Financial Instruments with Off-Balance Sheet Risk (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Entity Information
Off-Balance Sheet, Credit Loss, Liability	$ 5.2	$ 18.4	$ 16.2
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	(80.9)	(31.1)	$ (68.4)
Cumulative Effect, Period of Adoption, Adjusted Balance
Entity Information
Off-Balance Sheet, Credit Loss, Liability, Credit Loss Expense (Reversal)	(13.2)	2.2
Standby Letters of Credit
Entity Information
Credit extension commitments	73.5	97.1
Commitments to Extend Credit
Entity Information
Credit extension commitments	$ 3,076.5	$ 4,069.2