INVESTMENTS - Narrative (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) security	Dec. 31, 2021 USD ($) security
Debt and Equity Securities, FV-NI [Line Items]
Held-to maturity securities with unrealized losses of less than one year | security	7
Held-to maturity securities with unrealized losses of more than one year | security	0
Held-to maturity securities with unrealized losses | security		0
Available-for-sale securities with unrealized losses of less than one year | security	88	75
Available-for-sale securities with unrealized losses of more than one year | security	106	17
Number of securities pledged and held at FHLB	10	7
Carrying value of pledged securities	$ 13,500,000	$ 8,100,000
Public deposits	15,600,000	13,900,000
Amount of credit impairment	0	0
Accrued interest receivable on held to maturity debt securities	116,000	113,000
Accrued interest receivable on available-for-sale debt securities	$ 1,200,000	$ 1,100,000
Debt Securities, Available-for-Sale, Accrued Interest, after Allowance for Credit Loss, Statement of Financial Position [Extensible Enumeration]	Interest Receivable	Interest Receivable
Debt securities held to maturity classified as nonaccrual or 90 days or more past due and still accruing	$ 0
Asset pledged as collateral | Washington Public Deposit Protection Commission
Debt and Equity Securities, FV-NI [Line Items]
Collateral requirement	$ 6,300,000	$ 5,600,000
Cash Flow Hedges | Asset pledged as collateral
Debt and Equity Securities, FV-NI [Line Items]
Number of Securities Pledged	1
Carrying value of pledged securities	$ 2,800,000