Loans and Allowance for Loan Losses - Credit Risk Profile of Loan Portfolio on Amortized Cost Basis Based on Risk Rating Category (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Credit Quality Information [Abstract]
2020	$ 725,052
2019	616,209
2018	395,745
2017	357,400
2016	296,452
Prior	785,890
Revolving Loans	28,514
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	3,205,262	$ 2,695,347
Pass
Credit Quality Information [Abstract]
2020	708,239
2019	564,549
2018	385,866
2017	347,120
2016	281,055
Prior	738,929
Revolving Loans	27,209
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	3,052,967	2,558,157
Special Mention
Credit Quality Information [Abstract]
2020	13,758
2019	48,217
2018	5,393
2017	3,044
2016	8,403
Prior	17,601
Revolving Loans	30
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	96,446	71,611
Substandard
Credit Quality Information [Abstract]
2020	3,055
2019	3,443
2018	4,486
2017	7,236
2016	6,994
Prior	29,360
Revolving Loans	1,275
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	55,849	65,579
Agricultural Loans
Credit Quality Information [Abstract]
2020	82,479
2019	49,604
2018	8,674
2017	3,180
2016	1,660
Prior	3,446
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	149,043	136,124
Agricultural Loans \| Pass
Credit Quality Information [Abstract]
2020	72,118
2019	38,483
2018	8,353
2017	3,169
2016	959
Prior	3,400
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	126,482	129,811
Agricultural Loans \| Special Mention
Credit Quality Information [Abstract]
2020	9,754
2019	11,078
2018	296
2017	11
2016	701
Prior	35
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	21,875	3,862
Agricultural Loans \| Substandard
Credit Quality Information [Abstract]
2020	607
2019	43
2018	25
2017	0
2016	0
Prior	11
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	686	2,451
Commercial and Industrial Loans
Credit Quality Information [Abstract]
2020	365,002
2019	184,651
2018	101,333
2017	86,401
2016	56,508
Prior	141,333
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	935,228	655,580
Commercial and Industrial Loans \| Pass
Credit Quality Information [Abstract]
2020	362,238
2019	148,476
2018	100,766
2017	84,972
2016	55,893
Prior	138,743
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	891,088	603,047
Commercial and Industrial Loans \| Special Mention
Credit Quality Information [Abstract]
2020	1,642
2019	33,847
2018	185
2017	58
2016	407
Prior	952
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	37,091	40,395
Commercial and Industrial Loans \| Substandard
Credit Quality Information [Abstract]
2020	1,122
2019	2,328
2018	382
2017	1,371
2016	208
Prior	1,638
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	7,049	12,138
Consumer Loans
Credit Quality Information [Abstract]
2020	20,138
2019	30,769
2018	17,885
2017	10,277
2016	1,248
Prior	1,767
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	82,084	83,183
Consumer Loans \| Pass
Credit Quality Information [Abstract]
2020	20,116
2019	30,739
2018	17,657
2017	10,147
2016	148
Prior	9
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	78,816	82,117
Consumer Loans \| Special Mention
Credit Quality Information [Abstract]
2020	5
2019	0
2018	72
2017	1
2016	960
Prior	1,154
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	2,192	140
Consumer Loans \| Substandard
Credit Quality Information [Abstract]
2020	17
2019	30
2018	156
2017	129
2016	140
Prior	604
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,076	926
Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	2,038,907	1,820,460
Real Estate Loan \| Pass
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable		1,743,182
Real Estate Loan \| Special Mention
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable		27,214
Real Estate Loan \| Substandard
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable		50,064
Real Estate Loan \| Construction and Land Development
Credit Quality Information [Abstract]
2020	56,357
2019	61,726
2018	4,145
2017	3,380
2016	909
Prior	54,417
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	180,934	94,142
Real Estate Loan \| Construction and Land Development \| Pass
Credit Quality Information [Abstract]
2020	56,357
2019	61,418
2018	4,145
2017	2,848
2016	519
Prior	54,361
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	179,648	93,413
Real Estate Loan \| Construction and Land Development \| Special Mention
Credit Quality Information [Abstract]
2020	0
2019	0
2018	0
2017	0
2016	390
Prior	0
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	390	413
Real Estate Loan \| Construction and Land Development \| Substandard
Credit Quality Information [Abstract]
2020	0
2019	308
2018	0
2017	532
2016	0
Prior	56
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	896	316
Real Estate Loan \| Agricultural
Credit Quality Information [Abstract]
2020	45,176
2019	45,995
2018	44,171
2017	18,639
2016	16,882
Prior	80,519
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	251,382	240,241
Real Estate Loan \| Agricultural \| Pass
Credit Quality Information [Abstract]
2020	44,876
2019	42,885
2018	43,297
2017	18,278
2016	15,940
Prior	69,084
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	234,360	231,227
Real Estate Loan \| Agricultural \| Special Mention
Credit Quality Information [Abstract]
2020	300
2019	3,110
2018	387
2017	143
2016	875
Prior	11,186
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	16,001	6,902
Real Estate Loan \| Agricultural \| Substandard
Credit Quality Information [Abstract]
2020	0
2019	0
2018	487
2017	218
2016	67
Prior	249
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,021	2,112
Real Estate Loan \| Commercial
Credit Quality Information [Abstract]
2020	114,991
2019	206,281
2018	180,030
2017	202,156
2016	183,526
Prior	377,571
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,264,555	1,149,650
Real Estate Loan \| Commercial \| Pass
Credit Quality Information [Abstract]
2020	111,880
2019	206,159
2018	174,472
2017	197,260
2016	174,120
Prior	355,666
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	1,219,557	1,103,543
Real Estate Loan \| Commercial \| Special Mention
Credit Quality Information [Abstract]
2020	1,857
2019	23
2018	4,158
2017	1,781
2016	4,818
Prior	2,822
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	15,459	14,156
Real Estate Loan \| Commercial \| Substandard
Credit Quality Information [Abstract]
2020	1,254
2019	99
2018	1,400
2017	3,115
2016	4,588
Prior	19,083
Revolving Loans	0
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	29,539	31,951
1-4 Family \| Real Estate Loan \| Residential Properties
Credit Quality Information [Abstract]
2020	40,909
2019	37,183
2018	39,507
2017	33,367
2016	35,719
Prior	126,837
Revolving Loans	28,514
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	342,036	336,427
1-4 Family \| Real Estate Loan \| Residential Properties \| Pass
Credit Quality Information [Abstract]
2020	40,654
2019	36,389
2018	37,176
2017	30,446
2016	33,476
Prior	117,666
Revolving Loans	27,209
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	323,016	314,999
1-4 Family \| Real Estate Loan \| Residential Properties \| Special Mention
Credit Quality Information [Abstract]
2020	200
2019	159
2018	295
2017	1,050
2016	252
Prior	1,452
Revolving Loans	30
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	3,438	5,743
1-4 Family \| Real Estate Loan \| Residential Properties \| Substandard
Credit Quality Information [Abstract]
2020	55
2019	635
2018	2,036
2017	1,871
2016	1,991
Prior	7,719
Revolving Loans	1,275
Loans Receivable Aging Analysis [Abstract]
Total Loans Receivable	$ 15,582	$ 15,685

Loans and Allowance for Loan Losses - Credit Risk Profile of Loan Portfolio on Amortized Cost Basis Based on Risk Rating Category (Details) - USD ($)
$ in Thousands