Loans Receivable - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, net of allowance of $16,028, and $15,227	$ 1,184,750	$ 1,167,083
Ratio of nonperforming loans to all loans	0.02%	0.02%
Total TDR loans	$ 2,100
PPP Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, net	707		$ 5,200
Property total
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired financing receivable, related allowance		$ 13
Property total | Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable, net of allowance of $16,028, and $15,227	230	220
FHLB of Des Moines | Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	648,000	605,000
Federal Reserve Bank | Asset Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 85,200	$ 87,700