Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2021	Dec. 29, 2020	Dec. 31, 2019
Revenue:
Total revenue	$ 475,152	$ 393,655	$ 462,411
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Other restaurant operating costs	83,603	71,208	66,684
General and administrative	47,535	42,876	43,446
Depreciation and amortization	22,333	21,709	22,086
Pre-opening	665	443	402
Restaurant impairments, closure costs and asset disposals	5,727	6,540	7,747
Total costs and expenses	469,335	413,684	456,972
Income (loss) from operations	5,817	(20,029)	5,439
Loss on extinguishment of debt	0	0	746
Interest expense, net	2,082	3,146	2,942
Income (loss) before income taxes	3,735	(23,175)	1,751
Provision for income taxes	70	84	104
Net income (loss)	$ 3,665	$ (23,259)	$ 1,647
Earnings (loss) per Class A and Class B common stock, combined
Basic (USD per share)	$ 0.08	$ (0.53)	$ 0.04
Diluted (USD per share)	$ 0.08	$ (0.53)	$ 0.04
Weighted average Class A and Class B common stock outstanding, combined
Basic (in shares)	45,483,029	44,272,474	44,036,947
Diluted (in shares)	46,125,386	44,272,474	44,976,436
Restaurant revenue
Revenue:
Total revenue	$ 467,336	$ 388,480	$ 456,671
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	117,894	97,697	117,179
Franchising royalties and fees, and other
Revenue:
Total revenue	7,816	5,175	5,740
Labor
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	145,622	126,424	150,565
Occupancy
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	$ 45,956	$ 46,787	$ 48,863