FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financial assets and liabilities accounted for at fair value
Proved properties	$ 2,519,695	$ 1,618,970
Unproved properties	162,334	185,530
Asset retirement obligations	27,157	14,935
Level 1
Financial assets and liabilities accounted for at fair value
Derivative assets	0	0
Proved properties		0
Unproved properties	0	0
Asset retirement obligations		0
Level 2
Financial assets and liabilities accounted for at fair value
Derivative assets	2,093	29,566
Proved properties		0
Unproved properties	0	0
Asset retirement obligations		0
Level 3
Financial assets and liabilities accounted for at fair value
Derivative assets	0	0
Proved properties		811,913
Unproved properties	$ 162,202	185,530
Asset retirement obligations		$ 2,027

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition

Amount of a reclamation liability that is associated with a legal obligation for the closure and reclamation of oil and gas properties.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Oil and Gas properties with proved reserves under the successful effort method.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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