Additional principal amount of senior notes to be raised

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- Definition

Debt Issuance Costs and Unamortized Debt Discount

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- Definition

Letter Of Credit Sublimit

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- Definition

The cash outflow for incremental, external costs directly pertaining to an early extinguishment of debt and excluding interest and repayment of debt principal, reflected as a % of the principal paid.

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- Definition

Amount of the total principal payments made during the annual reporting period.

+ 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

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- 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

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- Definition

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

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- Definition

Increase for additional borrowings on the credit facility during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 4
-Section 08
-Paragraph f

Reference 2: 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=6881521&loc=d3e23780-122690

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- 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 Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4
-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.

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-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

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 210.5-02.19(b),22(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

The cash outflow for incremental, external costs directly pertaining to an early extinguishment of debt, including legal costs and prepayment penalties, and excluding interest and repayment of debt principal.

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Balance Type:	credit
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- Definition

The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 15
-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.

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-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
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-Paragraph 17
-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.

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-Publisher FASB
-Name Accounting Standards Codification
-Glossary Investing Activities
-URI http://asc.fasb.org/extlink&oid=6516133

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- Definition

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

+ Details

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Balance Type:	credit
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- Definition

Carrying value as of the balance sheet date of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer), excluding the current portion, if any. Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

+ 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

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Debt Obligations (Narrative) (Details) (USD $)	1 Months Ended	0 Months Ended	6 Months Ended				1 Months Ended		3 Months Ended		10 Months Ended
Debt Obligations (Narrative) (Details) (USD $)	Feb. 28, 2011	Feb. 23, 2011	Jun. 30, 2011	Jun. 30, 2010	Apr. 19, 2011	Mar. 01, 2011	Mar. 01, 2011 DP&L [Member] U.S. Government note maturing in February 2061 - 4.20% [Member]	Jun. 30, 2011 DP&L [Member] U.S. Government note maturing in February 2061 - 4.20% [Member]	Apr. 20, 2010 DP&L [Member] Revolving Credit Agreement with Bank Group [Member]	Apr. 21, 2009 DP&L [Member] Revolving Credit Agreement with Bank Group [Member]	Nov. 21, 2006 DP&L [Member]	Jun. 30, 2011 DP&L [Member]	Apr. 19, 2011 DP&L [Member]	Dec. 04, 2008 DP&L [Member]
Additional principal amount of senior notes to be raised			$ 1,250,000,000
Unsecured revolving credit agreement					200,000,000				200,000,000	100,000,000	220,000,000		220,000,000
Increase additional facility									50,000,000		50,000,000
Letter of credit sublimit									50,000,000		50,000,000
Letters of credit outstanding												0
Collateralized debt														100,000,000
Purchase of principal amount		122,000,000
Interest expenses		12,200,000
Premium percentage		10.00%
Debt issuance costs and unamortized debt discount		3,100,000
Repayments of Debt	13,500,000
Payments to Acquire Productive Assets			$ 91,400,000	$ 75,100,000			$ 18,700,000
Debt Instrument, Interest Rate, Stated Percentage			4.20%			4.20%		4.20%