Basis of Presentation and Accounting Policies - Effects of Adoption (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earned Premiums (Changes in Deferred Profit Liability for the Six and Three Months Ended: 2023 - $35.7 and $16.5; 2022 - $37.7 and $17.4)	$ 1,166.9	$ 1,337.6	$ 2,347.8	$ 2,657.6
Policyholders’ Benefits and Incurred Losses and Loss Adjustment Expenses (Changes in Liability for Future Policyholder Benefits for the Six and Three Months Ended: 2023 - $2.5 and $0.6; 2022 - $20.3 and $1.7)	984.7	1,151.1	2,036.7	2,274.3
Insurance Expenses	266.1	307.7	535.4	612.5
Income Tax Expense (Benefit)	(18.8)	(22.4)	(42.6)	(51.8)
Net Loss	$ (97.1)	$ (72.2)	$ (177.2)	$ (158.5)
Basic (in dollars per share)	$ (1.52)	$ (1.13)	$ (2.77)	$ (2.49)
Diluted (in dollars per share)	$ (1.52)	$ (1.13)	$ (2.77)	$ (2.49)
Deferred Policy Acquisition Costs	$ 646.2	$ 690.1	$ 646.2	$ 690.1	$ 635.6	$ 688.0
Deferred Income Tax Assets	(208.0)		(208.0)		(129.0)
Assets	(13,096.3)		(13,096.3)		(13,313.6)
Life and Health	(3,363.8)		(3,363.8)		(3,276.2)
Liabilities	(10,584.1)		(10,584.1)		(10,643.0)
Retained Earnings	1,149.0		1,149.0		1,366.4
Accumulated Other Comprehensive Loss	(480.8)		(480.8)		(514.9)
Stockholders' Equity Attributable to Parent	$ 2,512.2		$ 2,512.2		2,670.6
Effect of Modified Retrospective Application Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earned Premiums (Changes in Deferred Profit Liability for the Six and Three Months Ended: 2023 - $35.7 and $16.5; 2022 - $37.7 and $17.4)		16.1		34.7
Policyholders’ Benefits and Incurred Losses and Loss Adjustment Expenses (Changes in Liability for Future Policyholder Benefits for the Six and Three Months Ended: 2023 - $2.5 and $0.6; 2022 - $20.3 and $1.7)		(19.2)		(49.4)
Insurance Expenses		0.0		0.8
Income Tax Expense (Benefit)		(0.6)		(2.9)
Net Loss		$ 2.5		$ 11.0
Basic (in dollars per share)		$ 0.04		$ 0.17
Diluted (in dollars per share)		$ 0.04		$ 0.17
Deferred Policy Acquisition Costs					10.0
Deferred Income Tax Assets					(60.4)
Assets					(50.4)
Life and Health					(277.8)
Liabilities					(277.8)
Retained Earnings					(13.7)
Accumulated Other Comprehensive Loss					241.1
Stockholders' Equity Attributable to Parent					227.4
Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Earned Premiums (Changes in Deferred Profit Liability for the Six and Three Months Ended: 2023 - $35.7 and $16.5; 2022 - $37.7 and $17.4)		$ 1,353.7		$ 2,692.3
Policyholders’ Benefits and Incurred Losses and Loss Adjustment Expenses (Changes in Liability for Future Policyholder Benefits for the Six and Three Months Ended: 2023 - $2.5 and $0.6; 2022 - $20.3 and $1.7)		1,170.3		2,323.7
Insurance Expenses		307.7		611.7
Income Tax Expense (Benefit)		23.0		54.7
Net Loss		$ (74.7)		$ (169.5)
Basic (in dollars per share)		$ (1.17)		$ (2.66)
Diluted (in dollars per share)		$ (1.17)		$ (2.66)
Deferred Policy Acquisition Costs					625.6
Deferred Income Tax Assets					(189.4)
Assets					(13,364.0)
Life and Health					(3,554.0)
Liabilities					(10,920.8)
Retained Earnings					1,380.1
Accumulated Other Comprehensive Loss					(756.0)
Stockholders' Equity Attributable to Parent					$ 2,443.2