Goodwill and Intangible Assets (Tables)

6 Months Ended

Sep. 30, 2016

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Changes in the Carrying Amount of Goodwill

The changes in the carrying amount of goodwill are as follows:

	Consumer Security		Enterprise Security			Total
	(In millions)
Net balance as of April 1, 2016	$	1,231	$	1,917		$	3,148
Acquisition of Blue Coat	—		4,086			4,086
Translation adjustments	—		(2		)	(2		)
Net balance as of September 30, 2016	$	1,231	$	6,001		$	7,232

Schedule of Intangible Assets, Net, Indefinite-Lived

	September 30, 2016							April 1, 2016
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
	(In millions)
Customer relationships	$	1,247	$	(361	)	$	886	$	406	$	(320	)	$	86
Developed technology	883		(125		)	758		144		(84		)	60
Finite-lived trade names	19		(4		)	15		2		(2		)	—
Patents	21		(19		)	2		21		(18		)	3
Total finite-lived intangible assets	2,170		(509		)	1,661		573		(424		)	149
Indefinite-lived trade names	281		—			281		294		—			294
In-process research and development	19		—			19		—		—			—
Total	$	2,470	$	(509	)	$	1,961	$	867	$	(424	)	$	443

Schedule of Intangible Assets, Net, Finite-Lived

	September 30, 2016							April 1, 2016
	Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
	(In millions)
Customer relationships	$	1,247	$	(361	)	$	886	$	406	$	(320	)	$	86
Developed technology	883		(125		)	758		144		(84		)	60
Finite-lived trade names	19		(4		)	15		2		(2		)	—
Patents	21		(19		)	2		21		(18		)	3
Total finite-lived intangible assets	2,170		(509		)	1,661		573		(424		)	149
Indefinite-lived trade names	281		—			281		294		—			294
In-process research and development	19		—			19		—		—			—
Total	$	2,470	$	(509	)	$	1,961	$	867	$	(424	)	$	443

Schedule of Future Intangible Asset Amortization Expense

As of September 30, 2016, future amortization expense related to intangible assets that have finite lives is as follows by fiscal year:

	September 30, 2016
	(In millions)
Remainder of 2017	$	272
2018	347
2019	317
2020	301
2021	153
Thereafter	271
Total	$	1,661