Cybersecurity Risk Management and Strategy Disclosure	12 Months Ended
Dec. 31, 2024
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]	FirstEnergy seeks to protect its customers, employees, facilities and the ongoing reliability of the electric system. FirstEnergy works closely with state and federal agencies and its peers in the electric utility industry to identify physical and cyber security risks, exchange information, and put safeguards in place to comply with strict reliability and security standards. From a security standpoint, the electric utility sector is one of the most regulated industries. Risk Management and Strategy FirstEnergy has established a broad framework to assess, identify and manage material risks from cyber security threats. This program is established at the executive level, with regular reporting to, and oversight by, the FE Board as described below. At the highest level, FirstEnergy’s program includes multi-layered governance by management, the Audit Committee, the Operations and Safety Committee, and the FE Board, as described in greater detail below.
Cybersecurity Risk Management Processes Integrated [Flag]	true
Cybersecurity Risk Management Processes Integrated [Text Block]	Central management and coordination of the program helps FirstEnergy to comprehensively evaluate and protect against cyber threats. FirstEnergy’s written policies and procedures identify how cyber security measures and controls are developed, implemented, and regularly reviewed and updated. FirstEnergy aims to align its cyber security program with national standards. For example, FirstEnergy has implemented and maintains a set of controls to manage cyber security risk based on the National Institute of Standards and Technology Cyber Security Framework and, for Bulk Electric System assets, the NERC Critical Infrastructure Protection standards. FirstEnergy also complies with various state laws and regulations on cyber security.
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]	The FE Board has identified cyber security as a key enterprise risk and prioritizes the mitigation of this risk through FirstEnergy’s enterprise risk management process. Responsibility for oversight of risk management generally lies with the FE Board and the Audit Committee has primary responsibility to oversee enterprise risk management. To effectively manage oversight of FirstEnergy’s cyber security risk management practices, since 2022, the FE Board has delegated oversight authority to each of FirstEnergy’s Audit and Operations and Safety Committees, respectively, as detailed in each Committees’ charters. The Audit Committee has primary responsibility to oversee the disclosure of material cyber security incidents, as well as the general obligation to ensure the proper risk oversight structure of cyber security as part of FirstEnergy’s overall enterprise risk management program and the internal controls applicable to cyber security matters. The Operations and Safety Oversight Committee has primary responsibility to oversee the operational aspects of FirstEnergy’s cyber security policies, programs, initiatives and strategies, as well as operational risk considerations related to cyber security matters. FirstEnergy’s CISO regularly provides reports at the Audit Committee, Operations and Safety Oversight Committee, and to the full FE Board. Each such Committee and the full FE Board work collaboratively to ensure fulsome oversight with the proper focus of each respective Board body. These reports include, among other things, current and emerging cyber security risks to FirstEnergy, incidents that were escalated to management during the prior quarter, including those that did not require immediate escalation to the appropriate Committee and/or full FE Board, internal and external assessments of FirstEnergy’s cyber security program, and a roadmap of projects to manage its cyber security posture.
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]	Responsibility for oversight of risk management generally lies with the FE Board and the Audit Committee has primary responsibility to oversee enterprise risk management. To effectively manage oversight of FirstEnergy’s cyber security risk management practices, since 2022, the FE Board has delegated oversight authority to each of FirstEnergy’s Audit and Operations and Safety Committees, respectively, as detailed in each Committees’ charters. The Audit Committee has primary responsibility to oversee the disclosure of material cyber security incidents, as well as the general obligation to ensure the proper risk oversight structure of cyber security as part of FirstEnergy’s overall enterprise risk management program and the internal controls applicable to cyber security matters.
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]	The Operations and Safety Oversight Committee has primary responsibility to oversee the operational aspects of FirstEnergy’s cyber security policies, programs, initiatives and strategies, as well as operational risk considerations related to cyber security matters. FirstEnergy’s CISO regularly provides reports at the Audit Committee, Operations and Safety Oversight Committee, and to the full FE Board. Each such Committee and the full FE Board work collaboratively to ensure fulsome oversight with the proper focus of each respective Board body. These reports include, among other things, current and emerging cyber security risks to FirstEnergy, incidents that were escalated to management during the prior quarter, including those that did not require immediate escalation to the appropriate Committee and/or full FE Board, internal and external assessments of FirstEnergy’s cyber security program, and a roadmap of projects to manage its cyber security posture.
Cybersecurity Risk Role of Management [Text Block]	The FE Board has identified cyber security as a key enterprise risk and prioritizes the mitigation of this risk through FirstEnergy’s enterprise risk management process. Responsibility for oversight of risk management generally lies with the FE Board and the Audit Committee has primary responsibility to oversee enterprise risk management. To effectively manage oversight of FirstEnergy’s cyber security risk management practices, since 2022, the FE Board has delegated oversight authority to each of FirstEnergy’s Audit and Operations and Safety Committees, respectively, as detailed in each Committees’ charters. The Audit Committee has primary responsibility to oversee the disclosure of material cyber security incidents, as well as the general obligation to ensure the proper risk oversight structure of cyber security as part of FirstEnergy’s overall enterprise risk management program and the internal controls applicable to cyber security matters. The Operations and Safety Oversight Committee has primary responsibility to oversee the operational aspects of FirstEnergy’s cyber security policies, programs, initiatives and strategies, as well as operational risk considerations related to cyber security matters. FirstEnergy’s CISO regularly provides reports at the Audit Committee, Operations and Safety Oversight Committee, and to the full FE Board. Each such Committee and the full FE Board work collaboratively to ensure fulsome oversight with the proper focus of each respective Board body. These reports include, among other things, current and emerging cyber security risks to FirstEnergy, incidents that were escalated to management during the prior quarter, including those that did not require immediate escalation to the appropriate Committee and/or full FE Board, internal and external assessments of FirstEnergy’s cyber security program, and a roadmap of projects to manage its cyber security posture. At the executive and management level, the CISO has primary responsibility for the development, operation, and maintenance of FirstEnergy’s cyber security program. The CISO has 6 years of experience in technology risk management, all of which have been with FirstEnergy, and an additional 23 years of experience in information technology. The CISO has passed examinations and received the International Information System Security Certification Consortium Certified Information Systems Security Professional certification. The CISO reports directly to FirstEnergy’s Senior Vice President, Shared Services, who is responsible for all of FirstEnergy’s digital and technology services and is FirstEnergy’s most senior information technology executive. Under the CISO’s oversight, FirstEnergy’s cyber security team implements and provides governance and functional oversight for cyber security controls and services. Cyber security processes include escalation of certain risks and incidents, including those that originate or occur at third parties, to the Senior Vice President, Shared Services, legal, and the executive leaders as appropriate based on the severity of any such risk or incident. In addition, regular updates from the cyber security teams, in conjunction with real-time escalation on an as-needed basis, are also used to update the risk landscape.
Cybersecurity Risk Management Positions or Committees Responsible [Flag]	true
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]	At the executive and management level, the CISO has primary responsibility for the development, operation, and maintenance of FirstEnergy’s cyber security program. The CISO has 6 years of experience in technology risk management, all of which have been with FirstEnergy, and an additional 23 years of experience in information technology. The CISO has passed examinations and received the International Information System Security Certification Consortium Certified Information Systems Security Professional certification. The CISO reports directly to FirstEnergy’s Senior Vice President, Shared Services, who is responsible for all of FirstEnergy’s digital and technology services and is FirstEnergy’s most senior information technology executive. Under the CISO’s oversight, FirstEnergy’s cyber security team implements and provides governance and functional oversight for cyber security controls and services. Cyber security processes include escalation of certain risks and incidents, including those that originate or occur at third parties, to the Senior Vice President, Shared Services, legal, and the executive leaders as appropriate based on the severity of any such risk or incident. In addition, regular updates from the cyber security teams, in conjunction with real-time escalation on an as-needed basis, are also used to update the risk landscape.
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]	The CISO has 6 years of experience in technology risk management, all of which have been with FirstEnergy, and an additional 23 years of experience in information technology. The CISO has passed examinations and received the International Information System Security Certification Consortium Certified Information Systems Security Professional certification.
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]	In the event of any significant cyber security incident, FirstEnergy’s Cyber Security Incident Response Plan provides for a severity determination by the cyber security incident response team based on factors such as the number of assets affected, the likelihood of inappropriate data exposure, operational impact, reliability impact, and regulatory impact. Dependent upon the severity of an incident, it is FirstEnergy’s practice to escalate the incident to the Senior Vice President, Shared Services, the Chief Risk Officer, and the FE senior leadership team, including the Chief Legal Officer, Chief Financial Officer, and Chief Executive Officer.
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]	true

Cybersecurity Risk Management and Strategy Disclosure

12 Months Ended

Dec. 31, 2024

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

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

FirstEnergy seeks to protect its customers, employees, facilities and the ongoing reliability of the electric system. FirstEnergy works closely with state and federal agencies and its peers in the electric utility industry to identify physical and cyber security

risks, exchange information, and put safeguards in place to comply with strict reliability and security standards. From a security standpoint, the electric utility sector is one of the most regulated industries.

Risk Management and Strategy

FirstEnergy has established a broad framework to assess, identify and manage material risks from cyber security threats. This program is established at the executive level, with regular reporting to, and oversight by, the FE Board as described below. At the highest level, FirstEnergy’s program includes multi-layered governance by management, the Audit Committee, the Operations and Safety Committee, and the FE Board, as described in greater detail below.

Cybersecurity Risk Management Processes Integrated [Flag]

true

Cybersecurity Risk Management Processes Integrated [Text Block]

Central management and coordination of the program helps FirstEnergy to comprehensively evaluate and protect against cyber threats. FirstEnergy’s written policies and procedures identify how cyber security measures and controls are developed, implemented, and regularly reviewed and updated. FirstEnergy aims to align its cyber security program with national standards. For example, FirstEnergy has implemented and maintains a set of controls to manage cyber security risk based on the National Institute of Standards and Technology Cyber Security Framework and, for Bulk Electric System assets, the NERC Critical Infrastructure Protection standards. FirstEnergy also complies with various state laws and regulations on cyber security.

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]

The FE Board has identified cyber security as a key enterprise risk and prioritizes the mitigation of this risk through FirstEnergy’s enterprise risk management process. Responsibility for oversight of risk management generally lies with the FE Board and the Audit Committee has primary responsibility to oversee enterprise risk management. To effectively manage oversight of FirstEnergy’s cyber security risk management practices, since 2022, the FE Board has delegated oversight authority to each of FirstEnergy’s Audit and Operations and Safety Committees, respectively, as detailed in each Committees’ charters. The Audit Committee has primary responsibility to oversee the disclosure of material cyber security incidents, as well as the general obligation to ensure the proper risk oversight structure of cyber security as part of FirstEnergy’s overall enterprise risk management program and the internal controls applicable to cyber security matters. The Operations and Safety Oversight Committee has primary responsibility to oversee the operational aspects of FirstEnergy’s cyber security policies, programs, initiatives and strategies, as well as operational risk considerations related to cyber security matters. FirstEnergy’s CISO regularly provides reports at the Audit Committee, Operations and Safety Oversight Committee, and to the full FE Board. Each such Committee and the full FE Board work collaboratively to ensure fulsome oversight with the proper focus of each respective Board body. These reports include, among other things, current and emerging cyber security risks to FirstEnergy, incidents that were escalated to management during the prior quarter, including those that did not require immediate escalation to the appropriate Committee and/or full FE Board, internal and external assessments of FirstEnergy’s cyber security program, and a roadmap of projects to manage its cyber security posture.

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

Responsibility for oversight of risk management generally lies with the FE Board and the Audit Committee has primary responsibility to oversee enterprise risk management. To effectively manage oversight of FirstEnergy’s cyber security risk management practices, since 2022, the FE Board has delegated oversight authority to each of FirstEnergy’s Audit and Operations and Safety Committees, respectively, as detailed in each Committees’ charters. The Audit Committee has primary responsibility to oversee the disclosure of material cyber security incidents, as well as the general obligation to ensure the proper risk oversight structure of cyber security as part of FirstEnergy’s overall enterprise risk management program and the internal controls applicable to cyber security matters.

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

The Operations and Safety Oversight Committee has primary responsibility to oversee the operational aspects of FirstEnergy’s cyber security policies, programs, initiatives and strategies, as well as operational risk considerations related to cyber security matters. FirstEnergy’s CISO regularly provides reports at the Audit Committee, Operations and Safety Oversight Committee, and to the full FE Board. Each such Committee and the full FE Board work collaboratively to ensure fulsome oversight with the proper focus of each respective Board body. These reports include, among other things, current and emerging cyber security risks to FirstEnergy, incidents that were escalated to management during the prior quarter, including those that did not require immediate escalation to the appropriate Committee and/or full FE Board, internal and external assessments of FirstEnergy’s cyber security program, and a roadmap of projects to manage its cyber security posture.

Cybersecurity Risk Role of Management [Text Block]

At the executive and management level, the CISO has primary responsibility for the development, operation, and maintenance of FirstEnergy’s cyber security program. The CISO has 6 years of experience in technology risk management, all of which have been with FirstEnergy, and an additional 23 years of experience in information technology. The CISO has passed examinations and received the International Information System Security Certification Consortium Certified Information Systems Security Professional certification. The CISO reports directly to FirstEnergy’s Senior Vice President, Shared Services, who is responsible for all of FirstEnergy’s digital and technology services and is FirstEnergy’s most senior information technology executive. Under the CISO’s oversight, FirstEnergy’s cyber security team implements and provides governance and functional oversight for cyber security controls and services. Cyber security processes include escalation of certain risks and incidents, including those that originate or occur at third parties, to the Senior Vice President, Shared Services, legal, and the executive leaders as appropriate based on the severity of any such risk or incident. In addition, regular updates from the cyber security teams, in conjunction with real-time escalation on an as-needed basis, are also used to update the risk landscape.

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]

The CISO has 6 years of experience in technology risk management, all of which have been with FirstEnergy, and an additional 23 years of experience in information technology. The CISO has passed examinations and received the International Information System Security Certification Consortium Certified Information Systems Security Professional certification.

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

In the event of any significant cyber security incident, FirstEnergy’s Cyber Security Incident Response Plan provides for a severity determination by the cyber security incident response team based on factors such as the number of assets affected, the likelihood of inappropriate data exposure, operational impact, reliability impact, and regulatory impact. Dependent upon the severity of an incident, it is FirstEnergy’s practice to escalate the incident to the Senior Vice President, Shared Services, the Chief Risk Officer, and the FE senior leadership team, including the Chief Legal Officer, Chief Financial Officer, and Chief Executive Officer.

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

true