Redeemable Preferred Stock (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Amount above net income required for dividend issuance	$ 1.2
Retained Earnings (Accumulated Deficit)	(2,022.1)	(1,806.0)
DP&L [Member]
Amount above net income required for dividend issuance	1.2
Retained Earnings (Accumulated Deficit)	$ 426.8
$100 Redeemable Preferred Stock Twenty Five Dollar [Member]
Preferred stock par value	$ 100
Preferred stock shares authorized	4,000,000
Preferred stock shares outstanding	228,508
$100 Redeemable Preferred Stock Twenty Five Dollar [Member] | DP&L [Member]
Preferred stock par value	$ 100
Preferred stock shares authorized	4,000,000
Preferred stock shares outstanding	228,508
$25 Redeemable Preferred Stock [Member]
Preferred stock par value	$ 25
Preferred stock shares authorized	4,000,000
$25 Redeemable Preferred Stock [Member] | DP&L [Member]
Preferred stock par value	$ 25
Preferred stock shares authorized	4,000,000