Stock Compensation - Stock Options and RSUs Outstanding (Details) - Long-term incentive and director compensation plans - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Employee Stock Option
Stock Options, Shares
Options outstanding, Beginning balance (in shares)	25
Granted (in shares)	4
Exercised (in shares)	(3)
Options outstanding, Ending balance (in shares)	26	25
Stock Options, Weighted Average Exercise Price per Share
Weighted-average exercise price, Outstanding, Beginning of period (in dollars per share)	$ 105.75
Weighted-average exercise price, Granted (in dollars per share)	173.90
Weighted-average exercise price, Exercised (in dollars per share)	71.16
Weighted-average exercise price, Outstanding, End of period (in dollars per share)	$ 119.60	$ 105.75
Restricted Stock Units, Weighted Average Grant Date Fair Value per Share
Aggregate intrinsic values of options exercised	$ 319	$ 336	$ 611
Restricted Stock Units (RSUs)
Restricted Stock Units, Shares
Awards outstanding other than options, Beginning balance (in shares)	5
Granted (in shares)	2
Vested (in shares)	(2)
Awards outstanding other than options, Ending balance (in shares)	5	5
Restricted Stock Units, Weighted Average Grant Date Fair Value per Share
Weighted-average grant date fair value, Beginning of period (in dollars per share)	$ 147.30
Weighted-average grant-date fair value, Granted (in dollars per share)	172.59	$ 174.39	$ 176.08
Weighted-average grant date fair value, Vested (in dollars per share)	108.04
Weighted-average grant date fair value, Ending of period (in dollars per share)	161.40	147.30
Weighted-average grant-date fair value, Granted (in dollars per share)	$ 172.59	$ 174.39	$ 176.08
Total fair values of shares vested from RSU lapses	$ 106	$ 121	$ 115