Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 30	$ 464
Liabilities assumed	(2)	(38)
Contingent/deferred purchase consideration	(12)	(113)
Net cash outflow for current year acquisitions	16	313
Interest paid	40	44
Income taxes paid	$ 118	$ 120