Balance Sheet Details (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2015	[1]
Balance Sheet Related Disclosures [Abstract]
Depreciation expense	$ 31	$ 32	$ 91	$ 96
Deferred Revenue, Current	$ 1,844		$ 1,844		$ 1,283

[1] Derived from audited Consolidated Financial Statements.