Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share Reconciliation [Abstract]
Net income	$ 1,018	$ 733
Participating share-based awards — allocated income	(7)	(5)
Net income available to common shareholders -- basic	1,011	728
Net income available to common shareholders -- diluted	$ 1,011	$ 728
Weighted average shares outstanding, basic (in shares)	240.9	252.1
Weighted average effects of dilutive securities - stock options and performance shares (in shares)	2.8	2.0
Weighted average shares outstanding, diluted (in shares)	243.7	254.1
Net income per common share, basic (in dollars per share)	$ 4.20	$ 2.89
Net income per common share, diluted (in dollars per share)	$ 4.15	$ 2.87