Loans Receivable and Allowance for Loan Losses - Interest Income on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	$ 38,459	$ 22,350	$ 36,308	$ 21,375
Interest Income Recognized	381	261	1,160	841
Real estate loans \| One-to-four family
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	8,020	8,773	8,175	9,144
Interest Income Recognized	74	101	226	340
Real estate loans \| Multifamily and commercial
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	23,525	2,637	20,670	2,667
Interest Income Recognized	227	37	653	111
Real estate loans \| Construction
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	0	850	0	850
Interest Income Recognized	0	0	0	0
Commercial business loans
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	4,979	7,461	5,468	5,848
Interest Income Recognized	52	88	196	268
Consumer loans \| Home equity loans and advances
Financing Receivable, Impaired [Line Items]
Average Recorded Investment	1,935	2,629	1,995	2,866
Interest Income Recognized	$ 28	$ 35	$ 85	$ 122

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Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

+ References

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