Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities
Net Income	$ 131.3	$ 137.8	$ 152.8
AFUDC – Equity	(2.7)	(2.6)	(1.9)
Income from Equity Investments – Net of Dividends	2.4	2.2	(3.2)
(Gain) / Loss on Investments and Property, Plant and Equipment	1.2	(0.8)	(1.3)
Loss on Impairment of Assets	0.0	0.0	12.7
Depreciation Expense	242.0	231.6	217.7
Amortization of PSAs	(7.6)	(11.4)	(11.3)
Amortization of Other Intangible Assets and Other Assets	8.3	9.9	10.4
Deferred Income Tax Benefit	(38.5)	(26.9)	(43.4)
Share-Based and ESOP Compensation Expense	4.9	5.9	6.1
Defined Benefit Pension and Other Postretirement Benefit Expense	(3.0)	4.3	0.1
Bad Debt Expense	1.9	1.2	2.7
Provision (Payments) for Tax Reform Refund	0.0	0.0	(0.2)
Fuel Adjustment Clause	15.1	(56.4)	5.0
Provision (Payments) for Interim Rate Refund	18.4	0.0	0.0
Changes in Operating Assets and Liabilities
Accounts Receivable	(14.0)	(13.0)	(18.2)
Inventories	(256.1)	(23.5)	(1.4)
Prepayments and Other	(21.5)	(0.5)	0.9
Accounts Payable	(1.3)	15.0	11.8
Other Current Liabilities	116.2	28.0	11.7
Cash Contributions to Defined Benefit Pension Plans	0.0	(10.3)	(10.7)
Changes in Regulatory and Other Non-Current Assets	24.1	(12.0)	(31.0)
Changes in Regulatory and Other Non-Current Liabilities	0.2	(15.0)	(9.5)
Cash provided by Operating Activities	221.3	263.5	299.8
Investing Activities
Proceeds from Sale of Available-for-sale Securities	2.2	6.4	12.8
Payments for Purchase of Available-for-sale Securities	(2.4)	(3.6)	(8.7)
Acquisitions of Subsidiaries – Net of Cash and Restricted Cash Acquired	(155.0)	0.0	0.0
Payments for Equity Investments	(5.9)	(17.6)	(99.1)
Additions to Property, Plant and Equipment	(220.5)	(479.5)	(724.7)
Other Investing Activities	(2.4)	9.1	6.9
Cash used in Investing Activities	(384.0)	(485.2)	(812.8)
Financing Activities
Proceeds from Issuance of Common Stock	248.0	69.9	18.1
Equity Issuance Costs	(8.1)	0.0	0.0
Proceeds from Issuance of Short-Term and Long-Term Debt	785.4	733.0	672.4
Repayments of Short-Term and Long-Term Debt	(877.0)	(552.9)	(488.6)
Proceeds from Non-Controlling Interest in Subsidiaries - Net of Issuance Costs	155.7	90.9	414.5
Dividends on Common Stock	(145.9)	(131.9)	(128.2)
Other Financing Activities	(2.9)	(4.8)	(2.5)
Cash provided by Financing Activities	155.2	204.2	485.7
Change in Cash, Cash Equivalents and Restricted Cash	(7.5)	(17.5)	(27.3)
Cash and Cash Equivalents	$ 40.2	$ 47.7	$ 65.2