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, 2014	Mar. 31, 2013
Supplemental Cash Flow Information [Abstract]
Assets acquired, excluding cash	$ 464	$ 0
Liabilities assumed	(38)	0
Contingent/deferred purchase consideration	(113)	0
Net cash outflow for current year acquisitions	313	0
Deferred purchase consideration from prior years' acquisitions	6	1
Net cash outflow for acquisitions	319	1
Interest paid	44	59
Income taxes paid	$ 120	$ 85