Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Cash flows from operating activities:
Net income	$ 76.0	$ (1,777.3)
Adjustments to reconcile Net income to Net cash provided by operating activities:
Depreciation and amortization	99.0	95.6
Amortization of intangibles	5.3	71.2
Amortization of debt market value adjustments	(14.3)	(14.2)
Deferred income taxes	31.5	(10.5)
Goodwill Impairment		1,850.0
Recognition of deferred SECA revenue		(17.8)
Changes in certain assets and liabilities:
Accounts receivable	30.8	(10.2)
Inventories	18.6	29.5
Prepaid taxes	0.7	0.6
Taxes applicable to subsequent years	52.1	59.9
Deferred regulatory costs, net	11.6	2.7
Accounts payable	(7.2)	(16.7)
Accrued taxes payable	(69.3)	(49.4)
Accrued interest payable	24.3	25.2
Pension, retiree and other benefits	7.1	24.4
Unamortized investment tax credit	(0.4)	(0.2)
Insurance and claims costs	(2.4)	(1.3)
Other	(14.3)	(7.0)
Net cash provided by operating activities	249.1	254.5
Cash flows from investing activities:
Capital expenditures	(96.5)	(163.1)
Proceeds from sale of property - other	0.8
Insurance proceeds	7.6
Increase (Decrease) in Restricted Cash	3.4	(0.4)
Other	(1.6)
Net cash used for investing activities	(89.6)	(168.3)
Cash flows from financing activities:
Dividends paid on common stock		(45.0)
Payment to former warrant holders		(9.0)
Deferred Finance Costs	(11.6)	(0.3)
Payment of long-term debt	(425.1)	(0.1)
Issuance of long-term debt	644.2
Withdrawals from revolving credit facilities	50.0
Repayments of borrowings from revolving credit facilities	(50.0)
Contributions to additional paid-in capital from parent		0.3
Net cash used for financing activities	207.5	(54.1)
Cash and cash equivalents:
Net change	367.0	32.1
Balance at beginning of period	192.1	173.5
Cash and cash equivalents at end of period	559.1	205.6
Supplemental cash flow information:
Interest paid, net of amounts capitalized	79.5	78.1
Income taxes paid/(refund), net	(20.2)	43.0
Non-cash financing and investing activities:
Accruals for capital expenditures	5.4	12.5
THE DAYTON POWER AND LIGHT COMPANY [Member]
Cash flows from operating activities:
Net income	101.4	58.3
Adjustments to reconcile Net income to Net cash provided by operating activities:
Depreciation and amortization	104.5	107.3
Deferred income taxes	27.1	(3.4)
Fixed asset impairment		80.8
Recognition of deferred SECA revenue		(17.8)
Changes in certain assets and liabilities:
Accounts receivable	30.7	13.0
Inventories	18.5	28.1
Prepaid taxes	0.8	0.8
Taxes applicable to subsequent years	50.0	56.2
Deferred regulatory costs, net	12.4	2.4
Accounts payable	(7.3)	(16.3)
Accrued taxes payable	(48.2)	(35.2)
Accrued interest payable	2.7	7.4
Pension, retiree and other benefits	7.1	24.4
Unamortized investment tax credit	(1.9)	(1.9)
Other	(13.9)	0.5
Net cash provided by operating activities	283.9	304.6
Cash flows from investing activities:
Capital expenditures	(95.1)	(161.7)
Proceeds from sale of property - other	0.8
Insurance proceeds	12.1
Increase (Decrease) in Restricted Cash	3.4	(5.2)
Other	(1.7)
Net cash used for investing activities	(83.8)	(171.7)
Cash flows from financing activities:
Dividends paid on common stock	(155.0)	(145.0)
Dividends paid on preferred stock	(0.6)	(0.6)
Deferred Finance Costs	(6.7)
Payment of long-term debt	(0.1)	(0.1)
Issuance of long-term debt	444.2
Net cash used for financing activities	281.8	(145.7)
Cash and cash equivalents:
Net change	481.9	(12.8)
Balance at beginning of period	28.5	32.2
Cash and cash equivalents at end of period	510.4	19.4
Supplemental cash flow information:
Interest paid, net of amounts capitalized	28.7	22.6
Income taxes paid/(refund), net	(20.3)	30.3
Non-cash financing and investing activities:
Accruals for capital expenditures	5.4	12.5
Renewable Energy Certificates [Member]
Cash flows from investing activities:
Payments to Acquire Intangible Assets	(3.3)	(4.8)
Renewable Energy Certificates [Member] | THE DAYTON POWER AND LIGHT COMPANY [Member]
Cash flows from investing activities:
Payments to Acquire Intangible Assets	$ (3.3)	$ (4.8)