Loans, Non-accrual and Past Due Loans (Details) $ in Thousands	Dec. 31, 2020 USD ($) Loan	Dec. 31, 2019 USD ($) Loan	Dec. 31, 2018 USD ($)
Non-accrual and Past Due Loans [Abstract]
Current & accruing	$ 878,003	$ 779,162
Non-accrual	15,211	1,157
Total	893,214	780,645	$ 775,494
Commitments to lend additional funds to borrower whose loan was on non-accrual status	0	0
30-59 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	100
60-89 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	226
90 Days or More Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Commercial [Member]
Non-accrual and Past Due Loans [Abstract]
Current & accruing	255,563	105,741
Non-accrual	363	266
Total	$ 255,926	$ 106,140	125,177
Number of nonaccrual loans | Loan	4	3
Commercial [Member] | 30-59 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	$ 0	$ 0
Commercial [Member] | 60-89 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	133
Commercial [Member] | 90 Days or More Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Commercial Real Estate [Member]
Non-accrual and Past Due Loans [Abstract]
Current & accruing	449,178	451,215
Non-accrual	4,875	466
Total	$ 454,053	$ 451,774	420,106
Number of nonaccrual loans | Loan	3	2
Commercial Real Estate [Member] | 30-59 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	$ 0	$ 0
Commercial Real Estate [Member] | 60-89 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	93
Commercial Real Estate [Member] | 90 Days or More Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Agriculture [Member]
Non-accrual and Past Due Loans [Abstract]
Current & accruing	85,918	115,751
Non-accrual	9,130	0
Total	$ 95,048	115,751	123,626
Number of nonaccrual loans | Loan	3
Agriculture [Member] | 30-59 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	$ 0	0
Agriculture [Member] | 60-89 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Agriculture [Member] | 90 Days or More Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Residential Mortgage [Member]
Non-accrual and Past Due Loans [Abstract]
Current & accruing	64,344	64,771
Non-accrual	153	172
Total	$ 64,497	$ 64,943	51,064
Number of nonaccrual loans | Loan	1	1
Residential Mortgage [Member] | 30-59 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	$ 0	$ 0
Residential Mortgage [Member] | 60-89 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Residential Mortgage [Member] | 90 Days or More Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Residential Construction [Member]
Non-accrual and Past Due Loans [Abstract]
Current & accruing	4,223	15,212
Non-accrual	0	0
Total	4,223	15,212	20,124
Residential Construction [Member] | 30-59 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Residential Construction [Member] | 60-89 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Residential Construction [Member] | 90 Days or More Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Consumer [Member]
Non-accrual and Past Due Loans [Abstract]
Current & accruing	18,777	26,472
Non-accrual	690	253
Total	$ 19,467	$ 26,825	$ 35,397
Number of nonaccrual loans | Loan	5	4
Consumer [Member] | 30-59 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	$ 0	$ 100
Consumer [Member] | 60-89 Days Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	0	0
Consumer [Member] | 90 Days or More Past Due [Member]
Non-accrual and Past Due Loans [Abstract]
Past due & accruing	$ 0	$ 0