Computation of Basic and Diluted Earnings Per Share (Detail) - 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
Numerator:
Net income attributable to common shareowners	$ 1,264	$ 1,270	$ 3,806	$ 3,670
Denominator:
Weighted average shares	864	876	867	880
Deferred compensation obligations	1	1	1	1
Vested portion of restricted shares	4	3	4	4
Denominator for basic earnings per share	869	880	872	885
Effect of dilutive securities:
Denominator for diluted earnings per share	874	885	876	889
Basic earnings per share (usd per share)	$ 1.45	$ 1.44	$ 4.36	$ 4.15
Diluted earnings per share (usd per share)	$ 1.45	$ 1.44	$ 4.34	$ 4.13
Restricted performance units
Effect of dilutive securities:
Incremental common shares attributable to share-based payment arrangements	4	4	3	3
Stock option plans
Effect of dilutive securities:
Incremental common shares attributable to share-based payment arrangements	1	1	1	1