Employee Incentive Plans - Summary of Information for Stock Options Outstanding (Details) - Employee Stock Options - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Options Outstanding
Number (in shares)	6,696	6,992	8,490	9,742
Total intrinsic value	$ 652
Weighted average exercise price (in dollars per share)	$ 202.02	$ 186.54	$ 169.47	$ 152.40
Weighted average remaining contractual life	5 years 10 months 24 days
Options Exercisable
Number (in shares)	4,616	4,410	5,612
Total intrinsic value	$ 555
Weighted average exercise price (in dollars per share)	$ 179.28	$ 168.97	$ 152.92
Weighted average remaining contractual life	4 years 8 months 12 days