STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating activities
Net income	$ 263.1	$ 213.3	$ 159.2
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	232.2	210.0	193.9
Demand side management program amortization	0.0	1.7	1.7
Deferred income taxes	29.0	22.1	126.5
Allowance for equity funds used during construction	(26.8)	(19.1)	(9.3)
Provision for bad debts	5.7	4.9	5.1
Net derivative losses	0.0	0.1	0.1
Changes in operating assets and liabilities:
Accounts receivable	(9.0)	(19.5)	(10.4)
Accrued unbilled revenues	(0.6)	15.3	(10.4)
Inventories	(20.5)	(16.0)	(1.9)
Prepayments and other	2.8	0.5	4.3
Accounts payable	(8.5)	(6.6)	11.8
Net regulatory assets and liabilities	13.8	38.2	38.1
Other current liabilities	5.8	11.6	3.4
Pension and other employee benefit obligations	(17.7)	(16.0)	(21.7)
Other, net	3.5	5.8	(19.9)
Net cash provided by operating activities	472.8	446.3	470.5
Investing activities
Utility capital/construction expenditures	(844.4)	(1,020.9)	(550.6)
Investments in utility money pool arrangement	(133.0)	(285.0)	(142.0)
Receipts from utility money pool arrangement	133.0	350.0	77.0
Other	0.0	0.0	0.5
Net cash used in investing activities	(844.4)	(955.9)	(616.1)
Financing activities
(Repayments of) proceeds from short-term borrowings, net	(42.0)	42.0	(50.0)
Proceeds from issuance of long-term debt	292.2	295.0	442.3
Repayment of long-term debt, including reacquisition premiums	0.0	0.0	(271.6)
Borrowings under utility money pool arrangement	296.0	595.0	335.0
Repayments under utility money pool arrangement	(296.0)	(595.0)	(335.0)
Capital contributions from parent	426.3	336.8	143.7
Dividends paid to parent	(332.7)	(131.0)	(108.8)
Net cash provided by financing activities	343.8	542.8	155.6
Net change in cash and cash equivalents	(27.8)	33.2	10.0
Cash and cash equivalents at beginning of period	44.0	10.8	0.8
Cash and cash equivalents at end of period	16.2	44.0	10.8
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(83.6)	(71.2)	(76.0)
Cash paid for income taxes, net	(11.9)	10.6	(41.5)
Supplemental disclosure of non-cash investing transactions:
Property, plant and equipment additions in accounts payable	94.5	71.5	85.1
Inventory transfer additions in property, plant and equipment	23.3	22.5	13.7
Operating lease right-of-use assets	548.3	0.0	0.0
Allowance for equity funds used during construction	$ 26.8	$ 19.1	$ 9.3