Earnings Per Common Share - Earnings Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net earnings to common	$ 1,123	$ 2,182
Weighted average basic shares	358.0	379.8
Effect of dilutive:
RSUs	3.1	2.6
Weighted average diluted shares	361.1	382.4
Basic EPS	$ 3.12	$ 5.73
Diluted EPS	$ 3.11	$ 5.71