Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings Per Share Reconciliation [Abstract]
Net income	$ 2,991	$ 2,842	$ 3,662
Participating share-based awards — allocated income	(22)	(20)	(27)
Net income available to common shareholders -- basic	2,969	2,822	3,635
Net income available to common shareholders -- diluted	$ 2,969	$ 2,822	$ 3,635
Weighted average shares outstanding, basic (in shares)	229.7	237.0	248.5
Weighted average effects of dilutive securities - stock options and performance shares (in shares)	2.5	2.7	2.3
Weighted average shares outstanding, diluted (in shares)	232.2	239.7	250.8
Net income per common share, basic (in dollars per share)	$ 12.93	$ 11.91	$ 14.63
Net income per common share, diluted (in dollars per share)	$ 12.79	$ 11.77	$ 14.49