Share-Based Compensation (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
Stock-based compensation expense [Line Items]
Allocated share-based compensation expense			$ 22,120		$ 16,965	$ 106,089		$ 54,103
Income tax benefit			7,376	[1]	5,460	36,622	[1]	17,566
Net income effect of share-based compensation			14,744		11,505	69,467		36,537
Share-based compensation expense previously capitalized	[2]		3,500
Inventory
Stock-based compensation expense [Line Items]
Amount of share-based compensation expense capitalized to inventory			2,800		2,000	8,300		5,600
Share-based compensation expense previously capitalized	[2]					11,300
Cost of Sales
Stock-based compensation expense [Line Items]
Allocated share-based compensation expense	[2]		3,468		2,270	15,465		6,325
Research and development
Stock-based compensation expense [Line Items]
Allocated share-based compensation expense			9,881		7,855	37,569		23,623
Selling, General and Administrative
Stock-based compensation expense [Line Items]
Allocated share-based compensation expense			8,771		$ 6,840	53,055		$ 24,155
Atmel Corporation
Stock-based compensation expense [Line Items]
Allocated share-based compensation expense	[2]		3,900			53,300
Share-based compensation expense previously capitalized	[2]					4,200
Business combination fair value of assumed awards at acquisition date		$ 95,900
Non cash consideration of certain share-based payment awards		7,500
Nonvested awards, compensation cost not yet recognized		$ 88,400
Accelerated compensation cost						38,800
New Accounting Pronouncement, Early Adoption, Effect | Accounting Standards Update 2016-09, Excess Tax Benefit Component
Stock-based compensation expense [Line Items]
Allocated share-based compensation expense			$ 6,100			$ 18,600

[1] Amounts exclude excess tax benefits related to share-based compensation of $6.1 million and $18.6 million, respectively, for the three and nine months ended December 31, 2016. The Company elected to early adopt ASU 2016-09 in the three months ended June 30, 2016. Prior to the adoption of ASU 2016-09, the Company recognized excess tax benefits related to share-based compensation in additional paid-in capital. Refer to Note 2 for additional information on the adoption of this standard.

[2] During the three and nine months ended December 31, 2016, $2.8 million and $8.3 million, respectively, of share-based compensation expense was capitalized to inventory. The amount of share-based compensation included in cost of sales during the three months ended December 31, 2016 included $3.5 million of previously capitalized share-based compensation expense in inventory that was sold. The amount of share-based compensation included in cost of sales during the nine months ended December 31, 2016 included $11.3 million of previously capitalized share-based compensation expense in inventory that was sold and $4.2 million of share-based compensation expense related to the Company's acquisition of Atmel that was not previously capitalized to inventory. During the three and nine months ended December 31, 2015, $2.0 million and $5.6 million, respectively, of share-based compensation expense was capitalized to inventory and $2.3 million and $6.3 million, respectively, of previously capitalized share-based compensation expense in inventory was sold.