Intangible Assets, by Major Class (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 04, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2016
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		$ 2,956,282		$ 2,956,282		$ 1,075,013
Accumulated Amortization		(633,576)		(633,576)		(468,664)
Net Amount		2,322,706		2,322,706		606,349
In-process technology reaching technological feasibility and reclassified				8,900
Amortization of Intangible Assets		82,800	$ 44,900	165,300	$ 80,600
Impairment of Intangible Assets		0	500	1,984	530
Projected Amortization Expense
Future Amortization Expense, Remainder of Fiscal Year		170,507		170,507
Future Amortization Expense, Year Two		492,584		492,584
Future Amortization Expense, Year Three		364,138		364,138
Future Amortization Expense, Year Four		314,558		314,558
Future Amortization Expense, Year Five		257,223		257,223
Core and developed technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		1,813,689		1,813,689		724,883
Accumulated Amortization		(347,137)		(347,137)		(255,460)
Net Amount		1,466,552		1,466,552		469,423
Customer-related
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		909,141		909,141		278,542
Accumulated Amortization		(258,151)		(258,151)		(200,331)
Net Amount		650,990		650,990		78,211
Trademarks and trade names
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		11,700		11,700		11,700
Accumulated Amortization		(8,604)		(8,604)		(7,571)
Net Amount		3,096		3,096		4,129
Backlog
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		28,300		28,300
Accumulated Amortization		(14,150)		(14,150)
Net Amount		14,150		14,150
In-process technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		186,067		186,067		54,308
Accumulated Amortization		0		0		0
Net Amount		186,067		186,067		54,308
Distribution rights
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		5,580		5,580		5,580
Accumulated Amortization		(5,324)		(5,324)		(5,302)
Net Amount		256		256		$ 278
Other
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		1,805		1,805
Accumulated Amortization		(210)		(210)
Net Amount		1,595		$ 1,595
Minimum
Finite-Lived Intangible Assets, Net [Abstract]
Useful Life				1 year
Minimum expected useful life of finite lived intangible assets (in years)				1 year
Maximum
Finite-Lived Intangible Assets, Net [Abstract]
Useful Life				15 years
Minimum expected useful life of finite lived intangible assets (in years)				15 years
Atmel Corporation
Finite-Lived Intangible Assets, Net [Abstract]
Useful Life	9 years
Purchased Intangible Assets	$ 1,877,945
Minimum expected useful life of finite lived intangible assets (in years)	9 years
Atmel Corporation | Core and developed technology
Finite-Lived Intangible Assets, Net [Abstract]
Useful Life	11 years			11 years
Purchased Intangible Assets	$ 1,076,540			$ 1,076,500
Minimum expected useful life of finite lived intangible assets (in years)	11 years			11 years
Atmel Corporation | Customer-related
Finite-Lived Intangible Assets, Net [Abstract]
Useful Life	6 years			6 years
Purchased Intangible Assets	$ 630,600			$ 630,600
Minimum expected useful life of finite lived intangible assets (in years)	6 years			6 years
Atmel Corporation | Backlog
Finite-Lived Intangible Assets, Net [Abstract]
Useful Life	1 year			1 year
Purchased Intangible Assets	$ 28,300			$ 28,300
Minimum expected useful life of finite lived intangible assets (in years)	1 year			1 year
Atmel Corporation | In-process technology
Finite-Lived Intangible Assets, Net [Abstract]
Purchased Intangible Assets	$ 140,700			$ 140,700
Atmel Corporation | Other
Finite-Lived Intangible Assets, Net [Abstract]
Useful Life	5 years			5 years
Purchased Intangible Assets	$ 1,805			$ 1,800
Minimum expected useful life of finite lived intangible assets (in years)	5 years			5 years
Cost of Sales
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of Intangible Assets		1,000	900	$ 1,900	1,700
Operating Expense
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of Intangible Assets		$ 81,800	$ 44,000	$ 163,400	$ 78,900