Balance Sheet Details (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	[1]
Remaining Performance Obligations
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months
Depreciation expense	$ 31	$ 30
Deferred Revenue, Current	878		$ 945
Deferred Revenue, Revenue Recognized	$ 742	$ 797

[1] Derived from audited Consolidated Financial Statements.