ALLOWANCE FOR LOAN LOSSES: Reconciliation of the allowance for loan losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	$ 11,349	$ 10,597	$ 10,766	$ 10,528
Provision for (recapture of) loan losses	250	0	50	0
Charge-offs	(92)	(128)	(184)	(210)
Recoveries	6	148	881	299
Ending balance	11,513	10,617	11,513	10,617
Commercial and construction \| Commercial Business
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,799	1,391	1,668	1,418
Provision for (recapture of) loan losses	59	(53)	190	(83)
Charge-offs	0	0	0	0
Recoveries	0	2	0	5
Ending balance	1,858	1,340	1,858	1,340
Commercial and construction \| Commercial Real Estate
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	5,139	5,176	4,914	5,084
Provision for (recapture of) loan losses	222	(76)	(376)	16
Charge-offs	0	0	0	0
Recoveries	0	16	823	16
Ending balance	5,361	5,116	5,361	5,116
Commercial and construction \| Land
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	258	219	220	228
Provision for (recapture of) loan losses	(21)	(130)	17	(275)
Charge-offs	0	0	0	0
Recoveries	0	107	0	243
Ending balance	237	196	237	196
Commercial and construction \| Multi-Family
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	781	502	822	297
Provision for (recapture of) loan losses	(85)	2	(126)	207
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	696	504	696	504
Commercial and construction \| Real Estate Construction
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	855	668	618	714
Provision for (recapture of) loan losses	152	172	389	126
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	1,007	840	1,007	840
Consumer
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	1,788	1,932	1,809	2,099
Provision for (recapture of) loan losses	(61)	63	(42)	(34)
Charge-offs	(92)	(128)	(184)	(210)
Recoveries	6	23	58	35
Ending balance	1,641	1,890	1,641	1,890
Unallocated
Allowance for Loan and Lease Losses [Roll Forward]
Beginning balance	729	709	715	688
Provision for (recapture of) loan losses	(16)	22	(2)	43
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	$ 713	$ 731	$ 713	$ 731

Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts.

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Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount of expense related to estimated loss from loan and lease transactions.

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