Accounts Receivable (Allowance for Doubtful Accounts Activity) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at Beginning of Period	$ 4	$ 3	$ 5
Additions Charged to Expense	0	2	2
Accounts Recovered/ (Written- Off)	0	(1)	(4)
Foreign Exchange and Other	(1)	0	0
Balance at End of Period	$ 3	$ 4	$ 3