Summary of Significant Accounting Policies - Additional Information (Detail)	12 Months Ended
Dec. 31, 2011 MMcf
Barrel of liquids equivalents of natural gas	0.006
Oil and Gas Unproved Properties
Useful life	5
Useful lives	Over the lesser of five years or the average remaining lease term
Maximum
Revenue collection period	60 days

Revenue Recognition, Period of Recognition

No definition available.

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- Definition

This element represents the number of barrel of oil equivalents (BOE) which is a measurement used by oil and gas companies as a way of combining oil and natural gas reserves and production into a single measurement. Natural gas volumes are converted to BOE based on the energy content of 6,000 cubic feet of gas to one barrel of oil.

+ References

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

-Publisher SEC

-Name Industry Guide

-Number 2

-Paragraph 3

-Subparagraph A

+ Details

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Data Type:	us-types:boeItemType
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Period Type:	duration

- Definition

Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6367646&loc=d3e18780-107790

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-URI http://asc.fasb.org/subtopic&trid=2155824

+ Details

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Period Type:	duration

- Definition

The average useful life of long-lived, physical assets used in the normal conduct of business and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References

No definition available.

+ Details

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