Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
Cash flows from operating activities:
Net income	$ (116.8)	$ 76.0
Adjustments to reconcile Net income to Net cash provided by operating activities:
Depreciation and amortization	103.7	99.0
Amortization of intangibles	0.9	5.3
Amortization of debt market value adjustments	0.1	(14.3)
Deferred income taxes	(2.5)	31.5
Fixed asset impairment	11.5
Goodwill Impairment	135.8
Changes in certain assets and liabilities:
Accounts receivable	12.7	30.8
Inventories	(3.6)	18.6
Prepaid taxes	0.5	0.7
Taxes applicable to subsequent years	52.1	52.1
Deferred regulatory costs, net	4.8	11.6
Accounts payable	7.2	(7.2)
Accrued taxes payable	(27.5)	(69.3)
Accrued interest payable	14.5	24.3
Pension, retiree and other benefits	(5.2)	7.1
Unamortized investment tax credit	(0.4)	(0.4)
Insurance and claims costs	0.4	(2.4)
Other	(13.8)	(14.3)
Net cash provided by operating activities	174.4	249.1
Cash flows from investing activities:
Capital expenditures	(81.6)	(96.5)
Proceeds from sale of property - other		0.8
Insurance proceeds		7.6
Decrease (increase) in Restricted Cash	(9.0)	3.4
Other investing activities, net	1.1	(1.6)
Net cash used for investing activities	(93.1)	(89.6)
Cash flows from financing activities:
Deferred Finance Costs	(0.3)	(11.6)
Payment of long-term debt	(30.1)	(425.1)
Issuance of long-term debt		644.2
Withdrawals from revolving credit facilities	115.0	50.0
Repayments of borrowings from revolving credit facilities	(115.0)	(50.0)
Net cash used for financing activities	(30.4)	207.5
Cash and cash equivalents:
Net change	50.9	367.0
Balance at beginning of period	53.2	192.1
Cash and cash equivalents at end of period	104.1	559.1
Supplemental cash flow information:
Interest paid, net of amounts capitalized	73.8	79.5
Income taxes paid/(refund), net	0.2	(20.2)
Non-cash financing and investing activities:
Accruals for capital expenditures	6.7	5.4
THE DAYTON POWER AND LIGHT COMPANY [Member]
Cash flows from operating activities:
Net income	76.5	101.4
Adjustments to reconcile Net income to Net cash provided by operating activities:
Depreciation and amortization	108.2	104.5
Deferred income taxes	2.9	27.1
Changes in certain assets and liabilities:
Accounts receivable	4.8	30.7
Inventories	(3.5)	18.5
Prepaid taxes	0.2	0.8
Taxes applicable to subsequent years	50.5	50.0
Deferred regulatory costs, net	4.8	12.4
Accounts payable	7.9	(7.3)
Accrued taxes payable	(40.8)	(48.2)
Accrued interest payable	(5.7)	2.7
Pension, retiree and other benefits	(5.2)	7.1
Unamortized investment tax credit	(1.9)	(1.9)
Other	(9.5)	(13.9)
Net cash provided by operating activities	189.2	283.9
Cash flows from investing activities:
Capital expenditures	(78.6)	(95.1)
Proceeds from sale of property - other		0.8
Insurance proceeds	0.4	12.1
Decrease (increase) in Restricted Cash	(9.4)	3.4
Other investing activities, net	1.1	(1.7)
Net cash used for investing activities	(90.1)	(83.8)
Cash flows from financing activities:
Dividends paid on common stock	(90.0)	(155.0)
Dividends paid on preferred stock	(0.7)	(0.6)
Borrowings from related party	15.0
Repayment of borrowings from related party	(15.0)
Deferred Finance Costs	(0.2)	(6.7)
Payment of long-term debt	(0.1)	(0.1)
Issuance of long-term debt		444.2
Net cash used for financing activities	(91.0)	281.8
Cash and cash equivalents:
Net change	8.1	481.9
Balance at beginning of period	22.9	28.5
Cash and cash equivalents at end of period	31.0	510.4
Supplemental cash flow information:
Interest paid, net of amounts capitalized	26.1	28.7
Income taxes paid/(refund), net	0.2	(20.3)
Non-cash financing and investing activities:
Accruals for capital expenditures	6.7	5.4
Emission Allowances [Member]
Cash flows from investing activities:
Payments to Acquire Intangible Assets	(0.2)
Emission Allowances [Member] | THE DAYTON POWER AND LIGHT COMPANY [Member]
Cash flows from investing activities:
Payments to Acquire Intangible Assets	0.2
Renewable Energy Certificates [Member]
Cash flows from investing activities:
Payments to Acquire Intangible Assets	(3.4)	(3.3)
Renewable Energy Certificates [Member] | THE DAYTON POWER AND LIGHT COMPANY [Member]
Cash flows from investing activities:
Payments to Acquire Intangible Assets	$ 3.4	$ 3.3