Goodwill and Other Intangibles (Changes in the Carrying Amount of Goodwill) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Goodwill [Roll Forward]
Balance as of January 1, as reported		$ 8,369	$ 7,889
Goodwill acquired		363	61
Other adjustments	[1]	37	0
Balance at March 31,		$ 8,769	$ 7,950

[1] (a) The increase in 2017 primarily reflects the impact of foreign exchange.