Supplemental Disclosures (Schedule of Analysis for Doubtful Accounts) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of year	$ 106	$ 105	$ 114
Provision charged to operations	16	11	11
Accounts written-off, net of recoveries	(19)	(12)	(21)
Effect of exchange rate changes and other	(5)	2	1
Balance at end of year	$ 98	$ 106	$ 105