Share-Based Compensation Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Shares
Outstanding at beginning of period (in shares)	852	852	788
Granted (in shares)	0	0	130
Exercised (in shares)	(23)	0	(38)
Expired or cancelled (in shares)	(19)	0	(28)
Outstanding at end of period (in shares)	810	852	852
Exercisable (in shares)	706	639	510
Wtd. Avg. Exercise Price Per Share
Outstanding at beginning of period (in dollars per share)	$ 90	$ 90	$ 91
Granted (in dollars per share)			92
Exercised (in dollars per share)	76		93
Expired or cancelled (in dollars per share)	109		123
Outstanding at end of period (in dollars per share)	90	90	90
Exercisable (in dollars per share)	$ 90	$ 90	$ 89
Wtd. Avg. Remaining Contractual Term and Aggregate Intrinsic Value
Outstanding (in years)	4 years 4 months 24 days	5 years 1 month 6 days	6 years 1 month 6 days
Exercisable (in years)	4 years 1 month 6 days	4 years 4 months 24 days	4 years 9 months 18 days
Outstanding	$ 1	$ 2	$ 8
Exercised			0
Exercisable	$ 1	$ 2	$ 6