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Loans and Allowance for Credit Losses - Credit Risk Profile of Loan Portfolio on Amortized Cost Basis Based on Risk Rating Category (Details) - USD ($) $ in Thousands | Sep. 30, 2021 | Dec. 31, 2020
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Credit Quality Information [Abstract] |  |
Current fiscal year | $ 799,252 | $ 1,085,080
Fiscal year before current fiscal year | 911,425 | 558,953
Two years before current fiscal year | 624,971 | 386,847
Three years before current fiscal year | 397,185 | 300,829
Four years before current fiscal year | 241,548 | 247,242
Prior | 929,680 | 517,313
Revolving Loans | 43,708 | 42,155
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 3,947,769 | 3,138,419
Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 775,322 | 1,052,257
Fiscal year before current fiscal year | 907,023 | 511,427
Two years before current fiscal year | 604,031 | 367,652
Three years before current fiscal year | 387,870 | 279,274
Four years before current fiscal year | 218,694 | 230,730
Prior | 884,824 | 459,453
Revolving Loans | 42,664 | 40,363
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 3,820,428 | 2,941,156
Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 20,819 | 29,692
Fiscal year before current fiscal year | 2,350 | 44,049
Two years before current fiscal year | 12,071 | 8,731
Three years before current fiscal year | 3,073 | 15,165
Four years before current fiscal year | 14,318 | 9,344
Prior | 23,535 | 30,525
Revolving Loans | 56 | 293
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 76,222 | 137,799
Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 3,111 | 3,131
Fiscal year before current fiscal year | 2,052 | 3,477
Two years before current fiscal year | 8,869 | 10,464
Three years before current fiscal year | 6,242 | 6,390
Four years before current fiscal year | 8,536 | 7,168
Prior | 21,321 | 27,335
Revolving Loans | 988 | 1,499
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 51,119 | 59,464
Agricultural Loans |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 90,743 | 104,515
Fiscal year before current fiscal year | 20,384 | 20,401
Two years before current fiscal year | 8,539 | 6,697
Three years before current fiscal year | 3,808 | 2,062
Four years before current fiscal year | 1,234 | 783
Prior | 1,826 | 2,894
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 126,534 | 137,352
Agricultural Loans | Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 75,148 | 83,377
Fiscal year before current fiscal year | 19,930 | 15,680
Two years before current fiscal year | 5,582 | 5,978
Three years before current fiscal year | 3,653 | 1,838
Four years before current fiscal year | 1,074 | 635
Prior | 1,480 | 2,856
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 106,867 | 110,364
Agricultural Loans | Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 15,568 | 21,070
Fiscal year before current fiscal year | 436 | 4,483
Two years before current fiscal year | 2,957 | 694
Three years before current fiscal year | 155 | 224
Four years before current fiscal year | 160 | 148
Prior | 65 | 38
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 19,341 | 26,657
Agricultural Loans | Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 27 | 68
Fiscal year before current fiscal year | 18 | 238
Two years before current fiscal year | 0 | 25
Three years before current fiscal year | 0 | 0
Four years before current fiscal year | 0 | 0
Prior | 281 | 0
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 326 | 331
Consumer Loans |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 20,973 | 31,624
Fiscal year before current fiscal year | 21,642 | 21,424
Two years before current fiscal year | 27,447 | 12,219
Three years before current fiscal year | 6,694 | 8,375
Four years before current fiscal year | 2,670 | 3,218
Prior | 638 | 1,142
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 80,064 | 78,002
Consumer Loans | Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 20,854 | 31,609
Fiscal year before current fiscal year | 21,547 | 21,384
Two years before current fiscal year | 27,317 | 12,084
Three years before current fiscal year | 6,633 | 8,279
Four years before current fiscal year | 2,640 | 3,150
Prior | 492 | 1,022
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 79,483 | 77,528
Consumer Loans | Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 21 | 0
Fiscal year before current fiscal year | 78 | 24
Two years before current fiscal year | 55 | 24
Three years before current fiscal year | 10 | 1
Four years before current fiscal year | 0 | 1
Prior | 0 | 0
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 164 | 50
Consumer Loans | Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 98 | 15
Fiscal year before current fiscal year | 17 | 16
Two years before current fiscal year | 75 | 111
Three years before current fiscal year | 51 | 95
Four years before current fiscal year | 30 | 67
Prior | 146 | 120
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 417 | 424
Commercial and Industrial Loans |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 154,001 | 376,688
Fiscal year before current fiscal year | 186,054 | 166,638
Two years before current fiscal year | 168,726 | 71,878
Three years before current fiscal year | 79,480 | 81,068
Four years before current fiscal year | 3,889 | 43,676
Prior | 387,441 | 116,603
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 979,591 | 856,551
Commercial and Industrial Loans | Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 152,729 | 371,683
Fiscal year before current fiscal year | 184,801 | 132,148
Two years before current fiscal year | 166,553 | 70,497
Three years before current fiscal year | 77,324 | 78,890
Four years before current fiscal year | 3,402 | 42,439
Prior | 384,318 | 114,904
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 969,127 | 810,561
Commercial and Industrial Loans | Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 844 | 4,116
Fiscal year before current fiscal year | 542 | 32,130
Two years before current fiscal year | 1,725 | 849
Three years before current fiscal year | 568 | 489
Four years before current fiscal year | 416 | 1,101
Prior | 1,155 | 730
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 5,250 | 39,415
Commercial and Industrial Loans | Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 428 | 889
Fiscal year before current fiscal year | 711 | 2,360
Two years before current fiscal year | 448 | 532
Three years before current fiscal year | 1,588 | 1,689
Four years before current fiscal year | 71 | 136
Prior | 1,968 | 969
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 5,214 | 6,575
Real Estate Loan |  |
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 2,761,580 | 2,066,514
Real Estate Loan | Construction and Land Development |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 33,652 | 41,842
Fiscal year before current fiscal year | 68,429 | 41,117
Two years before current fiscal year | 26,623 | 31,500
Three years before current fiscal year | 35,654 | 3,277
Four years before current fiscal year | 3,841 | 871
Prior | 11,862 | 3,872
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 180,061 | 122,479
Real Estate Loan | Construction and Land Development | Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 33,540 | 41,842
Fiscal year before current fiscal year | 68,429 | 40,989
Two years before current fiscal year | 26,623 | 31,500
Three years before current fiscal year | 34,739 | 2,760
Four years before current fiscal year | 3,841 | 871
Prior | 11,328 | 3,822
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 178,500 | 121,784
Real Estate Loan | Construction and Land Development | Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 112 | 0
Fiscal year before current fiscal year | 0 | 0
Two years before current fiscal year | 0 | 0
Three years before current fiscal year | 0 | 0
Four years before current fiscal year | 0 | 0
Prior | 0 | 0
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 112 | 0
Real Estate Loan | Construction and Land Development | Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 0 | 0
Fiscal year before current fiscal year | 0 | 128
Two years before current fiscal year | 0 | 0
Three years before current fiscal year | 915 | 517
Four years before current fiscal year | 0 | 0
Prior | 534 | 50
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 1,449 | 695
Real Estate Loan | Agricultural |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 63,167 | 75,475
Fiscal year before current fiscal year | 66,079 | 38,382
Two years before current fiscal year | 34,752 | 39,172
Three years before current fiscal year | 37,429 | 16,815
Four years before current fiscal year | 13,540 | 14,729
Prior | 63,821 | 69,768
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 278,788 | 254,341
Real Estate Loan | Agricultural | Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 62,342 | 73,630
Fiscal year before current fiscal year | 65,820 | 34,412
Two years before current fiscal year | 30,303 | 37,839
Three years before current fiscal year | 36,823 | 16,138
Four years before current fiscal year | 13,095 | 13,559
Prior | 57,580 | 58,291
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 265,963 | 233,869
Real Estate Loan | Agricultural | Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 825 | 1,845
Fiscal year before current fiscal year | 259 | 3,970
Two years before current fiscal year | 4,184 | 533
Three years before current fiscal year | 417 | 469
Four years before current fiscal year | 388 | 1,106
Prior | 6,010 | 11,232
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 12,083 | 19,155
Real Estate Loan | Agricultural | Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 0 | 0
Fiscal year before current fiscal year | 0 | 0
Two years before current fiscal year | 265 | 800
Three years before current fiscal year | 189 | 208
Four years before current fiscal year | 57 | 64
Prior | 231 | 245
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 742 | 1,317
Real Estate Loan | Commercial |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 363,034 | 373,082
Fiscal year before current fiscal year | 446,957 | 238,459
Two years before current fiscal year | 318,548 | 184,780
Three years before current fiscal year | 183,271 | 161,567
Four years before current fiscal year | 177,071 | 155,046
Prior | 401,285 | 250,998
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 1,890,166 | 1,363,932
Real Estate Loan | Commercial | Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 357,285 | 368,750
Fiscal year before current fiscal year | 445,335 | 237,119
Two years before current fiscal year | 310,825 | 171,591
Three years before current fiscal year | 180,042 | 148,283
Four years before current fiscal year | 161,629 | 143,400
Prior | 376,631 | 215,616
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 1,831,747 | 1,284,759
Real Estate Loan | Commercial | Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 3,369 | 2,469
Fiscal year before current fiscal year | 886 | 1,300
Two years before current fiscal year | 1,198 | 6,108
Three years before current fiscal year | 1,418 | 11,262
Four years before current fiscal year | 10,726 | 6,741
Prior | 15,251 | 16,947
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 32,848 | 44,827
Real Estate Loan | Commercial | Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 2,380 | 1,863
Fiscal year before current fiscal year | 736 | 40
Two years before current fiscal year | 6,525 | 7,081
Three years before current fiscal year | 1,811 | 2,022
Four years before current fiscal year | 4,716 | 4,905
Prior | 9,403 | 18,435
Revolving Loans | 0 | 0
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 25,571 | 34,346
1-4 Family | Real Estate Loan | Residential Properties |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 73,682 | 81,854
Fiscal year before current fiscal year | 101,880 | 32,532
Two years before current fiscal year | 40,336 | 40,601
Three years before current fiscal year | 50,849 | 27,665
Four years before current fiscal year | 39,303 | 28,919
Prior | 62,807 | 72,036
Revolving Loans | 43,708 | 42,155
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 412,565 | 325,762
1-4 Family | Real Estate Loan | Residential Properties | Pass |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 73,424 | 81,366
Fiscal year before current fiscal year | 101,161 | 29,695
Two years before current fiscal year | 36,828 | 38,163
Three years before current fiscal year | 48,656 | 23,086
Four years before current fiscal year | 33,013 | 26,676
Prior | 52,995 | 62,942
Revolving Loans | 42,664 | 40,363
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 388,741 | 302,291
1-4 Family | Real Estate Loan | Residential Properties | Special Mention |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 80 | 192
Fiscal year before current fiscal year | 149 | 2,142
Two years before current fiscal year | 1,952 | 523
Three years before current fiscal year | 505 | 2,720
Four years before current fiscal year | 2,628 | 247
Prior | 1,054 | 1,578
Revolving Loans | 56 | 293
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | 6,424 | 7,695
1-4 Family | Real Estate Loan | Residential Properties | Substandard |  |
Credit Quality Information [Abstract] |  |
Current fiscal year | 178 | 296
Fiscal year before current fiscal year | 570 | 695
Two years before current fiscal year | 1,556 | 1,915
Three years before current fiscal year | 1,688 | 1,859
Four years before current fiscal year | 3,662 | 1,996
Prior | 8,758 | 7,516
Revolving Loans | 988 | 1,499
Loans Receivable Aging Analysis [Abstract] |  |
Total Loans Receivable | $ 17,400 | $ 15,776

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