Supplemental Oil And Gas Information (Schedule Of Oil And Gas Property Acquisition, Exploration And Development) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Oil And Gas Information [Abstract]
Property acquisitions proved
Property acquisitions unproved	598	488	188
Exploration cost	2,367us-gaap_CostsIncurredExplorationCosts	914us-gaap_CostsIncurredExplorationCosts	4,608us-gaap_CostsIncurredExplorationCosts
Development cost	864us-gaap_CostsIncurredDevelopmentCosts	998us-gaap_CostsIncurredDevelopmentCosts	2,649us-gaap_CostsIncurredDevelopmentCosts
Total	$ 3,829	$ 2,400	$ 7,445

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Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have proved reserves.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

-SubTopic 235

-Section 50

-Paragraph 19

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Costs incurred, including capitalized costs and costs charged to expense, associated with the acquisition of oil and gas properties that have unproved reserves.

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Development costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 932

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Exploration costs incurred, including capitalized costs and costs charged to expense, in oil and gas activities.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Exploration

-URI http://asc.fasb.org/extlink&oid=6512329

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Significant costs that have been incurred, including capitalized costs and costs charged to expense, to acquire mineral interests that have proved reserves.

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