Supplemental Disclosures to the Consolidated Statements of Cash Flows (Additional Information Concerning Acquisitions, Interest And Income Taxes Paid) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 338	$ 554
Liabilities assumed	(12)	(40)
Contingent/deferred purchase consideration	(95)	(140)
Net cash outflow for current year acquisitions	231	374
Cash paid into escrow for future acquisition	29	0
Net cash outflow for acquisitions	260	374
Interest paid	69	82
Income taxes paid	$ 223	$ 218