Introduction and Basis of Reporting - (Narrative) (Details)	12 Months Ended
	Dec. 27, 2023 restaurant state territory country
Franchisor Disclosure [Line Items]
Number of restaurants	1,631
Number of states in which entity operates | state	50
Number of territories in which entity operates | territory	2
Number of foreign countries in which entity operates | country	12
Geographic Concentration Risk | Geographic Area | California
Franchisor Disclosure [Line Items]
Percentage of restaurants operated by geographic region	23.00%
Geographic Concentration Risk | Geographic Area | Texas
Franchisor Disclosure [Line Items]
Percentage of restaurants operated by geographic region	13.00%
Geographic Concentration Risk | Geographic Area | Florida
Franchisor Disclosure [Line Items]
Percentage of restaurants operated by geographic region	8.00%
Denny's Brand
Franchisor Disclosure [Line Items]
Number of restaurants	1,573
Keke's
Franchisor Disclosure [Line Items]
Number of restaurants	58
Franchise
Franchisor Disclosure [Line Items]
Number of restaurants	1,558
Franchise | Denny's Brand
Franchisor Disclosure [Line Items]
Number of restaurants	1,508
Franchise | Keke's
Franchisor Disclosure [Line Items]
Number of restaurants	50
Company Restaurants
Franchisor Disclosure [Line Items]
Number of restaurants	73
Company Restaurants | Denny's Brand
Franchisor Disclosure [Line Items]
Number of restaurants	65
Company Restaurants | Keke's
Franchisor Disclosure [Line Items]
Number of restaurants	8