CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Operating Activities:
Net Income	$ 32.2	$ 44.2	$ 33.0
Adjustments to Reconcile Net Income to Cash Provided by Operating Activities:
Depreciation and Amortization	54.5	52.0	50.4
Deferred Tax Provision	9.3	13.5	8.0
Gain on Divestiture, net (See Note 1)		(13.4)
Changes in Working Capital Items:
Accounts Receivable	(6.9)	11.7	0.6
Accrued Revenue	(0.9)	4.7	(1.4)
Regulatory Liabilities	(1.9)	(4.1)	2.3
Exchange Gas Receivable	1.2	2.0	(2.3)
Accounts Payable	(4.4)	(5.0)	1.1
Other Changes in Working Capital Items	(2.4)	4.6	3.6
Deferred Regulatory and Other Charges	(9.3)	(5.3)	(11.3)
Other, net	4.3		(5.5)
Cash Provided by Operating Activities	75.7	104.9	78.5
Investing Activities:
Property, Plant and Equipment Additions	(122.6)	(119.2)	(102.4)
Proceeds from Divestiture, Net (See Note 1)		13.4
Cash Used In Investing Activities	(122.6)	(105.8)	(102.4)
Financing Activities:
(Repayment of) Proceeds from Short-Term Debt, net	(3.9)	(24.2)	44.5
Issuance of Long-Term Debt	99.7	70.0	30.0
Repayment of Long-Term Debt	(24.8)	(18.8)	(30.1)
Long-Term Debt Issuance Costs	(0.6)	(0.4)	(0.1)
Decrease in Capital Lease Obligations	(0.1)	(5.3)	(3.0)
Net (Decrease) Increase in Exchange Gas Financing	(1.1)	(2.0)	2.1
Dividends Paid	(22.6)	(22.1)	(21.8)
Proceeds from Issuance of Common Stock	1.1	1.1	1.2
Cash Provided by (Used In) Financing Activities	47.7	(1.7)	22.8
Net Increase (Decrease) in Cash and Cash Equivalents	0.8	(2.6)	(1.1)
Cash and Cash Equivalents at Beginning of Year	5.2	7.8	8.9
Cash and Cash Equivalents at End of Year	6.0	5.2	7.8
Supplemental Information:
Interest Paid	23.7	24.1	24.6
Income Taxes Paid	0.9	0.8	0.4
Payments on Capital Leases	0.3	5.5	3.3
Capital Expenditures Included in Accounts Payable	1.7	0.6	$ 0.5
Non-Cash Additions to Property, Plant and Equipment	0.0
Right-of-Use Assets Obtained in Exchange for Lease Obligations	$ 1.2	$ 4.0