Consolidated Condensed Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 29, 2018	Dec. 30, 2017
Income Statement [Abstract]
Net sales	$ 324,295	$ 482,741	$ 945,083	$ 1,229,013
Cost of sales	161,115	247,653	472,225	620,927
Gross profit	163,180	235,088	472,858	608,086
Operating expenses
Research and development	88,575	96,978	282,888	270,888
Selling, general and administrative	30,364	34,604	96,308	95,504
Total operating expenses	118,939	131,582	379,196	366,392
Income from operations	44,241	103,506	93,662	241,694
Interest income	1,999	1,191	5,510	3,125
Interest expense	(259)	(279)	(798)	(894)
U.K. pension settlement	(13,768)	0	(13,768)	0
Other income (expense)	101	322	(67)	(813)
Income before income taxes	32,314	104,740	84,539	243,112
Provision for income taxes	2,381	70,961	705	93,121
Net income	$ 29,933	$ 33,779	$ 83,834	$ 149,991
Basic earnings per share (in dollars per share)	$ 0.50	$ 0.53	$ 1.39	$ 2.36
Diluted earnings per share (in dollars per share)	$ 0.49	$ 0.52	$ 1.35	$ 2.26
Basic weighted average common shares outstanding (in shares)	59,511	63,453	60,482	63,655
Diluted weighted average common shares outstanding (in shares)	60,783	65,557	62,076	66,377