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Summary Of Significant Accounting Policies (Narrative) (Details) (USD $) | 12 Months Ended | 1 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Dec. 31, 2011 | Dec. 31, 2010 | Dec. 31, 2009 | Nov. 30, 2011 Barnett Shale [Member] | Dec. 31, 2009 Barnett Shale [Member] | Dec. 31, 2011 Proved Oil And Gas Properties [Member] | Dec. 31, 2010 Proved Oil And Gas Properties [Member] | Dec. 31, 2009 Proved Oil And Gas Properties [Member] | Dec. 31, 2011 Unproved Oil And Gas Properties [Member] | Dec. 31, 2010 Unproved Oil And Gas Properties [Member] | Dec. 31, 2009 Unproved Oil And Gas Properties [Member] | Dec. 31, 2011 2012 [Member] | Dec. 31, 2011 2013 [Member]
Proceeds from sale of property | $ 2,202,000 |  | $ 1,507,000 | $ 2,200,000 | $ 1,500,000 |  |  |  |  |  |  |  |
Gain (loss) on sale of properties | (207,000) |  | 1,455,000 | (200,000) | 1,400,000 |  |  |  |  |  |  |  |
US Results of Operations, Impairment of Oil and Gas Properties | 3,610,000 | 11,967,000 | 6,233,000 |  |  | 0 | 0 | 800,000 | 3,600,000 | 12,000,000 | 5,400,000 |  |
Capitalized interest costs | 3,100,000 | 0 |  |  |  |  |  |  |  |  |  |  |
Estimated life of assets, minimum (years) | 3 |  |  |  |  |  |  |  |  |  |  |  |
Estimated life of assets, maximum (years) | 5 |  |  |  |  |  |  |  |  |  |  |  |
Past-due receivables from counterparties | 0 |  |  |  |  |  |  |  |  |  |  |  |
Contractual commodity derivative volume, percent |  |  |  |  |  |  |  |  |  |  |  | 96.00% | 46.00%
Restricted stock awards vesting period | three |  |  |  |  |  |  |  |  |  |  |  |
Excess tax deduction related to stock compensation | $ 800,000 |  |  |  |  |  |  |  |  |  |  |  |

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- Definition Reductions in the entity's income taxes that arise when compensation cost (from non-qualified equity-based compensation) recognized on the entity's tax return exceeds compensation cost from equity-based compensation recognized in financial statements. This element reduces net cash provided by operating activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 123R -Paragraph A96 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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 718 -SubTopic 20 -Section 55 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=6576910&loc=d3e11374-113907 + Details
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- Definition Gain (loss) recognized on the sale of oil and gas property or timber property. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -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 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 + Details
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