Employee Stock Plans - Summary of Status of Senior Executive Plans (Detail) - $ / shares shares in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Shares
Granted (in shares)	1.8	1.8	3.0
Vested (in shares)	(2.3)	(1.5)	(1.1)
Restricted Stock | Executive Officer
Shares
Balance, at beginning of year (in shares)	3.4	3.2	1.6
Granted (in shares)	1.6	1.6	2.7
Vested (in shares)	(2.2)	(1.3)	(0.9)
Forfeited/expired (in shares)	(0.2)	(0.1)	(0.2)
Balance, at end of year (in shares)	2.6	3.4	3.2
Issued in calendar year (in shares)	0.7	0.5	0.6
Fair Value
Balance, at beginning of year (in dollars per share)	$ 15	$ 12	$ 10
Granted (in dollars per share)	16	17	14
Vested (in dollars per share)	19	16	17
Forfeited/expired (in dollars per share)	19	16	17
Balance, at end of year (in dollars per share)	17	15	12
Issued in calendar year (in dollars per share)	$ 16	$ 17	$ 15