Consolidated Condensed Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Income Statement [Abstract]
Net sales	$ 347,325	$ 388,912	$ 589,898	$ 627,165
Cost of sales	167,115	180,979	282,216	296,738
Gross profit	180,210	207,933	307,682	330,427
Operating expenses
Research and development	84,810	88,239	163,551	177,069
Selling, general and administrative	31,247	33,018	60,951	62,538
Restructuring costs	0	0	352	0
Total operating expenses	116,057	121,257	224,854	239,607
Income from operations	64,153	86,676	82,828	90,820
Interest income	1,658	2,530	3,493	5,074
Interest expense	(280)	(280)	(539)	(539)
Other income (expense)	784	(568)	895	(946)
Income before income taxes	66,315	88,358	86,677	94,409
Provision for income taxes	6,829	12,148	8,982	13,581
Net income	$ 59,486	$ 76,210	$ 77,695	$ 80,828
Basic earnings per share (in dollars per share)	$ 1.02	$ 1.31	$ 1.33	$ 1.39
Diluted earnings per share (in dollars per share)	$ 0.99	$ 1.27	$ 1.29	$ 1.34
Basic weighted average common shares outstanding (in shares)	58,191	58,011	58,252	58,276
Diluted weighted average common shares outstanding (in shares)	60,127	60,213	60,203	60,260