Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating Activities:
Net Income	$ 12.6	$ 10.8
Adjustments to Reconcile Net Income to Cash Provided by Operating Activities:
Depreciation and Amortization	10.2	9.5
Deferred Tax Provision	7.0	5.4
Changes in Working Capital Items:
Accounts Receivable	(17.3)	(14.3)
Accrued Revenue	7.0	16.0
Exchange Gas Receivable	9.5	7.7
Regulatory Liabilities	3.4	4.8
Accounts Payable	(6.3)	(5.6)
Other Changes in Working Capital Items	3.1	0.3
Deferred Regulatory and Other Charges	(1.9)	2.9
Other, net	1.4	3.3
Cash Provided by Operating Activities	28.7	40.8
Investing Activities:
Property, Plant and Equipment Additions	(9.2)	(14.4)
Cash (Used in) Investing Activities	(9.2)	(14.4)
Financing Activities:
Repayment of Short-Term Debt, net	(1.0)	(16.8)
Repayment of Long-Term Debt	(0.1)	(0.1)
Net Decrease in Exchange Gas Financing	(8.8)	(7.2)
Dividends Paid	(4.8)	(4.8)
Proceeds from Issuance of Common Stock	0.3	0.3
Other, net	(0.2)	(0.1)
Cash (Used in) Financing Activities	(14.6)	(28.7)
Net Increase (Decrease) in Cash	4.9	(2.3)
Cash at Beginning of Period	9.4	9.8
Cash at End of Period	14.3	7.5
Supplemental Cash Flow Information:
Interest Paid	3.0	2.9
Income Taxes Paid	0.3	0.8
Non-cash Investing Activity:
Capital Expenditures Included in Accounts Payable	$ 0.4	$ 1.0