Stock-based Compensation Plans - Restricted Stock Activity (Detail) - Restricted Stock - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unvested at beginning of year, Restricted Stock	14	18	22
Granted, Restricted Stock	6	5	7
Adjustments for performance achieved, Restricted Stock	1	2	2
Vested, Restricted Stock	(8)	(11)	(13)
Unvested at year-end, Restricted Stock	13	14	18
Unvested at beginning of year, Weighted-Average Grant Date Fair Value	$ 39.88	$ 30.24	$ 29.03
Granted, Weighted-Average Grant Date Fair Value	45.44	56.24	36.16
Adjustments for performance achieved, Weighted-Average Grant Date Fair Value	22.85	32.47	35.55
Vested, Weighted-Average Grant Date Fair Value	32.5	29.82	32.42
Unvested at year-end, Weighted-Average Grant Date Fair Value	$ 46.12	$ 39.88	$ 30.24