Derivatives 1 (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Interest Rate Swaps | Fair Value Hedges | Interest Expense, Net
Effect of interest rate and foreign exchange derivatives on Consolidated Statements of Operations
Amount of net (gain)/loss from derivative instruments recognized in the Consolidated Statements of Operations	$ (8)	$ (12)	$ (12)
Foreign Currency Contracts | Other Expenses (Gains), Net
Effect of interest rate and foreign exchange derivatives on Consolidated Statements of Operations
Amount of net (gain)/loss from derivative instruments recognized in the Consolidated Statements of Operations	$ (31)	$ (20)	$ 11