Consolidated Statements of Comprehensive Income/(Loss) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Net income	$ 98.4	$ 33.2	$ (116.8)	$ 76.0
Available-for-sale securities activity:
Change in fair value of available-for-sale securities	(0.4)	0.2	(0.6)	(1.3)
Reclassification to earnings of available-for-sale securities, net of income tax expense/(benefit)	0.2	0.4	0.4	1.4
Total change in fair value of available-for-sale securities	(0.2)	0.6	(0.2)	0.1
Derivative activity:
Change in derivative fair value	1.2	6.2	(23.8)	18.7
Reclassification of earnings, net of income tax (expense)/benefit of $0.6 and $(0.3), respectively	3.4	1.3	14.2	3.0
Total change in fair value of derivatives	4.6	7.5	(9.6)	21.7
Pension and postretirement activity:
Reclassification to earnings of Pension				0.3
Total change in unfunded pension obligation				0.3
Other comprehensive income / (loss)	4.4	8.1	(9.8)	22.1
Net comprehensive income / (loss)	102.8	41.3	(126.6)	98.1
THE DAYTON POWER AND LIGHT COMPANY [Member]
Net income	53.2	40.9	76.5	101.4
Available-for-sale securities activity:
Change in fair value of available-for-sale securities	(0.4)	(0.2)	(0.6)	(1.8)
Reclassification to earnings of available-for-sale securities, net of income tax expense/(benefit)	0.2	0.4	0.4	1.4
Total change in fair value of available-for-sale securities	(0.2)	0.2	(0.2)	(0.4)
Derivative activity:
Change in derivative fair value	1.4	(0.3)	(26.3)
Reclassification of earnings, net of income tax (expense)/benefit of $0.6 and $(0.3), respectively	3.2	1.0	15.3	2.3
Total change in fair value of derivatives	4.6	0.7	(11.0)	2.3
Pension and postretirement activity:
Reclassification to earnings of Pension	0.7	0.9	2.1	2.7
Total change in unfunded pension obligation	0.7	0.9	2.1	2.7
Other comprehensive income / (loss)	5.1	1.8	(9.1)	4.6
Net comprehensive income / (loss)	$ 58.3	$ 42.7	$ 67.4	$ 106.0