LOANS RECEIVABLE AND THE ALLOWANCE FOR LOAN LOSSES (Troubled Debt Restructuring) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	$ 12,744	$ 18,907
TDRs on Nonaccrual Status	929	1,024
Total TDRs	13,673	19,931
Commitments to advance funds related to TDRs, maximum additional amounts	59	127
Commerical real estate - owner-occupied [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	200	203
TDRs on Nonaccrual Status	89	96
Total TDRs	289	299
Commercial real estate - investment properties [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	3,207	4,304
TDRs on Nonaccrual Status	0	0
Total TDRs	3,207	4,304
Multifamily real estate [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	0	349
TDRs on Nonaccrual Status	0	0
Total TDRs	0	349
One- to four-family construction [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	0	1,180
TDRs on Nonaccrual Status	0	0
Total TDRs	0	1,180
Land and land development - residential [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	193	1,106
TDRs on Nonaccrual Status	0	0
Total TDRs	193	1,106
Commercial business [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	573	653
TDRs on Nonaccrual Status	0	0
Total TDRs	573	653
Agricultural business, including secured by farmland [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	3,172	3,125
TDRs on Nonaccrual Status	29	79
Total TDRs	3,201	3,204
One- to four-family residential [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	5,182	7,678
TDRs on Nonaccrual Status	810	843
Total TDRs	5,992	8,521
Consumer secured by one- to four-family [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	140	143
TDRs on Nonaccrual Status	1	6
Total TDRs	141	149
Consumer - other [Member]
Financing Receivable, Modifications [Line Items]
TDRs on Accrual Status	77	166
TDRs on Nonaccrual Status	0	0
Total TDRs	$ 77	$ 166