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, 2025	Mar. 31, 2024
Earnings Per Share [Abstract]
Net income available to common equity	$ 548	$ 506
Less: Income attributable to unvested stock-based compensation awards	(1)	(1)
Net income available to common shareholders	$ 547	$ 505
Adjusted weighted-average shares outstanding:
Common shares outstanding (including common stock issuable) and unvested stock-based compensation awards	164,520	166,738
Less: Unvested stock-based compensation awards	(311)	(278)
Plus: Incremental shares from assumed conversion of stock-based compensation awards	838	624
Adjusted weighted-average shares outstanding (in shares)	165,047	167,084
Diluted earnings per common share (in USD per share)	$ 3.32	$ 3.02