Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2023	Dec. 28, 2021	Dec. 29, 2020
Revenue:
Total revenue	$ 509,480	$ 475,152	$ 393,655
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Other restaurant operating costs	91,220	83,603	71,208
General and administrative	49,903	47,535	42,876
Depreciation and amortization	23,268	22,333	21,709
Pre-opening	1,662	665	443
Restaurant impairments, closure costs and asset disposals	6,164	5,727	6,540
Total costs and expenses	510,312	469,335	413,684
(Loss) income from operations	(832)	5,817	(20,029)
Interest expense, net	2,445	2,082	3,146
(Loss) income before income taxes	(3,277)	3,735	(23,175)
Provision for income taxes	37	70	84
Net (loss) income	$ (3,314)	$ 3,665	$ (23,259)
(Loss) earnings per Class A and Class B common stock, combined
Basic (USD per share)	$ (0.07)	$ 0.08	$ (0.53)
Diluted (USD per share)	$ (0.07)	$ 0.08	$ (0.53)
Weighted average Class A and Class B common stock outstanding, combined
Basic (in shares)	45,913,787	45,483,029	44,272,474
Diluted (in shares)	45,913,787	46,125,386	44,272,474
Restaurant revenue
Revenue:
Total revenue	$ 498,359	$ 467,336	$ 388,480
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	137,859	117,894	97,697
Franchising royalties and fees, and other
Revenue:
Total revenue	11,121	7,816	5,175
Labor
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	155,023	145,622	126,424
Occupancy
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	$ 45,213	$ 45,956	$ 46,787