Allowance for Loan Losses: Schedule of reconciliation of the allowance for loan losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	$ 9,960	$ 10,337	$ 9,885	$ 10,762
Provision for Loan and Lease Losses		(300)		(800)
Allowance for Loan and Lease Losses, Write-offs	(71)	(59)	(115)	(73)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	174	135	293	224
Loans and Leases Receivable, Allowance, Ending Balance	10,063	10,113	10,063	10,113
Commercial business
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	902	1,469	1,048	1,263
Provision for Loan and Lease Losses	1	(115)	(149)	79
Allowance for Loan and Lease Loss, Recovery of Bad Debts	6	6	10	18
Loans and Leases Receivable, Allowance, Ending Balance	909	1,360	909	1,360
Commercial Real Estate
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	4,473	4,246	4,273	4,268
Provision for Loan and Lease Losses	216	47	414	25
Allowance for Loan and Lease Loss, Recovery of Bad Debts			2
Loans and Leases Receivable, Allowance, Ending Balance	4,689	4,293	4,689	4,293
Land
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	312	502	325	539
Provision for Loan and Lease Losses	(264)	(74)	(359)	(172)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	106	62	188	123
Loans and Leases Receivable, Allowance, Ending Balance	154	490	154	490
Multi-Family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	671	219	712	348
Provision for Loan and Lease Losses	(58)	275	(99)	146
Loans and Leases Receivable, Allowance, Ending Balance	613	494	613	494
Real estate construction
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	565	622	416	769
Provision for Loan and Lease Losses	162	(342)	311	(489)
Allowance for Loan and Lease Loss, Recovery of Bad Debts		6		6
Loans and Leases Receivable, Allowance, Ending Balance	727	286	727	286
Consumer Member
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	2,327	2,354	2,403	2,548
Provision for Loan and Lease Losses	(28)	(27)	(91)	(223)
Allowance for Loan and Lease Losses, Write-offs	(71)	(59)	(115)	(73)
Allowance for Loan and Lease Loss, Recovery of Bad Debts	62	61	93	77
Loans and Leases Receivable, Allowance, Ending Balance	2,290	2,329	2,290	2,329
Unallocated
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Loans and Leases Receivable, Allowance, Beginning Balance	710	925	708	1,027
Provision for Loan and Lease Losses	(29)	(64)	(27)	(166)
Loans and Leases Receivable, Allowance, Ending Balance	$ 681	$ 861	$ 681	$ 861

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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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
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Amount of expense related to estimated loss from loan and lease transactions.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
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