LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring) (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	$ 13,422,000	$ 16,115,000
Nonaccrual Status	317,000	917,000
Total TDRs	13,739,000	17,032,000
Financing Receivable, Modifications, Commitments to Advance Funds	0	45,000
Commerical real estate - owner-occupied [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	200,000	199,000
Nonaccrual Status	78,000	87,000
Total TDRs	278,000	286,000
Commercial real estate - investment properties [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	5,606,000	6,884,000
Nonaccrual Status	0	0
Total TDRs	5,606,000	6,884,000
Commercial business [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	391,000	555,000
Nonaccrual Status	0	0
Total TDRs	391,000	555,000
Agricultural business, including secured by farmland [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	2,561,000	3,129,000
Nonaccrual Status	0	29,000
Total TDRs	2,561,000	3,158,000
One- to four-family residential [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	4,469,000	5,136,000
Nonaccrual Status	239,000	801,000
Total TDRs	4,708,000	5,937,000
Consumer secured by one- to four-family [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	133,000	139,000
Nonaccrual Status	0	0
Total TDRs	133,000	139,000
Consumer Loan [Member]
Financing Receivable, Troubled Debt Restructurings [Line Items]
Accrual Status	62,000	73,000
Nonaccrual Status	0	0
Total TDRs	$ 62,000	$ 73,000