Revenue Disaggregation of Revenue (Details) - USD ($)	4 Months Ended
	Jan. 17, 2021	Jan. 19, 2020
Disaggregation of Revenue [Line Items]
Initial franchise fee	$ 50,000
Royalty and marketing fee, percent of gross sales	5.00%
Revenues	$ 338,541,000	$ 307,673,000
Company Restaurant Sales
Disaggregation of Revenue [Line Items]
Revenues	114,278,000	105,364,000
Franchise Rental Revenues
Disaggregation of Revenue [Line Items]
Revenues	103,749,000	96,084,000
Franchise Royalties
Disaggregation of Revenue [Line Items]
Revenues	57,343,000	50,243,000
Marketing Fees
Disaggregation of Revenue [Line Items]
Revenues	55,776,000	48,835,000
Technology and Sourcing Fees
Disaggregation of Revenue [Line Items]
Revenues	5,090,000	4,924,000
Franchise Fees and Other Services
Disaggregation of Revenue [Line Items]
Revenues	$ 2,305,000	$ 2,223,000