Loans Receivable And Allowance For Loan Losses: Schedule of loans evaluated individually for impairment and collectively evaluated for impairment in the allowance for loan losses (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	$ 123		$ 127
Allowance for Loan Losses, Collectively Evaluated for Impairment	14,575		13,576
Allowance for Loan Losses, Total	14,698	$ 14,229	13,703	$ 13,433	$ 13,468	$ 13,469
Recorded Investment in Loans, Individually Evaluated for Impairment	4,518		4,532
Recorded Investment in Loans, Collectively Evaluated for Impairment	1,225,132		1,145,918
Loans receivable	1,229,650		1,150,450
Mortgage loans, one-to-four family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	2,052		1,658
Allowance for Loan Losses, Total	2,052	1,888	1,658	1,247	1,237	1,154
Recorded Investment in Loans, Individually Evaluated for Impairment	378		388
Recorded Investment in Loans, Collectively Evaluated for Impairment	216,261		175,728
Loans receivable	216,639		176,116
Mortgage loans, multi-family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	938		855
Allowance for Loan Losses, Total	938	871	855	735	748	765
Recorded Investment in Loans, Individually Evaluated for Impairment	0		0
Recorded Investment in Loans, Collectively Evaluated for Impairment	103,870		95,025
Loans receivable	103,870		95,025
Mortgage loans, commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	6,904		6,682
Allowance for Loan Losses, Total	6,904	6,794	6,682	6,931	6,807	6,813
Recorded Investment in Loans, Individually Evaluated for Impairment	3,006		2,988
Recorded Investment in Loans, Collectively Evaluated for Impairment	544,870		533,662
Loans receivable	547,876		536,650
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	726		675
Allowance for Loan Losses, Total	726	673	675	686	671	644
Recorded Investment in Loans, Individually Evaluated for Impairment	0		0
Recorded Investment in Loans, Collectively Evaluated for Impairment	71,750		67,091
Loans receivable	71,750		67,091
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	121		130
Allowance for Loan Losses, Total	121	125	130	126	153	188
Recorded Investment in Loans, Individually Evaluated for Impairment	0		0
Recorded Investment in Loans, Collectively Evaluated for Impairment	7,785		8,364
Loans receivable	7,785		8,364
Mortgage loans, construction – commercial
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	267		343
Allowance for Loan Losses, Total	267	323	343	463	593	784
Recorded Investment in Loans, Individually Evaluated for Impairment	0		0
Recorded Investment in Loans, Collectively Evaluated for Impairment	23,145		29,059
Loans receivable	23,145		29,059
Mortgage loans, construction - Multi-family
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	662		447
Allowance for Loan Losses, Total	662	577	447	436	460	436
Recorded Investment in Loans, Individually Evaluated for Impairment	0		0
Recorded Investment in Loans, Collectively Evaluated for Impairment	50,758		34,354
Loans receivable	50,758		34,354
Mortgage loans, construction - Land development
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	245		233
Allowance for Loan Losses, Total	245	222	233	126	157	124
Recorded Investment in Loans, Individually Evaluated for Impairment	0		0
Recorded Investment in Loans, Collectively Evaluated for Impairment	14,250		13,582
Loans receivable	14,250		13,582
Mortgage loans, land
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	363		397
Allowance for Loan Losses, Total	363	383	397	377	435	470
Recorded Investment in Loans, Individually Evaluated for Impairment	459		450
Recorded Investment in Loans, Collectively Evaluated for Impairment	24,061		26,404
Loans receivable	24,520		26,854
Consumer loans, home equity and second mortgage
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	507		440
Allowance for Loan Losses, Total	507	493	440	469	532	528
Recorded Investment in Loans, Individually Evaluated for Impairment	381		394
Recorded Investment in Loans, Collectively Evaluated for Impairment	36,515		34,793
Loans receivable	36,896		35,187
Consumer loans, other
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	47		42
Allowance for Loan Losses, Total	47	47	42	44	48	50
Recorded Investment in Loans, Individually Evaluated for Impairment	1		3
Recorded Investment in Loans, Collectively Evaluated for Impairment	2,282		2,125
Loans receivable	2,283		2,128
Commercial business loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	123		127
Allowance for Loan Losses, Collectively Evaluated for Impairment	1,743		1,674
Allowance for Loan Losses, Total	1,866	$ 1,833	1,801	$ 1,793	$ 1,627	$ 1,513
Recorded Investment in Loans, Individually Evaluated for Impairment	293		309
Recorded Investment in Loans, Collectively Evaluated for Impairment	129,013		124,730
Loans receivable	129,306		125,039
SBA PPP Loans
Financing Receivable, Allowance for Credit Loss [Line Items]
Allowance for Loan Losses, Individually Evaluated for Impairment	0		0
Allowance for Loan Losses, Collectively Evaluated for Impairment	0		0
Allowance for Loan Losses, Total	0		0
Recorded Investment in Loans, Individually Evaluated for Impairment	0		0
Recorded Investment in Loans, Collectively Evaluated for Impairment	572		1,001
Loans receivable	$ 572		$ 1,001