Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Shareholders’ net income	$ 1,388	$ 1,351	$ 4,323	$ 4,127
Shares:
Weighted average (in shares)	364,427	374,842	367,410	377,381
Common stock equivalents (in shares)	2,763	3,479	3,421	3,710
Total shares (in shares)	367,190	378,321	370,831	381,091
EPS, basic (in dollars per share)	$ 3.81	$ 3.60	$ 11.77	$ 10.94
EPS, effect of dilution (in dollars per share)	(0.03)	(0.03)	(0.11)	(0.11)
EPS, diluted (in dollars per share)	$ 3.78	$ 3.57	$ 11.66	$ 10.83