Derivatives 2 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Mar. 31, 2012
Derivatives, Fair Value [Line Items]
Total value of Senior Notes subject to fair value interest rate swaps	$ 500
Fair value of interest rate derivative assets	22	27
Notional value of purchase and sales contracts for foreign currency contracts outstanding	740	893
Tenure of foreign currency contracts outstanding	less than three months	less than six months
Net liability position of foreign currency contracts	less than $1 million
Net fair value of foreign currency contracts		(2)
6.125% Notes due December 2014 [Member]
Derivatives, Fair Value [Line Items]
Long-term debt, interest rate	6.125%
Interest Rate Swaps [Member]
Derivatives, Fair Value [Line Items]
Notional amount of fair value hedge instruments	500
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Fair value of interest rate derivative assets	12	11
Fair value of foreign currency contracts included in "Other current assets"	4	2
Other Noncurrent Assets, Net [Member]
Derivatives, Fair Value [Line Items]
Fair value of interest rate derivative assets	10	16
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"	$ 4	$ 4