Share-Based Compensation (Information About Performance Shares Activity) (Details) (USD $)	11 Months Ended	12 Months Ended
	Nov. 27, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of share based compensation award granted during the period	$ 500,000
Intrinsic value of share based compensation award exercised during the period	1,000,000
Fair value of shares that vested during the period	1,000,000
Weighted average period to recognize compensation expense (in years)	0 years
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of share based compensation award granted during the period		2,200,000
Intrinsic value of share based compensation award exercised during the period	6,000,000
Excess tax benefit from proceeds of share-based compensation award exercised	700,000
Fair value of shares that vested during the period	4,700,000
DP&L [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average grant date fair value of share based compensation award granted during the period	2,200,000
Intrinsic value of share based compensation award exercised during the period	6,000,000
Excess tax benefit from proceeds of share-based compensation award exercised	700,000
Fair value of shares that vested during the period	$ 4,700,000
Weighted average period to recognize compensation expense (in years)	0 months