Name:	tbnk_FairValueInputsDiscountRateBasisSpreadOnVariableRate
Namespace Prefix:	tbnk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The reference rate for the variable rate of the financial instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR, used to find the present value of an amount to be paid or received in the future as an input to measure fair value.

No definition available.

Name:	tbnk_FairValueInputsDiscountRateDescriptionOfVariableRateBasis
Namespace Prefix:	tbnk_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the number of transactions of the security in the market during the period.

No definition available.

Name:	tbnk_NumberOfTransactionsInMarketOfSecurityDuringPeriod
Namespace Prefix:	tbnk_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

The period of time during which a minimal number of transactions have occurred in the tranche of trust preferred securities owned by the entity, determining the securities market to be considered inactive, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

No definition available.

Name:	tbnk_PeriodOfMinimalActivityInSecuritiesTrancheConsideredInactive
Namespace Prefix:	tbnk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

Represents the number of securities issued.

No definition available.

Name:	tbnk_SharesSubjectToMandatoryRedemptionSettlementTermsSecuritiesIssued
Namespace Prefix:	tbnk_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

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.

No definition available.

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

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_TrustPreferredSecuritiesSubjectToMandatoryRedemptionMember
Namespace Prefix:
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Name:	us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_ValuationTechniqueAxis=tbnk_DiscountedCashFlowValuationTechniqueMember
Namespace Prefix:
Data Type:	na
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