Loans - Schedule of Credit Risk Profile Based on Payment Activity (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	$ 710,709	$ 687,868
Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	705,962	682,316
Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	4,747	5,552
Real estate loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	585,924	562,190
Real estate loans: | One-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	221,832	207,660
Real estate loans: | One-to-four family | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	220,156	205,453
Real estate loans: | One-to-four family | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	1,676	2,207
Real estate loans: | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	13,798	13,250
Real estate loans: | Home equity | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	13,643	13,110
Real estate loans: | Home equity | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	155	140
Real estate loans: | Commercial and multifamily
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	279,892	278,175
Real estate loans: | Commercial and multifamily | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	277,556	275,795
Real estate loans: | Commercial and multifamily | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	2,336	2,380
Real estate loans: | Construction and land
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	70,402	63,105
Real estate loans: | Construction and land | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	70,371	63,072
Real estate loans: | Construction and land | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	31	33
Consumer loans:
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	100,333	97,652
Consumer loans: | Manufactured homes
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	22,179	21,636
Consumer loans: | Manufactured homes | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	22,044	21,514
Consumer loans: | Manufactured homes | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	135	122
Consumer loans: | Floating homes
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	59,784	59,268
Consumer loans: | Floating homes | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	59,784	58,775
Consumer loans: | Floating homes | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	0	493
Consumer loans: | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	18,370	16,748
Consumer loans: | Other consumer | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	18,126	16,748
Consumer loans: | Other consumer | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	244	0
Commercial business
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	24,452	28,026
Commercial business | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	24,282	27,850
Commercial business | Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans held-for-portfolio	$ 170	$ 176