Goodwill Allocated to DP&L Reporting Unit

No definition available.

Name:	dpl_GoodwillAllocatedToDpLReportingUnit
Namespace Prefix:	dpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

+ Details

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

- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13854-109267

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267

+ Details

Name:	us-gaap_GoodwillImpairmentLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The aggregate amount of write-downs for impairments recognized during the period for long lived assets held for use (including those held for disposal by means other than sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6391110&loc=d3e2921-110230

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 958

-SubTopic 225

-Section 45

-Paragraph 11

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=28367520&loc=d3e92212-112881

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Impairment

-URI http://asc.fasb.org/extlink&oid=6515133

+ Details

Name:	us-gaap_ImpairmentOfLongLivedAssetsHeldForUse
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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=25499696&loc=d3e19190-110258

+ Details

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

- Definition

Amount after accumulated depreciation, depletion and amortization 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 360

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.13)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 13

-Subparagraph a

-Article 5

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 8

-Article 7

+ Details

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

- Details

Name:	dei_LegalEntityAxis=dpl_DpLMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
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_PublicUtilityAxis=dpl_ConesvilleUnitFourMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_PublicUtilityAxis=dpl_DplerMember
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:

Fair Value Measurements (Fair Value of Assets and Liabilities Measured on a Nonrecurring Basis) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
	Oct. 01, 2013	Dec. 31, 2012	Dec. 31, 2013	Dec. 31, 2014
Carrying Value			$ 2,534.2us-gaap_PropertyPlantAndEquipmentNet	$ 2,517.6us-gaap_PropertyPlantAndEquipmentNet
Goodwill (Note 5)			452.8us-gaap_Goodwill	317.0us-gaap_Goodwill
Goodwill Impairment	306.3us-gaap_GoodwillImpairmentLoss
Goodwill Allocated to DP&L Reporting Unit				2.4dpl_GoodwillAllocatedToDpLReportingUnit
Estimate of Fair Value, Fair Value Disclosure [Member]
Goodwill Allocated to DP&L Reporting Unit			306.3
Level 1 [Member]
Goodwill Allocated to DP&L Reporting Unit			623.3
Level 3 [Member]
Goodwill Allocated to DP&L Reporting Unit			317.0
Parent Company [Member]
Goodwill Impairment		1,817.2
DP&L [Member]
Goodwill (Note 5)		623.3	317.0	317.0
Goodwill Impairment			(306.3)
Conesville [Member]
Fixed asset impairment			26.2
Fair Value			0
Conesville [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Carrying Value			26.2
Conesville [Member] \| Level 1 [Member]
Carrying Value			26.2
Conesville [Member] \| DP&L [Member]
Carrying Value		97.5	30.0
Fixed asset impairment		72.5	10.0
Fair Value		25.0	0
Goodwill Impairment			10.0
Conesville [Member] \| DP&L [Member] \| Level 3 [Member]
Fair Value			20.0
East Bend Station [Member]
Carrying Value				14.2
Fixed asset impairment			11.5
Fair Value			2.7
East Bend Station [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value				11.5
East Bend Station [Member] \| Level 3 [Member]
Fixed asset impairment				2.7
East Bend Station [Member] \| DP&L [Member]
Carrying Value			76.0
Fixed asset impairment			76.0
Goodwill Impairment			76.0
DPLER [Member]
Goodwill (Note 5)				135.8
DPLER [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]
Goodwill (Note 5)				$ 135.8