Acquisitions / Dispositions (Pro-Forma Information) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Combinations [Abstract]
Revenue	$ 13,503	$ 13,528	$ 13,395
Income from continuing operations	1,792	1,643	1,475
Net income attributable to the Company	$ 1,765	$ 1,606	$ 1,469
Basic net income per share:
Basic net income per share - Continuing operations (in dollars per share)	$ 3.40	$ 3.02	$ 2.65
Basic net income per share - Net income attributable to the Company (in dollars per share)	3.40	3.02	2.69
Diluted net income per share:
Diluted net income per share - Continuing operations (in dollars per share)	3.37	2.99	2.61
Diluted net income per share - Net income attributable to the Company (in dollars per share)	$ 3.37	$ 2.99	$ 2.66