Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
NET INCOME / (LOSS)	$ 13.8	$ 35.7	$ (4.7)
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	13.8	35.7	(4.7)
Adjustments to reconcile net income / (loss) to net cash provided by operating activities:
Depreciation and amortization	95.2	82.1	80.0
Amortization of deferred financing costs and debt discounts	3.5	3.8	1.3
Deferred income taxes	14.8	26.2	(2.0)
Gain (Loss) on Disposition of Business	1.3	0.0	0.0
Changes in certain assets and liabilities:
Accounts receivable, net	(14.3)	(0.6)	(20.4)
Inventories	(15.3)	(17.7)	(12.5)
Taxes applicable to subsequent years	(24.1)	(19.0)	(10.9)
Current and non-current regulatory assets and liabilities, net	(14.2)	(75.1)	38.4
Accounts payable	21.0	(19.7)	14.0
Accrued taxes payable / receivable	19.7	34.1	5.8
Accrued interest	6.0	0.8	0.8
Increase (Decrease) in Deferred Liabilities	6.9	(2.2)	2.6
Accrued pension and other postretirement obligations	(7.0)	(4.1)	(11.4)
Increase (Decrease) in Other Noncurrent Liabilities	(0.5)	(3.8)	(0.6)
Other	(0.3)	(3.5)	1.2
Net cash provided by operating activities	118.7	26.7	86.4
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(549.5)	(387.9)	(287.3)
Payments for (Proceeds from) Removal Costs	(27.5)	(26.8)	(22.4)
Other investing activities, net	(0.5)	0.2	(0.2)
Net cash used in investing activities	(577.5)	(414.5)	(309.9)
Cash flows from financing activities:
Equity Contribution from Parent	200.0	239.0	0.0
Premium paid for early redemption of debt	(3.2)	(0.7)	(2.6)
Issuance of long-term debt	0.0	300.0	140.0
Borrowings from revolving credit facilities	485.0	315.0	255.0
Repayment of borrowings from revolving credit facilities	(360.0)	(455.0)	(165.0)
Net cash from financing activities	471.8	398.3	227.4
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	13.0	10.5	3.9
Cash and cash equivalents:
Restricted Cash and Cash Equivalents	54.1	41.1	30.6
Supplemental cash flow information:
Interest paid, net of amounts capitalized	78.4	71.0	62.0
Non-cash financing and investing activities:
Accruals for capital expenditures	48.8	101.6	47.0
Non-cash capital contribution		239.0
Increase (Decrease) in Other Noncurrent Assets	18.4	(5.3)	5.8
Public Utilities, Allowance for Funds Used During Construction, Additions	(6.2)	(5.0)	(1.0)
Proceeds from Short-Term Debt	150.0	0.0	0.0
THE DAYTON POWER AND LIGHT COMPANY [Member]
NET INCOME / (LOSS)	36.9	61.4	18.9
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	36.9	61.4	18.9
Adjustments to reconcile net income / (loss) to net cash provided by operating activities:
Depreciation and amortization	93.4	80.7	78.7
Amortization of deferred financing costs and debt discounts	1.4	1.7	0.8
Deferred income taxes	3.4	9.0	(2.3)
Gain (Loss) on Disposition of Business	(1.1)	0.0	0.0
Gain (Loss) on Sale of Assets and Asset Impairment Charges	(6.2)	(5.0)	(1.0)
Changes in certain assets and liabilities:
Accounts receivable, net	13.5	0.7	20.5
Inventories	13.8	17.7	12.5
Taxes applicable to subsequent years	24.2	19.0	10.9
Current and non-current regulatory assets and liabilities, net	14.2	75.1	(38.4)
Accounts payable	21.1	(19.9)	13.6
Accrued taxes payable / receivable	37.5	37.3	12.5
Accrued interest	6.0	0.8	0.8
Increase (Decrease) in Deferred Liabilities	6.8	(2.0)	2.6
Accrued pension and other postretirement obligations	(7.0)	(4.1)	(11.4)
Increase (Decrease) in Other Noncurrent Liabilities	1.9	(3.0)	4.9
Other	(1.4)	4.1	0.6
Net cash provided by operating activities	150.6	35.4	117.6
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(547.9)	(384.3)	(283.7)
Payments for (Proceeds from) Removal Costs	(27.5)	(26.8)	(22.4)
Other investing activities, net	(0.9)	0.2	0.4
Net cash used in investing activities	(576.3)	(410.9)	(305.7)
Cash flows from financing activities:
Equity Contribution from Parent	200.0	260.0	0.0
Premium paid for early redemption of debt	0.2	(0.7)	(2.6)
Issuance of long-term debt	0.0	300.0	140.0
Borrowings from revolving credit facilities	485.0	315.0	255.0
Repayment of borrowings from revolving credit facilities	(360.0)	(420.0)	(135.0)
Dividends paid on common stock to parent	(40.0)		(64.0)
Net cash from financing activities	434.8	371.3	193.4
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	9.1	(4.2)	5.3
Cash and cash equivalents:
Restricted Cash and Cash Equivalents	24.7	15.6	19.8
Supplemental cash flow information:
Interest paid, net of amounts capitalized	42.6	34.4	15.9
Non-cash financing and investing activities:
Accruals for capital expenditures	48.8	101.5	47.0
Increase (Decrease) in Other Noncurrent Assets	18.6	(4.9)	5.6
Proceeds from Short-Term Debt	$ 150.0	$ 0.0	$ 0.0