Loans Receivable and Allowance for Loan Losses - Troubled Debt Restructuring (Details) $ in Thousands	3 Months Ended
Dec. 31, 2017 USD ($) loan	Dec. 31, 2016 USD ($) loan
Financing Receivable, Modifications [Line Items]
No of loans \| loan	0	3,000
Pre-modification recorded investment	$ 0	$ 365
Post-modification recorded investment	$ 0	$ 365
Real estate loans \| One to four family
Financing Receivable, Modifications [Line Items]
No of loans \| loan	0	2,000
Pre-modification recorded investment	$ 0	$ 257
Post-modification recorded investment	$ 0	$ 257
Consumer loans \| Home equity loans and advances
Financing Receivable, Modifications [Line Items]
No of loans \| loan	0	1,000
Pre-modification recorded investment	$ 0	$ 108
Post-modification recorded investment	$ 0	$ 108

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Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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