MORTGAGE LOANS - Troubled Debt Restructuring (Details) - Commercial mortgage loans $ in Thousands	9 Months Ended	12 Months Ended
Sep. 30, 2019 USD ($) contract	Dec. 31, 2018 USD ($) contract
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Contracts \| contract	2	1
Pre-Modification Outstanding Recorded Investment	$ 3,776	$ 2,688
Post-Modification Outstanding Recorded Investment	$ 3,776	$ 1,742

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

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953676-111524

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- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

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- Definition

Amount, before troubled debt restructuring, of financing receivable to be modified.

+ References

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