Loans Receivable And Allowance For Loan Losses: Schedule of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	$ 9,533	$ 9,565	$ 9,530	$ 9,553
Provision for (Recapture of) Loan Losses	0	0	0	0
Charge- offs	(14)	(29)	(16)	(30)
Recoveries	222	8	227	21
Allowance for loan losses, Ending Allowance	9,741	9,544	9,741	9,544
Mortgage loans, one-to-four family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	1,159	1,125	1,086	1,082
Provision for (Recapture of) Loan Losses	(72)	(65)	1	(22)
Charge- offs	0	0	0	0
Recoveries	67	0	67	0
Allowance for loan losses, Ending Allowance	1,154	1,060	1,154	1,060
Mortgage loans, multi-family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	449	430	433	447
Provision for (Recapture of) Loan Losses	21	(44)	37	(61)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	470	386	470	386
Mortgage loans, commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	4,239	4,093	4,248	4,184
Provision for (Recapture of) Loan Losses	(267)	133	(276)	42
Charge- offs	0	(28)	0	(28)
Recoveries	150	0	150	0
Allowance for loan losses, Ending Allowance	4,122	4,198	4,122	4,198
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	643	788	671	699
Provision for (Recapture of) Loan Losses	23	(83)	(5)	6
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	666	705	666	705
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	206	75	178	128
Provision for (Recapture of) Loan Losses	43	21	71	(40)
Charge- offs	0	0	0	0
Recoveries	0	3	0	11
Allowance for loan losses, Ending Allowance	249	99	249	99
Mortgage loans, construction – commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	386	396	563	303
Provision for (Recapture of) Loan Losses	(2)	49	(179)	142
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	384	445	384	445
Mortgage loans, construction - Multi-family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	209	228	135	173
Provision for (Recapture of) Loan Losses	63	56	137	111
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	272	284	272	284
Mortgage loans, construction - Land development
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	143	0	49
Provision for (Recapture of) Loan Losses	101	48	195	48
Charge- offs	0		0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	244	48	244	48
Mortgage loans, land
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	757	780	844	918
Provision for (Recapture of) Loan Losses	(112)	(94)	(203)	(236)
Charge- offs	0	0	0	0
Recoveries	4	5	8	9
Allowance for loan losses, Ending Allowance	649	691	649	691
Consumer loans, home equity and second mortgage
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	666	958	649	983
Provision for (Recapture of) Loan Losses	5	(13)	22	(38)
Charge- offs	(4)	0	(4)	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	667	945	667	945
Consumer loans, other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	101	129	117	121
Provision for (Recapture of) Loan Losses	11	(8)	(4)	0
Charge- offs	(1)	(1)	(3)	(2)
Recoveries	1	0	2	1
Allowance for loan losses, Ending Allowance	112	120	112	120
Commercial business loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	575	563	557	515
Provision for (Recapture of) Loan Losses	186	0	204	48
Charge- offs	(9)	0	(9)	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	$ 752	$ 563	$ 752	$ 563

A valuation allowance for financing receivables that are expected to be uncollectible.

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Amount of recovery of financing receivables doubtful of collection that were previously charged off.

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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 direct write-downs of financing receivables charged against the allowance.

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Amount of expense related loan transactions, lease transactions, credit loss from transactions other than loan and lease transactions, and other loss based on assessment of uncollectability from the counterparty to reduce the account to their net realizable value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11B
-Subparagraph (c)(2)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953423-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.11)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585

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