Revenue from Contracts with Customers - Revenues Disaggregated by Revenue Source and Market (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2020	Dec. 25, 2019	Dec. 26, 2018
Disaggregation of Revenue [Line Items]
Total revenue	$ 426,087	$ 442,330	$ 435,828
Core Market
Disaggregation of Revenue [Line Items]
Total revenue	371,510	377,591	365,396
Non-Core Market
Disaggregation of Revenue [Line Items]
Total revenue	54,577	64,739	70,432
Company-operated restaurant revenue | Core Market
Disaggregation of Revenue [Line Items]
Total revenue	346,662	351,624	340,421
Company-operated restaurant revenue | Non-Core Market
Disaggregation of Revenue [Line Items]
Total revenue	27,402	39,488	48,414
Franchise revenue
Disaggregation of Revenue [Line Items]
Total revenue	29,418	28,819	25,771
Franchise revenue | Core Market
Disaggregation of Revenue [Line Items]
Total revenue	14,216	14,918	14,144
Franchise revenue | Non-Core Market
Disaggregation of Revenue [Line Items]
Total revenue	15,202	13,901	11,627
Franchise advertising fee revenue
Disaggregation of Revenue [Line Items]
Total revenue	22,605	22,399	21,222
Franchise advertising fee revenue | Core Market
Disaggregation of Revenue [Line Items]
Total revenue	10,632	11,049	10,831
Franchise advertising fee revenue | Non-Core Market
Disaggregation of Revenue [Line Items]
Total revenue	$ 11,973	$ 11,350	$ 10,391