Cover Page - shares	9 Months Ended
	Sep. 29, 2021	Oct. 28, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 29, 2021
Document Transition Report	false
Entity File Number	0-18051
Entity Registrant Name	DENNY’S CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	13-3487402
Entity Address, Address Line One	203 East Main Street
Entity Address, City or Town	Spartanburg,
Entity Address, State or Province	SC
Entity Address, Postal Zip Code	29319-0001
City Area Code	864
Local Phone Number	597-8000
Title of 12(b) Security	$.01 Par Value, Common Stock
Trading Symbol	DENN
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		63,386,061
Entity Central Index Key	0000852772
Current Fiscal Year End Date	--12-29
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q3
Amendment Flag	false