Loans Receivable: Financing Receivables, Aging of loans (Details) - USD ($)	Dec. 31, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Total Loans	$ 1,182,159,000	$ 1,119,536,000
Financing Receivable, 90 Days or More Past Due, Still Accruing	0	0
One-to-four family, residential, owner occupied
Financing Receivable, Past Due [Line Items]
Total Loans	233,785,000	185,320,000
One-to-four family residential non-owner occupied
Financing Receivable, Past Due [Line Items]
Total Loans	242,051,000	199,796,000
Multifamily
Financing Receivable, Past Due [Line Items]
Total Loans	126,895,000	130,146,000
Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Total Loans	407,882,000	419,417,000
Construction Land Development
Financing Receivable, Past Due [Line Items]
Total Loans	78,120,000	93,455,000
Real Estate, Total
Financing Receivable, Past Due [Line Items]
Total Loans	1,088,733,000	1,028,134,000
Business
Financing Receivable, Past Due [Line Items]
Total Loans	31,371,000	46,590,000
Consumer
Financing Receivable, Past Due [Line Items]
Total Loans	62,055,000	44,812,000
30-59 Days
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	27,000	255,000
30-59 Days | One-to-four family, residential, owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
30-59 Days | One-to-four family residential non-owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	27,000	0
30-59 Days | Multifamily
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
30-59 Days | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
30-59 Days | Construction Land Development
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
30-59 Days | Real Estate, Total
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	27,000	0
30-59 Days | Business
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	76,000
30-59 Days | Consumer
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	179,000
60-89 Days
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | One-to-four family, residential, owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | One-to-four family residential non-owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | Multifamily
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | Construction Land Development
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | Real Estate, Total
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | Business
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
60-89 Days | Consumer
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	193,000	0
90 Days and Greater | One-to-four family, residential, owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater | One-to-four family residential non-owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater | Multifamily
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater | Construction Land Development
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater | Real Estate, Total
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater | Business
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
90 Days and Greater | Consumer
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	193,000	0
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	220,000	255,000
Financial Asset, Past Due | One-to-four family, residential, owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
Financial Asset, Past Due | One-to-four family residential non-owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	27,000	0
Financial Asset, Past Due | Multifamily
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
Financial Asset, Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
Financial Asset, Past Due | Construction Land Development
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	0
Financial Asset, Past Due | Real Estate, Total
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	27,000	0
Financial Asset, Past Due | Business
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	0	76,000
Financial Asset, Past Due | Consumer
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	193,000	179,000
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	1,181,939,000	1,119,281,000
Financial Asset, Not Past Due | One-to-four family, residential, owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	233,785,000	185,320,000
Financial Asset, Not Past Due | One-to-four family residential non-owner occupied
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	242,024,000	199,796,000
Financial Asset, Not Past Due | Multifamily
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	126,895,000	130,146,000
Financial Asset, Not Past Due | Commercial Real Estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	407,882,000	419,417,000
Financial Asset, Not Past Due | Construction Land Development
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	78,120,000	93,455,000
Financial Asset, Not Past Due | Real Estate, Total
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	1,088,706,000	1,028,134,000
Financial Asset, Not Past Due | Business
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	31,371,000	46,514,000
Financial Asset, Not Past Due | Consumer
Financing Receivable, Past Due [Line Items]
Financing Receivable, Excluding Accrued Interest, after Allowance for Credit Loss	$ 61,862,000	$ 44,633,000