Non-Residential Loans Held for Sale (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance	$ 59.1		$ 79.9
Transfer of loans to held-for-sale	3.1	$ 12.4
Loans held for sale	59.1		79.9
Agricultural
Debt Securities, Available-for-sale [Line Items]
Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance	49.5		62.5
Proceeds from Collection of Loans Held-for-sale	(15.2)
Transfer of loans to held-for-sale	0.0
Increase (Decrease) in Fair Value Adjustments on Other Assets (Liabilities) Carried at Fair Value under Fair Value Option	2.2
Loans held for sale	49.5		62.5
Proceeds from Sale of Loans Held-for-sale	0.0
Commercial construction
Debt Securities, Available-for-sale [Line Items]
Financing Receivable, Held-for-Sale, Not Part of Disposal Group, after Valuation Allowance	6.4		10.5
Proceeds from Collection of Loans Held-for-sale	0.0
Transfer of loans to held-for-sale	3.1
Increase (Decrease) in Fair Value Adjustments on Other Assets (Liabilities) Carried at Fair Value under Fair Value Option	(4.1)
Loans held for sale	6.4		$ 10.5
Proceeds from Sale of Loans Held-for-sale	$ (3.1)