Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
NET INCOME / (LOSS)	$ 35.7	$ (4.7)	$ 22.1
Adjustments to reconcile net income / (loss) to net cash provided by operating activities:
Depreciation and amortization	82.1	80.0	76.1
Deferred income taxes	26.2	(2.0)	4.7
Gain (Loss) on Disposition of Business	0.0	(0.6)	0.0
Gain (Loss) on Disposition of Business	0.0	0.6	0.0
Changes in certain assets and liabilities:
Accounts receivable, net	(0.6)	(20.4)	(2.0)
Inventories	(17.7)	(12.5)	(5.5)
Taxes applicable to subsequent years	(19.0)	(10.9)	(5.2)
Current and non-current regulatory assets and liabilities, net	(75.1)	38.4	10.3
Accounts payable	(19.7)	14.0	15.7
Accrued taxes payable / receivable	34.1	5.8	20.6
Accrued interest	0.8	0.8	(0.7)
Accrued pension and other postretirement obligations	(4.1)	(11.4)	(12.2)
Increase (Decrease) in Other Noncurrent Liabilities	(3.8)	(0.6)	0.6
Other	(6.9)	4.7	(3.6)
Net cash provided by operating activities	26.7	86.4	116.9
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(387.9)	(287.3)	(191.3)
Proceeds from disposal and sale of business interests	0.0	0.5	0.0
Payments for Removal Costs	0.0	(0.6)	(3.9)
Payments for (Proceeds from) Removal Costs	(26.8)	(22.4)	(17.2)
Other investing activities, net	0.2	(0.1)	(0.6)
Net cash used in investing activities	(414.5)	(309.9)	(213.0)
Cash flows from financing activities:
Deferred financing costs	(0.7)	(2.6)	(0.2)
Equity Contribution from Parent	239.0	0.0	132.5
Issuance of long-term debt	300.0	140.0	0.0
Borrowings from revolving credit facilities	315.0	255.0	120.0
Repayment of borrowings from revolving credit facilities	(455.0)	(165.0)	(155.0)
Net cash from financing activities	398.3	227.4	97.3
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	10.5	3.9	1.2
Cash and cash equivalents:
Restricted Cash and Cash Equivalents	41.1	30.6	26.7
Supplemental cash flow information:
Interest paid, net of amounts capitalized	71.0	62.0	59.3
Income taxes paid / (refunded), net	0.0	0.0	(17.5)
Non-cash financing and investing activities:
Accruals for capital expenditures	101.6	47.0	42.6
Non-cash capital contribution			132.5
Increase (Decrease) in Other Noncurrent Assets	(5.3)	5.8	(4.0)
THE DAYTON POWER AND LIGHT COMPANY [Member]
NET INCOME / (LOSS)	61.4	18.9	47.1
Adjustments to reconcile net income / (loss) to net cash provided by operating activities:
Depreciation and amortization	80.7	78.7	74.6
Deferred income taxes	9.0	(2.3)	4.5
Gain (Loss) on Disposition of Business	0.0	0.6	0.0
Changes in certain assets and liabilities:
Accounts receivable, net	0.7	20.5	1.9
Inventories	17.7	12.5	5.5
Taxes applicable to subsequent years	19.0	10.9	5.4
Current and non-current regulatory assets and liabilities, net	75.1	(38.4)	(10.3)
Accounts payable	(19.9)	13.6	15.1
Accrued taxes payable / receivable	37.3	12.5	10.0
Accrued interest	0.8	0.8	0.0
Accrued pension and other postretirement obligations	(4.1)	(11.4)	(12.2)
Increase (Decrease) in Other Noncurrent Liabilities	(3.0)	4.9	(1.8)
Other	9.4	(2.4)	(0.3)
Net cash provided by operating activities	35.4	117.6	130.2
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(384.3)	(283.7)	(189.3)
Payments for (Proceeds from) Removal Costs	(26.8)	(22.4)	(17.1)
Other investing activities, net	0.2	0.4	0.9
Net cash used in investing activities	(410.9)	(305.7)	(205.5)
Cash flows from financing activities:
Deferred financing costs	(0.7)	(2.6)	0.0
Equity Contribution from Parent	260.0	0.0	150.0
Issuance of long-term debt	300.0	140.0	0.0
Borrowings from revolving credit facilities	315.0	255.0	120.0
Repayment of borrowings from revolving credit facilities	(420.0)	(135.0)	(140.0)
Dividends paid on common stock to parent	(83.0)		(52.0)
Net cash from financing activities	371.3	193.4	78.0
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect	(4.2)	5.3	2.7
Cash and cash equivalents:
Restricted Cash and Cash Equivalents	15.6	19.8	14.5
Supplemental cash flow information:
Interest paid, net of amounts capitalized	34.4	15.9	21.2
Non-cash financing and investing activities:
Accruals for capital expenditures	101.5	47.0	42.5
Increase (Decrease) in Other Noncurrent Assets	$ (4.9)	$ 5.6	$ (4.9)