Letter Of Credit Sublimit

No definition available.

Name:	dpl_LetterOfCreditSublimit
Namespace Prefix:	dpl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of long-term debt before deduction of unamortized discount or premium. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, with initial maturities beyond one year or the normal operating cycle, if longer.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-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)

-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 22

-Article 5

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 9

+ Details

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the 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

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format.

+ 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)(2))

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

+ Details

Name:	us-gaap_DebtInstrumentMaturityDateRangeEnd1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Net increase or decrease in the carrying amount of the credit facility for the period for reasons other than accrued, but unpaid interest, additional borrowings, repayments, and forgiveness.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityIncreaseDecreaseOtherNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of long-term debt, after unamortized discount or premium, scheduled to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19,20)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19

-Article 5

+ Details

Name:	us-gaap_LongTermDebtCurrent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of cash inflow from contractual arrangement with the lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(f))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph f

-Article 4

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

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

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

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

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_BankTermLoanMaturingInMay2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_EightPointOneTwoFivePercentageOfNoteToCapitalTrustIiMaturingInSeptemberTwoThousandThirtyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_FiveYearSeniorUnsecuredNotesAt650MaturingOnOctober152016Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_FourPointTwoZeroPercentageOfUSGovernmentNoteMaturingInFebruaryTwoThousandSixtyOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_OnePointNinePercentageOfFirstMortgageBondsMaturingSeptemberTwoThousandSixteenMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_RevolvingCreditAgreeementWithBankGroupExpiring2018Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_RevolvingCreditAgreementWithBankGroupMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_TenYearSeniorUnsecuredNotesAt725MaturingAtOctober152021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=dpl_ZeroPointTwoThreeToZeroPointTwoNineAndZeroPointOneSixToZeroPointThreeSixPercentageOfPollutionControlSeriesMaturingInNovemberTwoThousandFortyMember
Namespace Prefix:
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Debt Obligations (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		0 Months Ended	4 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	May 10, 2013	May 10, 2013	Dec. 31, 2014
Withdrawals from revolving credit facilities	$ 15.0us-gaap_ProceedsFromLinesOfCredit	$ 65.0us-gaap_ProceedsFromLinesOfCredit
Current portion - long-term debt	30.1us-gaap_LongTermDebtCurrent				20.1us-gaap_LongTermDebtCurrent
DP&L [Member]
Current portion - long-term debt	0.1				0.1
DPL [Member] \| Credit Facility [Member]
Letters of credit outstanding	2.3
Line of Credit Facility, Remaining Borrowing Capacity	97.7
Repayments of debt			50.0
U.S. Government note maturing in February 2061 - 4.20% [Member]
Debt Instrument, Maturity Date Range, End	Feb. 01, 2061
Long-term Debt, Gross	(18.1)				(18.1)
Debt instrument interest percentage	4.20%
U.S. Government note maturing in February 2061 - 4.20% [Member] \| DP&L [Member]
Debt Instrument, Maturity Date Range, End	Feb. 01, 2061
Long-term Debt, Gross	18.1				18.1
Current portion - long-term debt	0.1				0.1
Debt instrument interest percentage	4.20%
Revolving Credit Agreement with Bank Group [Member] \| DP&L [Member]
Line of Credit Facility, Remaining Borrowing Capacity	298.6
Revolving Credit Agreeement with Bank Group Expiring 2018 [Member]
Increase/decrease additional facility			100.0
Letter of credit sublimit			100.0
Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] \| DP&L [Member]
Unsecured revolving credit agreement			300.0	300.0
Increase/decrease additional facility				100.0
Letter of credit sublimit				100.0
Letters of credit outstanding	1.4
Line of Credit Facility, Remaining Borrowing Capacity	298.6
Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] \| DPL [Member]
Unsecured revolving credit agreement			100.0	100.0
Increase/decrease additional facility			100.0
Letter of credit sublimit			100.0
Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]
Debt Instrument, Maturity Date Range, End	Oct. 01, 2016
Long-term Debt, Gross	130.0				130.0
Debt instrument interest percentage	6.50%
Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]
Debt Instrument, Maturity Date Range, End	Oct. 01, 2021
Long-term Debt, Gross	780.0				780.0
Debt instrument interest percentage	7.25%
First Mortgage Bonds Maturing in September 2016
Debt Instrument, Maturity Date Range, End	Sep. 01, 2016
Long-term Debt, Gross	445.0				445.0
Debt instrument interest percentage	1.875%
First Mortgage Bonds Maturing in September 2016 \| DP&L [Member]
Debt Instrument, Maturity Date Range, End	Sep. 01, 2016
Long-term Debt, Gross	445.0				445.0
Debt instrument interest percentage	1.875%
Note to DPL Capital Trust II Maturing in September 2031 - 8.125% [Member]
Debt Instrument, Maturity Date Range, End	Sep. 01, 2031
Long-term Debt, Gross	15.6				15.6
Debt instrument interest percentage	8.125%
Pollution control series maturing in November 2040 - variable rates: 0.04% - 0.26% and 0.06% - 0.32% [Member]
Debt Instrument, Maturity Date Range, End	Nov. 01, 2040
Long-term Debt, Gross	100.0				100.0
Pollution control series maturing in November 2040 - variable rates: 0.04% - 0.26% and 0.06% - 0.32% [Member] \| DP&L [Member]
Debt Instrument, Maturity Date Range, End	Nov. 01, 2040
Long-term Debt, Gross	100.0				100.0
Bank Term Loan maturing in May 2018 [Member]
Debt Instrument, Maturity Date Range, End	May 01, 2018
Long-term Debt, Gross	$ 130.0				$ 140.0