Loans Receivable And Allowance For Loan Losses: Schedule of Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	$ 9,590	$ 10,043	$ 9,826	$ 9,924
Provision for (Recapture of) Loan Losses	(1,000)	0	(1,250)	0
Charge- offs	(51)	(212)	(70)	(347)
Recoveries	1,071	11	1,104	265
Allowance for loan losses, Ending Allowance	9,610	9,842	9,610	9,842
Mortgage loans, one-to-four family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	1,126	1,323	1,239	1,480
Provision for (Recapture of) Loan Losses	(11)	(83)	(145)	(267)
Charge- offs	0	(27)	0	(55)
Recoveries	0	1	21	56
Allowance for loan losses, Ending Allowance	1,115	1,214	1,115	1,214
Mortgage loans, multi-family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	480	315	473	392
Provision for (Recapture of) Loan Losses	(16)	33	(9)	(44)
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	464	348	464	348
Mortgage loans, commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	4,316	4,083	4,384	4,065
Provision for (Recapture of) Loan Losses	(1,040)	19	(1,095)	118
Charge- offs	0	(128)	(13)	(209)
Recoveries	1,061	0	1,061	0
Allowance for loan losses, Ending Allowance	4,337	3,974	4,337	3,974
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	695	542	619	451
Provision for (Recapture of) Loan Losses	17	93	93	184
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	712	635	712	635
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	85	96	130	123
Provision for (Recapture of) Loan Losses	(15)	25	(60)	(4)
Charge- offs	0	0	0	0
Recoveries	5	0	5	2
Allowance for loan losses, Ending Allowance	75	121	75	121
Mortgage loans, construction – commercial
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	268	617	268	426
Provision for (Recapture of) Loan Losses	15	7	15	198
Charge- offs	0	0	0	0
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	283	624	283	624
Mortgage loans, construction - Multi-family
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	96	409	316	283
Provision for (Recapture of) Loan Losses	36	(22)	(184)	(77)
Charge- offs	0	0	0	0
Recoveries	0	0	0	181
Allowance for loan losses, Ending Allowance	132	387	132	387
Mortgage loans, land
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	947	954	820	1,021
Provision for (Recapture of) Loan Losses	1	9	120	(63)
Charge- offs	(49)	(50)	(51)	(58)
Recoveries	5	6	15	19
Allowance for loan losses, Ending Allowance	904	919	904	919
Consumer loans, home equity and second mortgage
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	957	1,021	939	1,073
Provision for (Recapture of) Loan Losses	(2)	(55)	16	(94)
Charge- offs	0	(5)	0	(18)
Recoveries	0	0	0	0
Allowance for loan losses, Ending Allowance	955	961	955	961
Consumer loans, other
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	130	162	156	187
Provision for (Recapture of) Loan Losses	6	(4)	(18)	(25)
Charge- offs	(2)	(2)	(6)	(7)
Recoveries	0	1	2	2
Allowance for loan losses, Ending Allowance	134	157	134	157
Commercial business loans
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Allowance for loan losses, Beginning Allowance	490	521	482	423
Provision for (Recapture of) Loan Losses	9	(22)	17	74
Charge- offs	0	0	0	0
Recoveries	0	3	0	5
Allowance for loan losses, Ending Allowance	$ 499	$ 502	$ 499	$ 502

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

Name:	us-gaap_FinancingReceivableAllowanceForCreditLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

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

+ References

No definition available.

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

Name:	us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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

+ Details

Name:	us-gaap_ProvisionForLoanLeaseAndOtherLosses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_MortgageLoansOneToFourFamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_MortgageLoansMultiFamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_ConstructionCustomAndOwnerbuilderMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_ConstructionSpeculativeOneToFourFamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_ConstructionCommercialMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_ConstructionMultiFamilyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_MortgageLoansLandMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tsbk_ConsumerLoansHomeEquityAndSecondMortgageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConsumerPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: