Balance Sheet Details (Property And Equipment, Net Schedule) (Details) - USD ($) $ in Millions	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 1,385		$ 1,359
Less: accumulated depreciation	(939)		(911)
Property and equipment, net	446		448	[1]
Depreciation expense	30	$ 30
Computer, equipment and software
Property and Equipment, Net [Line Items]
Property and equipment, gross	722		710
Buildings
Property and Equipment, Net [Line Items]
Property and equipment, gross	347		343
Leasehold improvements
Property and Equipment, Net [Line Items]
Property and equipment, gross	145		139
Equipment, furniture and fixtures, and other
Property and Equipment, Net [Line Items]
Property and equipment, gross	83		80
Land
Property and Equipment, Net [Line Items]
Property and equipment, gross	66		66
Construction in progress
Property and Equipment, Net [Line Items]
Property and equipment, gross	$ 22		$ 21

[1] Derived from audited Consolidated Financial Statements.