Condensed Consolidated Statements Of Income And Comprehensive Income (Unaduited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 13, 2017	Jun. 14, 2016	Jun. 13, 2017	Jun. 14, 2016
Income Statement [Abstract]
Revenues	$ 82,301	$ 79,916	$ 166,191	$ 161,110
Costs and expenses:
Costs of sales	23,433	22,637	47,214	45,855
Restaurant operating expenses	40,388	38,017	81,280	76,643
Marketing and advertising costs	1,618	2,133	2,918	3,454
Pre-opening costs	1,619	591	2,008	685
General and administrative costs	5,921	6,030	12,076	11,780
Consulting project costs	597	0	2,633	0
Reorganization severance	563	0	719	0
Lease termination and closing costs	540	20	538	41
Depreciation and amortization	4,997	4,163	9,813	8,448
Total costs and expenses	79,676	73,591	159,199	146,906
Insurance settlements	308	0	348	0
Operating income	2,933	6,325	7,340	14,204
Other income (expense), net:
Interest, net of capitalized interest	(9)	(24)	(19)	(55)
Other	(10)	(5)	(11)	(5)
Income before income taxes	2,914	6,296	7,310	14,144
Income tax expense	824	1,852	1,910	4,289
Net income	$ 2,090	$ 4,444	$ 5,400	$ 9,855
Basic earnings per common share (in usd per share)	$ 0.10	$ 0.19	$ 0.24	$ 0.42
Diluted earnings per common share (in usd per share)	$ 0.09	$ 0.19	$ 0.24	$ 0.42
Shares used in computing earnings per common share:
Basic (in shares)	21,722,126	23,349,718	22,390,745	23,332,397
Diluted (in shares)	22,060,927	23,436,983	22,719,891	23,418,735
Comprehensive income	$ 2,090	$ 4,444	$ 5,400	$ 9,855