Stock-Based Compensation Plans (Tables)

9 Months Ended

Dec. 30, 2017

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock-Based compensation expense

The following table summarizes stock-based compensation expense related to stock awards granted under the Company’s equity incentive plans and rights to acquire stock granted under the Company’s Employee Stock Purchase Plan (ESPP):

	Three Months Ended				Nine Months Ended
(In thousands)	December 30, 2017		December 31, 2016		December 30, 2017		December 31, 2016
Stock-based compensation included in:
Cost of revenues	$	2,188	$	1,945	$	6,486	$	5,994
Research and development	20,217		17,154		57,779		48,803
Selling, general and administrative	14,396		11,768		40,944		35,276
	$	36,801	$	30,867	$	105,209	$	90,073

Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value

The per share weighted-average fair value of RSUs granted during the third quarter of fiscal year 2018 was $67.40 ($49.50 for the third quarter of fiscal year 2017), and for the first nine months of fiscal year 2018 was $60.36 ($43.40 for the first nine months of fiscal year 2017), which were calculated based on estimates at the date of grant using the following weighted-average assumptions:

	Three Months Ended				Nine Months Ended
	December 30, 2017		December 31, 2016		December 30, 2017		December 31, 2016
Risk-free interest rate	1.9	%	1.4	%	1.8	%	0.9	%
Dividend yield	2.0	%	2.5	%	2.2	%	2.8	%

Schedule of Share-based Payment Award, Employee Stock Purchase Plan, Valuation Assumptions [Table Text Block]

The fair values of stock purchase plan rights granted in the second quarter of fiscal years 2018 and 2017 were estimated using the Black-Scholes option pricing model at the date of grant using the following assumptions:

	2018		2017
Expected life of options (years)	1.25		1.25
Expected stock price volatility	0.28		0.23
Risk-free interest rate	1.3	%	0.5	%
Dividend yield	2.2	%	2.6	%

Restricted Stock Units (RSUs) [Member]

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Summary of restricted stock unit activity and related information

A summary of the Company’s RSU activity and related information is as follows:

	RSUs Outstanding
(Shares in thousands)	Number of Shares		Weighted-Average Grant-Date Fair Value Per Share
April 2, 2016	6,619		$	40.74
Granted	3,398		$	44.38
Vested	(2,619	)	$	39.49
Cancelled	(410	)	$	41.63
April 1, 2017	6,988		$	42.93
Granted	3,468		$	60.36
Vested	(2,426	)	$	42.18
Cancelled	(416	)	$	46.94
December 30, 2017	7,614		$	50.48