Introduction and Basis of Reporting - (Narrative) (Details)	12 Months Ended
	Dec. 25, 2024 state territory restaurant country
Franchisor Disclosure [Line Items]
Number of restaurants	1,568
Denny's Brand
Franchisor Disclosure [Line Items]
Number of restaurants	1,499
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
Denny's Brand | Geographic Concentration Risk | Geographic Area | California
Franchisor Disclosure [Line Items]
Percentage of restaurants operated by geographic region	24.00%
Denny's Brand | Geographic Concentration Risk | Geographic Area | Texas
Franchisor Disclosure [Line Items]
Percentage of restaurants operated by geographic region	13.00%
Denny's Brand | Geographic Concentration Risk | Geographic Area | Florida
Franchisor Disclosure [Line Items]
Percentage of restaurants operated by geographic region	8.00%
Keke's
Franchisor Disclosure [Line Items]
Number of restaurants	69
Number of states in which entity operates | state	6
Keke's | Geographic Concentration Risk | Geographic Area | Florida
Franchisor Disclosure [Line Items]
Percentage of restaurants operated by geographic region	88.00%
Franchise
Franchisor Disclosure [Line Items]
Number of restaurants	1,493
Franchise | Denny's Brand
Franchisor Disclosure [Line Items]
Number of restaurants	1,438
Franchise | Keke's
Franchisor Disclosure [Line Items]
Number of restaurants	55
Company Restaurants
Franchisor Disclosure [Line Items]
Number of restaurants	75
Company Restaurants | Denny's Brand
Franchisor Disclosure [Line Items]
Number of restaurants	61
Company Restaurants | Keke's
Franchisor Disclosure [Line Items]
Number of restaurants	14