Consolidated Statement of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Operating Activities
Net Income	$ 178.9	$ 131.3	$ 137.8
Adjustments to Reconcile Net Income to Cash provided by Operating Activities:
AFUDC – Equity	(3.6)	(2.7)	(2.6)
Income from Equity Investments – Net of Dividends	1.0	2.4	2.2
(Gain) / Loss on Investments and Property, Plant and Equipment	0.0	1.2	(0.8)
Depreciation Expense	251.7	242.0	231.6
Amortization of PSAs	(5.2)	(7.6)	(11.4)
Amortization of Other Intangible Assets and Other Assets	7.1	8.3	9.9
Deferred Income Tax Expense (Benefit)	17.6	(38.5)	(26.9)
Share-Based and ESOP Compensation Expense	7.3	4.9	5.9
Defined Benefit Pension and Other Postretirement Plan Expense (Benefit)	(6.1)	(3.0)	4.3
Bad Debt Expense	1.3	1.9	1.2
Fuel Adjustment Clause	44.0	15.1	(56.4)
Provision (Payments) for Interim Rate Refund	(18.4)	18.4	0.0
Changes in Operating Assets and Liabilities
Accounts Receivable	1.8	(14.0)	(13.0)
Inventories	277.1	(256.1)	(23.5)
Prepayments and Other	(7.9)	(21.5)	(0.5)
Accounts Payable	(4.0)	(1.3)	15.0
Other Current Liabilities	(157.6)	116.2	28.0
Cash Contributions to Defined Benefit Pension Plans	(17.3)	0.0	(10.3)
Changes in Regulatory and Other Non-Current Assets	15.6	24.1	(12.0)
Changes in Regulatory and Other Non-Current Liabilities	2.0	0.2	(15.0)
Cash provided by Operating Activities	585.3	221.3	263.5
Investing Activities
Proceeds from Sale of Available-for-sale Securities	1.0	2.2	6.4
Payments for Purchase of Available-for-sale Securities	(1.2)	(2.4)	(3.6)
Acquisitions of Subsidiaries – Net of Cash and Restricted Cash Acquired	0.0	(155.0)	0.0
Payments for Equity Investments	(8.2)	(5.9)	(17.6)
Additions to Property, Plant and Equipment	(271.2)	(220.5)	(479.5)
Other Investing Activities	(4.0)	(2.4)	9.1
Cash used in Investing Activities	(283.6)	(384.0)	(485.2)
Financing Activities
Proceeds from Issuance of Common Stock	14.9	248.0	69.9
Equity Issuance Costs	0.0	(8.1)	0.0
Proceeds from Issuance of Short-Term and Long-Term Debt	437.0	785.4	733.0
Repayments of Short-Term and Long-Term Debt	(566.7)	(877.0)	(552.9)
Proceeds from Non-Controlling Interest in Subsidiaries – Net of Issuance Costs	17.8	155.7	90.9
Distributions to Non-Controlling Interest	(8.5)	(1.7)	(3.1)
Dividends on Common Stock	(155.5)	(145.9)	(131.9)
Other Financing Activities	(1.5)	(1.2)	(1.7)
Cash provided (used in) by Financing Activities	(262.5)	155.2	204.2
Change in Cash, Cash Equivalents and Restricted Cash	39.2	(7.5)	(17.5)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	40.2	47.7	65.2
Cash, Cash Equivalents and Restricted Cash at End of Period	$ 79.4	$ 40.2	$ 47.7