Loans Receivable and Allowance for Loan Losses - Interest Income on Impaired Loans (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Financing Receivable, Impaired [Line Items]
Average recorded Investment	$ 21,446	$ 21,044
Interest Income Recognized	300	190
Real estate loans \| One-to-four family
Financing Receivable, Impaired [Line Items]
Average recorded Investment	8,807	11,235
Interest Income Recognized	106	102
Real estate loans \| Multifamily and commercial
Financing Receivable, Impaired [Line Items]
Average recorded Investment	2,683	3,136
Interest Income Recognized	37	26
Real estate loans \| Construction
Financing Receivable, Impaired [Line Items]
Average recorded Investment	1,700	0
Interest Income Recognized	25	0
Commercial business loans
Financing Receivable, Impaired [Line Items]
Average recorded Investment	5,409	3,836
Interest Income Recognized	80	26
Consumer loans \| Home equity loans and advances
Financing Receivable, Impaired [Line Items]
Average recorded Investment	2,847	2,837
Interest Income Recognized	$ 52	$ 36

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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- Definition

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=84173941&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=84173941&loc=d3e5258-111524

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- Definition

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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