Accumulated other Comprehensive Income (Tables)

12 Months Ended

Mar. 31, 2020

Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]

Components of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

The changes in accumulated other comprehensive income (loss) by component, net of tax, for the fiscal years ended March 31, 2020, 2019 and 2018 are as follows (in millions):

	Unrealized Net Gains (Losses) on Available-for-Sale Securities		Unrealized Net Gains (Losses) on Derivative Instruments		Foreign Currency Translation Adjustments		Total
Balances as of March 31, 2017	$	(3)	$	32	$	(48)	$	(19)
Other comprehensive income (loss) before reclassifications	(9)		(126)		28		(107)
Amounts reclassified from accumulated other comprehensive income (loss)	4		5		(10)		(1)
Total other comprehensive income (loss), net of tax	(5)		(121)		18		(108)
Balances as of March 31, 2018	$	(8)	$	(89)	$	(30)	$	(127)
Cumulative-effect adjustment from the adoption of ASC 606	—		22		—		22
Cumulative-effect adjustment from the adoption of ASU 2018-02	—		1		—		1
Balances as of April 1, 2018	$	(8)	$	(66)	$	(30)	$	(104)
Other comprehensive income (loss) before reclassifications	6		96		(21)		81
Amounts reclassified from accumulated other comprehensive income (loss)	1		(8)		—		(7)
Total other comprehensive income (loss), net of tax	7		88		(21)		74
Balances as of March 31, 2019	$	(1)	$	22	$	(51)	$	(30)
Other comprehensive income (loss) before reclassifications	(1)		79		(34)		44
Amounts reclassified from accumulated other comprehensive income (loss)	(2)		(62)		—		(64)
Total other comprehensive income (loss), net of tax	(3)		17		(34)		(20)
Balances as of March 31, 2020	$	(4)	$	39	$	(85)	$	(50)

Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]

The effects on net income of amounts reclassified from accumulated other comprehensive income (loss) for the fiscal years ended March 31, 2020, 2019 and 2018 were as follows (in millions):

Statement of Operations Classification	Amount Reclassified From Accumulated Other Comprehensive Income (Loss)
	Year Ended March 31,
	2020		2019		2018
(Gains) losses on available-for-sale securities:
Interest and other income (expense), net	$	(2)	$	1	$	4
Total, net of tax	(2)		1		4
(Gains) losses on foreign currency forward contracts designated as cash flow hedges
Net revenue	(71)		(18)		10
Research and development	9		10		(5)
Total, net of tax	(62)		(8)		5
(Gains) losses on foreign currency translation:
Interest and other income (expense), net	—		—		(10)
Total, net of tax	—		—		(10)
Total net (gain) loss reclassified, net of tax	$	(64)	$	(7)	$	(1)