DERIVATIVE INSTRUMENTS - Notional Amount (Details) - Derivative instruments not designated as hedging instruments	6 Months Ended
Jun. 30, 2020 USD ($) investment	Dec. 31, 2019 USD ($) investment
Interest Rate Swap
Derivative [Line Items]
Number of Instruments \| investment	11	11
Notional Amount \| $	$ 1,189,503,000	$ 960,963,000
Weighted-Average Fix Pay Rate	1.86%
Weighted-Average Remaining Term in Years	2 years 2 months 12 days
Interest Rate Swap \| Minimum \| One-month LIBOR
Derivative [Line Items]
Reference Rate	1.16%
Interest Rate Swap \| Maximum \| One-month LIBOR
Derivative [Line Items]
Reference Rate	2.15%
Interest Rate Swap Which Will Become Effective in 2020 and Mature in 2023
Derivative [Line Items]
Number of Instruments \| investment	2
Notional Amount \| $	$ 115,000,000.0

Derivative Instruments, Weighted-Average Fix Pay Rate

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Derivative Instruments, Weighted-Average Remaining Term in Years

+ References

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Fixed interest rate related to the interest rate derivative.

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Nominal or face amount used to calculate payment on derivative.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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The number of derivative instruments of a particular group held by the entity.

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-Name Accounting Standards Codification
-Topic 815
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