Loans Receivable And Allowance For Loan Losses: Financing Receivable Credit Quality Indicators (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Sep. 30, 2018
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	$ 886,451	$ 737,558
Mortgage loans, one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	129,050	115,941
Mortgage loans, multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	70,374	61,928
Mortgage loans, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	418,778	345,113
Mortgage loans, construction - custom and owner/builder
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	70,237	67,024
Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	10,545	7,107
Mortgage loans, construction – commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	27,567	23,440
Mortgage loans, construction - Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	18,418	5,983
Mortgage loans, construction - Land development
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	2,990	1,567
Mortgage loans, land
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	26,653	25,546
Consumer loans, home equity and second mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	42,204	37,341
Consumer loans, other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	4,450	3,515
Commercial business loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	65,185	43,053
Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	868,760	720,600
Pass | Mortgage loans, one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	126,094	113,148
Pass | Mortgage loans, multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	70,374	61,928
Pass | Mortgage loans, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	408,798	334,908
Pass | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	70,004	66,720
Pass | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	10,545	7,107
Pass | Mortgage loans, construction – commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	27,567	23,440
Pass | Mortgage loans, construction - Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	18,418	5,983
Pass | Mortgage loans, construction - Land development
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	2,766	1,567
Pass | Mortgage loans, land
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	24,049	22,810
Pass | Consumer loans, home equity and second mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	41,369	36,697
Pass | Consumer loans, other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	4,402	3,480
Pass | Commercial business loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	64,374	42,812
Watch
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	9,817	10,653
Watch | Mortgage loans, one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	302	882
Watch | Mortgage loans, multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Watch | Mortgage loans, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	8,237	8,375
Watch | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	233	304
Watch | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Watch | Mortgage loans, construction – commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Watch | Mortgage loans, construction - Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Watch | Mortgage loans, construction - Land development
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Watch | Mortgage loans, land
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	956	988
Watch | Consumer loans, home equity and second mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	42	82
Watch | Consumer loans, other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	34	0
Watch | Commercial business loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	13	22
Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	2,477	3,123
Special Mention | Mortgage loans, one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	566	581
Special Mention | Mortgage loans, multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Mortgage loans, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	636	988
Special Mention | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Mortgage loans, construction – commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Mortgage loans, construction - Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Mortgage loans, construction - Land development
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Mortgage loans, land
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	1,226	1,505
Special Mention | Consumer loans, home equity and second mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Consumer loans, other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Special Mention | Commercial business loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	49	49
Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	5,397	3,182
Substandard | Mortgage loans, one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	2,088	1,330
Substandard | Mortgage loans, multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Substandard | Mortgage loans, commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	1,107	842
Substandard | Mortgage loans, construction - custom and owner/builder
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Substandard | Mortgage loans, construction - speculative one-to-four family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Substandard | Mortgage loans, construction – commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Substandard | Mortgage loans, construction - Multi-family
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	0	0
Substandard | Mortgage loans, construction - Land development
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	224	0
Substandard | Mortgage loans, land
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	422	243
Substandard | Consumer loans, home equity and second mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	793	562
Substandard | Consumer loans, other
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	14	35
Substandard | Commercial business loans
Financing Receivable, Credit Quality Indicator [Line Items]
Loans receivable	$ 749	$ 170