Derivatives 1 (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2011	Dec. 31, 2010
Other (gains) expenses, net [Member] | Foreign Exchange Contract [Member]
Effect of interest rate and foreign exchange derivatives on Consolidated Statement of Operations
Amount of Net (Gain)/Loss Recognized in the Consolidated Statement of Operations	$ 8	$ 1	$ 9	$ 9
Cash Flow Hedging [Member] | Interest Expense [Member] | Interest Rate Swap [Member]
Effect of interest rate and foreign exchange derivatives on Consolidated Statement of Operations
Amount of Net (Gain)/Loss Recognized in the Consolidated Statement of Operations	0	1	0	4
Fair Value Hedging [Member] | Interest Expense [Member] | Interest Rate Swap [Member]
Effect of interest rate and foreign exchange derivatives on Consolidated Statement of Operations
Amount of Net (Gain)/Loss Recognized in the Consolidated Statement of Operations	$ (3)	$ (3)	$ (9)	$ (9)