Loans and Allowance for Credit Losses - Allowance for Credit Losses and Recorded Investment in Loans (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	$ 26,911	$ 26,189	$ 19,977
Provision for credit loss expense	16,103	6,433	8,667
Loans charged off	3,844	6,326	2,993
Recoveries collected	1,068	615	538
Allowance for credit losses, Ending Balance	41,910	26,911	26,189
Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,672
Allowance for credit losses, Ending Balance		1,672
Construction and Land Development \| Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,146	561	1,202
Provision for credit loss expense	646	585	(631)
Loans charged off	13	0	10
Recoveries collected	0	0	0
Allowance for credit losses, Ending Balance	1,666	1,146	561
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	(113)
Allowance for credit losses, Ending Balance		(113)
Agricultural \| Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,093	1,246	1,001
Provision for credit loss expense	(239)	(153)	245
Loans charged off	0	0	0
Recoveries collected	0	0	0
Allowance for credit losses, Ending Balance	1,084	1,093	1,246
Agricultural \| Real Estate Loan \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	230
Allowance for credit losses, Ending Balance		230
Residential Properties \| Real Estate Loan \| 1-4 Family
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,386	1,504	886
Provision for credit loss expense	274	1,268	1,628
Loans charged off	393	1,478	1,111
Recoveries collected	299	92	101
Allowance for credit losses, Ending Balance	2,322	1,386	1,504
Residential Properties \| Real Estate Loan \| Cumulative Change in Accounting Principal, Adjustment \| 1-4 Family \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	756
Allowance for credit losses, Ending Balance		756
Commercial \| Real Estate Loan
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	11,198	11,102	7,918
Provision for credit loss expense	8,581	1,827	3,353
Loans charged off	829	1,743	170
Recoveries collected	169	12	1
Allowance for credit losses, Ending Balance	19,660	11,198	11,102
Commercial \| Real Estate Loan \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	541
Allowance for credit losses, Ending Balance		541
Agricultural Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,386	951	743
Provision for credit loss expense	503	459	301
Loans charged off	0	24	93
Recoveries collected	0	0	0
Allowance for credit losses, Ending Balance	1,526	1,386	951
Agricultural Loans \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	(363)
Allowance for credit losses, Ending Balance		(363)
Commercial and Industrial Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	9,273	9,893	7,425
Provision for credit loss expense	5,869	1,053	3,155
Loans charged off	1,991	1,828	832
Recoveries collected	179	155	145
Allowance for credit losses, Ending Balance	13,485	9,273	9,893
Commercial and Industrial Loans \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	155
Allowance for credit losses, Ending Balance		155
Consumer Loans
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	1,429	932	802
Provision for credit loss expense	469	1,394	616
Loans charged off	618	1,253	777
Recoveries collected	421	356	291
Allowance for credit losses, Ending Balance	2,167	1,429	$ 932
Consumer Loans \| Cumulative Change in Accounting Principal, Adjustment \| ASU 2016-13
Allowance for loan losses [Abstract]
Allowance for credit losses, Beginning Balance	$ 466
Allowance for credit losses, Ending Balance		$ 466

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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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Amount of increase (decrease) in allowance for credit loss on financing receivable.

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