v3.25.4

Loans And Allowance For Credit Losses (Schedule Of Activity In The Allowance For Loan Losses) (Details) - USD ($) $ in Thousands | 3 Months Ended
--- | ---
Dec. 31, 2025 | Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Roll Forward] |  |
Unfunded Loan Commitments, Beginning Balance | $ 30,116 | $ 27,811
Total Allowance for Credit Loss, Beginning Balance | 104,360 | 97,813
Commitment Provisions(Releases) | (1,042) | (609)
Total Allowance for Credit Loss, Provision(Reversal) | (1,000) | (1,500)
Commitment Charge-offs | 0 | 0
Total Allowance for Credit Loss, Charge-offs | (448) | (317)
Commitment Recoveries | 0 | 0
Total Allowance for Credit Loss, Recoveries | 1,146 | 1,765
Unfunded Loan Commitments, Ending Balance | 29,074 | 27,202
Total Allowance for Credit Loss, Ending Balance | 104,058 | 97,761
Real Estate Loans |  |
Financing Receivable, Allowance for Credit Loss [Roll Forward] |  |
Allowance for Credit Loss on Loans, Beginning Balance | 74,244 | 70,002
Loan Provision(Releases) | 42 | (891)
Loan Charge-offs | (448) | (317)
Loan Recoveries | 1,146 | 1,765
Allowance for Credit Loss on Loans, Ending Balance | 74,984 | 70,559
Real Estate Loans | Residential Core |  |
Financing Receivable, Allowance for Credit Loss [Roll Forward] |  |
Allowance for Credit Loss on Loans, Beginning Balance | 39,939 | 44,402
Loan Provision(Releases) | (1,728) | (2,444)
Loan Charge-offs | (15) | (1)
Loan Recoveries | 169 | 519
Allowance for Credit Loss on Loans, Ending Balance | 38,365 | 42,476
Real Estate Loans | Residential Home Today |  |
Financing Receivable, Allowance for Credit Loss [Roll Forward] |  |
Allowance for Credit Loss on Loans, Beginning Balance | (2,438) | (2,672)
Loan Provision(Releases) | (150) | (336)
Loan Charge-offs | (36) | 0
Loan Recoveries | 485 | 479
Allowance for Credit Loss on Loans, Ending Balance | (2,139) | (2,529)
Real Estate Loans | Home Equity Line of Credit |  |
Financing Receivable, Allowance for Credit Loss [Roll Forward] |  |
Allowance for Credit Loss on Loans, Beginning Balance | 22,069 | 16,590
Loan Provision(Releases) | 756 | 1,162
Loan Charge-offs | (260) | (316)
Loan Recoveries | 480 | 758
Allowance for Credit Loss on Loans, Ending Balance | 23,045 | 18,194
Real Estate Loans | Home Equity Loan |  |
Financing Receivable, Allowance for Credit Loss [Roll Forward] |  |
Allowance for Credit Loss on Loans, Beginning Balance | 14,645 | 11,642
Loan Provision(Releases) | 1,181 | 724
Loan Charge-offs | (137) | 0
Loan Recoveries | 12 | 9
Allowance for Credit Loss on Loans, Ending Balance | 15,701 | 12,375
Real Estate Loans | Construction |  |
Financing Receivable, Allowance for Credit Loss [Roll Forward] |  |
Allowance for Credit Loss on Loans, Beginning Balance | 29 | 40
Loan Provision(Releases) | (17) | 3
Loan Charge-offs | 0 | 0
Loan Recoveries | 0 | 0
Allowance for Credit Loss on Loans, Ending Balance | $ 12 | $ 43

X
- Definition Amount of credit loss expense (reversal of expense for financing receivable allowance for credit loss and off balance sheet. Excludes net investment in lease. + References No definition available. + Details
Name: | tfsl_FinancingReceivableAllowanceForCreditLossAndOffBalanceSheetCreditLossIncomeExpenseCreditLossExcludingAccruedInterest
Namespace Prefix: | tfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount excluding accrued interest, of allowance for credit loss and Allowance for Off Balance Sheet Commitments. Excludes net investment in lease. + References No definition available. + Details
Name: | tfsl_FinancingReceivableAllowanceForCreditLossAndOffBalanceSheetCreditLossLiability
Namespace Prefix: | tfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of increase in allowance for credit loss. Excludes net investment in lease. + References No definition available. + Details
Name: | tfsl_FinancingReceivableAllowanceForCreditLossAndOffBalanceSheetCreditLossRecovery
Namespace Prefix: | tfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of decrease in allowance for credit loss from writeoff. Excludes net investment in lease. + References No definition available. + Details
Name: | tfsl_FinancingReceivableAllowanceForCreditLossAndOffBalanceSheetCreditLossWriteoff
Namespace Prefix: | tfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure from recoveries. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References No definition available. + Details
Name: | tfsl_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversalRecovery
Namespace Prefix: | tfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure from writeoffs. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References No definition available. + Details
Name: | tfsl_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversalWriteoff
Namespace Prefix: | tfsl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount excluding accrued interest, of allowance for credit loss on financing receivable. Excludes net investment in lease. + 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_FinancingReceivableAllowanceForCreditLossExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- 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

X
- Definition Amount, excluding accrued interest, of increase in allowance for credit loss on financing receivable from recovery. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (e) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossRecovery
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of decrease in allowance for credit loss on financing receivable from writeoff. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 6 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-6 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestAllowanceForCreditLossWriteoff
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, excluding accrued interest, of credit loss expense (reversal of expense) on financing receivable. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476148/220-40-50-22 + Details
Name: | us-gaap_FinancingReceivableExcludingAccruedInterestCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of expected credit loss for credit exposure on off-balance-sheet commitment, including but not limited to, loan commitment, standby letter of credit, financial guarantee not accounted for as insurance. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479344/326-20-45-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 460 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482454/460-10-45-1 + Details
Name: | us-gaap_OffBalanceSheetCreditLossLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of expense (reversal of expense) for expected credit loss for off-balance sheet credit exposure. Excludes off-balance sheet credit exposure accounted for as insurance and instrument accounted for under derivatives and hedging. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 326 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147479319/326-20-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 220 -SubTopic 40 -Name Accounting Standards Codification -Section 50 -Paragraph 22 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147476148/220-40-50-22 + Details
Name: | us-gaap_OffBalanceSheetCreditLossLiabilityCreditLossExpenseReversal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_CollateralAxis=us-gaap_ResidentialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tfsl_ResidentialNonHomeTodayMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=tfsl_ResidentialHomeTodayMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_HomeEquityLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |