CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 2.0	$ 2.0
Accounts receivable, net	66.0	70.0
Accrued unbilled revenues	43.0	53.0
Other Receivables	1.0	1.0
Inventories	13.0	15.0
Regulatory assets	59.0	19.0
Prepaid taxes	18.0	24.0
Prepayments and other	5.0	7.0
Total current assets	207.0	191.0
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment, net	2,505.0	2,484.0
Other assets
Regulatory assets	210.0	215.0
Other Investments	3.0	3.0
Other	2.0	1.0
Total other assets	215.0	219.0
Total assets	2,927.0	2,894.0
Current liabilities
Current portion of long-term debt	19.0	19.0
Short-term debt	13.0	19.0
Accounts payable	33.0	41.0
Accounts payable to affiliates	20.0	15.0
Dividends payable to parent	19.0	19.0
Regulatory liabilities	23.0	31.0
Taxes accrued	11.0	12.0
Environmental liabilities	5.0	4.0
Accrued interest	9.0	10.0
Other	13.0	15.0
Total current liabilities	165.0	185.0
Deferred credits and other liabilities
Deferred income taxes	318.0	307.0
Regulatory liabilities	354.0	350.0
Environmental liabilities	16.0	16.0
Customer advances	21.0	20.0
Pension and employee benefit obligations	23.0	28.0
Other	32.0	33.0
Total deferred credits and other liabilities	764.0	754.0
Commitments and Contingencies
Capitalization
Long-term debt	888.0	887.0
Common Stock - 1,000,000 shares authorized of $100 par value; 933,000 shares outstanding at Sept. 30, 2020 and Dec. 31, 2019, respectively	$ 93.0	$ 93.0
Common stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, par value (in dollars per share)	$ 100	$ 100
Common stock, shares outstanding (in shares)	933,000	933,000
Additional paid in capital	$ 635.0	$ 605.0
Retained earnings	382.0	370.0
Total common stockholder's equity	1,110.0	1,068.0
Total liabilities and equity	$ 2,927.0	$ 2,894.0