Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Earnings Per Share [Abstract]
Net income	$ 252	$ 1,040
Weighted-average shares outstanding	451,868,658	458,805,185
Share-based compensation plans	2,651,610	2,731,755
Weighted-average shares outstanding and assumed conversions	454,520,268	461,536,940
Basic earnings per share (US$ per share)	$ 0.56	$ 2.27
Diluted earnings per share (US$ per share)	$ 0.55	$ 2.25
Potential anti-dilutive share conversions	3,154,406	4,343,204