Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Earnings Per Share [Abstract]
Shareholders' net income	$ 1,351	$ 772	$ 4,127	$ 2,493
Shares:
Weighted average	374,842	242,577	377,381	242,404
Common stock equivalents	3,479	3,535	3,710	3,343
Total shares	378,321	246,112	381,091	245,747
EPS, basic	$ 3.60	$ 3.18	$ 10.94	$ 10.28
EPS, effect of dilution	(0.03)	(0.04)	(0.11)	(0.14)
EPS, diluted	$ 3.57	$ 3.14	$ 10.83	$ 10.14
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Common shares held in Treasury	10,400		10,400		52,600
Employee Stock Option [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive options	3,600	900	3,900	900