Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities:
Net income	$ 20.4	$ (51.2)
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	41.6	54.5
Charge for early retirement of debt	6.4	0.3
Deferred income taxes	(20.0)	(1.8)
Impairment of Long-Lived Assets Held-for-use	1.2	66.4
Gain (Loss) on Disposition of Business	(13.5)	0.0
Gain (Loss) on Sale of Assets and Asset Impairment Charges	1.1	16.2
Changes in certain assets and liabilities:
Accounts receivable	20.9	22.4
Inventories	13.5	7.7
Taxes applicable to subsequent years	39.3	40.0
Deferred regulatory costs, net	(6.7)	(9.1)
Accounts payable	(11.1)	(38.4)
Accrued taxes payable	(19.9)	(65.3)
Accrued interest payable	(1.7)	(0.1)
Security deposits	(1.2)	1.7
Increase (Decrease) Deferred Investment Tax Credit	(0.2)	(0.2)
Increase (Decrease) in Self Insurance Reserve	(0.3)	(0.1)
Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits	(5.3)	2.0
Other	6.2	(4.8)
Net cash provided by operating activities	97.7	40.2
Cash flows from investing activities:
Capital expenditures	(50.7)	(66.4)
Proceeds from sale of business	234.9	0.0
Payments for Removal Costs	(14.5)	0.0
Proceeds from Sale of Property, Plant, and Equipment	10.6	0.1
Insurance proceeds	2.8	0.9
Other investing activities, net	(0.5)	0.0
Net cash provided by investing activities	182.6	(65.4)
Cash flows from financing activities:
Repayments of Lines of Credit	(30.0)	0.0
Proceeds from Lines of Credit	30.0	0.0
Retirement of long-term debt	(238.3)	(22.8)
Net cash provided by financing activities	(238.3)	(22.8)
Net Cash Provided by (Used in) Discontinued Operations	1.5	27.5
Other deferred credits	8.0
Cash and cash equivalents:
Net change	43.5	(20.5)
Supplemental cash flow information:
Interest paid, net of amounts capitalized	49.2	51.8
Proceeds from Income Tax Refunds	(2.0)	0.0
Non-cash financing and investing activities:
Accruals for capital expenditures	7.2	9.9
Restricted Cash and Cash Equivalents	68.4	34.1
Non-cash Proceeds from Sale of Business	4.1	0.0
Non-cash capital contribution	26.7	0.0
THE DAYTON POWER AND LIGHT COMPANY [Member]
Cash flows from operating activities:
Net income	30.7	(25.7)
Adjustments to reconcile net income to net cash from operating activities:
Depreciation and amortization	37.4	45.5
Charge for early retirement of debt	0.6	0.1
Deferred income taxes	(6.7)	3.2
Impairment of Long-Lived Assets Held-for-use	0.0	66.3
Gain (Loss) on Disposition of Business	(12.4)	0.0
Gain (Loss) on Sale of Assets and Asset Impairment Charges	0.1	16.2
Changes in certain assets and liabilities:
Accounts receivable	10.9	26.3
Inventories	(0.3)	8.0
Taxes applicable to subsequent years	36.4	39.1
Deferred regulatory costs, net	(6.7)	(9.1)
Accounts payable	(5.6)	(38.0)
Accrued taxes payable	(31.7)	(75.7)
Accrued interest payable	0.0	(0.1)
Security deposits	(1.2)	1.7
Increase (Decrease) in Obligation, Pension and Other Postretirement Benefits	(4.4)	2.0
Other	7.2	(2.3)
Net cash provided by operating activities	79.1	57.5
Cash flows from investing activities:
Capital expenditures	(44.5)	(57.6)
Payments for Removal Costs	(14.5)	0.0
Proceeds from Sale of Property, Plant, and Equipment	10.6	0.1
Insurance proceeds	0.1	1.3
Other investing activities, net	(0.2)	0.0
Net cash provided by investing activities	(48.5)	(56.2)
Cash flows from financing activities:
Repayments of Lines of Credit	(30.0)	0.0
Proceeds from Lines of Credit	30.0	0.0
Retirement of long-term debt	(62.2)	(10.3)
Payments of Ordinary Dividends, Common Stock	(23.8)	(9.0)
Issuance of short-term debt - related party	0.0	30.0
Repayments of Related Party Debt	0.0	(35.0)
Proceeds from Contributions from Parent	80.0	0.0
Net cash provided by financing activities	(6.0)	(24.3)
Net Cash Provided by (Used in) Discontinued Operations	0.0	27.5
Other deferred credits	7.0
Cash and cash equivalents:
Net change	24.6	4.5
Supplemental cash flow information:
Interest paid, net of amounts capitalized	11.5	13.6
Income Taxes Paid, Net	2.7	26.2
Non-cash financing and investing activities:
Accruals for capital expenditures	5.6	9.1
Restricted Cash and Cash Equivalents	$ 30.2	$ 6.1