Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill.

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 360

-SubTopic 10

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2420-110228

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- Definition

Amount of gain (loss) on sale or disposal of proven and unproven oil and gas properties.

+ References

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- Definition

The excess of unamortized costs capitalized within a cost center, less related deferred income taxes, over the cost center ceiling limitation, which is charged to expense for oil and gas producing companies that use full cost method of accounting for investments in oil and gas producing properties.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 10

-Paragraph c

-Subparagraph 4(ii)

-Article 4

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Summarized Financial Information Concerning Segments (Parenthetical) (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information
Full cost ceiling limitation impairment			$ 164,800,000
Impairment	3,133,000	15,643,000	167,912,000	15,643,000
Permian Properties
Segment Reporting Information
Gain (loss) on sale of oil and gas property				(399,100,000)
Exploration and Production
Segment Reporting Information
Full cost ceiling limitation impairment			164,800,000
Exploration and Production \| Permian Properties
Segment Reporting Information
Gain (loss) on sale of oil and gas property				(399,100,000)
Drilling and Oil Field Services
Segment Reporting Information
Impairment	$ 3,133,000	$ 10,600,000	$ 3,100,000	$ 10,600,000