Income Taxes - Schedule of Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Deferred tax assets:
Operating losses	$ 69.6	$ 69.7
Interest expense carryforward	225.7	183.3
Bad debts	7.2	6.5
Accrued expenses	16.7	12.9
Capital loss and credit carryforwards	13.3	13.6
Pension and postretirement benefits	21.2	28.5
ASC 842 - Lease liability	10.1	10.2
Equity Compensation	12.2	11.6
Other	7.7	7.3
Total deferred tax assets	383.7	343.6
Valuation allowance	(38.2)	(39.2)
Net deferred tax assets	345.5	304.4
Deferred tax liabilities:
Intangibles	(995.3)	(1,109.0)
Commission Assets	(42.3)	(39.2)
Fixed assets	(13.6)	(14.7)
ASC 842 - ROU asset	(9.8)	(9.8)
Other	(2.5)	(1.8)
Total deferred tax liabilities	(1,063.5)	(1,174.5)
Net deferred tax (liabilities) assets	$ (718.0)	$ (870.1)