Condensed Consolidated Statement Of Changes In Stockholders' Equity - 3 months ended Mar. 21, 2017 - USD ($) $ in Thousands	Common Stock Outstanding [Member]	Additional Paid In Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Total
Balance at Dec. 27, 2016	$ 24	$ 143,325	$ (17,823)	$ 120,840	$ 246,366
Balance, shares at Dec. 27, 2016	23,272,274
Net income				3,310	3,310
Share-based compensation costs		533			533
Stock option exercises		68			$ 68
Stock option exercises, including tax effects, shares	30,100				30,100
Shares issued under stock compensation plan, net of shares withheld for tax effects, shares	6,694
Treasury stock purchases			(25,097)		$ (25,097)
Treasury stock purchases, shares	(1,482,592)
Balance at Mar. 21, 2017	$ 24	$ 143,926	$ (42,920)	$ 124,150	$ 225,180
Balance, shares at Mar. 21, 2017	21,826,476