Insurance Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022		Dec. 31, 2021
Insurance Expenses [Abstract]
Commissions	$ 584.2	$ 724.8		$ 817.6
General Expenses	342.8	358.4		339.5
Taxes, Licenses and Fees	79.6	99.5		104.3
Total Costs Incurred	1,006.6	1,182.7		1,261.4
Policy Acquisition Costs:
Deferred	(563.3)	(691.5)		(772.6)
Amortized	607.1	705.7		695.1
Net Policy Acquisition Costs Amortized (Deferred)	43.8	14.2		(77.5)
Amortization of Value of Business Acquired	2.0	4.1		45.0
Insurance Expenses				1,228.9
Insurance Expenses	$ 1,052.4	$ 1,201.0	[1]	$ 1,228.8	[1]

[1] As of January 1, 2023, the Company adopted ASU 2018-12 using the modified retrospective method applied as of the transition date of January 1, 2021. Prior period amounts in the financial statements have been recast to reflect application of the new guidance. See Note 2 to the Consolidated Financial Statements for additional information.