Insurance and Other Expenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Insurance and Other Expenses [Abstract]
Commissions	$ 596.3	$ 584.2	$ 724.8
Taxes, Licenses and Fees	83.7	79.6	99.5
Policy Acquisition Costs:
Deferred	(576.4)	(563.3)	(691.5)
Amortized	538.0	607.1	705.7
Net Policy Acquisition Costs (Deferred) Amortized	(38.4)	43.8	14.2
Policy Acquisition Costs	641.6	707.6	838.5
Business Unit Operating Costs	277.4	256.1	282.4
Corporate Overhead Costs	194.9	200.0	207.8
Insurance Expenses	1,113.9	1,163.7	1,328.7
Acquisition and Disposition Related Transaction, Integration, Restructuring and Other Costs	40.3	120.3	62.9
Pension Settlement	(2.6)	70.2	0.0
Other Corporate Costs	28.5	11.4	12.3
Other Expenses	66.2	201.9	75.2
Insurance and Other Expenses	$ 1,180.1	$ 1,365.6	$ 1,403.9