XML 84 R70.htm IDEA: XBRL DOCUMENT
v3.25.3

Investment Securities: Credit Loan By Portfolio Segment (Details) - USD ($) | 12 Months Ended
--- | ---
Sep. 30, 2025 | Sep. 30, 2024
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] |  |
Beginning Allowance | $ 60,000 | $ 0
Provision for (Recapture of ) Credit Losses | (24,000) | (32,000)
Ending Allowance | 36,000 | 60,000
Impact of Adopting CECL (ASU 2016-13) |  |
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] |  |
Beginning Allowance |  | 92,000
Private label residential |  |
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] |  |
Beginning Allowance | 55,000 | 0
Provision for (Recapture of ) Credit Losses | (20,000) | (27,000)
Ending Allowance | 35,000 | 55,000
Private label residential | Impact of Adopting CECL (ASU 2016-13) |  |
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] |  |
Beginning Allowance |  | 82,000
Bank issued trust preferred securities |  |
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] |  |
Beginning Allowance | 5,000 | 0
Provision for (Recapture of ) Credit Losses | (4,000) | (5,000)
Ending Allowance | $ 1,000 | 5,000
Bank issued trust preferred securities | Impact of Adopting CECL (ASU 2016-13) |  |
Debt Securities, Held-to-Maturity, Allowance for Credit Loss [Line Items] |  |
Beginning Allowance |  | $ 10,000

X
- Definition Debt Securities, Held-to-Maturity, Excluding Accrued Interest, Provision for (Recapture of) Credit Losses + References No definition available. + Details
Name: | tsbk_DebtSecuritiesHeldToMaturityExcludingAccruedInterestProvisionForRecaptureOfCreditLosses
Namespace Prefix: | tsbk_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of allowance for credit loss on investment in debt security measured at amortized cost (held-to-maturity). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-1 + Details
Name: | us-gaap_DebtSecuritiesHeldToMaturityAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_DebtSecuritiesHeldtomaturityAllowanceForCreditLossLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_CumulativeEffectPeriodOfAdoptionAxis=srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_TrustPreferredSecuritiesSubjectToMandatoryRedemptionMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |