FAIR VALUE OF FINANCIAL INSTRUMENTS - NONRECURRING (Details) - Fair Value, Measurements, Nonrecurring $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021 USD ($) item	Sep. 30, 2020 USD ($) item	Sep. 30, 2021 USD ($) item	Sep. 30, 2020 USD ($) item	Dec. 31, 2020 USD ($)
Fair value of financial instruments
Number of vessels written down as part of impairment \| item	0	7	0	21
Impairment of operating lease right of use asset	$ 0	$ 0	$ 0	$ 0
Level 3
Fair value of financial instruments
Financial assets	0		0		$ 0
Financial liabilities	$ 0		$ 0		$ 0

Number of vessels written down as part of impairment recorded during the period.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

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- Definition

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.

+ References

No definition available.

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- Definition

Fair value of financial obligations, including, but not limited to, debt instruments, derivative liabilities, federal funds purchased and sold under agreements to repurchase, securities loaned or sold under agreements to repurchase, financial instruments sold not yet purchased, guarantees, line of credit, loans and notes payable, servicing liability, and trading liabilities.

+ References

No definition available.

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- Definition

Amount of loss from impairment of right-of-use asset from operating lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 25
-Paragraph 6
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121593497&loc=SL77918431-209957

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