INVESTMENTS IN DEBT AND EQUITY SECURITIES (Schedule of Corporate Bonds) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Amortised Cost	$ 12,118	$ 12,601
Unrealised gains/ (losses)	635	644
Fair value	12,753	13,245	$ 41,742
NorAm Drilling
Debt Securities, Available-for-sale [Line Items]
Amortised Cost	4,132	4,715
Unrealised gains/ (losses)	558	477
Fair value	4,690	5,192	$ 5,500
Oro Negro 7.5%
Debt Securities, Available-for-sale [Line Items]
Amortised Cost	5,705	7,886
Unrealised gains/ (losses)	0	167
Fair value	5,705	8,053
Oro Negro 12%
Debt Securities, Available-for-sale [Line Items]
Amortised Cost	2,281	0
Unrealised gains/ (losses)	77	0
Fair value	$ 2,358	$ 0

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

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=118939692&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

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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 326
-SubTopic 30
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=118942338&loc=SL82898722-210454

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=118954083&loc=d3e26610-111562

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