Loans Receivable Held for Investment - Average of Loans Individually Evaluated for Impairment by Loan Type and Related Interest Income (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Impaired loans
Average Recorded Investment	$ 9,003	$ 12,150
Cash Basis Interest Income Recognized	189	246
Foregone interest income if impaired loans had performed according to terms	10	46
Single family
Impaired loans
Average Recorded Investment	625	642
Cash Basis Interest Income Recognized	8	7
Multi-family
Impaired loans
Average Recorded Investment	332	640
Cash Basis Interest Income Recognized	6	11
Commercial real estate
Impaired loans
Average Recorded Investment		331
Church
Impaired loans
Average Recorded Investment	7,981	10,471
Cash Basis Interest Income Recognized	174	227
Commercial - other
Impaired loans
Average Recorded Investment	65	66
Cash Basis Interest Income Recognized	$ 1	$ 1

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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://www.xbrl.org/2003/role/presentationRef
-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://www.xbrl.org/2003/role/presentationRef
-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 on a cash-basis method of accounting 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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- Definition

Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18794-111554

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