LOANS RECEIVABLE AND ALLOWANCE FOR CREDIT LOSSES - Impaired Financing Receivables (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves	$ 8,000
Unpaid Principal Balance with specific reserves	29,000
Interest Income Recognized with specific reserves	1,000
Specific Reserves	21,000	$ 200,000
Average Recorded Investment	48,000
Recorded Investments with no specific reserve	387,000	269,000
Unpaid Principal Balance with no specific reserves	387,000	269,000
Interest Income Recognized with no specific reserve	4,000	11,000
Average Recorded Investment, no specific reserve	367,000	234,000
Real Estate Loan
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves	8,000	9,000
Unpaid Principal Balance with specific reserves	29,000	30,000
Interest Income Recognized with specific reserves	1,000	4,000
Specific Reserves	21,000	21,000
Average Recorded Investment	48,000	48,000
Recorded Investments with no specific reserve	110,000	115,000
Unpaid Principal Balance with no specific reserves	110,000	115,000
Interest Income Recognized with no specific reserve	1,000	5,000
Average Recorded Investment, no specific reserve	123,000	130,000
Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves		120,000
Unpaid Principal Balance with specific reserves		299,000
Specific Reserves		179,000
Average Recorded Investment		499,000
Recorded Investments with no specific reserve	141,000
Unpaid Principal Balance with no specific reserves	141,000
Interest Income Recognized with no specific reserve	1,000
Average Recorded Investment, no specific reserve	141,000
Consumer Loans
Financing Receivable, Impaired [Line Items]
Recorded Investments with no specific reserve	136,000	154,000
Unpaid Principal Balance with no specific reserves	136,000	154,000
Interest Income Recognized with no specific reserve	2,000	6,000
Average Recorded Investment, no specific reserve	103,000	104,000
Single-family Residential | Real Estate Loan
Financing Receivable, Impaired [Line Items]
Recorded Investment with specific reserves	8,000	9,000
Unpaid Principal Balance with specific reserves	29,000	30,000
Interest Income Recognized with specific reserves	1,000	4,000
Specific Reserves	21,000	21,000
Average Recorded Investment	48,000	48,000
Recorded Investments with no specific reserve	110,000	115,000
Unpaid Principal Balance with no specific reserves	110,000	115,000
Interest Income Recognized with no specific reserve	1,000	5,000
Average Recorded Investment, no specific reserve	123,000	130,000
Commercial and Industrial | Commercial and Industrial
Financing Receivable, Impaired [Line Items]
Specific Reserves		179,000
Recorded Investments with no specific reserve	141,000
Unpaid Principal Balance with no specific reserves	141,000
Interest Income Recognized with no specific reserve	1,000
Average Recorded Investment, no specific reserve	141,000
Automobile | Consumer Loans
Financing Receivable, Impaired [Line Items]
Recorded Investments with no specific reserve	136,000	154,000
Unpaid Principal Balance with no specific reserves	136,000	154,000
Interest Income Recognized with no specific reserve	2,000	6,000
Average Recorded Investment, no specific reserve	$ 103,000	$ 104,000