Consolidated Statements of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Earned Premiums	$ 5,266.3	$ 5,253.7	$ 4,672.2
Net Investment Income	422.6	427.3	348.2
Change in Value of Alternative Energy Partnership Investments	(19.9)	(61.2)	0.0
Other Income	9.2	4.8	94.6
(Loss) Income from Change in Fair Value of Equity and Convertible Securities	(79.9)	114.6	72.1
Net Realized Investment Gains	4.3	64.8	38.1
Net Impairment Losses Recognized in Earnings	(25.8)	(11.0)	(19.5)
Other-than-temporary Impairment Losses:
Total Revenues	5,576.8	5,793.0	5,205.7
Expenses:
Policyholders’ Benefits and Incurred Losses and Loss Adjustment Expenses	4,504.4	4,600.8	3,323.6
Insurance Expenses	1,200.6	1,218.1	1,100.5
Loss from Early Extinguishment of Debt	3.7	0.0	0.0
Interest and Other Expenses	257.6	219.4	271.5
Total Expenses	5,966.3	6,038.3	4,695.6
(Loss) Income before Income Taxes	(389.5)	(245.3)	510.1
Income Tax Benefit (Expense)	88.3	124.8	(100.2)
Net (Loss) Income	$ (301.2)	$ (120.5)	$ 409.9
Income (Loss) from Continuing Operations Per Unrestricted Share:
Basic (in dollars per share)			$ 6.24
Diluted (in dollars per share)			6.14
Net (Loss) Income Per Unrestricted Share:
Basic (in dollars per share)	$ (4.72)	$ (1.87)	6.24
Diluted (in dollars per share)	$ (4.72)	$ (1.87)	$ 6.14