Loans Receivable And Allowance For Loan Losses: Impaired Financing Receivables (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Jun. 30, 2020		Jun. 30, 2020	Sep. 30, 2019
Recorded Investment
With no related allowance recorded	$ 5,511		$ 5,511	$ 5,237
With an allowance recorded	380		380	700
Total:	5,891		5,891	5,937
Unpaid Principal Balance (Loan Balance Plus Charge Off)
With no related allowance recorded	5,604		5,604	5,446
With an allowance recorded	380		380	700
Total:	5,984		5,984	6,146
Related Allowance	63		63	172
Average Recorded Investment
With no related allowance recorded	5,293	[1]	5,304	4,731
With an allowance recorded	701	[1]	667	606
Total	5,994	[1]	5,971	5,337
Interest Income Recognized
With no related allowance recorded	56	[1]	128	331	[1]
With an allowance recorded	0	[1]	0	30
Total	56	[1]	128	361
Cash Basis Interest Income Recognized
With no related allowance recorded	39	[1]	99	287
With an allowance recorded	0	[1]	0	30
Total	39	[1]	99	317
Mortgage loans, one-to-four family
Recorded Investment
With no related allowance recorded	1,411		1,411	1,192
With an allowance recorded	0		0
Total:	1,411		1,411	1,192
Unpaid Principal Balance (Loan Balance Plus Charge Off)
With no related allowance recorded	1,454		1,454	1,236
With an allowance recorded	0		0
Total:	1,454		1,454	1,236
Related Allowance	0		0	0
Average Recorded Investment
With no related allowance recorded	1,176	[1]	1,244	1,110
With an allowance recorded	243	[1]	121
Total	1,419	[1]	1,365	1,110
Interest Income Recognized
With no related allowance recorded	15	[1]	36	71	[1]
With an allowance recorded	0	[1]	0
Total	15	[1]	36	71
Cash Basis Interest Income Recognized
With no related allowance recorded	7	[1]	25	62
With an allowance recorded	0	[1]	0
Total	7	[1]	25	62
Mortgage loans, commercial
Recorded Investment
With no related allowance recorded	3,267		3,267	3,190
Total:	3,267		3,267	3,190
Unpaid Principal Balance (Loan Balance Plus Charge Off)
With no related allowance recorded	3,267		3,267	3,190
Total:	3,267		3,267	3,190
Related Allowance	0		0	0
Average Recorded Investment
With no related allowance recorded	3,303	[1]	3,234	2,920
Total	3,303	[1]	3,234	2,920
Interest Income Recognized
With no related allowance recorded	41	[1]	92	227	[1]
Total	41	[1]	92	227
Cash Basis Interest Income Recognized
With no related allowance recorded	32	[1]	74	192
Total	32	[1]	74	192
Mortgage loans, land
Recorded Investment
With no related allowance recorded	53		53	63
With an allowance recorded	132		132	141
Total:	185		185	204
Unpaid Principal Balance (Loan Balance Plus Charge Off)
With no related allowance recorded	103		103	126
With an allowance recorded	132		132	141
Total:	235		235	267
Related Allowance	25		25	27
Average Recorded Investment
With no related allowance recorded	55	[1]	58	100
With an allowance recorded	134	[1]	137	246
Total	189	[1]	195	346
Interest Income Recognized
With no related allowance recorded	0	[1]	0	3	[1]
With an allowance recorded	0	[1]	0	0
Total	0	[1]	0	3
Cash Basis Interest Income Recognized
With no related allowance recorded	0	[1]	0	3
With an allowance recorded	0	[1]	0	0
Total	0	[1]	0	3
Consumer loans, home equity and second mortgage
Recorded Investment
With no related allowance recorded	586		586	603
Total:	586		586	603
Unpaid Principal Balance (Loan Balance Plus Charge Off)
With no related allowance recorded	586		586	603
Total:	586		586	603
Related Allowance	0		0	0
Average Recorded Investment
With no related allowance recorded	584	[1]	588	459
Total	584	[1]	588	459
Interest Income Recognized
With no related allowance recorded	0	[1]	0	0	[1]
Total	0	[1]	0	0
Cash Basis Interest Income Recognized
With no related allowance recorded	0	[1]	0	0
Total	0	[1]	0	0
Consumer loans, other
Recorded Investment
With no related allowance recorded	10		10
With an allowance recorded	0		0	23
Total:	10		10	23
Unpaid Principal Balance (Loan Balance Plus Charge Off)
With no related allowance recorded	10		10
With an allowance recorded	0		0	23
Total:	10		10	23
Related Allowance	0		0	17
Average Recorded Investment
With no related allowance recorded	11	[1]	5
With an allowance recorded	0	[1]	9	10
Total	11	[1]	14	10
Interest Income Recognized
With no related allowance recorded	0	[1]	0
With an allowance recorded	0	[1]	0	0
Total	0	[1]	0	0
Cash Basis Interest Income Recognized
With no related allowance recorded	0	[1]	0
With an allowance recorded	0	[1]	0
Total	0	[1]	0	0
Commercial business loans
Recorded Investment
With no related allowance recorded	184		184	189
With an allowance recorded	248		248	536
Total:	432		432	725
Unpaid Principal Balance (Loan Balance Plus Charge Off)
With no related allowance recorded	184		184	291
With an allowance recorded	248		248	536
Total:	432		432	827
Related Allowance	38		38	128
Average Recorded Investment
With no related allowance recorded	164	[1]	175	142
With an allowance recorded	324		400	350
Total	488	[1]	575	492
Interest Income Recognized
With no related allowance recorded	0	[1]	0	30	[1]
With an allowance recorded	0	[1]	0	30
Total	0	[1]	0	60
Cash Basis Interest Income Recognized
With no related allowance recorded	0	[1]	0	30
With an allowance recorded	0	[1]	0	30
Total	$ 0	[1]	$ 0	$ 60

[1] For the three months ended June 30, 2020