Organization and Relationships - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 26, 2021 USD ($) franchise location segment	Dec. 27, 2020 USD ($)	Oct. 20, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Initial public offering percentage			20.00%
Number of franchise brands | franchise	17
Number of stores | location	2,369
Number of franchise units | franchise	2,240
Percent of total restaurants franchised	95.00%
Number of operating segments | segment	1
(Loss) income from operations	$ 824	$ (16,266)
Accumulated deficit	(52,479)	(20,896)
Working capital	(80,000)
Current portion of redeemable preferred stock, net	$ 67,500	7,961
Interest rate on unpaid cash proceeds	10.00%
Cash	$ 56,656	$ 3,944