Advances from the Federal Reserve Bank (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
Jun. 30, 2024	Dec. 31, 2023
Federal Home Loan Bank Stock and Federal Reserve Bank Stock [Abstract]
Due within one year	$ 50,000	$ 50,000
Due within one year (Weighted Average Rate)	4.76%	4.89%

Discloses the single interest rate [if] applicable to the advances from the Federal Reserve Bank, as part of their Bank Term Funding Program, as of the Balance Sheet date.

No definition available.

Name:	tbnk_FederalReserveBankAdvancesBankTermFundingProgramInterestRate
Namespace Prefix:	tbnk_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant