Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jul. 01, 2014	Jun. 30, 2015	Jul. 01, 2014
Revenue:
Restaurant revenue	$ 113,834	$ 98,197	$ 218,616	$ 186,646
Franchising royalties and fees	1,399	1,262	2,378	2,333
Total revenue	115,233	99,459	220,994	188,979
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Cost of sales	29,863	26,326	57,674	50,174
Labor	35,149	29,328	68,178	56,526
Occupancy	12,480	10,245	24,698	20,110
Other restaurant operating costs	15,158	12,243	29,875	24,449
General and administrative	9,232	8,251	17,650	15,261
Depreciation and amortization	6,923	5,905	13,843	11,515
Pre-opening	1,162	1,027	2,042	2,140
Restaurant impairment, asset disposals and closure costs	250	193	6,336	408
Total costs and expenses	110,217	93,518	220,296	180,583
Income from operations	5,016	5,941	698	8,396
Interest expense	198	36	427	56
Income before income taxes	4,818	5,905	271	8,340
Provision (benefit) for income taxes	1,756	2,378	(39)	3,389
Net income	$ 3,062	$ 3,527	$ 310	$ 4,951
Earnings per share of Class A and Class B common stock, combined:
Basic (USD per share)	$ 0.10	$ 0.12	$ 0.01	$ 0.17
Diluted (USD per share)	$ 0.10	$ 0.11	$ 0.01	$ 0.16
Weighted average shares of Class A and Class B common stock outstanding, combined:
Basic (in shares)	29,950,122	29,703,884	29,896,663	29,655,102
Diluted (in shares)	30,720,102	31,063,774	30,792,278	31,061,722