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, 2022	Mar. 31, 2021	Dec. 31, 2021
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	$ 54,655	$ 41,910	$ 41,910
Initial allowance on loans purchased with credit deterioration	863	2,074
Provision for credit loss expense	2,952	12,136	15,151
Loans charged off	774	968	5,634
Recoveries collected	778	266	1,154
Allowance for credit losses, Ending Balance	58,474	55,418	54,655
Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		2,074	2,074
Construction and Land Development \| Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,743	1,666	1,666
Initial allowance on loans purchased with credit deterioration	272	261
Provision for credit loss expense	(25)	359	21
Loans charged off	2	0	205
Recoveries collected	0	0	0
Allowance for credit losses, Ending Balance	1,988	2,286	1,743
Construction and Land Development \| Real Estate Loan \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		261	261
Agricultural \| Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,257	1,084	1,084
Initial allowance on loans purchased with credit deterioration	0	44
Provision for credit loss expense	714	500	129
Loans charged off	0	0	0
Recoveries collected	0	0	0
Allowance for credit losses, Ending Balance	1,971	1,628	1,257
Agricultural \| Real Estate Loan \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		44	44
Residential Properties \| Real Estate Loan \| 1-4 Family
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	2,330	2,322	2,322
Initial allowance on loans purchased with credit deterioration	3	328
Provision for credit loss expense	1,264	617	(160)
Loans charged off	72	182	371
Recoveries collected	203	8	211
Allowance for credit losses, Ending Balance	3,728	3,093	2,330
Residential Properties \| Real Estate Loan \| 1-4 Family \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		328	328
Commercial \| Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	26,246	19,660	19,660
Initial allowance on loans purchased with credit deterioration	478	646
Provision for credit loss expense	3,613	5,902	6,415
Loans charged off	339	480	535
Recoveries collected	347	9	60
Allowance for credit losses, Ending Balance	30,345	25,737	26,246
Commercial \| Real Estate Loan \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		646	646
Agricultural Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	983	1,526	1,526
Initial allowance on loans purchased with credit deterioration	0	0
Provision for credit loss expense	68	(645)	(544)
Loans charged off	0	0	0
Recoveries collected	0	0	1
Allowance for credit losses, Ending Balance	1,051	881	983
Agricultural Loans \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		0	0
Commercial and Industrial Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	19,241	13,485	13,485
Initial allowance on loans purchased with credit deterioration	94	795
Provision for credit loss expense	(2,045)	4,674	7,940
Loans charged off	3	18	3,118
Recoveries collected	61	18	139
Allowance for credit losses, Ending Balance	17,348	18,954	19,241
Commercial and Industrial Loans \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		795	795
Consumer Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	2,855	2,167	2,167
Initial allowance on loans purchased with credit deterioration	16	0
Provision for credit loss expense	(637)	729	1,350
Loans charged off	358	288	1,405
Recoveries collected	167	231	743
Allowance for credit losses, Ending Balance	$ 2,043	2,839	2,855
Consumer Loans \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance		$ 0	$ 0

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Amount of increase in allowance for credit loss on financing receivable purchased with credit deterioration.

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Amount of allowance for credit loss on financing receivable. Excludes allowance for financing receivable covered under loss sharing agreement.

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