Consolidated Condensed Statements of Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 25, 2016	Jun. 27, 2015
Consolidated Condensed Statements of Income [Abstract]
Net sales	$ 259,428	$ 282,633
Cost of sales	132,743	150,179
Gross profit	126,685	132,454
Operating expenses:
Research and development	73,934	65,835
Selling, general and administrative	30,540	29,119
Patent agreement and other		(12,500)
Total operating expenses	104,474	82,454
Income from operations	22,211	50,000
Interest income	267	254
Interest expense	(956)	(999)
Other income	147	243
Income before income taxes	21,669	49,498
Provision for income taxes	5,805	16,144
Net income	$ 15,864	$ 33,354
Basic earnings per share	$ 0.25	$ 0.53
Diluted earnings per share	$ 0.24	$ 0.50
Basic weighted average common shares outstanding	62,450	63,274
Diluted weighted average common shares outstanding	65,232	66,410