Goodwill and Other Intangibles (Changes in the Carrying Amount of Goodwill) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Goodwill [Roll Forward]
Balance as of January 1, as reported		$ 7,889	$ 7,241
Goodwill acquired		61	12
Other adjustments	[1]	0	(93)
Balance at March 31,		$ 7,950	$ 7,160

[1] Primarily reflects the impact of foreign exchange in each period.