Regulatory Matters (Notes)	3 Months Ended
Regulatory Matters (Notes)	Mar. 31, 2025
Schedule of Regulatory Assets and Liabilities [Text Block]	REGULATORY MATTERS AES Ohio ESPs and Smart Grid Plans AES Ohio ESP Ohio law requires utilities to file either an ESP or MRO plan to establish SSO rates. AES Ohio is currently operating pursuant to ESP 4, described in the paragraph below. From November 1, 2017 through December 18, 2019, AES Ohio operated pursuant to an approved ESP plan, which was initially approved on October 20, 2017 (ESP 3). On December 18, 2019, the PUCO approved AES Ohio's Notice of Withdrawal of ESP 3 and reversion to its prior rate plan (ESP 1). Among other items, the PUCO Order approving the ESP 1 rate plan included reinstating the non-bypassable RSC Rider, which provided annual revenue of approximately $79.0 million. The OCC has appealed to the Ohio Supreme Court the PUCO’s decision approving the reversion to ESP 1 as well as argued for a refund of the RSC revenue dating back to August 2021. Oral arguments regarding this appeal were held on April 22, 2025, and a court decision is pending. Smart Grid Comprehensive Settlement On October 23, 2020, AES Ohio entered into a Stipulation and Recommendation (the Settlement) with the staff of the PUCO, various customers and organizations representing customers of AES Ohio and certain other parties with respect to, among other matters, AES Ohio's applications pending at the PUCO for (i) approval of AES Ohio's plan to modernize its distribution grid (Smart Grid Phase 1), (ii) findings that DP&L passed the SEET for 2018 and 2019, and (iii) findings that AES Ohio's ESP 1 satisfies the SEET and the more favorable in the aggregate (MFA) regulatory test. On June 16, 2021, the PUCO issued their opinion and order accepting the stipulation as filed. The OCC appealed the final PUCO order with respect to the 2018 and 2019 SEET to the Ohio Supreme Court on December 6, 2021. Oral arguments regarding this appeal were held on April 2, 2025, and a court decision is pending.
Subsidiaries [Member]
Schedule of Regulatory Assets and Liabilities [Text Block]	REGULATORY MATTERS AES Ohio ESPs and Smart Grid Plans AES Ohio ESP Ohio law requires utilities to file either an ESP or MRO plan to establish SSO rates. AES Ohio is currently operating pursuant to ESP 4, described in the paragraph below. From November 1, 2017 through December 18, 2019, AES Ohio operated pursuant to an approved ESP plan, which was initially approved on October 20, 2017 (ESP 3). On December 18, 2019, the PUCO approved AES Ohio's Notice of Withdrawal of ESP 3 and reversion to its prior rate plan (ESP 1). Among other items, the PUCO Order approving the ESP 1 rate plan included reinstating the non-bypassable RSC Rider, which provided annual revenue of approximately $79.0 million. The OCC has appealed to the Ohio Supreme Court the PUCO’s decision approving the reversion to ESP 1 as well as argued for a refund of the RSC revenue dating back to August 2021. Oral arguments regarding this appeal were held on April 22, 2025, and a court decision is pending. Smart Grid Comprehensive Settlement On October 23, 2020, AES Ohio entered into a Stipulation and Recommendation (the Settlement) with the staff of the PUCO, various customers and organizations representing customers of AES Ohio and certain other parties with respect to, among other matters, AES Ohio's applications pending at the PUCO for (i) approval of AES Ohio's plan to modernize its distribution grid (Smart Grid Phase 1), (ii) findings that DP&L passed the SEET for 2018 and 2019, and (iii) findings that AES Ohio's ESP 1 satisfies the SEET and the more favorable in the aggregate (MFA) regulatory test. On June 16, 2021, the PUCO issued their opinion and order accepting the stipulation as filed. The OCC appealed the final PUCO order with respect to the 2018 and 2019 SEET to the Ohio Supreme Court on December 6, 2021. Oral arguments regarding this appeal were held on April 2, 2025, and a court decision is pending. Smart Grid Phase 2 Plan In February 2024, AES Ohio filed a Smart Grid Phase 2 with the PUCO proposing a ten-year investment plan to begin after Smart Grid Phase 1 ends. On September 13, 2024, AES Ohio reached a settlement with the PUCO staff and other parties on the pending Smart Grid Phase 2 application. The settlement provides for a four-year plan to invest $240.5 million of capital and $18.6 million of operations and maintenance expenses related to grid modernization, support of Distributed Energy Resources, Economic Development and an enhanced Telecommunications network. These costs will be recovered through the existing Infrastructure Investment Rider. If approved, AES Ohio will implement a comprehensive grid modernization project that will deliver benefits to customers, society as a whole and to AES Ohio. An evidentiary hearing was held on October 29, 2024, and we expect an order from the PUCO by the second quarter of 2025, prior to the end of Smart Grid Phase 1. Distribution Rate Case 2024 Distribution Rate Case application On November 29, 2024, AES Ohio filed a new distribution rate case with the PUCO. The investments reflected in this distribution rate case include investments to enhance the safety, reliability, and resilience of the distribution system. Among other matters, the application requests: •An increase to its annual distribution revenue requirement of $235.2 million, which incorporates certain investments that are currently recovered through the Distribution Investment Rider; •A return on equity of 10.95% and a cost of long-term debt of 4.49% on a distribution rate base of $1.3 billion and based on a capital structure of 53.87% equity and 46.13% long-term debt; and •A date certain of September 30, 2024 and a test period of June 1, 2024 – May 31, 2025 The rate case application also includes a proposal for increased tree-trimming expenses. AES Ohio proposed an evidentiary hearing be held beginning June 2, 2025; however, the PUCO has not yet established a procedural schedule for the proceeding.