Fair Value Measurements: Estimated Fair Values of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Sep. 30, 2016
Recorded Amount
Fair value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	$ 148,188	$ 108,941
CDs held for investment	43,034	53,000
Investment securities	8,380	8,853
FHLB stock	1,107	2,204
Other investments	3,000
Loans held for sale	3,599	3,604
Loans receivable, net	690,364	663,146
Accrued interest receivable	2,520	2,348
Non-interest-bearing demand	205,952	172,283
Interest-bearing	631,946	589,251
Total deposits	837,898	761,534
FHLB borrowings		30,000
Accrued interest payable	161	247
Fair Value
Fair value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	148,188	108,941
CDs held for investment	43,034	53,000
Investment securities	8,985	9,737
FHLB stock	1,107	2,204
Other investments	3,000
Loans held for sale	3,619	3,714
Loans receivable, net	688,332	671,017
Accrued interest receivable	2,520	2,348
Non-interest-bearing demand	205,952	172,283
Interest-bearing	632,629	589,762
Total deposits	838,581	762,045
FHLB borrowings		30,684
Accrued interest payable	161	247
Fair Value \| Fair Value, Inputs, Level 1
Fair value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	148,188	108,941
CDs held for investment	43,034	53,000
Investment securities	3,954	4,029
FHLB stock	1,107	2,204
Other investments	3,000
Loans held for sale	3,619	3,714
Loans receivable, net	0	0
Accrued interest receivable	2,520	2,348
Non-interest-bearing demand	205,952	172,283
Interest-bearing	492,305	441,277
Total deposits	698,257	613,560
FHLB borrowings		0
Accrued interest payable	161	247
Fair Value \| Fair Value, Inputs, Level 2
Fair value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
CDs held for investment	0	0
Investment securities	5,031	5,708
FHLB stock	0	0
Other investments	0
Loans held for sale	0	0
Loans receivable, net	0	0
Accrued interest receivable	0	0
Non-interest-bearing demand	0	0
Interest-bearing	0	0
Total deposits	0	0
FHLB borrowings		30,684
Accrued interest payable	0	0
Fair Value \| Fair Value, Inputs, Level 3
Fair value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents	0	0
CDs held for investment	0	0
Investment securities	0	0
FHLB stock	0	0
Other investments	0
Loans held for sale	0	0
Loans receivable, net	688,332	671,017
Accrued interest receivable	0	0
Non-interest-bearing demand	0	0
Interest-bearing	140,324	148,485
Total deposits	140,324	148,485
FHLB borrowings		0
Accrued interest payable	$ 0	$ 0

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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Fair value portion of borrowing from Federal Home Loan Bank (FHLBank).

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-Publisher FASB
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The fair value as of the balance sheet date of firm holdings in mortgages, mortgage backed securities (investment instruments that represent ownership of an undivided interest in a group of mortgages, where principal and interest from the individual mortgages are used to pay investors' principal and interest on the mortgage backed security) and asset-backed securities that are primarily paid from the cash flows of a discrete pool of receivables or other financial assets (such as credit-card receivables), either fixed or revolving, that by their terms convert into cash within a finite time period. Includes both pledged (to counterparties as collateral for financing transactions) and unpledged holdings.

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Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

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Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

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Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables.

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Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

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Amount of investments classified as other.

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