Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2016	Jun. 30, 2015	Jun. 28, 2016	Jun. 30, 2015
Revenue:
Restaurant revenue	$ 120,204	$ 113,834	$ 233,069	$ 218,616
Franchising royalties and fees	1,203	1,399	2,324	2,378
Total revenue	121,407	115,233	235,393	220,994
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Cost of sales	32,164	29,863	62,353	57,674
Labor	39,316	35,149	76,750	68,178
Occupancy	13,688	12,480	27,002	24,698
Other restaurant operating costs	18,596	15,158	35,488	29,875
General and administrative	9,840	9,232	19,877	17,650
Depreciation and amortization	7,071	6,923	13,977	13,843
Pre-opening	796	1,162	1,833	2,042
Restaurant impairments, closure costs and asset disposals	11,248	250	12,264	6,336
Total costs and expenses	132,719	110,217	249,544	220,296
(Loss) income from operations	(11,312)	5,016	(14,151)	698
Interest expense, net	598	198	1,226	427
(Loss) income before income taxes	(11,910)	4,818	(15,377)	271
Provision (benefit) for income taxes	2,177	1,756	1,083	(39)
Net (loss) income	$ (14,087)	$ 3,062	$ (16,460)	$ 310
(Loss) earnings per share of Class A and Class B common stock, combined:
Basic (USD per share)	$ (0.51)	$ 0.10	$ (0.59)	$ 0.01
Diluted (USD per share)	$ (0.51)	$ 0.10	$ (0.59)	$ 0.01
Weighted average shares of Class A and Class B common stock outstanding, combined:
Basic (in shares)	27,776,094	29,950,122	27,754,615	29,896,663
Diluted (in shares)	27,776,094	30,720,102	27,754,615	30,792,278