Condensed Consolidated Statements of Operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 24, 2014	Sep. 25, 2013	Sep. 24, 2014	Sep. 25, 2013
Revenue
Company-operated restaurant revenue	$ 80,861	$ 74,470	$ 238,432	$ 223,059
Franchise revenue	5,696	5,297	16,456	15,430
Total revenue	86,557	79,767	254,888	238,489
Cost of operations
Food and paper cost	25,881	23,705	75,834	70,608
Labor and related expenses	20,137	18,972	59,552	57,260
Occupancy and other operating expenses	18,102	16,393	51,091	47,791
Company restaurant expenses	64,120	59,070	186,477	175,659
General and administrative expenses	7,509	6,263	20,974	18,754
Franchise expenses	901	980	2,827	2,930
Depreciation and amortization	2,924	2,625	8,271	7,570
Loss on disposal of assets	118	153	609	734
Asset impairment and close-store reserves	22	25	415	126
Total expenses	75,594	69,116	219,573	205,773
Gain on sale of restaurants	2,658		2,658
Income from operations	13,621	10,651	37,973	32,716
Interest expense, net	3,960	9,863	15,286	29,443
Early extinguishment of debt	5,082		5,082
Income tax receivable agreement expense	40,119		40,119
(Loss) income before provision for income taxes	(35,540)	788	(22,514)	3,273
(Benefit) provision for income taxes	(61,389)	(130)	(60,402)	2,005
Net income	$ 25,849	$ 918	$ 37,888	$ 1,268
Net income per share
Basic	$ 0.76	$ 0.03	$ 1.24	$ 0.04
Diluted	$ 0.70	$ 0.03	$ 1.13	$ 0.04
Weighted-average shares used in computing net income per share
Basic	34,221,829	28,712,622	30,549,979	28,712,622
Diluted	37,171,670	29,564,795	33,499,820	29,564,795