Share-Based Compensation (Summarized Share-Based Compensation Expense) (Details) (USD $) In Millions, unless otherwise specified	11 Months Ended
	Nov. 27, 2011
Share-based compensation included in Operation and maintenance expense	$ 10.1
Income tax expense / (benefit)	(3.5)
Total share-based compensation, net of tax	6.6
DP&L [Member]
Share-based compensation included in Operation and maintenance expense	10.1
Income tax expense / (benefit)	(3.5)
Total share-based compensation, net of tax	6.6
Restricted Shares [Member]
Share-based compensation included in Operation and maintenance expense	5.3
Restricted Shares [Member] | DP&L [Member]
Share-based compensation included in Operation and maintenance expense	5.3
Director RSU's [Member]
Share-based compensation included in Operation and maintenance expense	0.6
Director RSU's [Member] | DP&L [Member]
Share-based compensation included in Operation and maintenance expense	0.6
Management Performance Shares [Member]
Share-based compensation included in Operation and maintenance expense	1.8
Management Performance Shares [Member] | DP&L [Member]
Share-based compensation included in Operation and maintenance expense	1.8
Performance Shares [Member]
Share-based compensation included in Operation and maintenance expense	2.4
Performance Shares [Member] | DP&L [Member]
Share-based compensation included in Operation and maintenance expense	$ 2.4