CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Activities:
Net Income	$ 36.1	$ 32.2	$ 44.2
Adjustments to Reconcile Net Income to Cash Provided by Operating Activities:
Depreciation and Amortization	59.5	54.5	52.0
Deferred Tax Provision	10.8	9.3	13.5
Gain on Divestiture, net (See Note 1)			(13.4)
Changes in Working Capital Items:
Accounts Receivable	(4.9)	(6.9)	11.7
Accrued Revenue	(10.3)	(0.9)	4.7
Regulatory Liabilities	4.0	(1.9)	(4.1)
Exchange Gas Receivable	(2.5)	1.2	2.0
Accounts Payable	19.2	(4.4)	(5.0)
Other Changes in Working Capital Items	0.7	(2.4)	4.6
Deferred Regulatory and Other Charges	(2.7)	(9.3)	(5.3)
Other, net	(2.1)	4.3
Cash Provided by Operating Activities	107.8	75.7	104.9
Investing Activities:
Property, Plant and Equipment Additions	(115.0)	(122.6)	(119.2)
Proceeds from Divestiture, Net (See Note 1)			13.4
Cash Used In Investing Activities	(115.0)	(122.6)	(105.8)
Financing Activities:
Proceeds from (Repayment of) Short-Term Debt, net	9.4	(3.9)	(24.2)
Issuance of Long-Term Debt		99.7	70.0
Repayment of Long-Term Debt	(25.8)	(24.8)	(18.8)
Long-Term Debt Issuance Costs		(0.6)	(0.4)
Decrease in Capital Lease Obligations	(0.1)	(0.1)	(5.3)
Net Increase (Decrease) in Exchange Gas Financing	2.3	(1.1)	(2.0)
Dividends Paid	(23.6)	(22.6)	(22.1)
Proceeds from Issuance of Common Stock	45.5	1.1	1.1
Cash Provided by (Used In) Financing Activities	7.7	47.7	(1.7)
Net Increase (Decrease) in Cash and Cash Equivalents	0.5	0.8	(2.6)
Cash and Cash Equivalents at Beginning of Year	6.0	5.2	7.8
Cash and Cash Equivalents at End of Year	6.5	6.0	5.2
Supplemental Information:
Interest Paid	26.0	23.7	24.1
Income Taxes Paid	1.4	0.9	0.8
Payments on Capital Leases	0.2	0.3	5.5
Capital Expenditures Included in Accounts Payable	4.9	1.7	0.6
Right-of-Use Assets Obtained in Exchange for Lease Obligations	$ 0.7	$ 1.2	$ 4.0