Derivatives 2 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
6.125% Senior Notes due December 2014 (6.125% Notes) [Member]
Derivatives, Fair Value [Line Items]
Total value of Senior Notes subject to fair value interest rate swaps	$ 500
Senior Notes, Interest rate	6.125%
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Fair value of interest rate derivative assets	8	19
Interest Rate Swaps [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of interest rate derivative assets	8	11
Interest Rate Swaps [Member] | Other Noncurrent Assets, Net [Member]
Derivatives, Fair Value [Line Items]
Fair value of interest rate derivative assets		8
Interest Rate Swaps [Member] | Fair Value Hedges [Member]
Derivatives, Fair Value [Line Items]
Notional value of derivative instruments	500
Foreign Currency Contracts [Member]
Derivatives, Fair Value [Line Items]
Notional value of derivative instruments	250	597
Tenure of foreign currency contracts outstanding	less than three months	less than one month
Net fair value of foreign currency contracts	1	1
Foreign Currency Contracts [Member] | Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of foreign currency contracts included in "Other current assets"	2	1
Foreign Currency Contracts [Member] | Accrued Expenses and Other Current Liabilities [Member]
Derivatives, Fair Value [Line Items]
Fair value of foreign currency contracts included in "Accrued expenses and other current liabilities"	$ 1