Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2023	Sep. 27, 2022	Oct. 03, 2023	Sep. 27, 2022
Revenue:
Total revenue	$ 127,854	$ 129,381	$ 379,085	$ 373,010
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Other restaurant operating costs	22,558	22,709	69,163	67,367
General and administrative	11,864	11,596	37,968	36,180
Depreciation and amortization	6,626	5,826	19,313	17,310
Pre-opening	541	337	1,642	1,098
Restaurant impairments, closure costs and asset disposals	2,135	1,672	5,313	5,032
Total costs and expenses	125,820	127,852	379,558	375,678
Income (loss) from operations	2,034	1,529	(473)	(2,668)
Interest expense, net	1,186	735	3,201	1,661
Income (loss) before taxes	848	794	(3,674)	(4,329)
Provision for (benefit from) income taxes	148	(1)	45	(40)
Net income (loss)	$ 700	$ 795	$ (3,719)	$ (4,289)
Earnings (loss) per Class A and Class B common stock, combined
Basic (USD per share)	$ 0.02	$ 0.02	$ (0.08)	$ (0.09)
Diluted (USD per share)	$ 0.02	$ 0.02	$ (0.08)	$ (0.09)
Weighted average shares of Class A and Class B common stock outstanding, combined:
Basic (in shares)	45,935,305	46,010,824	46,166,320	45,872,893
Diluted (in shares)	46,008,651	46,197,511	46,166,320	45,872,893
Restaurant revenue
Revenue:
Total revenue	$ 125,208	$ 126,638	$ 370,829	$ 364,873
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	31,457	35,528	93,182	101,963
Franchising royalties and fees, and other
Revenue:
Total revenue	2,646	2,743	8,256	8,137
Labor
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	39,139	39,049	118,626	113,370
Occupancy
Restaurant operating costs (exclusive of depreciation and amortization shown separately below):
Restaurant operating costs	$ 11,500	$ 11,135	$ 34,351	$ 33,358