Subsequent Events (Notes)

12 Months Ended

Dec. 31, 2017

Subsequent Event [Line Items]

Subsequent Events [Text Block]

Subsequent Event

On February 26, 2018, DP&L and its co-owners of the retired Beckjord Facility agreed to transfer their interests in the retired Facility to a third party, including their obligations to remediate the Facility and its site, and the transfer occurred on that same date. As a result, DPL estimates that it will recognize aggregate pre-tax loss on disposal charges of approximately $11.7 million and that cash expenditures of $15.0 million in the aggregate will be made, inclusive of cash expenditures for the disposal charges.

THE DAYTON POWER AND LIGHT COMPANY [Member]

Subsequent Event [Line Items]

Subsequent Events [Text Block]

Subsequent Event

On February 26, 2018, DP&L and its co-owners of the retired Beckjord Facility agreed to transfer their interests in the retired Facility to a third party, including their obligations to remediate the Facility and its site, and the transfer occurred on that same date. As a result, DP&L estimates that it will recognize aggregate pre-tax loss on disposal charges of approximately $12.4 million and that cash expenditures of $15.0 million in the aggregate will be made, inclusive of cash expenditures for the disposal charges.