SUPPLEMENTAL OIL AND GAS INFORMATION (UNAUDITED) - Costs Incurred (Details) - USD ($) $ in Thousands	12 Months Ended
Jun. 30, 2017	Jun. 30, 2016
Property acquisition:
Unproved	$ 0	$ 0
Exploration	13,316	0
Development	0	0
Total costs incurred	13,316	0
United States
Property acquisition:
Unproved	0	0
Exploration	0	0
Development	0	0
Total costs incurred	0	0
Republic of Guinea
Property acquisition:
Unproved	0	0
Exploration	13,316	0
Development	0	0
Total costs incurred	$ 13,316	$ 0

Represents the total costs incurred in oil and gas activities.

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- References

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- Definition

Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have unproved reserves.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62038-109447

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 18
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447

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- Definition

Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 18
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447

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- Definition

Exploration costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Exploration
-URI http://asc.fasb.org/extlink&oid=6512329

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 18
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e62014-109447

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