Balance Sheet Details (Property And Equipment, Net Schedule) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 1,433		$ 1,391
Less: accumulated depreciation	(983)		(942)
Property and equipment, net	450		449	[1]
Depreciation expense	31	$ 30
Computer, equipment and software
Property and Equipment, Net [Line Items]
Property and equipment, gross	762		722
Buildings
Property and Equipment, Net [Line Items]
Property and equipment, gross	348		340
Leasehold improvements
Property and Equipment, Net [Line Items]
Property and equipment, gross	165		161
Equipment, furniture and fixtures, and other
Property and Equipment, Net [Line Items]
Property and equipment, gross	86		83
Land
Property and Equipment, Net [Line Items]
Property and equipment, gross	66		65
Construction in progress
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 6		$ 20

[1] Derived from audited Consolidated Financial Statements.