Oil And Gas Properties (Changes In Suspended Exploratory Well Costs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Oil And Gas Properties [Abstract]
Capitalized Exploratory Well Costs, Beginning Balance	$ 5,840	$ 3,252	$ 3,059
Capitalized Exploratory Well Cost, Additions Pending Determination of Proved Reserves	135,311	2,513	(944)
Reclassification to Well, Facilities, and Equipment Based on Determination of Proved Reserves	(132,959)	5	713
Capitalized Exploratory Well Cost, Charged to Expense	55	70	424
Capitalized Exploratory Well Costs, Ending Balance	$ 8,247	$ 5,840	$ 3,252

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

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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