Balance Sheet Details (Deferred Net Revenue) (Details) - USD ($) $ in Millions	6 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Mar. 31, 2020
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Current	$ 639		$ 945	[1]
Deferred Revenue, Revenue Recognized	985	$ 1,131
Online enabled games [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Current	639		945
Other [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Current	149		104
Noncurrent [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue, Noncurrent	11		8
Total [Member]
Deferred Revenue Arrangement [Line Items]
Deferred Revenue	$ 799		$ 1,057

[1] Derived from audited Consolidated Financial Statements.