Fair Value Measurements (Significant unobservalbe inputs, nonrecurring) (Details) (DP&L [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2013
Conesville Unit 4 [Member]
Assets, Fair Value Disclosure, Nonrecurring	$ 20.0
Fair Value Measurements, Valuation Techniques	Discounted cash flows
East Bend Station [Member]
Fair Value Measurements, Valuation Techniques	Discounted cash flows

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

No definition available.

Name:	us-gaap_AssetsFairValueDisclosureNonrecurring
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant