Share-Based Compensation (Summarized Stock Option Activity) (Details) (Stock Options [Member], USD $)	11 Months Ended	12 Months Ended
Nov. 27, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of year	351,500	417,500
Exercised	(75,500)	(66,000)
Expired	(276,000)
Outstanding at year-end		351,500
Exercisable at year-end		351,500
Outstanding at beginning of year	$ 28.04	$ 27.16
Exercised	$ 21.02	$ 21.00
Weighted Average Price Expired	$ 29.42
Outstanding at year-end		$ 28.04
Exercisable at year-end		$ 28.04
DP&L [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding at beginning of year	351,500	417,500
Exercised	(75,500)	(66,000)
Expired	(276,000)
Outstanding at year-end		351,500
Exercisable at year-end		351,500
Outstanding at beginning of year	$ 28.04	$ 27.16
Exercised	$ 21.02	$ 21.00
Weighted Average Price Expired	$ 29.42
Outstanding at year-end		$ 28.04
Exercisable at year-end		$ 28.04

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

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-Name Accounting Standards Codification

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

+ References

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

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- Definition

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

+ References

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- Definition

The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

+ References

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-Publisher FASB

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

+ References

No definition available.

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- Definition

Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

+ References

No definition available.

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Number of share options (or share units) exercised during the current period.

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