Goodwill And Other Intangible Asset (Narrative) (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended			3 Months Ended
	Oct. 01, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014	Mar. 31, 2014
Goodwill (Note 5)		$ 317.0	$ 452.8
Goodwill, Impairment Loss	306.3
Goodwill Allocated to DP&L Reporting Unit		2.4
Effective Income Tax Rate, Continuing Operations		(31.80%)	(11.20%)	(2.80%)
Parent Company [Member]
Goodwill, Impairment Loss				1,817.2
DP&L [Member]
Goodwill (Note 5)		317.0	317.0	623.3
Goodwill, Impairment Loss			(306.3)
DPLER [Member]
Goodwill (Note 5)			135.8	135.8		135.8
Goodwill, Impairment Loss		$ (135.8)			$ 135.8