Stockholders' Equity (Details) - USD ($)		3 Months Ended		9 Months Ended
		Dec. 31, 2016	Dec. 26, 2015	Dec. 31, 2016	Dec. 26, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, common stock, shares				8,927,989
Beginning balance				$ 353,226,000
Stock option exercises, amount				866,000
Stock-based compensation				1,743,000
Net income		$ 12,283,000	$ 8,098,000	27,067,000	$ 21,553,000
Other comprehensive loss	[1]			$ 1,077,000
Ending balance, common stock, shares		8,992,968		8,992,968
Ending balance		$ 383,979,000		$ 383,979,000
Pre-tax unrealized loss on available-for-sale investments				$ 1,720,000
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance, common stock, shares				8,927,989
Beginning balance				$ 89,000
Stock option exercises, shares				64,979
Stock option exercises, amount				$ 1,000
Stock-based compensation				0
Net income				0
Other comprehensive loss				$ 0
Ending balance, common stock, shares		8,992,968		8,992,968
Ending balance		$ 90,000		$ 90,000
Additional paid-in capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				241,662,000
Stock option exercises, amount				865,000
Stock-based compensation				1,743,000
Net income				0
Other comprehensive loss				0
Ending balance		244,270,000		244,270,000
Retained earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				110,186,000
Stock option exercises, amount				0
Stock-based compensation				0
Net income				27,067,000
Other comprehensive loss				0
Ending balance		137,253,000		137,253,000
Accumulated other comprehensive income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance				1,289,000
Stock option exercises, amount				0
Stock-based compensation				0
Net income				0
Other comprehensive loss	[1]			1,077,000
Ending balance		$ 2,366,000		$ 2,366,000

[1] Other comprehensive income is comprised of unrealized gains and losses on available-for-sale investments. Unrealized gains before tax effect on available-for-sale securities were $1.7 million for the nine months ended December 31, 2016.