FAIR VALUE MEASUREMENTS: Assets measured at fair value on a non-recurring basis (Details 2) - Nonrecurring basis - Total Estimated Fair Value - Impaired loans - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nonrecurring assets measured at fair value	$ 2,143	$ 2,281
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nonrecurring assets measured at fair value	0	0
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nonrecurring assets measured at fair value	0	0
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total nonrecurring assets measured at fair value	$ 2,143	$ 2,281