LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring) (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	$ 13,481,000	$ 16,115,000
TDRs on Nonaccrual Status	320,000	917,000
Total TDRs	13,801,000	17,032,000
Commitments to advance funds related to TDRs, maximum additional amounts	7,000	45,000
Commerical real estate - owner-occupied [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	201,000	199,000
TDRs on Nonaccrual Status	80,000	87,000
Total TDRs	281,000	286,000
Commercial real estate - investment properties [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	5,637,000	6,884,000
TDRs on Nonaccrual Status	0	0
Total TDRs	5,637,000	6,884,000
Commercial business [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	384,000	555,000
TDRs on Nonaccrual Status	0	0
Total TDRs	384,000	555,000
Agricultural business, including secured by farmland [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	2,560,000	3,129,000
TDRs on Nonaccrual Status	0	29,000
Total TDRs	2,560,000	3,158,000
One- to four-family residential [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	4,498,000	5,136,000
TDRs on Nonaccrual Status	240,000	801,000
Total TDRs	4,738,000	5,937,000
Consumer secured by one- to four-family [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	135,000	139,000
TDRs on Nonaccrual Status	0	0
Total TDRs	135,000	139,000
Consumer - other [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	66,000	73,000
TDRs on Nonaccrual Status	0	0
Total TDRs	$ 66,000	$ 73,000