Consolidated Statement Of Changes In Stockholders' Equity - USD ($) $ in Thousands	Common Stock Outstanding [Member]	Additional Paid In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2013	$ 24	$ 129,961	$ (3,681)	$ 70,479	$ 196,783
Balance, shares at Dec. 31, 2013	23,626,642
Net income				16,597	16,597
Share-based compensation costs		2,567			2,567
Stock option exercises, including tax effects		1,355			1,355
Stock option exercises, including tax effects, shares	85,400
Treasury stock purchases			(6,319)		(6,319)
Treasury stock purchases, shares	(268,996)
Balance at Dec. 30, 2014	$ 24	133,883	(10,000)	87,076	210,983
Balance, shares at Dec. 30, 2014	23,443,046
Net income				15,998	15,998
Share-based compensation costs		2,900			2,900
Stock option exercises, including tax effects		818			818
Stock option exercises, including tax effects, shares	59,150
Treasury stock purchases			(3,000)		(3,000)
Treasury stock purchases, shares	(189,027)
Balance at Dec. 29, 2015	$ 24	137,601	(13,000)	103,074	227,699
Balance, shares at Dec. 29, 2015	23,313,169
Net income				17,766	17,766
Share-based compensation costs		2,602			2,602
Stock option exercises, including tax effects		3,207			$ 3,207
Stock option exercises, including tax effects, shares	228,800				228,800
Shares issued under stock compensation plan, net of shares withheld for tax effects		(85)			$ (85)
Shares issued under stock compensation plan, net of shares withheld for tax effects, shares	33,492
Treasury stock purchases			(4,823)		(4,823)
Treasury stock purchases, shares	(303,187)
Balance at Dec. 27, 2016	$ 24	$ 143,325	$ (17,823)	$ 120,840	$ 246,366
Balance, shares at Dec. 27, 2016	23,272,274