Consolidated Statements of Results of Operations (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Revenues	$ 494,500,000	$ 460,300,000
Cost of revenues:
Fuel	76,400,000	90,000,000
Purchased power	194,200,000	174,100,000
Amortization of intangibles		300,000
Total cost of revenues	270,600,000	264,400,000
Gross margin	223,900,000	195,900,000
Operating expenses:
Operation and maintenance	91,700,000	104,700,000
Depreciation and amortization	35,000,000	35,300,000
General taxes	24,100,000	27,600,000
Goodwill Impairment		135,800,000
Fixed asset impairment		11,500,000
Other	500,000	300,000
Total operating expenses	151,300,000	315,200,000
Operating income	72,600,000	(119,300,000)
Other income / (expense), net:
Investment income/ (loss)	(200,000)	400,000
Interest expense	(30,500,000)	(30,800,000)
Other deductions	(500,000)	(500,000)
Total other income / (expense), net	(31,200,000)	(30,900,000)
Earnings before income tax	41,400,000	(150,200,000)
Income tax expense	12,700,000	98,800,000
Net income/ (loss)	28,700,000	(249,000,000)
THE DAYTON POWER AND LIGHT COMPANY [Member]
Revenues	461,300,000	432,100,000
Cost of revenues:
Fuel	69,300,000	84,300,000
Purchased power	189,700,000	168,000,000
Total cost of revenues	259,000,000	252,300,000
Gross margin	202,300,000	179,800,000
Operating expenses:
Operation and maintenance	83,900,000	95,400,000
Depreciation and amortization	34,700,000	36,500,000
General taxes	23,000,000	26,400,000
Other	400,000	200,000
Total operating expenses	142,000,000	158,500,000
Operating income	60,300,000	21,300,000
Other income / (expense), net:
Investment income/ (loss)	(100,000)	300,000
Interest expense	(8,700,000)	(7,800,000)
Other deductions	(200,000)	(400,000)
Total other income / (expense), net	(9,000,000)	(7,900,000)
Earnings before income tax	51,300,000	13,400,000
Income tax expense	14,800,000	4,000,000
Net income/ (loss)	36,500,000	9,400,000
Dividends on preferred stock	200,000	200,000
Earnings on common stock	$ 36,300,000	$ 9,200,000