Loans Receivable and Allowance for Loan Losses - Troubled Debt Restructuring (Details) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan	Sep. 30, 2020 USD ($) loan	Sep. 30, 2019 USD ($) loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
No. of Loans \| loan	5	0	6	1
Pre-modification Recorded Investment	$ 17,682	$ 0	$ 27,894	$ 4,095
Post-modification Recorded Investment	$ 17,682	$ 0	$ 29,189	$ 4,095
Real estate loans \| Multifamily and commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
No. of Loans \| loan	4	0	4	0
Pre-modification Recorded Investment	$ 16,387	$ 0	$ 16,387	$ 0
Post-modification Recorded Investment	$ 16,387	$ 0	$ 16,387	$ 0
Commercial business loans
Financing Receivable, Troubled Debt Restructuring [Line Items]
No. of Loans \| loan	1	0	2	1
Pre-modification Recorded Investment	$ 1,295	$ 0	$ 11,507	$ 4,095
Post-modification Recorded Investment	$ 1,295	$ 0	$ 12,802	$ 4,095

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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=121611835&loc=SL6953676-111524

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

+ References

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- Definition

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

+ References

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