BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 2.3	$ 8.9
Accounts receivable and unbilled revenues, net of reserves of $4.2	210.0	217.1
Accounts receivable from related parties	38.7	26.6
Materials, supplies, and inventories	106.4	103.0
Prepaid taxes	63.4	41.4
Other	11.2	9.2
Current assets	432.0	406.2
Long-term assets
Property, plant, and equipment, net of accumulated depreciation and amortization of $1,672.1 and $1,620.5, respectively	4,544.5	4,150.1
Regulatory assets	437.9	485.6
Goodwill	36.4	36.4
Pension and OPEB assets	148.3	92.8
Other	42.5	46.6
Long-term assets	5,209.6	4,811.5
Total assets	5,641.6	5,217.7
Current liabilities
Short-term debt	91.5	284.4
Accounts payable	176.9	145.4
Accounts payable to related parties	68.5	54.2
Accrued payroll and benefits	26.5	24.1
Other	55.7	55.3
Current liabilities	419.1	563.4
Long-term liabilities
Long-term debt	1,642.8	1,314.7
Deferred income taxes	654.6	520.8
Regulatory liabilities	782.5	785.7
Environmental remediation liabilities	83.8	90.3
Pension and OPEB obligations	18.6	37.3
Other	100.4	135.6
Long-term liabilities	3,282.7	2,884.4
Commitments and contingencies (Note 20)
Common shareholder's equity [Abstract]
Common stock – $4 par value; 32,000,000 shares authorized; 23,896,962 shares issued and outstanding	95.6	95.6
Additional paid in capital	1,221.1	1,115.9
Retained earnings	623.1	558.4
Common shareholder's equity	1,939.8	1,769.9
Total liabilities and equity	$ 5,641.6	$ 5,217.7