Property, Plant And Equipment (Net Changes in Capitalized Exploratory Well Costs (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2014	Sep. 30, 2013
Property, Plant And Equipment [Abstract]
Beginning balance at January 1	$ 393,030	$ 445,697
Additions pending the determination of proved reserves	13,595	28,168
Reclassifications to proved properties based on the determination of proved reserves		(52,865)
Ending balance at September 30	$ 406,625	$ 421,000

Additions to capitalized exploratory well costs that were added during the reporting period pending the determination of proved reserves.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 1B

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The amount of capitalized exploratory well costs that is pending the determination of proved reserves. This does not include amounts that were capitalized and subsequently expensed in the same annual period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 1B

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447

+ Details

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- Details

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Balance Type:	na
Period Type:	duration

- Definition

Previously capitalized costs of the drilling of wells that were reclassified as part of the costs of the enterprise's wells and related equipment and facilities at the time that proved reserves were found.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 1B

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=8451039&loc=SL6806780-109447

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration