Acquisitions and Dispositions (Pro-Forma Information) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Business Combinations [Abstract]
Revenue	$ 4,080	$ 4,098
Net income attributable to the Company	$ 717	$ 694
Basic net income per share:
Basic net income per share attributable to the Company (in dollars per share)	$ 1.42	$ 1.37
Diluted net income per share:
Diluted net income per share attributable to the Company (in dollars per share)	$ 1.40	$ 1.35