Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 105	$ 30
Liabilities assumed	(4)	(2)
Contingent/deferred purchase consideration	(26)	(12)
Net cash outflow for acquisitions	75	16
Interest paid	58	40
Income taxes paid, net of refunds	$ 187	$ 118