Loans Receivable and Allowance for Credit Losses - Aging of Loans and Accrual Status by Class (Details) - USD ($)	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Recorded Investment, Past Due
Total Loans	$ 1,286,662,000	$ 1,308,552,000
Nonaccrual Loans	1,933,000	2,260,000
One- to four-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,246,381,000	1,275,615,000
Nonaccrual Loans	1,771,000	2,079,000
Multi-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	5,142,000	5,848,000
Construction, commercial, and other mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	11,578,000	11,570,000
Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans	14,854,000	7,060,000
Nonaccrual Loans	2,000	11,000
Loans on deposit accounts
Financing Receivable, Recorded Investment, Past Due
Total Loans	411,000	196,000
Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	8,296,000	8,263,000
Nonaccrual Loans	160,000	170,000
Loans Not Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,284,108,000	1,307,893,000
Loans Not Past Due \| One- to four-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,243,831,000	1,274,960,000
Loans Not Past Due \| Multi-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	5,142,000	5,848,000
Loans Not Past Due \| Construction, commercial, and other mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	11,578,000	11,570,000
Loans Not Past Due \| Home equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due
Total Loans	14,854,000	7,060,000
Loans Not Past Due \| Loans on deposit accounts
Financing Receivable, Recorded Investment, Past Due
Total Loans	411,000	196,000
Loans Not Past Due \| Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	8,292,000	8,259,000
Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	2,554,000	659,000
Past Due \| One- to four-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	2,550,000	655,000
Past Due \| Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	4,000	4,000
30 - 59 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,334,000	432,000
30 - 59 Days Past Due \| One- to four-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,331,000	428,000
30 - 59 Days Past Due \| Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	3,000	4,000
60 - 89 Days Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,000
60 - 89 Days Past Due \| Consumer and other
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,000
90 Days or More Past Due
Financing Receivable, Recorded Investment, Past Due
Total Loans	1,219,000	227,000
90 Days or More Past Due \| One- to four-family residential mortgages
Financing Receivable, Recorded Investment, Past Due
Total Loans	$ 1,219,000	$ 227,000

Territorial Bancorp Inc. 10-K