Balance Sheet Details (Property And Equipment, Net Schedule) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Mar. 31, 2021
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 1,581		$ 1,581		$ 1,521
Less: accumulated depreciation	(1,059)		(1,059)		(1,030)
Property and equipment, net	522		522		491	[1]
Depreciation expense	41	$ 37	120	$ 100
Computer, equipment and software
Property and Equipment, Net [Line Items]
Property and equipment, gross	835		835		808
Buildings
Property and Equipment, Net [Line Items]
Property and equipment, gross	370		370		370
Leasehold improvements
Property and Equipment, Net [Line Items]
Property and equipment, gross	198		198		172
Equipment, furniture and fixtures, and other
Property and Equipment, Net [Line Items]
Property and equipment, gross	91		91		93
Land
Property and Equipment, Net [Line Items]
Property and equipment, gross	66		66		66
Construction in progress
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 21		$ 21		$ 12

[1] Derived from audited Consolidated Financial Statements.