Acquisitions (Pro-Forma Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Business Combinations [Abstract]
Revenue	$ 3,137	$ 3,177	$ 9,860	$ 9,838
Income from continuing operations	384	333	1,357	1,283
Net income attributable to the Company	$ 379	$ 328	$ 1,335	$ 1,251
Basic net income per share:
Basic net income per share - Continuing operations (in dollars per share)	$ 0.73	$ 0.62	$ 2.57	$ 2.35
Basic net income per share - Net income attributable to the Company (in dollars per share)	0.73	0.62	2.57	2.34
Diluted net income per share:
Diluted net income per share - Continuing operations (in dollars per share)	0.73	0.61	2.54	2.32
Diluted net income per share - Net income attributable to the Company (in dollars per share)	$ 0.73	$ 0.61	$ 2.54	$ 2.32