Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Basic EPS
Net earnings	$ 1,631	$ 1,598	$ 5,257	$ 4,562
Earnings allocated to participating securities	8	8	26	23
Earnings available to common shareholders	$ 1,623	$ 1,590	$ 5,231	$ 4,539
Weighted-average basic shares outstanding (in shares)	1,597	1,632	1,596	1,624
Basic earnings per share (in dollars per share)	$ 1.02	$ 0.97	$ 3.28	$ 2.79
Diluted EPS
Net earnings	$ 1,631	$ 1,598	$ 5,257	$ 4,562
Earnings allocated to participating securities	8	8	26	23
Earnings available to common shareholders	$ 1,623	$ 1,590	$ 5,231	$ 4,539
Weighted-average basic shares outstanding (in shares)	1,597	1,632	1,596	1,624
Effect of dilutive securities (in shares)	6	8	6	9
Weighted-average diluted shares outstanding (in shares)	1,603	1,640	1,602	1,633
Diluted earnings per share (in dollars per share)	$ 1.01	$ 0.97	$ 3.27	$ 2.78