Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2016	Jul. 01, 2015	Jun. 29, 2016	Jul. 01, 2015
Revenue
Company-operated restaurant revenue	$ 90,877	$ 83,575	$ 179,246	$ 168,308
Franchise revenue	6,597	5,879	12,582	11,572
Total revenue	97,474	89,454	191,828	179,880
Cost of operations
Food and paper cost	27,032	27,055	53,800	54,178
Labor and related expenses	24,361	21,089	48,868	42,671
Occupancy and other operating expenses	19,496	17,388	38,330	34,524
Company restaurant expenses	70,889	65,532	140,998	131,373
General and administrative expenses	8,287	6,405	17,524	13,890
Franchise expenses	1,239	840	2,163	1,695
Depreciation and amortization	3,964	3,200	7,722	6,346
Loss on disposal of assets	267	85	466	166
Expenses related to fire loss			48
Gain on recovery of insurance proceeds	(600)		(889)
Asset impairment and closed-store reserves	60	(190)	134	(139)
Total expenses	84,106	75,872	168,166	153,331
Gain on disposition of restaurants	33		33
Income from operations	13,401	13,582	23,695	26,549
Interest expense-net of interest income	830	1,014	1,656	2,225
Expenses related to selling shareholders		50		50
Income tax receivable agreement (income) expense	(35)	226	229	477
Income before provision for income taxes	12,606	12,292	21,810	23,797
Provision for income taxes	5,339	5,062	9,100	9,776
Net income	$ 7,267	$ 7,230	$ 12,710	$ 14,021
Net income per share
Basic	$ 0.19	$ 0.19	$ 0.33	$ 0.37
Diluted	$ 0.19	$ 0.18	$ 0.33	$ 0.36
Weighted-average shares used in computing net income per share
Basic	38,294,575	37,812,767	38,289,505	37,618,756
Diluted	38,962,802	39,085,206	38,981,610	39,002,974