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.

+ Details

Name:	us-gaap_FairValueInputsAssetsQuantitativeInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of assumed long-term growth in revenues, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

+ Details

Name:	us-gaap_FairValueInputsLongTermRevenueGrowthRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of the inputs and valuation technique(s) used to measure fair value.

+ References

+ Details

Name:	us-gaap_FairValueMeasurementsValuationTechniques
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value portion of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19190-110258

+ Details

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

- Details

Name:	us-gaap_PublicUtilityAxis=dpl_ConesvilleUnitFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityAxis=dpl_EastBendStationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=us-gaap_SubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_WeightedAverageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Fair Value Measurements (Significant unobservalbe inputs, nonrecurring) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Conesville [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Long-lived assets held and used, fair value		$ 0.0
East Bend Station [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Long-lived assets held and used, fair value	$ 2.7
THE DAYTON POWER AND LIGHT COMPANY [Member] \| Conesville [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Long-lived assets held and used, fair value		$ 0.0
Discounted Cash Flows		Discounted cash flows
Level 3 [Member] \| East Bend Station [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Long-lived assets held and used, fair value	$ 2.7
Level 3 [Member] \| THE DAYTON POWER AND LIGHT COMPANY [Member] \| Conesville [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Long-lived assets held and used, fair value		$ 20.0
Level 3 [Member] \| Minimum [Member] \| THE DAYTON POWER AND LIGHT COMPANY [Member] \| Conesville [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Annual revenue growth (percent)	(31.00%)
Level 3 [Member] \| Maximum [Member] \| THE DAYTON POWER AND LIGHT COMPANY [Member] \| Conesville [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Annual revenue growth (percent)	18.00%
Level 3 [Member] \| Weighted Average [Member] \| THE DAYTON POWER AND LIGHT COMPANY [Member] \| Conesville [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Annual revenue growth (percent)	0.00%