LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - Troubled debt restructured loans (Details) $ in Thousands	Sep. 30, 2024 USD ($) borrower loan	Dec. 31, 2023 USD ($)
Impaired Financing Receivables
Restructured loans to borrowers with financial difficulty	$ 27	$ 30
Non-accrual and 90+ days past due and still accruing loans to average loans	0.14%	0.29%
Allowance for credit losses to nonaccrual & 90+ days past due and still accruing loans	937.50%	409.30%
Single-family Residential
Impaired Financing Receivables
Number of loans | borrower	1
Troubled debt restructured loans	$ 27,000
Real Estate Loan | Single-family Residential
Impaired Financing Receivables
Restructured loans to borrowers with financial difficulty	$ 27	$ 30
Number of loans | loan	1