Loans Receivable And Allowance For Loan Losses: Past Due Status of Loans (Details) - USD ($) $ in Thousands		Jun. 30, 2023		Sep. 30, 2022
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		$ 1,280,911		$ 1,150,450
Loans receivable, Non-Accrual	[1]	1,586		2,059
Mortgage loans, one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		229,274		176,116
Loans receivable, Non-Accrual	[1]	373		388
Mortgage loans, multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		111,777		95,025
Loans receivable, Non-Accrual	[1]	0		0
Mortgage loans, commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		557,015		536,650
Loans receivable, Non-Accrual	[1]	686		657
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		78,739		67,091
Loans receivable, Non-Accrual	[1]	0		0
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		7,037		8,364
Loans receivable, Non-Accrual	[1]	0		0
Mortgage loans, construction – commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		24,300		29,059
Loans receivable, Non-Accrual	[1]	0		0
Mortgage loans, construction - Multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		52,941		34,354
Loans receivable, Non-Accrual	[1]	0		0
Mortgage loans, construction - Land development
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		13,810		13,582
Loans receivable, Non-Accrual	[1]	0		0
Mortgage loans, land
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		25,908		26,854
Loans receivable, Non-Accrual	[1]	54		450
Consumer loans, home equity and second mortgage
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		40,008		35,187
Loans receivable, Non-Accrual	[1]	184		252
Consumer loans, other
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		2,469		2,128
Loans receivable, Non-Accrual	[1]	0		3
Commercial business loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		137,114		125,039
Loans receivable, Non-Accrual		289	[1]	309
SBA PPP Loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		519		1,001
Loans receivable, Non-Accrual		0		0	[1]
30 to 59 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		71		37
30 to 59 Days Past Due | Mortgage loans, one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, construction – commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, construction - Multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, construction - Land development
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Mortgage loans, land
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Consumer loans, home equity and second mortgage
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		49		37
30 to 59 Days Past Due | Consumer loans, other
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
30 to 59 Days Past Due | Commercial business loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		22		0
30 to 59 Days Past Due | SBA PPP Loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		186		0
60 to 89 Days Past Due | Mortgage loans, one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, construction – commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, construction - Multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, construction - Land development
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Mortgage loans, land
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Consumer loans, home equity and second mortgage
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Consumer loans, other
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
60 to 89 Days Past Due | Commercial business loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		186		0
60 to 89 Days Past Due | SBA PPP Loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Past Due 90 Days or More and Still Accruing
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, one-to-four family
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, multi-family
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, commercial
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, construction – commercial
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, construction - Multi-family
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, construction - Land development
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Mortgage loans, land
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Consumer loans, home equity and second mortgage
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Consumer loans, other
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | Commercial business loans
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Past Due 90 Days or More and Still Accruing | SBA PPP Loans
Financing Receivable, Past Due [Line Items]
Past Due 90 Days or More and Still Accruing		0		0
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		1,843		2,096
Financial Asset, Past Due | Mortgage loans, one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		373		388
Financial Asset, Past Due | Mortgage loans, multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Financial Asset, Past Due | Mortgage loans, commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		686		657
Financial Asset, Past Due | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Financial Asset, Past Due | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Financial Asset, Past Due | Mortgage loans, construction – commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Financial Asset, Past Due | Mortgage loans, construction - Multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Financial Asset, Past Due | Mortgage loans, construction - Land development
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Financial Asset, Past Due | Mortgage loans, land
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		54		450
Financial Asset, Past Due | Consumer loans, home equity and second mortgage
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		233		289
Financial Asset, Past Due | Consumer loans, other
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		3
Financial Asset, Past Due | Commercial business loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		497		309
Financial Asset, Past Due | SBA PPP Loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		0		0
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		1,279,068		1,148,354
Financial Asset, Not Past Due | Mortgage loans, one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		228,901		175,728
Financial Asset, Not Past Due | Mortgage loans, multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		111,777		95,025
Financial Asset, Not Past Due | Mortgage loans, commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		556,329		535,993
Financial Asset, Not Past Due | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		78,739		67,091
Financial Asset, Not Past Due | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		7,037		8,364
Financial Asset, Not Past Due | Mortgage loans, construction – commercial
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		24,300		29,059
Financial Asset, Not Past Due | Mortgage loans, construction - Multi-family
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		52,941		34,354
Financial Asset, Not Past Due | Mortgage loans, construction - Land development
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		13,810		13,582
Financial Asset, Not Past Due | Mortgage loans, land
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		25,854		26,404
Financial Asset, Not Past Due | Consumer loans, home equity and second mortgage
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		39,775		34,898
Financial Asset, Not Past Due | Consumer loans, other
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		2,469		2,125
Financial Asset, Not Past Due | Commercial business loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		136,617		124,730
Financial Asset, Not Past Due | SBA PPP Loans
Financing Receivable, Past Due [Line Items]
Loans receivable, Total Past Due		$ 519		$ 1,001

[1] Includes non-accrual loans past due 90 days or more and other loans classified as non-accrual.