Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 2,238	$ 11,010	$ 4,794	$ 17,010
Changes in fair value of marketable securities:
Changes in unrealized gains	214	(347)	(241)	(148)
Net realized losses (gains) reclassified into earnings	(27)	64	(1)	127
Total changes in fair value of marketable securities	187	(283)	(242)	(21)
Foreign currency translation adjustments	(436)	(269)	(320)	(211)
Total other comprehensive loss	(249)	(552)	(562)	(232)
Comprehensive income	$ 1,989	$ 10,458	$ 4,232	$ 16,778