Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2020	Dec. 31, 2019	Jan. 01, 2019
Revenue:
Total revenue	$ 393,655	$ 462,411	$ 457,841
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Other restaurant operating costs	71,208	66,684	65,575
General and administrative	42,876	43,446	46,092
Depreciation and amortization	21,709	22,086	22,872
Pre-opening	443	402	50
Restaurant impairments, closure costs and asset disposals	6,540	7,747	7,142
Total costs and expenses	413,684	456,972	461,599
(Loss) income from operations	(20,029)	5,439	(3,758)
Loss on extinguishment of debt	0	746	626
Interest expense, net	3,146	2,942	4,305
(Loss) income before income taxes	(23,175)	1,751	(8,689)
Provision (benefit) for income taxes	84	104	(248)
Net (loss) income	$ (23,259)	$ 1,647	$ (8,441)
(Loss) earnings per Class A and Class B common stock, combined
Basic (USD per share)	$ (0.53)	$ 0.04	$ (0.20)
Diluted (USD per share)	$ (0.53)	$ 0.04	$ (0.20)
Weighted average Class A and Class B common stock outstanding, combined
Basic (in shares)	44,272,474	44,036,947	42,329,556
Diluted (in shares)	44,272,474	44,976,436	42,329,556
Restaurant revenue
Revenue:
Total revenue	$ 388,480	$ 456,671	$ 453,671
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	97,697	117,179	121,102
Franchising royalties and fees, and other
Revenue:
Total revenue	5,175	5,740	4,170
Labor
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	126,424	150,565	149,746
Occupancy
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	$ 46,787	$ 48,863	$ 49,020