CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current assets
Cash and cash equivalents	$ 10.4	$ 12.3
Accounts receivable and unbilled revenues, net of reserves of $43.5 and $39.5, respectively	489.1	513.8
Accounts receivable from related parties	146.3	109.1
Materials, supplies, and inventories	214.7	250.7
Prepayments	114.3	144.3
Other	7.1	9.4
Current assets	981.9	1,039.6
Long-term assets
Property, plant, and equipment, net of accumulated depreciation of $3,798.9 and $3,741.8, respectively	10,086.2	10,007.7
Regulatory assets	2,122.4	1,984.9
Other	104.9	89.4
Long-term assets	12,313.5	12,082.0
Total assets	13,295.4	13,121.6
Current liabilities
Short-term debt	60.0	210.9
Current portion of long-term debt	250.0	250.0
Current portion of capital lease obligations	44.6	42.5
Accounts payable	217.6	329.3
Accounts payable to related parties	249.5	131.5
Accrued payroll and benefits	37.5	53.4
Accrued taxes	65.7	58.2
Other	142.1	111.8
Current liabilities	1,067.0	1,187.6
Long-term liabilities
Long-term debt	2,412.8	2,412.3
Capital lease obligations	2,811.5	2,823.8
Deferred income taxes	1,179.7	1,155.5
Regulatory liabilities	1,891.1	1,708.0
Pension and OPEB obligations	156.9	143.2
Other	288.1	276.9
Long-term liabilities	8,740.1	8,519.7
Commitments and contingencies (Note 15)
Common shareholder's equity
Common stock – $10 par value; 65,000,000 shares authorized; 33,289,327 shares outstanding	332.9	332.9
Additional paid in capital	830.9	802.7
Retained earnings	2,294.1	2,248.3
Common shareholder's equity	3,457.9	3,383.9
Preferred stock	30.4	30.4
Total liabilities and equity	$ 13,295.4	$ 13,121.6