Consolidated Statements of Comprehensive Income/(Loss) (USD $) In Millions, unless otherwise specified	1 Months Ended	12 Months Ended		11 Months Ended	12 Months Ended
	Dec. 31, 2011 Successor [Member]	Dec. 31, 2013 Successor [Member]	Dec. 31, 2012 Successor [Member]	Nov. 27, 2011 Predecessor [Member]	Dec. 31, 2013 THE DAYTON POWER AND LIGHT COMPANY [Member]	Dec. 31, 2012 THE DAYTON POWER AND LIGHT COMPANY [Member]	Dec. 31, 2011 THE DAYTON POWER AND LIGHT COMPANY [Member]
Net income	$ (6.2)	$ (222.0)	$ (1,729.8)	$ 150.5	$ 83.6	$ 91.2	$ 193.2
Available-for-sale securities activity:
Change in fair value of available-for-sale securities		(1.2)	0.5		(1.6)	0.5	(7.8)
Reclassification to earnings of available-for-sale securities, net of income tax expense/(benefit)		1.4	(0.1)		1.4	(0.1)
Total change in fair value of available-for-sale securities		0.2	0.4		(0.2)	0.4	(7.8)
Derivative activity:
Change in derivative fair value	(0.5)	19.7	(1.5)	(58.2)	1.0	(3.0)	(1.2)
Reclassification of earnings, net of income tax (expense)/benefit of $0.6 and $(0.3), respectively		3.4	(0.5)	(0.3)	2.6	(3.4)	(0.2)
Total change in fair value of derivatives	(0.5)	23.1	(2.0)	(58.5)	3.6	(6.4)	(1.4)
Pension and postretirement activity:
Prior service cost for the period	(0.2)			0.1	0.5	0.8	0.5
Unrealized losses on pension and postretirement benefits net of income tax benefits	0.3	4.9	(1.9)	0.3	4.3	(1.5)	(8.0)
Reclassification to earnings of Pension		0.3		2.8	3.8	2.7	2.3
Total change in unfunded pension obligation	0.1	5.2	(1.9)	3.2	8.6	2.0	(5.2)
Other comprehensive income / (loss)	(0.4)	28.5	(3.5)	(55.3)	12.0	(4.0)	(14.4)
Net comprehensive income / (loss)	$ (6.6)	$ (193.5)	$ (1,733.3)	$ 95.2	$ 95.6	$ 87.2	$ 178.8