Loans and Allowance for Credit Losses - Weighted Average Interest Rate on Loans Receivable (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Loans Receivable, Weighted Average Interest Rate	4.26%	4.29%
Commercial loan participations sold to other financial institutions	$ 249.5	$ 308.4
Residential mortgage loans sold	136.3	154.3
Unpaid principal balances
Loans serviced for others	385.8	462.7
Unused lines of Credit
Loans serviced for others	$ 130.9	$ 46.1