Other Operating Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Components of Other Operating Income [Line Items]
Total Other Operating Income	$ 60.6	$ 111.8	$ 167.7	$ 1,097.5
Pre-tax gain on sale of equity investment		68.1
Loan Service Fees
Components of Other Operating Income [Line Items]
Total Other Operating Income	14.9	14.0	41.1	43.4
Banking Service Fees
Components of Other Operating Income [Line Items]
Total Other Operating Income	14.1	14.2	42.5	40.8
Bank Owned Life Insurance
Components of Other Operating Income [Line Items]
Total Other Operating Income	19.4	18.4	58.3	60.4
Other Income
Components of Other Operating Income [Line Items]
Total Other Operating Income	$ 12.2	$ 65.2	$ 25.7	$ 952.9