Loans and Allowance for Credit Losses - Loan Portfolio Aging Analysis (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Loans Receivable Aging Analysis [Abstract]
Total Past Due	$ 51,284	$ 13,849
Current	3,745,020	3,124,570
Total Loans Receivable	3,796,304	3,138,419
Total Loans> 90 Days and Accruing	0	0
Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	39,878	9,372
Current	2,529,062	2,057,142
Total Loans Receivable	2,568,940	2,066,514
Total Loans> 90 Days and Accruing	0	0
Construction and Land Development | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	4,981	128
Current	136,587	122,351
Total Loans Receivable	141,568	122,479
Total Loans> 90 Days and Accruing	0	0
Agricultural | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	1	1,232
Current	277,361	253,109
Total Loans Receivable	277,362	254,341
Total Loans> 90 Days and Accruing	0	0
Residential Properties | Real Estate Loan | 1-4 Family
Loans Receivable Aging Analysis [Abstract]
Total Past Due	5,944	4,259
Current	388,958	321,503
Total Loans Receivable	394,902	325,762
Total Loans> 90 Days and Accruing	0	0
Residential Properties | Real Estate Loan | Multifamily
Loans Receivable Aging Analysis [Abstract]
Total Past Due	9,978	0
Current	264,932	189,632
Total Loans Receivable	274,910	189,632
Total Loans> 90 Days and Accruing	0	0
Commercial | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	18,974	3,753
Current	1,461,224	1,170,547
Total Loans Receivable	1,480,198	1,174,300
Total Loans> 90 Days and Accruing	0	0
Agricultural Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	1,358	279
Current	121,743	137,073
Total Loans Receivable	123,101	137,352
Total Loans> 90 Days and Accruing	0	0
Commercial and Industrial Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	9,734	3,854
Current	854,820	734,459
Total Loans Receivable	864,554	738,313
Total Loans> 90 Days and Accruing	0	0
Consumer Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	314	344
Current	84,227	77,658
Total Loans Receivable	84,541	78,002
Total Loans> 90 Days and Accruing	0	0
All Other Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	0
Current	155,168	118,238
Total Loans Receivable	155,168	118,238
Total Loans> 90 Days and Accruing	0	0
Financial Asset, 30 to 59 Days Past Due
Loans Receivable Aging Analysis [Abstract]
Total Past Due	33,605	7,551
Financial Asset, 30 to 59 Days Past Due | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	25,650	4,937
Financial Asset, 30 to 59 Days Past Due | Construction and Land Development | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	4,778	0
Financial Asset, 30 to 59 Days Past Due | Agricultural | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	1,198
Financial Asset, 30 to 59 Days Past Due | Residential Properties | Real Estate Loan | 1-4 Family
Loans Receivable Aging Analysis [Abstract]
Total Past Due	1,848	1,121
Financial Asset, 30 to 59 Days Past Due | Residential Properties | Real Estate Loan | Multifamily
Loans Receivable Aging Analysis [Abstract]
Total Past Due	8,297	0
Financial Asset, 30 to 59 Days Past Due | Commercial | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	10,727	2,618
Financial Asset, 30 to 59 Days Past Due | Agricultural Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	713	43
Financial Asset, 30 to 59 Days Past Due | Commercial and Industrial Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	7,121	2,426
Financial Asset, 30 to 59 Days Past Due | Consumer Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	121	145
Financial Asset, 30 to 59 Days Past Due | All Other Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	0
Financial Asset, 60 to 89 Days Past Due
Loans Receivable Aging Analysis [Abstract]
Total Past Due	3,248	1,538
Financial Asset, 60 to 89 Days Past Due | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	2,450	1,480
Financial Asset, 60 to 89 Days Past Due | Construction and Land Development | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	0
Financial Asset, 60 to 89 Days Past Due | Agricultural | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	34
Financial Asset, 60 to 89 Days Past Due | Residential Properties | Real Estate Loan | 1-4 Family
Loans Receivable Aging Analysis [Abstract]
Total Past Due	408	1,105
Financial Asset, 60 to 89 Days Past Due | Residential Properties | Real Estate Loan | Multifamily
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	0
Financial Asset, 60 to 89 Days Past Due | Commercial | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	2,042	341
Financial Asset, 60 to 89 Days Past Due | Agricultural Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	0
Financial Asset, 60 to 89 Days Past Due | Commercial and Industrial Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	792	8
Financial Asset, 60 to 89 Days Past Due | Consumer Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	6	50
Financial Asset, 60 to 89 Days Past Due | All Other Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due
Loans Receivable Aging Analysis [Abstract]
Total Past Due	14,431	4,760
Financial Asset, Equal to or Greater than 90 Days Past Due | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	11,778	2,955
Financial Asset, Equal to or Greater than 90 Days Past Due | Construction and Land Development | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	203	128
Financial Asset, Equal to or Greater than 90 Days Past Due | Agricultural | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	1	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Residential Properties | Real Estate Loan | 1-4 Family
Loans Receivable Aging Analysis [Abstract]
Total Past Due	3,688	2,033
Financial Asset, Equal to or Greater than 90 Days Past Due | Residential Properties | Real Estate Loan | Multifamily
Loans Receivable Aging Analysis [Abstract]
Total Past Due	1,681	0
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial | Real Estate Loan
Loans Receivable Aging Analysis [Abstract]
Total Past Due	6,205	794
Financial Asset, Equal to or Greater than 90 Days Past Due | Agricultural Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	645	236
Financial Asset, Equal to or Greater than 90 Days Past Due | Commercial and Industrial Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	1,821	1,420
Financial Asset, Equal to or Greater than 90 Days Past Due | Consumer Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	187	149
Financial Asset, Equal to or Greater than 90 Days Past Due | All Other Loans
Loans Receivable Aging Analysis [Abstract]
Total Past Due	$ 0	$ 0