Goodwill and Other Intangibles (Changes in the Carrying Amount of Goodwill) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Goodwill [Roll Forward]
Balance as of January 1,		$ 9,599	$ 9,089
Goodwill acquired		97	15
Other adjustments	[1]	43	90
Balance at March 31,		$ 9,739	$ 9,194

[1] Primarily reflects the impact of foreign exchange.