Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Dec. 25, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	Denny’s recognizes that cybersecurity is a critical aspect of our business operations and that the protection of sensitive data and information systems is of paramount importance. We have implemented cybersecurity measures and processes to address and mitigate material risks from cybersecurity threats. On an annual basis, we perform a cybersecurity risk assessment to identify and evaluate risks and potential vulnerabilities that could impact our business. Cybersecurity is also assessed as part of our compliance program. In addition, we have preventative and detective monitoring controls that include robust access controls, privileged access management, vulnerability scanning, penetration testing of our online systems and internal networks, annual employee-wide awareness education, data encryption and incident response plans. These controls help to ensure our cybersecurity program reduces the cyber risk for our environment. We utilize third-party providers and acknowledge that these providers and partners may pose cybersecurity risks. We have implemented due diligence and oversight processes to ensure our third-party providers adhere to our cybersecurity standards when handling our data and accessing our systems. This includes a risk assessment before acceptance as a provider and continued monitoring through our third-party risk management program. Denny’s faces various risks associated with cybersecurity threats that could materially affect our business. In the event of a material cybersecurity incident, we are committed to promptly informing our shareholders, customers, and regulatory authorities, as required by applicable law and regulations. We have not identified any risks from cybersecurity threats (including as a result of any previous cybersecurity incidents) that have materially affected or are reasonably likely to materially affect our business strategy, results of operations or financial condition.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	Denny’s recognizes that cybersecurity is a critical aspect of our business operations and that the protection of sensitive data and information systems is of paramount importance. We have implemented cybersecurity measures and processes to address and mitigate material risks from cybersecurity threats. On an annual basis, we perform a cybersecurity risk assessment to identify and evaluate risks and potential vulnerabilities that could impact our business. Cybersecurity is also assessed as part of our compliance program. In addition, we have preventative and detective monitoring controls that include robust access controls, privileged access management, vulnerability scanning, penetration testing of our online systems and internal networks, annual employee-wide awareness education, data encryption and incident response plans. These controls help to ensure our cybersecurity program reduces the cyber risk for our environment.
Cybersecurity Risk Management Third Party Engaged [Flag]	true
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]	true
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]	false
Cybersecurity Risk Board of Directors Oversight [Text Block]	Our Senior Vice President and Chief Technology Officer leads our cybersecurity efforts with periodic updates that include certain metrics, data privacy, and other information technology risks, provided to the Audit and Finance Committee of our Board of Directors.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our Senior Vice President and Chief Technology Officer leads our cybersecurity efforts with periodic updates that include certain metrics, data privacy, and other information technology risks, provided to the Audit and Finance Committee of our Board of Directors. Cybersecurity is a top priority for our Audit and Finance Committee.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	Our Senior Vice President and Chief Technology Officer leads our cybersecurity efforts with periodic updates that include certain metrics, data privacy, and other information technology risks, provided to the Audit and Finance Committee of our Board of Directors. Cybersecurity is a top priority for our Audit and Finance Committee. In addition, the Company has a Compliance Committee comprised of members of management from our IT Security & Compliance, Legal and Internal Audit teams who work cross-functionally to assess and manage enterprise-wide risks, including cybersecurity. Our Senior Vice President and Chief Technology Officer leads a team of qualified individuals with decades of combined experience in cybersecurity risk management and compliance.
Cybersecurity Risk Role of Management [Text Block]	Our Senior Vice President and Chief Technology Officer leads our cybersecurity efforts with periodic updates that include certain metrics, data privacy, and other information technology risks, provided to the Audit and Finance Committee of our Board of Directors. Cybersecurity is a top priority for our Audit and Finance Committee. In addition, the Company has a Compliance Committee comprised of members of management from our IT Security & Compliance, Legal and Internal Audit teams who work cross-functionally to assess and manage enterprise-wide risks, including cybersecurity. Our Senior Vice President and Chief Technology Officer leads a team of qualified individuals with decades of combined experience in cybersecurity risk management and compliance. Our cybersecurity program and leadership strive to appropriately protect our brands, employees and guests.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	Our Senior Vice President and Chief Technology Officer leads our cybersecurity efforts with periodic updates that include certain metrics, data privacy, and other information technology risks, provided to the Audit and Finance Committee of our Board of Directors.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	Our Senior Vice President and Chief Technology Officer leads a team of qualified individuals with decades of combined experience in cybersecurity risk management and compliance.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	Our Senior Vice President and Chief Technology Officer leads our cybersecurity efforts with periodic updates that include certain metrics, data privacy, and other information technology risks, provided to the Audit and Finance Committee of our Board of Directors. Cybersecurity is a top priority for our Audit and Finance Committee. In addition, the Company has a Compliance Committee comprised of members of management from our IT Security & Compliance, Legal and Internal Audit teams who work cross-functionally to assess and manage enterprise-wide risks, including cybersecurity. Our Senior Vice President and Chief Technology Officer leads a team of qualified individuals with decades of combined experience in cybersecurity risk management and compliance.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Cybersecurity Risk Management and Strategy Disclosure

12 Months Ended

Dec. 25, 2024

Cybersecurity Risk Management, Strategy, and Governance [Line Items]

Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]

Denny’s recognizes that cybersecurity is a critical aspect of our business operations and that the protection of sensitive data and information systems is of paramount importance.

We have implemented cybersecurity measures and processes to address and mitigate material risks from cybersecurity threats. On an annual basis, we perform a cybersecurity risk assessment to identify and evaluate risks and potential vulnerabilities that could impact our business. Cybersecurity is also assessed as part of our compliance program. In addition, we have preventative and detective monitoring controls that include robust access controls, privileged access management, vulnerability scanning, penetration testing of our online systems and internal networks, annual employee-wide awareness education, data encryption and incident response plans. These controls help to ensure our cybersecurity program reduces the cyber risk for our environment.

We utilize third-party providers and acknowledge that these providers and partners may pose cybersecurity risks. We have implemented due diligence and oversight processes to ensure our third-party providers adhere to our cybersecurity standards when handling our data and accessing our systems. This includes a risk assessment before acceptance as a provider and continued monitoring through our third-party risk management program.

Denny’s faces various risks associated with cybersecurity threats that could materially affect our business. In the event of a material cybersecurity incident, we are committed to promptly informing our shareholders, customers, and regulatory authorities, as required by applicable law and regulations.

We have not identified any risks from cybersecurity threats (including as a result of any previous cybersecurity incidents) that have materially affected or are reasonably likely to materially affect our business strategy, results of operations or financial condition.

Cybersecurity Risk Management Processes Integrated [Flag]

true

Cybersecurity Risk Management Processes Integrated [Text Block]

Denny’s recognizes that cybersecurity is a critical aspect of our business operations and that the protection of sensitive data and information systems is of paramount importance.

Cybersecurity Risk Management Third Party Engaged [Flag]

true

Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]

true

Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]

false

Cybersecurity Risk Board of Directors Oversight [Text Block]

Our Senior Vice President and Chief Technology Officer leads our cybersecurity efforts with periodic updates that include certain metrics, data privacy, and other information technology risks, provided to the Audit and Finance Committee of our Board of Directors.

Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]

Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]

In addition, the Company has a Compliance Committee comprised of members of management from our IT Security & Compliance, Legal and Internal Audit teams who work cross-functionally to assess and manage enterprise-wide risks, including cybersecurity. Our Senior Vice President and Chief Technology Officer leads a team of qualified individuals with decades of combined experience in cybersecurity risk management and compliance.

Cybersecurity Risk Role of Management [Text Block]

Our cybersecurity program and leadership strive to appropriately protect our brands, employees and guests.

Cybersecurity Risk Management Positions or Committees Responsible [Flag]

true

Cybersecurity Risk Management Positions or Committees Responsible [Text Block]

Cybersecurity Risk Management Expertise of Management Responsible [Text Block]

Our Senior Vice President and Chief Technology Officer leads a team of qualified individuals with decades of combined experience in cybersecurity risk management and compliance.

Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]

Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]

true