Loans Held for Sale - By Segment (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	$ 335.2	$ 0.9
Agricultural
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	6.5	0.0
Commercial
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	248.7	0.0
Total construction loans
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	0.2	0.0
Residential Mortgage
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	1.3	0.0
Agricultural
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	4.7	0.0
Total real estate
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	259.1	0.9
Consumer Loan
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	0.6	0.0
Total consumer loans
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	0.6	0.0
Commercial
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	69.0	0.0
Residential Mortgage, at fair value
Debt Securities, Available-for-sale [Line Items]
Loans held for sale ($4.2 and $0.9 of which is recorded at fair value at June 30, 2025 and December 31, 2024, respectively)	$ 4.2	$ 0.9