Condensed Consolidated Statements of Comprehensive Income/(Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Net income/ (loss)	$ 21.7	$ 33.8	$ 50.4	$ (215.2)
Available-for-sale securities activity:
Change in fair value of available-for-sale securities, net of income tax	(0.4)	0.1	0.1	(0.2)
Reclassification to earnings, net of income tax	0.4	0.0	0.0	0.2
Total change in fair value of available-for-sale securities	0.0	0.1	0.1	0.0
Derivative activity:
Change in derivative fair value, net of income tax	1.7	(12.1)	1.8	(25.0)
Reclassification of earnings, net of income tax	(1.9)	5.3	(1.4)	10.8
Total change in fair value of derivatives	(0.2)	(6.8)	0.4	(14.2)
Pension and postretirement activity:
Reclassification to earnings, net of income tax	(0.4)	0.0	(0.2)	0.0
Total change in unfunded pension obligation	(0.4)	0.0	(0.2)	0.0
Other comprehensive income / (loss)	(0.6)	(6.7)	0.3	(14.2)
Net comprehensive income / (loss)	21.1	27.1	50.7	(229.4)
THE DAYTON POWER AND LIGHT COMPANY [Member]
Net income/ (loss)	23.9	13.9	60.4	23.3
Available-for-sale securities activity:
Change in fair value of available-for-sale securities, net of income tax	(0.5)	0.1	0.0	(0.2)
Reclassification to earnings, net of income tax	0.4	0.0	0.0	0.2
Total change in fair value of available-for-sale securities	(0.1)	0.1	0.0	0.0
Derivative activity:
Change in derivative fair value, net of income tax	1.7	(14.8)	1.8	(27.7)
Reclassification of earnings, net of income tax	(1.8)	6.4	(1.3)	12.1
Total change in fair value of derivatives	(0.1)	(8.4)	0.5	(15.6)
Pension and postretirement activity:
Reclassification to earnings, net of income tax	0.9	0.8	1.8	1.4
Total change in unfunded pension obligation	0.9	0.8	1.8	1.4
Other comprehensive income / (loss)	0.7	(7.5)	2.3	(14.2)
Net comprehensive income / (loss)	$ 24.6	$ 6.4	$ 62.7	$ 9.1