The total of assets that are measured on a recurring basis.

No definition available.

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Period Type:	instant

- Definition

Amount of cash paid to acquire the entity.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph f(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 141

-Paragraph 51

-Subparagraph d

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

+ Details

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Period Type:	instant

- Definition

The net realized gain (loss) on investments sold during the period, not including gains (losses) on securities separately or otherwise categorized as trading, available-for-sale, or held-to-maturity, which, for cash flow reporting, is a component of proceeds from investing activities.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

+ Details

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investment securities as of the balance sheet date which may include marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-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 SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=16383099&loc=d3e24584-111560

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. Fair value of lines of credit at the balance sheet date.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Line-of-Credit Arrangement

-URI http://asc.fasb.org/extlink&oid=6517033

+ Details

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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- Definition

Includes other investments and securities that are not at fair value as of the balance sheet date and those that are not accounted for under the equity method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.1)

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

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph a

-Subparagraph 1(g)

-Article 7

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Fair Value Measurements (Fair Value and Cost of Non-Derivative Instruments) (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended
	Jun. 30, 2012	Dec. 31, 2011 DP&L [Member]	Jun. 30, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member]	Jun. 30, 2012 Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Dec. 31, 2011 Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Jun. 30, 2012 Fair Value [Member] DP&L [Member]	Dec. 31, 2011 Fair Value [Member] DP&L [Member]	Jun. 30, 2012 Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Estimate of Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Equity Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Equity Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Equity Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Jun. 30, 2012 Equity Securities [Member] Fair Value [Member] DP&L [Member]	Dec. 31, 2011 Equity Securities [Member] Fair Value [Member] DP&L [Member]	Jun. 30, 2012 Equity Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Equity Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Jun. 30, 2012 Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Dec. 31, 2011 Debt Securities [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Jun. 30, 2012 Debt Securities [Member] Fair Value [Member] DP&L [Member]	Dec. 31, 2011 Debt Securities [Member] Fair Value [Member] DP&L [Member]	Jun. 30, 2012 Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Debt Securities [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Hedge Funds, Multi-strategy [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Hedge Funds, Multi-strategy [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Jun. 30, 2012 Hedge Funds, Multi-strategy [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Dec. 31, 2011 Hedge Funds, Multi-strategy [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Jun. 30, 2012 Hedge Funds, Multi-strategy [Member] Fair Value [Member] DP&L [Member]	Dec. 31, 2011 Hedge Funds, Multi-strategy [Member] Fair Value [Member] DP&L [Member]	Jun. 30, 2012 Hedge Funds, Multi-strategy [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Hedge Funds, Multi-strategy [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Money Market Funds [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Money Market Funds [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Jun. 30, 2012 Money Market Funds [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Dec. 31, 2011 Money Market Funds [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Jun. 30, 2012 Money Market Funds [Member] Fair Value [Member] DP&L [Member]	Dec. 31, 2011 Money Market Funds [Member] Fair Value [Member] DP&L [Member]	Jun. 30, 2012 Money Market Funds [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Money Market Funds [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Jun. 30, 2012 Debt [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Dec. 31, 2011 Debt [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member]	Jun. 30, 2012 Debt [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Dec. 31, 2011 Debt [Member] Carrying (Reported) Amount, Fair Value Disclosure [Member] DP&L [Member]	Dec. 31, 2011 Debt [Member] Fair Value [Member] DP&L [Member]	Jun. 30, 2012 Debt [Member] Estimate of Fair Value, Fair Value Disclosure [Member]	Dec. 31, 2011 Debt [Member] Estimate of Fair Value, Fair Value Disclosure [Member]
Total Master Trust Assets, Cost					$ 9.5	$ 9.4					$ 4.0	$ 3.9	$ 3.9					$ 5.0	$ 5.0	$ 5.0	$ 5.0					$ 0.3	$ 0.3	$ 0.3	$ 0.3					$ 0.2	$ 0.2	$ 0.2	$ 0.2
Total Master Trust Assets, Fair Value							10.8	10.3	10.8					4.9	4.4	4.9	4.4					5.5	5.5	5.5	5.5					0.2	0.2	0.2	0.2					0.2	0.2	0.2	0.2
Total Assets			9.5	9.4						10.3
Debt, Cost																																										2,619.6	2,629.3	903.2	903.4
Debt, Fair Value																																														934.5	2,744.4	2,710.6
Gross Proceeeds	3,483.6	26.9
Gain from Sale of Stock		$ 14.6