LOANS - Summary of Loans Investments Activity (Details) $ in Thousands	9 Months Ended
Sep. 30, 2018 USD ($)
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance	$ 2,999,148
Purchases	1,747,902
Syndications	(44,125)
Principal Payments	(516,180)
Change in fair value	(13,812)
Amortization	8,945
Ending balance	4,181,878
Residential
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance	958,546
Purchases	430,854
Syndications	0
Principal Payments	(156,198)
Change in fair value	(13,812)
Amortization	(2,251)
Ending balance	1,217,139
Commercial
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance	1,029,327
Purchases	528,835
Syndications	0
Principal Payments	(124,559)
Change in fair value	0
Amortization	2,262
Ending balance	1,435,865
Corporate
Movement in Mortgage Loans on Real Estate [Roll Forward]
Beginning balance	1,011,275
Purchases	788,213
Syndications	(44,125)
Principal Payments	(235,423)
Change in fair value	0
Amortization	8,934
Ending balance	$ 1,528,874

Mortgage loans on real estate change in fair value.

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Balance Type:	debit
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- Definition

Total carrying amount of mortgage loans as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29.6)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

+ Details

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- Definition

Amount of decrease in mortgage loans on real estate from amortization of premium.

+ References

+ Details

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- Definition

The amount of principal collected on mortgage loans on real estate during the reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29.6)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

+ Details

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- Definition

The carrying amount of mortgage loans on real estate that were sold during the reporting period.

+ References

+ Details

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- Definition

Total amount of new mortgage loans on real estate during the reporting period.

+ References

+ Details

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

+ References

No definition available.

+ Details

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