Oil And Gas Properties (Changes In Suspended Exploratory Well Costs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Oil And Gas Properties [Abstract]
Beginning balance	$ 3,252	$ 3,059	$ 2,105
Additions pending the determination of proved reserves	2,513	(944)	36,208
Reclassifications to proved properties	5	713	(34,622)
Charged to dry hole expense	70	424	(632)
Ending balance	$ 5,840	$ 3,252	$ 3,059

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.

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS19-1

-Paragraph 10

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: 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=6821537&loc=SL6806780-109447

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration