Earnings Per Share (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 734	$ 953
Weighted-average shares outstanding	338,869,562	340,778,142
Share-based compensation plans	3,171,174	3,128,226
Adjusted weighted-average shares outstanding and assumed conversions	342,040,736	343,906,368
Basic earnings per share (US$ per share)	$ 2.16	$ 2.80
Diluted earnings per share (US$ per share)	$ 2.14	$ 2.77
Potential anti-dilutive share conversions	657,182	634,385