Derivatives 1 (Details) - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
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	$ 0	$ 0	$ (8)
Foreign Currency Contracts | Other Expenses, 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	$ 4	$ 6	$ (31)