Derivatives 2 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010	Mar. 31, 2011	Sep. 30, 2011 Other Current Assets [Member]	Mar. 31, 2011 Other Current Assets [Member]	Sep. 30, 2011 Other Noncurrent Assets, Net [Member]	Mar. 31, 2011 Other Noncurrent Assets, Net [Member]	Sep. 30, 2011 Accrued expenses and other current liabilities [Member]	Mar. 31, 2011 Accrued expenses and other current liabilities [Member]	Sep. 30, 2011 Interest Rate Swap [Member]	Mar. 31, 2009 Interest Rate Swap [Member]	Sep. 30, 2011 6.125% Notes due December 2014 [Member]
Derivatives (Textual) [Abstract]
Notional amount of fair value hedge instruments											$ 500
Fair value of interest rate derivative assets		30		15	11	11	19	4
Notional amount of cash flow hedge instruments												250
Fair value of foreign currency contracts included in "Other current assets"					22	7
Fair value of foreign currency contracts included in "Accrued expenses and other current liabilities"									12	1
Debt Instrument [Line Items]
Long-term debt, interest rate													6.125%
Derivative Instrument (Textual) [Abstract]
Total value of senior notes subject to fair value interest rate swaps		500
Accumulated other comprehensive income loss reclassified into interest expense	1		3
Purchase and sale of notional value of foreign currency contracts outstanding		574
Tenure of foreign currency contracts outstanding		less than six months
Net fair value of foreign currency contracts		$ 10		$ 6