Risks and Uncertainties (Tables)

12 Months Ended

Dec. 31, 2025

Risks and Uncertainties [Abstract]

Schedule of Fair Value, off-Balance-Sheet Risks

	December 31, 2025		December 31, 2024
Commitments to extend credit	$	2,638.8	$	3,076.5
Standby letters of credit	60.4		73.5

Schedule of Allowance for Loan Losses by Portfolio Segment

The following tables represent, by loan portfolio segments, the activity in the allowance for credit losses for loans held for investment:

December 31, 2025	Beginning Balance		Provision for Credit Losses		Loans Charged-Off(2)		Recoveries Collected		Ending Balance
Allowance for credit losses (1)
Real estate	$	139.4	$	7.8	$	(23.6)	$	7.6	$	131.2
Consumer	16.8		6.2		(17.5)		5.7		11.2
Commercial	38.9		4.6		(8.9)		2.3		36.9
Agricultural	9.0		7.9		(5.0)		0.2		12.1
Total allowance for credit losses	$	204.1	$	26.5	$	(55.0)	$	15.8	$	191.4

December 31, 2024	Beginning Balance		Provision for Credit Loss		Loans Charged-Off(2)		Recoveries Collected		Ending Balance
Allowance for credit losses (1)
Real estate	$	160.1	$	17.7	$	(39.6)	$	1.2	$	139.4
Consumer	13.0		14.3		(15.4)		4.9		16.8
Commercial	50.2		44.3		(59.4)		3.8		38.9
Agricultural	4.4		4.6		(0.3)		0.3		9.0
Total allowance for credit losses	$	227.7	$	80.9	$	(114.7)	$	10.2	$	204.1

December 31, 2023	Beginning Balance		Provision for (reversal of) Credit Loss		Loans Charged-Off(2)		Recoveries Collected		Ending Balance
Allowance for credit losses (1)
Real estate	$	138.7	$	35.2	$	(18.5)	$	4.7	$	160.1
Consumer	23.3		(1.0)		(14.0)		4.7		13.0
Commercial	54.9		(3.9)		(3.4)		2.6		50.2
Agricultural	3.2		0.8		—		0.4		4.4
Total allowance for credit losses	$	220.1	$	31.1	$	(35.9)	$	12.4	$	227.7
(1) Amounts presented exclude the allowance for credit losses related to unfunded commitments and investment securities. The allowance for credit losses related to unfunded commitments and investment securities are included in the “Financial Instruments with Off-Balance Sheet Risk” Note and “Investment Securities” Note, respectively.
(2) Loans, or portions thereof, are charged-off against the allowance for credit losses when management believes the collectability of the principal is unlikely, or, with respect to consumer installment loans, according to an established delinquency schedule.

Commitments Off Balance Sheet Allowance for Credit Losses

The following table presents our financial instruments with off-balance sheet risk, as well as the activity in the allowance for off-balance sheet credit losses related to those financial instruments:

	December 31, 2025		December 31, 2024
Beginning balance	$	5.2	$	18.4
Provision for credit loss expense	0.7		(13.2)
Ending balance	$	5.9	$	5.2