SHAREHOLDERS' EQUITY AND REGULATORY CAPITAL REQUIREMENTS: Compliance with Regulatory Capital Requirements under Banking Regulations (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Shareholders Equity And Regulatory Capital Requirements [Abstract]
Total capital to risk weighted assets actual amount	$ 123,061	$ 112,421
Total capital to risk weighted assets actual ratio	15.41%	14.06%
Total capital to risk weighted assets for capital adequacy purposes amount	$ 63,868	$ 63,955
Total capital to risk weighted assets for capital adequacy purposes ratio	8.00%	8.00%
Total capital to risk weighted assets for capital adequacy purposes well capitalized under prompt corrective action amount	$ 79,835	$ 79,944
Total capital to risk weighted assets for capital adequacy purposes well capitalized under prompt corrective action ratio	10.00%	10.00%
Tier 1 to risk weighted assets actual amount	$ 113,066	$ 102,411
Tier 1 to risk weighted assets actual ratio	14.16%	12.81%
Tier 1 to risk weighted assets for capital adequacy purposes amount	$ 47,901	$ 47,966
Tier 1to risk weighted assets for capital adequacy purposes ratio	6.00%	6.00%
Tier 1 to risk weighted assets well capitalized under prompt corrective action amount	$ 63,868	$ 63,955
Tier 1 to risk weighted assets well capitalized under prompt corrective action ratio	8.00%	8.00%
Common equity Tier 1 capital to risk weighted assets actual amount	$ 113,066	$ 102,411
Common equity Tier 1 capital to risk weighted assets actual ratio	14.16%	12.81%
Common equity Tier 1 to risk weighted assets for capital adequacy purposes amount	$ 35,926	$ 35,975
Common equity Tier 1 to risk weighted assets for capital adequacy purposes ratio	4.50%	4.50%
Common equity Tier 1 capital well capitalized under prompt corrective action amount	$ 51,893	$ 51,963
Common equity Tier 1 capital well capitalized under prompt corrective action ratio	6.50%	6.50%
Tier 1 leverage to adjusted tangible assets actual amount	$ 113,066	$ 102,411
Tier 1 leverage to adjusted tangible assets actual ratio	10.26%	10.21%
Tier 1 leverage capital assets for capital adequacy purposes amount	$ 44,093	$ 40,110
Tier 1 leverage capital assets for capital adequacy purposes ratio	4.00%	4.00%
Tier 1 leverage capital assets well capitalized under prompt corrective action amount	$ 55,116	$ 50,138
Tier1 leverage capital assets well capitalized under prompt corrective action ratio	5.00%	5.00%