Intangible Assets, by Major Class (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Apr. 04, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2016
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		$ 2,935,390		$ 2,935,390		$ 1,075,013
Accumulated Amortization		(701,769)		(701,769)		(468,664)
Net Amount		2,233,621		2,233,621		606,349
In-process technology reaching technological feasibility and reclassified				149,600
Amortization of Intangible Assets		85,200	$ 49,400	250,600	$ 130,000
Impairment of Intangible Assets		8,200		10,226	577
Projected Amortization Expense
2017		84,229		84,229
2018		490,789		490,789
2019		362,836		362,836
2020		314,211		314,211
2021		257,368		257,368
Core and developed technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		1,933,307		1,933,307		724,883
Accumulated Amortization		(378,750)		(378,750)		(255,460)
Net Amount		1,554,557		1,554,557		469,423
Customer-related
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		909,141		909,141		278,542
Accumulated Amortization		(287,024)		(287,024)		(200,331)
Net Amount		622,117		622,117		78,211
Trademarks and trade names
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		11,700		11,700		11,700
Accumulated Amortization		(9,120)		(9,120)		(7,571)
Net Amount		2,580		2,580		4,129
Backlog
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		28,300		28,300
Accumulated Amortization		(21,225)		(21,225)
Net Amount		7,075		7,075
In-process technology
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		45,557		45,557		54,308
Accumulated Amortization		0		0		0
Net Amount		45,557		45,557		54,308
Distribution rights
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		5,580		5,580		5,580
Accumulated Amortization		(5,335)		(5,335)		(5,302)
Net Amount		245		245		$ 278
Other
Finite-Lived Intangible Assets, Net [Abstract]
Gross Amount		1,805		1,805
Accumulated Amortization		(315)		(315)
Net Amount		1,490		$ 1,490
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
Minimum expected useful life of finite lived intangible assets (in years)	9 years
Purchased intangible assets	$ 1,877,945
Atmel Corporation | Core and developed technology
Finite-Lived Intangible Assets, Net [Abstract]
Useful life	11 years			11 years
Minimum expected useful life of finite lived intangible assets (in years)	11 years			11 years
Purchased intangible assets	$ 1,076,540			$ 1,076,500
Atmel Corporation | Customer-related
Finite-Lived Intangible Assets, Net [Abstract]
Useful life	6 years			6 years
Minimum expected useful life of finite lived intangible assets (in years)	6 years			6 years
Purchased intangible assets	$ 630,600			$ 630,600
Atmel Corporation | Backlog
Finite-Lived Intangible Assets, Net [Abstract]
Useful life	1 year			1 year
Minimum expected useful life of finite lived intangible assets (in years)	1 year			1 year
Purchased intangible assets	$ 28,300			$ 28,300
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
Minimum expected useful life of finite lived intangible assets (in years)	5 years			5 years
Purchased intangible assets	$ 1,805			$ 1,800
Cost of Sales
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of Intangible Assets		900	900	2,800	2,600
Operating Expense
Finite-Lived Intangible Assets, Net [Abstract]
Amortization of Intangible Assets		$ 84,300	$ 48,500	$ 247,800	$ 127,400