Quarterly Financial Information (Consolidated Financial Information) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						4 Months Ended		12 Months Ended
	Sep. 06, 2016	Jun. 14, 2016	Mar. 22, 2016	Sep. 08, 2015	Jun. 16, 2015	Mar. 24, 2015	Dec. 27, 2016	Dec. 29, 2015	Dec. 27, 2016	Dec. 29, 2015	Dec. 30, 2014
Quarterly Financial Information [Abstract]
Revenues	$ 71,407	$ 79,916	$ 81,194	$ 68,629	$ 73,776	$ 75,102	$ 119,164	$ 114,105	$ 351,681	$ 331,612	$ 301,805
Operating income (loss)	1,118	6,325	7,879	(2,080)	5,494	7,800	9,754	10,604	25,076	21,818	24,540
Net income (loss)	$ 786	$ 4,444	$ 5,411	$ (1,035)	$ 3,713	$ 5,394	$ 7,125	$ 7,926	$ 17,766	$ 15,998	$ 16,597
Basic income (loss) per common share	$ 0.03	$ 0.19	$ 0.23	$ (0.04)	$ 0.16	$ 0.23	$ 0.31	$ 0.34	$ 0.76	$ 0.68	$ 0.71
Basic weighted average shares outstanding	23,354,000	23,350,000	23,315,000	23,361,000	23,446,000	23,443,000	23,282,000	23,298,000	23,322,344	23,380,085	23,517,883
Diluted income (loss) per common share	$ 0.03	$ 0.19	$ 0.23	$ (0.04)	$ 0.16	$ 0.23	$ 0.30	$ 0.34	$ 0.76	$ 0.68	$ 0.70
Diluted weighted average shares outstanding	23,431,000	23,437,000	23,398,000	23,361,000	23,672,000	23,596,000	23,415,000	23,308,000	23,435,275	23,517,288	23,740,318