Income Taxes (Tax or Benefit credited to AOCI) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	11 Months Ended	12 Months Ended
	Dec. 31, 2011	Nov. 27, 2011	Dec. 31, 2012	Dec. 31, 2013 DP&L [Member]	Dec. 31, 2012 DP&L [Member]	Dec. 31, 2011 DP&L [Member]	Dec. 31, 2013 Successor [Member]
Other Tax Expense (Benefit)	$ (1.2)	$ (33.2)	$ (2.5)	$ 7.0	$ (0.8)	$ (7.2)	$ 15.4