Annual discount rate for discounting future cash flows.

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- Definition

The calculated weighted average natural gas price per mcf utilized for purposes of estimating the company's proved reserves and future net revenue.

+ References

No definition available.

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- Definition

The calculated weighted average natural gas liquids price per barrel utilized for purposes of estimating the company's proved reserves and future net revenue.

+ References

No definition available.

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- Definition

The calculated weighted average oil price per barrel utilized for purposes of estimating the company's proved reserves and future net revenue.

+ References

No definition available.

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- Definition

Increase In Impairment Of Oil And Gas Properties

+ References

No definition available.

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- Definition

Interest costs capitalized on unevaluated properties.

+ References

No definition available.

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- Definition

The description of the weighted average prices used in calculating the company's proved reserves and future net revenues.

+ References

No definition available.

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- Definition

The period of time in which unproved oil and gas properties/projects are expected to be evaluated and included in the amortization base for oil and gas properties.

+ References

No definition available.

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- Definition

The number of unproved oil and gas properties/projects associated with capitalized costs excluded from amortization.

+ References

No definition available.

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- Definition

The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 360

-Section 35

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=28370743&loc=d3e66150-109466

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-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 50

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- Definition

Additions to proved reserves that result from (1) extension of the proved acreage of previously discovered (old) reservoirs through additional drilling in periods after discovery and (2) discovery of new fields with proved reserves or of new reservoirs of proved reserves in old fields.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 5

-Subparagraph (d)

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- Definition

Revisions represent changes in previous estimates of proved reserves, either upward or downward, resulting from new information (except for an increase in proved acreage) normally obtained from development drilling and production history or resulting from change in economic factors.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 5

-Subparagraph (a)

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- Definition

Sales of minerals in place.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 5

-Subparagraph (f)

-URI http://asc.fasb.org/extlink&oid=8451039&loc=d3e61831-109447

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Supplemental Information on Oil and Natural Gas Operations - Unaudited - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended	12 Months Ended
	Dec. 31, 2014 Project	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2014 Project	Dec. 31, 2013	Dec. 31, 2012
Reserve Quantities [Line Items]
Average 12-month oil prices net of differentials	89.46	94.94	94.94	89.46	102.21	101.20
Increase in written down value of oil and gas properties			$ 29,001	$ 13,342
Average 12-month gas prices net of differentials	3.68	4.19	4.19	3.68	3.66	2.68
Cost of revenues written down	304,062us-gaap_ImpairmentOfOilAndGasProperties	47,130us-gaap_ImpairmentOfOilAndGasProperties		351,192us-gaap_ImpairmentOfOilAndGasProperties
Interest costs capitalized on unevaluated properties				45,722	46,860	37,656
Specifically identified drilling projects	108			108
Projects expected to be evaluated				4 years
Adoption of assumption due to revision of oil and gas reporting requirements				Using a historical 12-month average pricing assumption
Annual discount rate for discounting future cash flows				10.00%
Oil And Gas [Member]
Reserve Quantities [Line Items]
Cost of revenues written down			$ 47,130	$ 304,062
Natural Gas Liquids (MBbls) [Member]
Reserve Quantities [Line Items]
Average 12-month gas prices net of differentials	36.79	41.33	41.33	36.79
Extensions, discoveries and other additions				7,521	4,395	4,856
Sale of reserves primarily related to sale				556
Revisions of previous estimates				(331)	2,439	9,349
Average 12-month natural gas liquids prices net of differentials	36.79			36.79	37.59	38.23
Appalachia drilling program [Member]
Reserve Quantities [Line Items]
Extensions, discoveries and other additions				118	117	162
Sale of reserves primarily related to sale				15
Deep gas development project at LaCantera [Member]
Reserve Quantities [Line Items]
Extensions, discoveries and other additions						17
Deep water drilling program [Member]
Reserve Quantities [Line Items]
Extensions, discoveries and other additions				116
GOM conventional shelf properties [Member]
Reserve Quantities [Line Items]
Sale of reserves primarily related to sale				63
Positive reserve report pricing changes [Member]
Reserve Quantities [Line Items]
Revisions of previous estimates					18
Well performance [Member]
Reserve Quantities [Line Items]
Revisions of previous estimates					55