Stockholders' Equity (Details) - USD ($)		3 Months Ended
		Jul. 01, 2017	Jul. 02, 2016
New Accounting Pronouncement or Change in Accounting Principle, Cumulative Effect of Change on Equity or Net Assets		$ 69,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, common stock, shares		8,994,968
Beginning balance		$ 394,408,000
Stock option exercises, amount		(1,780,000)
Stock-based compensation		513,000
Net income		11,753,000	$ 5,443,000
Other comprehensive loss	[1]	$ (555,000)
Ending balance, common stock, shares		9,018,820
Ending balance		$ 404,408,000
Pre-tax unrealized loss on available-for-sale investments		$ (909,000)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, common stock, shares		8,994,968
Beginning balance		$ 90,000
Stock option exercises, shares		23,852
Stock option exercises, amount		$ 0
Stock-based compensation		0
Net income		0
Other comprehensive loss		$ 0
Ending balance, common stock, shares		9,018,820
Ending balance		$ 90,000
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		244,791,000
Stock option exercises, amount		(1,780,000)
Stock-based compensation		513,000
Net income		0
Other comprehensive loss		0
Ending balance		243,524,000
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		148,141,000
Stock option exercises, amount
Stock-based compensation		0
Net income		11,753,000
Other comprehensive loss		0
Ending balance		159,963,000
Accumulated other comprehensive income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance		1,386,000
Stock option exercises, amount		0
Stock-based compensation		0
Net income		0
Other comprehensive loss	[1]	(555,000)
Ending balance		$ 831,000

[1] Other comprehensive income is comprised of unrealized gains and losses on available-for-sale investments. Unrealized losses before tax effect on available-for-sale securities were $909,000 for the three months ended July 1, 2017.