Loans Receivable and Allowance for Loan Losses - Troubled Debt Restructuring (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019 USD ($) loan	Jun. 30, 2018 USD ($) loan	Jun. 30, 2019 USD ($) loan	Jun. 30, 2018 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
No. of Loans \| loan	0	3	1	5
Pre-modification Recorded Investment	$ 0	$ 378	$ 4,095	$ 1,050
Post-modification Recorded Investment	$ 0	$ 378	$ 4,095	$ 1,050
Real estate loans \| One-to-four family
Financing Receivable, Troubled Debt Restructuring [Line Items]
No. of Loans \| loan	0	3	0	4
Pre-modification Recorded Investment	$ 0	$ 378	$ 0	$ 462
Post-modification Recorded Investment	$ 0	$ 378	$ 0	$ 462
Real estate loans \| Multifamily and commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
No. of Loans \| loan			1	0
Pre-modification Recorded Investment			$ 4,095	$ 0
Post-modification Recorded Investment			$ 4,095	$ 0
Consumer loans \| Home equity loans and advances
Financing Receivable, Troubled Debt Restructuring [Line Items]
No. of Loans \| loan			0	1
Pre-modification Recorded Investment			$ 0	$ 588
Post-modification Recorded Investment			$ 0	$ 588

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No definition available.

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

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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Amount, after troubled debt restructuring, of modified financing receivable.

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- Definition

Amount, before troubled debt restructuring, of financing receivable to be modified.

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