Loans Receivable and Allowance for Loan Losses (Composition of the Loan Portfolio) (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 1,424,328	$ 1,412,289
Deferred fees, net	(2,760)	(1,557)
Total loans receivable	1,421,568	1,410,732
Allowance for loan losses	(14,509)	(13,150)	$ (9,088)	$ (8,509)
Net loans receivable	$ 1,407,059	$ 1,397,582
Percent of Loans	100.00%	100.00%
Residential Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 261,450	$ 263,127
Allowance for loan losses	$ (2,124)	$ (1,960)	(1,644)	(1,552)
Percent of Loans	18.40%	18.60%
Commercial Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 581,329	$ 579,104
Allowance for loan losses	$ (9,084)	$ (8,004)	(4,915)	(4,687)
Percent of Loans	40.80%	41.00%
Agricultural Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 64,954	$ 66,334
Percent of Loans	4.60%	4.70%
Construction Real Estate Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 20,237	$ 21,005
Allowance for loan losses	$ (122)	$ (150)	(87)	(95)
Percent of Loans	1.40%	1.50%
Commercial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 302,431	$ 283,741
Allowance for loan losses	$ (1,405)	$ (1,360)	(1,064)	(949)
Percent of Loans	21.20%	20.10%
Other Agricultural Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 40,122	$ 40,929
Percent of Loans	2.80%	2.90%
Consumer Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans	$ 153,805	$ 158,049
Allowance for loan losses	$ (1,774)	$ (1,676)	$ (1,378)	$ (1,226)
Percent of Loans	10.80%	11.20%