Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income / (loss)	$ 22.1	$ (1.0)	$ 105.4
Adjustments to reconcile Net income / (loss) to Net cash from operating activities
Depreciation and amortization	76.1	73.6	53.1
Deferred income taxes	4.7	39.8	15.2
Loss on early extinguishment of debt	0.0	31.7	44.9
Impairment of Long-Lived Assets Held-for-use, Including Discontinued Operation	0.0	0.0	3.5
Gain (Loss) on Disposition of Business	0.0	(1.4)	(20.1)
Gain (Loss) on Disposition of Business	0.0	(4.7)	0.0
Changes in certain assets and liabilities:
Accounts receivable, net	(2.0)	11.2	10.2
Inventories	(5.5)	4.9	(4.2)
Taxes applicable to subsequent years	(5.2)	(0.2)	(2.8)
Deferred regulatory costs, net	10.3	(34.0)	(2.2)
Accounts payable	15.7	(10.1)	9.7
Accrued taxes payable / receivable	20.6	8.0	(21.2)
Accrued interest	(0.7)	4.6	(2.9)
Accrued pension and other post-retirement benefits	(12.2)	(11.8)	(8.8)
Other	(7.0)	(1.4)	0.5
Net cash provided by operating activities	116.9	113.9	180.3
Cash flows from investing activities:
Capital expenditures	(191.3)	(157.3)	(156.5)
Proceeds from disposal and sale of business interests	0.0	1.6	0.0
Payments for Removal Costs	(3.9)	(8.9)	(51.0)
Proceeds from Sale of Property, Plant, and Equipment	0.0	5.1	0.0
Payments for (Proceeds from) Removal Costs	(17.2)	(25.5)	(11.6)
Other investing activities, net	(0.6)	(0.7)	(3.5)
Net cash used in investing activities	(213.0)	(185.7)	(222.6)
Cash flows from financing activities:
Deferred financing costs	(0.2)	(7.8)	(9.9)
Retirement of debt	0.0	(550.8)	(978.0)
Equity Contribution from Parent	132.5	98.0	0.0
Premium paid for early redemption of debt	0.0	(0.1)	(0.2)
Issuance of long-term debt	0.0	555.0	821.7
Borrowings from revolving credit facilities	120.0	185.0	204.0
Repayment of borrowings from revolving credit facilities	(155.0)	(229.0)	(60.0)
Net cash from financing activities	97.3	50.3	(22.4)
Cash and cash equivalents:
Net increase / (decrease) in cash	1.2	(21.5)	(64.7)
Restricted Cash and Cash Equivalents	26.7	25.5	47.0
Supplemental cash flow information:
Interest paid, net of amounts capitalized	59.3	67.8	80.8
Income taxes paid / (refunded), net	(17.5)	(51.9)	1.8
Non-cash financing and investing activities:
Accruals for capital expenditures	42.6	31.7	16.9
Non-cash capital contribution		98.0
Accruals from sale of business	0.0	2.2	0.0
THE DAYTON POWER AND LIGHT COMPANY [Member]
Net income / (loss)	47.1	51.1	124.9
Adjustments to reconcile Net income / (loss) to Net cash from operating activities
Depreciation and amortization	74.6	71.8	70.8
Deferred income taxes	4.5	3.4	(9.7)
Gain (Loss) on Disposition of Business	0.0	(4.7)	0.0
Changes in certain assets and liabilities:
Accounts receivable, net	(1.9)	0.7	19.6
Inventories	(5.5)	1.4	(2.8)
Taxes applicable to subsequent years	(5.4)	(0.2)	(5.0)
Deferred regulatory costs, net	10.3	(34.0)	(2.2)
Accounts payable	15.1	(4.0)	12.9
Accrued taxes payable / receivable	10.0	4.5	(7.2)
Accrued interest	0.0	1.3	0.9
Accrued pension and other post-retirement benefits	(12.2)	(11.8)	(8.8)
Other	(6.4)	2.1	6.5
Net cash provided by operating activities	130.2	91.0	199.9
Cash flows from investing activities:
Capital expenditures	(189.3)	(153.3)	(155.5)
Payments for Removal Costs	0.0	(7.0)	0.0
Payments for (Proceeds from) Removal Costs	(17.1)	(25.5)	(11.6)
Other investing activities, net	0.9	(0.7)	(3.5)
Net cash used in investing activities	(205.5)	(186.5)	(170.6)
Cash flows from financing activities:
Deferred financing costs	0.0	(1.2)	(5.2)
Retirement of debt	0.0	(140.0)	(436.1)
Equity Contribution from Parent	150.0	150.0	0.0
Premium paid for early redemption of debt	0.0	(0.1)	(0.2)
Issuance of long-term debt	0.0	140.0	422.3
Borrowings from revolving credit facilities	120.0	95.0	60.0
Repayment of borrowings from revolving credit facilities	(140.0)	(115.0)	(20.0)
Dividends paid on common stock to parent	(52.0)		(95.0)
Net cash from financing activities	78.0	86.0	(74.2)
Cash and cash equivalents:
Net increase / (decrease) in cash	2.7	(9.5)	(44.9)
Restricted Cash and Cash Equivalents	14.5	11.8	21.3
Supplemental cash flow information:
Interest paid, net of amounts capitalized	21.2	19.3	20.3
Income taxes paid / (refunded), net	0.0	0.1	24.3
Non-cash financing and investing activities:
Accruals for capital expenditures	$ 42.5	$ 31.6	$ 16.5