INVESTMENTS IN DEBT SECURITIES (Bonds and Related Unrealized Gains and Losses) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Available-for-sale Securities [Line Items]
Fair Value	$ 34,121	$ 97,190
Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Unpaid principal balance of bond investments	33,330	92,332
Amortized Cost	21,614	59,565
Gross Unrealized Gains	12,507	37,625
Fair Value	$ 34,121	$ 97,190
FV as a % of UPB	102.00%	105.00%
Multifamily Tax-Exempt Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Unpaid principal balance of bond investments	$ 6,160	$ 65,162
Amortized Cost	576	38,653
Gross Unrealized Gains	8,145	33,564
Fair Value	$ 8,721	$ 72,217
FV as a % of UPB	142.00%	111.00%
Infrastructure Bond [Member]
Schedule of Available-for-sale Securities [Line Items]
Unpaid principal balance of bond investments	$ 27,170	$ 27,170
Amortized Cost	21,038	20,912
Gross Unrealized Gains	4,362	4,061
Fair Value	$ 25,400	$ 24,973
FV as a % of UPB	93.00%	92.00%

Available-For-Sale Securities, Debt Securities, Fair Value as a Percentage of Unpaid Principal Balance

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- Definition

The value of unpaid principal amount on investments securities.

+ References

No definition available.

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- Definition

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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- Definition

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562

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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.

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