Loans and Allowance for Credit Losses - Allowance for Credit Losses Based on Portfolio Segment (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	$ 68,675	$ 59,093	$ 59,093
Initial allowance on loans purchased with credit deterioration	0	0	3,791
Provision for credit loss expense	(357)	(817)	6,104
Loans charged off	819	480	2,631
Recoveries collected	437	427	2,318
Allowance for credit losses, Ending Balance	67,936	58,223	68,675
Construction and Land Development | Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	2,918	2,250	2,250
Initial allowance on loans purchased with credit deterioration	0	0	308
Provision for credit loss expense	(217)	176	374
Loans charged off	0	0	14
Recoveries collected	0	0	0
Allowance for credit losses, Ending Balance	2,701	2,426	2,918
Agricultural | Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,366	1,433	1,433
Initial allowance on loans purchased with credit deterioration	0	0	0
Provision for credit loss expense	(8)	(29)	(67)
Loans charged off	0	0	0
Recoveries collected	0	0	0
Allowance for credit losses, Ending Balance	1,358	1,404	1,366
Residential Properties | Real Estate Loan | 1-4 Family
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	4,220	3,742	3,742
Initial allowance on loans purchased with credit deterioration	0	0	124
Provision for credit loss expense	(424)	(306)	225
Loans charged off	67	40	87
Recoveries collected	49	24	216
Allowance for credit losses, Ending Balance	3,778	3,420	4,220
Commercial | Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	31,758	28,157	28,157
Initial allowance on loans purchased with credit deterioration	0	0	1,066
Provision for credit loss expense	618	(834)	1,755
Loans charged off	0	0	25
Recoveries collected	161	4	805
Allowance for credit losses, Ending Balance	32,537	27,327	31,758
Agricultural Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	705	585	585
Initial allowance on loans purchased with credit deterioration	0	0	0
Provision for credit loss expense	125	(8)	490
Loans charged off	52	0	408
Recoveries collected	0	3	38
Allowance for credit losses, Ending Balance	778	580	705
Commercial and Industrial Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	25,450	20,808	20,808
Initial allowance on loans purchased with credit deterioration	0	0	2,273
Provision for credit loss expense	(609)	91	2,322
Loans charged off	274	13	529
Recoveries collected	64	256	576
Allowance for credit losses, Ending Balance	24,631	21,142	25,450
Consumer Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	2,258	2,118	2,118
Initial allowance on loans purchased with credit deterioration	0	0	20
Provision for credit loss expense	158	93	1,005
Loans charged off	426	427	1,568
Recoveries collected	163	140	683
Allowance for credit losses, Ending Balance	$ 2,153	$ 1,924	$ 2,258