ALLOWANCE FOR LOAN LOSSES: Financing Receivables, Aging of Loans (Details 3) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual	$ 2,418	$ 2,715
Total Past Due and Non-accrual	2,938	2,990
Current	808,438	776,442
Total Loans Receivable	811,376	779,432
30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	520	241
90 Days and Greater Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	34
Commercial and construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total Loans Receivable	706,270	660,189
Commercial and construction | Commercial business
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual	178	294
Total Past Due and Non-accrual	185	307
Current	137,487	107,064
Total Loans Receivable	137,672	107,371
Commercial and construction | Commercial business | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	7	13
Commercial and construction | Commercial business | 90 Days and Greater Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual	1,200	1,342
Total Past Due and Non-accrual	1,200	1,342
Current	449,397	445,729
Total Loans Receivable	450,597	447,071
Commercial and construction | Commercial real estate | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Commercial real estate | 90 Days and Greater Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Land
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual	763	801
Total Past Due and Non-accrual	763	801
Current	14,574	15,074
Total Loans Receivable	15,337	15,875
Commercial and construction | Land | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Land | 90 Days and Greater Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Multi-family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual	0	0
Total Past Due and Non-accrual	0	0
Current	63,080	43,715
Total Loans Receivable	63,080	43,715
Commercial and construction | Multi-family | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Multi-family | 90 Days and Greater Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Real estate construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual	0	0
Total Past Due and Non-accrual	0	0
Current	39,584	46,157
Total Loans Receivable	39,584	46,157
Commercial and construction | Real estate construction | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Commercial and construction | Real estate construction | 90 Days and Greater Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	0	0
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual	277	278
Total Past Due and Non-accrual	790	540
Current	104,316	118,703
Total Loans Receivable	105,106	119,243
Consumer | 30-89 Days Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	513	228
Consumer | 90 Days and Greater Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Past Due	$ 0	$ 34