Loans Receivable - Loans on Non-accrual Status (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Sep. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual percent of total loans	0.27%	0.28%
Non-accrual loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 32,610	$ 33,731
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	100.00%	100.00%
Non-accrual loans \| Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 22,859	$ 25,271
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	70.10%	74.90%
Non-accrual loans \| Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 3,353	$ 0
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	10.30%	0.00%
Non-accrual loans \| Land - acquisition & development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 82	$ 169
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	0.30%	0.50%
Non-accrual loans \| Land - consumer lot loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 408	$ 246
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	1.20%	0.70%
Non-accrual loans \| Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 4,374	$ 5,835
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	13.40%	17.30%
Non-accrual loans \| Commercial & industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 470	$ 1,292
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	1.40%	3.80%
Non-accrual loans \| HELOC
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 1,064	$ 907
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	3.30%	2.70%
Non-accrual loans \| Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Non-accrual loans	$ 0	$ 11
Ratio of non-accrual loan by portfolio segment to total loans on non-accrual status	0.00%	0.00%

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Reflects the carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=d3e5111-111524

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Loans and Leases Receivable, Ratio of Type of Nonperforming Loans to All Nonperforming Loans

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Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest, Percent of Total Loans

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