Costs of Oil and Gas Properties (Details 2) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Oil and Gas Property, Successful Effort Method, Gross [Abstract]
Proved properties	$ 1,643,038	$ 2,539,480
Unproved properties	74,171	46,022
Total capitalized costs	1,717,209	2,585,502
Accumulated depletion	(928,927)	(1,460,404)
Net capitalized costs	$ 788,282	$ 1,125,098

Amount of accumulated depreciation, depletion and amortization of oil and gas property carried under the successful effort method. Oil and gas property include, but not limited to, the entity's wells and related equipment and facilities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61901-109447

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10.(b))
-URI http://asc.fasb.org/extlink&oid=50486907&loc=d3e511914-122862

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- Definition

Oil and Gas properties, gross, carried under the successful effort method.

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No definition available.

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Oil and gas properties net of accumulated depreciation, depletion, amortization, impairment, and abandonment, carried under the successful effort method.

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- Definition

Oil and Gas properties with proved reserves under the successful effort method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Glossary Proved Properties
-URI http://asc.fasb.org/extlink&oid=6522428

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Section 25
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=56951519&loc=d3e64746-109465

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- Definition

Oil and Gas properties with unproved reserves under the successful effort method.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 235
-Section 50
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=68064819&loc=d3e61926-109447

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-Glossary Unproved Properties
-URI http://asc.fasb.org/extlink&oid=6527831

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 360
-Section 25
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=56951519&loc=d3e64746-109465

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