Basis of Presentation and Accounting Policies (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Stockholders' equity	$ (2,646.9)	$ (2,969.2)	$ (2,670.6)	$ (3,129.7)
Retained earnings	1,266.3		1,366.4
Accumulated Other Comprehensive Loss	(454.7)		(514.9)
Present Value of Expected Future Policyholder benefits	3,699.5	4,348.7	3,561.0	4,933.1
Liability for Future Policy Benefit, Expected Future Policy Benefit, Original Discount Rate, before Cash Flow and Reinsurance	3,916.9	3,812.2	3,906.2	3,788.1
AOCI, Liability for Future Policy Benefit, Expected Future Policy Benefit, before Tax	(217.4)	536.5
Liability for Future Policy Benefit, Expected Future Policy Benefit, Cumulative Increase (Decrease) from Cash Flow Change	0.0	0.0
Liability for Future Policy Benefit, Expected Future Policy Benefit, Cumulative Increase (Decrease) of Actual Variance from Expected Experience	0.3	12.7
Liability for Future Policy Benefit, Expected Future Benefit, Original Discount Rate, before Reinsurance, after Cash Flow Change	3,906.5	3,800.8
Liability for Future Policy Benefit, Expected Future Policy Benefit, Issuance	31.8	41.6
Liability for Future Policy Benefit, Expected Future Policy Benefit, Interest Expense	42.4	40.8
Liability for Future Policy Benefit, Expected Future Policy Benefit, Benefit Payment	(63.8)	(71.0)
Net Liability for Future Policyholder benefits	10,177.7		9,536.9
Liability for Future Policy Benefit, Expected Future Gross Premium, Undiscounted, before Reinsurance	4,464.2		3,808.5
Liability for Future Policy Benefit, Expected Future Gross Premium, Discounted, before Reinsurance	2,931.1	2,912.1
Liability for Future Policy Benefit, Reinsurance Recoverable, after Allowance	0.0		0.0
Liability for Future Policy Benefit, after Reinsurance	2,977.1		3,687.7
Net Liability for Future Policyholder benefits	2,977.1	3,687.7	3,687.7
Liability for Future Policy Benefit, Expected Net Premium, before Reinsurance, after Discount Rate Change	722.4	661.0	688.6	669.0
Liability for Future Policy Benefit, Expected Net Premium, Original Discount Rate, before Cash Flow and Reinsurance	744.5	637.9	728.9	599.8
Liability for Future Policy Benefit, Expected Net Premium, Cumulative Increase (Decrease) from Cash Flow Change	0.0	0.0
Liability for Future Policy Benefit, Expected Net Premium, Cumulative Increase (Decrease) of Actual Variance from Expected Experience	0.7	12.5
Liability for Future Policy Benefit, Expected Net Premium, Original Discount Rate, before Reinsurance, after Cash Flow Change	729.6	612.3
Liability for Future Policy Benefit, Expected Net Premium, Issuance	31.8	41.6
Liability for Future Policy Benefit, Expected Net Premium, Interest Income	7.0	5.1
Liability for Future Policy Benefit, Expected Net Premium, Net Premium Collected	23.9	21.1
AOCI, Liability for Future Policy Benefit, Expected Net Premium, before Tax	(22.1)	23.1
Deferred Policy Acquisition Costs	651.5	689.6	635.6	688.0
Deferred Policy Acquisition Cost, Capitalization	164.9	182.2
Deferred Policy Acquisition Costs, Amortization Expense	(147.9)	(178.7)
Deferred Policy Acquisition Cost, Experience Adjustment	(1.1)	(1.9)
Earned Premiums (Changes in Deferred Profit Liability: 2023 - $19.2; 2022 - $20.3)	(1,180.9)	(1,320.0)
Income Tax Benefit	23.8	29.4
Net Loss	$ (80.1)	$ (86.3)
Basic (in dollars per share)	$ (1.25)	$ (1.36)
Diluted (in dollars per share)	$ (1.25)	$ (1.36)
Assets	$ (13,403.7)		(13,313.6)
Liabilities	(10,756.8)		(10,643.0)
Stockholders' Equity Attributable to Parent	2,646.9		2,670.6
Policyholders’ Benefits and Incurred Losses and Loss Adjustment Expenses (Changes in Liability for Future Policyholder Benefits: 2023 - $1.9; 2022 - $18.6)	1,052.0	$ 1,123.2
Insurance Expenses	269.3	304.8
Deferred Income Tax Assets	(166.0)		(129.0)
Life and Health	(3,399.6)		(3,276.2)
Change in Discount Rate on Future Life Policyholder Benefits	(109.8)	562.3
Other Comprehensive Income (Loss), before Tax	76.9	(83.7)
Other Comprehensive Income Tax (Expense) Benefit	(16.7)	17.5
Other Comprehensive Income (Loss), Net of Taxes	60.2	(66.2)
Total Comprehensive Loss	(19.9)	(152.5)
Increase (Decrease) in Deferred Policy Acquisition Costs	15.9	1.6
Insurance Reserves	(21.8)	(8.7)
Income Taxes	106.2	(28.2)
Net Cash Provided by (Used in) Operating Activities	$ 5.2	(18.2)
Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings			1,380.1
Accumulated Other Comprehensive Loss			(756.0)
Deferred Policy Acquisition Costs			625.6
Earned Premiums (Changes in Deferred Profit Liability: 2023 - $19.2; 2022 - $20.3)		(1,338.6)
Income Tax Benefit		(31.7)
Net Loss		$ (94.8)
Basic (in dollars per share)		$ (1.49)
Diluted (in dollars per share)		$ (1.49)
Assets			(13,364.0)
Liabilities			(10,920.8)
Stockholders' Equity Attributable to Parent			2,443.2
Policyholders’ Benefits and Incurred Losses and Loss Adjustment Expenses (Changes in Liability for Future Policyholder Benefits: 2023 - $1.9; 2022 - $18.6)		$ 1,153.4
Insurance Expenses		304.0
Deferred Income Tax Assets			(189.4)
Life and Health			(3,554.0)
Change in Discount Rate on Future Life Policyholder Benefits		0.0
Other Comprehensive Income (Loss), before Tax		(646.0)
Other Comprehensive Income Tax (Expense) Benefit		135.6
Other Comprehensive Income (Loss), Net of Taxes		(510.4)
Total Comprehensive Loss		(605.2)
Increase (Decrease) in Deferred Policy Acquisition Costs		(2.4)
Insurance Reserves		2.9
Income Taxes		(30.5)
Net Cash Provided by (Used in) Operating Activities		$ (18.2)
Term Life Insurance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Liability for Future Policy Benefit, Weighted-Average Interest Accretion Rate	4.55%	4.55%
Liability for Future Policy Benefit, Current Weighted-Average Discount Rate	5.05%	3.76%
Life & Health Insurance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Policy Acquisition Costs	$ 413.2	$ 426.7	404.5	419.3
Deferred Policy Acquisition Cost, Capitalization	15.4	16.5
Deferred Policy Acquisition Costs, Amortization Expense	(5.6)	(7.2)
Deferred Policy Acquisition Cost, Experience Adjustment	(1.1)	(1.9)
Property and Casualty Insurance Reserves
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred Policy Acquisition Costs	238.3	262.9	231.1	$ 268.7
Deferred Policy Acquisition Cost, Capitalization	149.5	165.7
Deferred Policy Acquisition Costs, Amortization Expense	(142.3)	(171.5)
Deferred Policy Acquisition Cost, Experience Adjustment	$ 0.0	0.0
Effect of Retrospective Application of Accounting Standards Update 2018-12 | Adjustments to Retained Earnings for Net Pemiums
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					$ 25.1
Accumulated Other Comprehensive Loss					0.0
Effect of Retrospective Application of Accounting Standards Update 2018-12 | Adjustments to AOCI
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					0.0
Accumulated Other Comprehensive Loss					1,030.3
Effect of Retrospective Application of Accounting Standards Update 2018-12 | Pre Adoption Balance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					(2,071.2)
Accumulated Other Comprehensive Loss					(680.5)
Effect of Retrospective Application of Accounting Standards Update 2018-12 | Post Adoption Balance
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings					(2,046.1)
Accumulated Other Comprehensive Loss					$ 349.8
Effect of Modified Retrospective Application Accounting Standards Update 2018-12
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Retained earnings			(13.7)
Accumulated Other Comprehensive Loss			241.1
Deferred Policy Acquisition Costs			10.0
Earned Premiums (Changes in Deferred Profit Liability: 2023 - $19.2; 2022 - $20.3)		(18.6)
Income Tax Benefit		2.3
Net Loss		$ 8.5
Basic (in dollars per share)		$ 0.13
Diluted (in dollars per share)		$ 0.13
Assets			(50.4)
Liabilities			(277.8)
Stockholders' Equity Attributable to Parent			227.4
Policyholders’ Benefits and Incurred Losses and Loss Adjustment Expenses (Changes in Liability for Future Policyholder Benefits: 2023 - $1.9; 2022 - $18.6)		$ (30.2)
Insurance Expenses		0.8
Deferred Income Tax Assets			(60.4)
Life and Health			$ (277.8)
Change in Discount Rate on Future Life Policyholder Benefits		562.3
Other Comprehensive Income (Loss), before Tax		562.3
Other Comprehensive Income Tax (Expense) Benefit		118.1
Other Comprehensive Income (Loss), Net of Taxes		444.2
Total Comprehensive Loss		452.7
Increase (Decrease) in Deferred Policy Acquisition Costs		0.8
Insurance Reserves		(11.6)
Income Taxes		2.3
Net Cash Provided by (Used in) Operating Activities		$ 0.0