FAIR VALUE MEASUREMENTS - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans	$ 901	$ 2,509
Related allowance	25	815
Single family residential
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans	901	2,509
Related allowance	25	815
Single family residential \| Permanent mortgages
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans	1,600	1,600
Level 3 \| Single family residential \| Permanent mortgages \| Nonrecurring Basis
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Impaired loans	878	790
Related allowance	$ 722	$ 790

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- Definition

Amount of allowance for credit losses related to recorded investment.

+ 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 (a)(3)
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Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953550-111524

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