Condensed Consolidated Statements of Operations - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues	$ 178.8	$ 192.9	$ 505.1	$ 576.5
Operating costs and expenses
Net fuel cost	0.4	0.6	1.3	2.0
Utilities Operating Expense, Purchased Power	66.0	66.3	178.0	194.2
Operating expenses:
Operation and maintenance	47.9	42.5	138.7	136.9
Depreciation and amortization	18.6	17.7	54.8	54.0
Taxes other than income taxes	17.7	20.8	59.6	58.3
Other Operating Income (Expense), Net	0.1	0.0	0.1	0.0
Costs and Expenses	150.7	147.9	432.5	445.4
Operating income	28.1	45.0	72.6	131.1
Other income / (expense), net:
Interest expense	(17.1)	(18.3)	(55.4)	(63.7)
Gain (Loss) on Extinguishment of Debt	31.7	0.0	31.7	44.9
Other income / (expense)	1.0	0.4	0.9	3.2
Total other expense, net	(47.8)	(17.9)	(86.2)	(105.4)
Income / (loss) from continuing operations before income tax	(19.7)	27.1	(13.6)	25.7
Income tax benefit from continuing operations	(10.4)	(9.1)	(7.7)	(11.8)
Net income / (loss) from continuing operations	(9.3)	36.2	(5.9)	37.5
Income / (loss) from discontinued operations before income tax	1.4	(1.0)	(0.6)	30.1
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	0.0	0.0	4.5	0.1
Income tax expense / (benefit) from discontinued operations	0.3	(0.2)	0.8	6.3
Net income / (loss) from discontinued operations	1.1	(0.8)	3.1	23.9
Net income / (loss)	(8.2)	35.4	(2.8)	61.4
Subsidiaries [Member]
Revenues	177.0	191.1	499.1	570.2
Operating costs and expenses
Net fuel cost	0.4	0.6	1.3	2.0
Utilities Operating Expense, Purchased Power	65.7	65.9	177.1	193.3
Operating expenses:
Operation and maintenance	47.8	42.2	137.7	135.2
Depreciation and amortization	18.2	17.4	53.7	52.9
Taxes other than income taxes	17.8	20.8	59.6	58.2
Gain (Loss) on Sale of Assets and Asset Impairment Charges, excluding Discontinued Operations	0.1	(0.1)	0.1	0.0
Costs and Expenses	150.0	146.8	429.5	441.6
Operating income	27.0	44.3	69.6	128.6
Other income / (expense), net:
Interest expense	(5.9)	(6.1)	(18.5)	(19.9)
Other income / (expense)	0.2	(0.5)	(1.4)	0.1
Total other expense, net	(5.7)	(6.6)	(19.9)	(19.8)
Income / (loss) from continuing operations before income tax	21.3	37.7	49.7	108.8
Income tax benefit from continuing operations	3.5	(7.2)	2.4	5.1
Net income / (loss)	$ 17.8	$ 44.9	$ 47.3	$ 103.7