Share-Based Compensation (Information About Non-Employee Director Restricted Stock Units Activity) (Details) (USD $) In Millions, unless otherwise specified	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	$ 0.5	$ 0.5
Intrinsic value of share based compensation award exercised during the period	1.0	0.5
Fair value of shares that vested during the period	1.0	0.6
Unrecognized compensation expense		0.1
Weighted average period to recognize compensation expense (in years)	0 years	3 months 18 days
DP&L [Member] | Director RSU's [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	0.5	0.5
Intrinsic value of share based compensation award exercised during the period	1.0	0.5
Fair value of shares that vested during the period	1.0	0.6
Unrecognized compensation expense		$ 0.1
Weighted average period to recognize compensation expense (in years)	0 years	3 months 18 days