Consolidated Statements of Results of Operations (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues	$ 441.2	$ 471.7	$ 1,210.7	$ 1,287.7
Cost of revenues:
Fuel	99.7	112.7	274.0	279.0
Purchased power	113.1	90.7	282.6	265.8
Amortization of intangibles	1.8	24.2	5.3	71.2
Total cost of revenues	214.6	227.6	561.9	616.0
Gross margin	226.6	244.1	648.8	671.7
Operating expenses:
Operation and maintenance	97.3	106.6	297.4	312.1
Depreciation and amortization	33.9	33.1	99.0	95.6
General taxes	19.4	15.7	60.8	58.7
Goodwill Impairment		1,850.0		1,850.0
Total operating expenses	150.6	2,005.4	457.2	2,316.4
Operating income	76.0	(1,761.3)	191.6	(1,644.7)
Other income / (expense), net:
Investment income	(0.5)	1.9	1.2	2.2
Interest expense	(31.0)	(31.1)	(91.1)	(93.1)
Other expense		(0.2)	(4.9)	(1.4)
Total other income / (expense), net	(31.5)	(29.4)	(94.8)	(92.3)
Earnings before income tax	44.5	(1,790.7)	96.8	(1,737.0)
Income tax expense	11.3	20.2	20.8	40.3
Net income	33.2	(1,810.9)	76.0	(1,777.3)
THE DAYTON POWER AND LIGHT COMPANY [Member]
Revenues	413.1	426.8	1,141.5	1,173.0
Cost of revenues:
Fuel	96.7	108.1	269.6	272.3
Purchased power	110.4	79.9	276.7	234.1
Total cost of revenues	207.1	188.0	546.3	506.4
Gross margin	206.0	238.8	595.2	666.6
Operating expenses:
Operation and maintenance	87.6	103.6	270.4	298.8
Depreciation and amortization	35.8	36.5	104.5	107.3
General taxes	18.2	14.3	57.4	54.1
Fixed asset impairment		80.8		80.8
Total operating expenses	141.6	235.2	432.3	541.0
Operating income	64.4	3.6	162.9	125.6
Other income / (expense), net:
Investment income	0.1	1.9	1.7	2.1
Interest expense	(10.4)	(10.0)	(29.7)	(29.0)
Other expense		(0.2)	(4.3)	(1.0)
Total other income / (expense), net	(10.3)	(8.3)	(32.3)	(27.9)
Earnings before income tax	54.1	(4.7)	130.6	97.7
Income tax expense	13.2	6.5	29.2	39.4
Net income	40.9	(11.2)	101.4	58.3
Dividends on preferred stock	0.2	0.2	0.6	0.6
Earnings on common stock	$ 40.7	$ (11.4)	$ 100.8	$ 57.7