Risk & Uncertainties (Notes)	6 Months Ended
Risk & Uncertainties (Notes)	Jun. 30, 2020
Unusual Risk or Uncertainty [Line Items]
Risks and Uncertainties [Text Block]	Risks and Uncertainties COVID-19 Pandemic The COVID-19 pandemic has severely impacted global economic activity, including electricity and energy consumption, and caused significant volatility and negative pressure in financial markets. The global impact of the outbreak has been rapidly evolving and many countries, including the United States, have reacted by instituting quarantines, mandating business and school closures, and restricting travel. The State of Ohio has implemented, among other things, stay-at-home and other social distancing measures to slow the spread of the virus, which has resulted in decreased energy demand within our service territory, though these stay-at-home restrictions have now been lifted in our service territory. On March 12, 2020, the PUCO also issued an emergency order prohibiting electric utilities, including us, from discontinuing electric utility service to customers. This prohibition is currently scheduled to end for DP&L on September 1, 2020, pending approval by the PUCO. We are taking a variety of measures in response to the spread of COVID-19 to ensure our ability to transmit, distribute and sell electric energy, ensure the health and safety of our employees, contractors, customers and communities and provide essential services to the communities in which we operate. In addition to reduced revenues and lower margins resulting from decreased energy demand within our service territory, we also have incurred and expect to continue to incur expenses relating to COVID-19, and such expenses may include those that relate to events outside of our control. For the three and six months ended June 30, 2020, the COVID-19 pandemic primarily impacted our retail sales demand, as the economic impact of the pandemic started to materialize in Ohio in the second half of March 2020 and more so in the second quarter of 2020. For commercial and industrial customers, weather-normalized volumes of kWh sold decreased by 11.0% and 19.9%, respectively, for the three months ended June 30, 2020 as compared to the same period in the prior year. For residential customers, weather-normalized volumes of kWh sold increased by 8.5% for the three months ended June 30, 2020 as compared to the same period in the prior year. We also have incurred, and expect to continue to incur, expenses relating to COVID-19; however, see Note 3 – Regulatory Matters for a discussion of regulatory measures, which partially mitigate the impact of these expenses. The magnitude and duration of the COVID-19 pandemic is unknown at this time and may have material and adverse effects on our results of operations, financial condition and cash flows in future periods.
Subsidiaries [Member]
Unusual Risk or Uncertainty [Line Items]
Risks and Uncertainties [Text Block]	Risks and Uncertainties COVID-19 Pandemic The COVID-19 pandemic has severely impacted global economic activity, including electricity and energy consumption, and caused significant volatility and negative pressure in financial markets. The global impact of the outbreak has been rapidly evolving and many countries, including the United States, have reacted by instituting quarantines, mandating business and school closures, and restricting travel. The State of Ohio has implemented, among other things, stay-at-home and other social distancing measures to slow the spread of the virus, which has resulted in decreased energy demand within our service territory, though these stay-at-home restrictions have now been lifted in our service territory. On March 12, 2020, the PUCO also issued an emergency order prohibiting electric utilities, including us, from discontinuing electric utility service to customers. This prohibition is currently scheduled to end for DP&L on September 1, 2020, pending approval by the PUCO. We are taking a variety of measures in response to the spread of COVID-19 to ensure our ability to transmit, distribute and sell electric energy, ensure the health and safety of our employees, contractors, customers and communities and provide essential services to the communities in which we operate. In addition to reduced revenues and lower margins resulting from decreased energy demand within our service territory, we also have incurred and expect to continue to incur expenses relating to COVID-19, and such expenses may include those that relate to events outside of our control. For the three and six months ended June 30, 2020, the COVID-19 pandemic primarily impacted our retail sales demand, as the economic impact of the pandemic started to materialize in Ohio in the second half of March 2020 and more so in the second quarter of 2020. For commercial and industrial customers, weather-normalized volumes of kWh sold decreased by 11.0% and 19.9%, respectively, for the three months ended June 30, 2020 as compared to the same period in the prior year. For residential customers, weather-normalized volumes of kWh sold increased by 8.5% for the three months ended June 30, 2020 as compared to the same period in the prior year. We also have incurred, and expect to continue to incur, expenses relating to COVID-19; however, see Note 3 – Regulatory Matters for a discussion of regulatory measures, which partially mitigate the impact of these expenses. The magnitude and duration of the COVID-19 pandemic is unknown at this time and may have material and adverse effects on our results of operations, financial condition and cash flows in future periods.