Additional cost allocation pending appeal of litigation

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- Definition

The annual total of carbon dioxide emissions from wholly-owned electric generating power plants or units, including the proportionate share of emissions from power plants or units that are owned jointly with other partners.

+ Details

Name:	dpl_AnnualCo2EmissionsGenerationAtStations
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- Definition

An agreement under which a supplier commits to supply a specified amount of coal over a specified period, and DP&L commits to purchase the coal supplied over the specified period.

+ Details

Name:	dpl_CoalSupplyAgreement
Namespace Prefix:	dpl
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

- Definition

Coal Supply Failure By Suppliers

+ Details

Name:	dpl_CoalSupplyFailureBySuppliers
Namespace Prefix:	dpl
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

- Definition

This item represents the amount of total guarantees provided to third parties for future financial or performance assurance. The guarantees are provided to enhance the creditworthiness attributed DPL's subsidiaries, DPLE and DPLER, on a stand-alone basis. Any, against the loss of value in the underlying assets in the security which were considered and relied upon as one of the potential factors in reaching a conclusion that the available-for-sale investments are not other-than -temporarily impaired.

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

Due to third parties current.

+ Details

Name:	dpl_DueToThirdPartiesCurrent
Namespace Prefix:	dpl
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of Auxiliary Boilers

+ Details

Name:	dpl_NumberOfAuxiliaryBoilers
Namespace Prefix:	dpl
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of diesel electric generating engines that are impacted by the National Emissions Standards for Hazardous Air Pollutants, a regulatory standard issued by the EPA.

+ Details

Name:	dpl_NumberOfDieselElectricGeneratingEngines
Namespace Prefix:	dpl
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of emergency black start engines that are impacted by the National Emissions Standards for Hazardous Air Pollutants, a regulatory standard issued by the EPA.

+ Details

Name:	dpl_NumberOfEmergencyBlackStartEngines
Namespace Prefix:	dpl
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration

- Definition

+ Details

Name:	dpl_NumberOfTonsOfCo2EmittedPerYearIncludingElectricGeneratingUnits
Namespace Prefix:	dpl
Data Type:	num:massItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage ownership in a coal-fired power plant or electric generating unit

+ Details

Name:	dpl_PercentageOfCoalFirePowerPlantHoldings
Namespace Prefix:	dpl
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage of total electric energy generated from coal sources.

+ Details

Name:	dpl_PercentageOfEnergyGeneratedByCoal
Namespace Prefix:	dpl
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The noncontrolling equity interest in an electric generation company, accounted for under the cost method of accounting.

+ Details

Name:	dpl_PublicUtilitiesEquityInterestCostMethodPercentage
Namespace Prefix:	dpl
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The amount of estimated penalties per day collected by a regulating authority for each environmental violation.

+ Details

Name:	dpl_ReliefAndCivilPenalties
Namespace Prefix:	dpl
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Interest rate stated in the contractual debt agreement.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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 210.5-02.22(a)(1))

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

+ Details

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Namespace Prefix:	us-gaap
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 12

-Article 5

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 210.5-02.12)

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

+ Details

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Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of reserves for the costs of settling insured claims and costs incurred in the claims settlement process attributable to asbestos and environmental claims, net of estimated reinsurance recoveries.

+ References

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

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-PLI

-Chapter 4

-Paragraph 132, 133, 135, 136, 137

-IssueDate 2006-09-01

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 11, 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

+ Details

Name:	us-gaap_LiabilityForAsbestosAndEnvironmentalClaimsNet
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Balance Type:	credit
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- Definition

Liability as of the balance sheet date for amounts representing estimated cost of settling unpaid claims under the terms of the underlying insurance policies, less estimated reinsurance recoveries on such claims. This includes an estimate for claims which have been incurred but not reported. Claim adjustment expenses represent the costs estimated to be incurred in the settlement of unpaid claims.

+ References

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 01-5

-Paragraph 10

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 113

-Paragraph 21, 22, 23, 24, 25

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher AICPA

-Name Statement of Position (SOP)

-Number 94-5

-Paragraph 11

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 60

-Paragraph 17, 18, 19, 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher SEC

-Name Financial Reporting Release (FRR)

-Number 403

-Paragraph 04

-Subparagraph b

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Article 7

-Section 03

-Paragraph 13

-Subparagraph a

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 40

-Section 50

-Paragraph 3

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437

+ Details

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- Definition

Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section H

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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

+ Details

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- Definition

The cash inflow from the amounts received by the insured under the terms of an insurance contract settlement. This element pertains only to insurance proceeds related to operating activities. It excludes insurance settlements classified as investing cash flows, for example, insurance settlements related to fixed assets.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 22

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 16

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3337-108585

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Contractual Obligations, Commercial Commitments and Contingencies (Narrative) (Details) (USD $)	0 Months Ended	9 Months Ended							3 Months Ended		1 Months Ended	0 Months Ended	3 Months Ended	4 Months Ended	9 Months Ended
	Feb. 15, 2010	Sep. 30, 2011	Sep. 30, 2010 T	Sep. 22, 2009 MT	Mar. 01, 2011	Dec. 31, 2010	Sep. 30, 2011 DPLE and DPLER [Member]	Sep. 30, 2011 MC Squared [Member]	Sep. 30, 2011 DP&L [Member] Beckjord Unit 6 [Member]	Sep. 30, 2011 DP&L [Member] Hutchings Plant [Member]	Feb. 28, 2007 DP&L [Member] Coal Supply Agreements [Member] T	May 03, 2010 DP&L [Member]	Sep. 30, 2010 DP&L [Member]	May 03, 2010 DP&L [Member]	Sep. 30, 2011 DP&L [Member]	Dec. 31, 2010 DP&L [Member]
Third party guarantees		$ 86,700,000					$ 69,700,000	$ 17,000,000
Due to third parties, current		500,000				1,700,000
Equity ownership interest															4.90%
Equity ownership interest aggregate cost															61,000,000
Debt obligation		1,244,500,000
Debt instrument interest percentage					4.20%
Environmental reserves		2,200,000
Percentage of coal-fire power plant holdings									50.00%	100.00%
Percentage of energy generated by coal		99.00%
Annual CO2 emissions generation at stations, in tons			16,000,000
Number of tons of CO2 emitted per year including electric generating units				25,000
Number of Auxiliary Boilers		7
Number of diesel electric generating engines														18
Number of emergency black start engines												8
Relief and civil penalties, per day													27,500
Coal supply failure by suppliers											1,500,000
Coal supply agreement, in tons											570,000
Proceeds from legal settlements	3,400,000
Additional cost allocation pending appeal of litigation															12,000,000
Deferred liability claims															$ 14,100,000	$ 15,400,000