Goodwill Impairment Goodwill Impairment (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2011 business
Goodwill [Line Items]
Goodwill impairment expense	$ 58,000,000	$ 1,850,000,000	$ 58,000,000	$ 1,850,000,000
Number Of Reporting Units To Which Purchase Price Is Allocated					2
Ebute [Member]
Goodwill [Line Items]
Generation capacity mega watts	294		294
Goodwill impairment expense	58,000,000
DPL Subsidiary [Member]
Goodwill [Line Items]
Goodwill					2,600,000,000
Effective tax rates		(13.00%)		(167.00%)
DP&L [Member]
Goodwill [Line Items]
Goodwill impairment expense		1,850,000,000
Goodwill					$ 2,400,000,000