CONDENSED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 16.2	$ 6.1
Adjustments to reconcile net income to net cash provided from operating activities
Depreciation and amortization	54.7	76.7
Deferred income taxes and investment tax credits, net	7.5	2.3
Allowance for equity funds used during construction	(6.9)	(1.6)
Stock-based compensation expense	0.8	0.8
Regulatory assets	(6.4)	(2.3)
Regulatory liabilities	(4.6)	(4.6)
Other assets	(3.1)	1.5
Other liabilities	0.7	2.8
Change in certain current assets and liabilities
Accounts receivable, net	36.6	38.0
Accrued unbilled revenues	3.5	2.1
Fuel, materials and supplies inventories	(7.7)	10.1
Fuel clause under recoveries	(22.1)	0.0
Other current assets	0.7	(7.7)
Accounts payable	26.3	(33.6)
Accounts payable - affiliates	0.1	(0.5)
Income taxes payable - parent	5.6	(0.1)
Fuel clause over recoveries	0.0	2.0
Other current liabilities	(37.5)	(35.6)
Net Cash Provided from Operating Activities	64.4	56.4
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures (less allowance for equity funds used during construction)	(219.9)	(177.7)
Net Cash Used in Investing Activities	(219.9)	(177.7)
CASH FLOWS FROM FINANCING ACTIVITIES
Changes in advances with parent	(76.5)	261.3
Payment of long-term debt	(0.1)	(110.0)
Dividends paid on common stock	(65.0)	(30.0)
Net Cash Provided from Financing Activities	155.5	121.3
NET CHANGE IN CASH AND CASH EQUIVALENTS	0.0	0.0
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	0.0	0.0
CASH AND CASH EQUIVALENTS AT END OF PERIOD	0.0	0.0
Proceeds from Issuance of Long-term Debt	$ 297.1	$ 0.0