Loans Held for Sale - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Nonaccrual loans	$ 37.5		$ 39.8
Transfer of loans from held-for-sale to held for investment	0.0	$ 19.8
Commercial
Debt Securities, Available-for-sale [Line Items]
Nonaccrual loans	12.8		10.2
Agricultural
Debt Securities, Available-for-sale [Line Items]
Nonaccrual loans	28.0		29.3
Commercial Loan [Member]
Debt Securities, Available-for-sale [Line Items]
Nonaccrual loans	3.1
Commercial construction
Debt Securities, Available-for-sale [Line Items]
Nonaccrual loans	$ 6.4		$ 10.5