Additional principal amount of senior notes to be raised

No definition available.

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- Definition

Letter Of Credit Sublimit

+ References

No definition available.

+ Details

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- Definition

Percentage amount term loan amortizes in first year

+ References

No definition available.

+ Details

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- 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

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-Name Regulation S-X (SX)

-Number 210

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22)

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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

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

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+ Details

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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

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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

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- Definition

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

+ References

No definition available.

+ Details

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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

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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))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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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

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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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)

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-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

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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

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of loans payable (with maturities initially due after one year or beyond the operating cycle if longer), excluding current portion.

+ 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)

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

+ Details

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

- Definition

The amount for notes payable (written promise to pay), due to related parties.

+ 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.(k)(1))

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

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-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (d)

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-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph k

-Subparagraph 1

-Article 4

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.17)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 17

-Article 7

+ Details

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

- 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

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

- Definition

Carrying amount of collateralized debt obligations with maturities initially due after one year or beyond the operating cycle, if longer, excluding the current portion. Obligations include, but not limited to, mortgage loans, chattel loans, and other borrowings secured by assets.

+ 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)

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

+ Details

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

- Details

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

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Debt Obligations (Narrative) (Details) (USD $)	0 Months Ended	12 Months Ended	0 Months Ended	12 Months Ended	1 Months Ended
Debt Obligations (Narrative) (Details) (USD $)	Oct. 03, 2011	Dec. 31, 2014	May 10, 2013	Dec. 31, 2013	Oct. 31, 2014	Dec. 04, 2008	Mar. 31, 2014	Mar. 01, 2011	Sep. 19, 2013	Sep. 06, 2014	Oct. 06, 2014
Additional principal amount of senior notes to be raised	$ 1,250,000,000
Letters of credit outstanding		2,300,000
Collateralized debt						100,000,000us-gaap_SecuredLongTermDebt
Line of Credit Facility, Remaining Borrowing Capacity		97,700,000
Long-term Debt, Gross		2,139,600,000us-gaap_DebtInstrumentCarryingAmount		2,284,200,000us-gaap_DebtInstrumentCarryingAmount
Current portion - long-term debt		20,100,000us-gaap_LongTermDebtCurrent		10,200,000us-gaap_LongTermDebtCurrent
DP&L [Member]
Collateralized debt						100,000,000
Long-term Debt, Gross		877,000,000		876,900,000
Current portion - long-term debt		100,000		200,000
Notes Payable, Related Parties							15,000,000
DP&L [Member] \| Related Party Notes Payable [Member]
Debt instrument interest percentage							2.00%
U.S. Government note maturing in February 2061 - 4.20% [Member]
Debt Instrument, Maturity Date Range, End		Feb. 01, 2061
Long-term Debt, Gross		18,100,000		18,300,000				18,700,000
Debt instrument interest percentage		4.20%						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		18,100,000		18,200,000				18,700,000
Debt instrument interest percentage		4.20%						4.20%
Revolving Credit Agreement with Bank Group [Member]
Unsecured revolving credit agreement			100,000,000
Increase/decrease additional facility			100,000,000
Letter of credit sublimit			100,000,000
Revolving Credit Agreeement with Bank Group Expiring 2018 [Member]
Unsecured revolving credit agreement			300,000,000
Increase/decrease additional facility			50,000,000
Letter of credit sublimit			100,000,000
Letters of credit outstanding		700,000
Line of Credit Facility, Remaining Borrowing Capacity		299,300,000
Revolving Credit Agreeement with Bank Group Expiring 2018 [Member] \| DP&L [Member]
Unsecured revolving credit agreement			300,000,000
Increase/decrease additional facility			100,000,000
Letter of credit sublimit			100,000,000
Letters of credit outstanding		700,000
Line of Credit Facility, Remaining Borrowing Capacity		299,300,000
Five Year Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]
Additional principal amount of senior notes to be raised	450,000,000
Debt Instrument, Maturity Date Range, End		Oct. 01, 2016
Long-term Debt, Gross		130,000,000		430,000,000
Repayments of debt				20,000,000
Debt instrument interest percentage	6.50%	6.50%		6.50%
Ten Year Senior Unsecured Notes at 7.25% maturing at October 15, 2021 [Member]
Additional principal amount of senior notes to be raised	800,000,000
Debt Instrument, Maturity Date Range, End		Oct. 01, 2021
Long-term Debt, Gross		780,000,000		780,000,000
Repayments of debt				20,000,000
Debt instrument interest percentage	7.25%	7.25%		7.25%
Unsecured Term Loan Agreement [Member]
Long-term Debt, Gross			200,000,000
Term Loan Amortization Year 1			5.00%
Repayments of debt			200,000,000
First Mortgage Bonds Maturing in September 2016 - 1.9%
Debt Instrument, Maturity Date Range, End		Sep. 01, 2016
Long-term Debt, Gross		445,000,000		445,000,000					445,000,000
Debt instrument interest percentage		1.875%
First Mortgage Bonds Maturing in September 2016 - 1.9% \| DP&L [Member]
Debt Instrument, Maturity Date Range, End		Sep. 01, 2016
Long-term Debt, Gross		445,000,000		445,000,000
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		15,600,000		20,600,000
Repayments of debt					5,000,000
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		100,000,000		100,000,000
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		100,000,000		100,000,000
Bank Term Loan maturing in May 2018 [Member]
Debt Instrument, Maturity Date Range, End		May 01, 2018
Loans Payable, Noncurrent		160,000,000
Long-term Debt, Gross		140,000,000		180,000,000
Current portion - long-term debt		20,000,000		10,000,000
Debt instrument interest percentage		2.41%
Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member]
Debt Instrument, Face Amount										280,000,000
Senior Unsecured Notes at 6.50% maturing on October 15, 2016 [Member] \| Tender offer [Member]
Debt Instrument, Face Amount											300,000,000
Senior Unsecured notes maturing October 2019 at 6.75% [Member]
Debt instrument interest percentage											6.75%
Debt Instrument, Face Amount											$ 200,000,000