Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Net income	$ 1,305	$ 726	$ 2,398	$ 1,165
Weighted-average shares outstanding	467,981,077	467,701,328	468,244,458	457,102,802
Share-based compensation plans	3,872,860	3,455,969	3,900,678	3,379,559
Weighted-average shares outstanding and assumed conversions	471,853,937	471,157,297	472,145,136	460,482,361
Basic earnings per share (US$ per share)	$ 2.79	$ 1.55	$ 5.12	$ 2.55
Diluted earnings per share (US$ per share)	$ 2.77	$ 1.54	$ 5.08	$ 2.53
Potential anti-dilutive share conversions	2,066,578	2,103,281	1,467,556	2,056,018