Regulatory Assets and Liabilities (Details) $ in Millions	6 Months Ended
Jun. 30, 2015 USD ($)
THE DAYTON POWER AND LIGHT COMPANY [Member]
Regulatory Assets [Line Items]
Recovery of deferred storm costs	$ 11.1

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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