	$ 4.01