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Supplemental Oil and Natural Gas Reserve Data (unaudited) (Summarized Average 12-month Oil and Natural Gas Prices Net of Differentials) (Details)
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12 Months Ended | ||
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Dec. 31, 2012
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Dec. 31, 2011
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Dec. 31, 2010
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Natural Gas [Member]
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| Average Sales Price and Production Costs Per Unit of Production [Line Items] | |||
| Average 12-month price, net of differentials | 4.81 | 5.60 | 5.10 |
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Crude Oil [Member]
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| Average Sales Price and Production Costs Per Unit of Production [Line Items] | |||
| Average 12-month price, net of differentials | 94.68 | 98.98 | 78.07 |
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- Details
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- Definition
The revenues derived from sales of oil or gas in each geographic area during the reporting period divided by the number of barrels of oil produced or thousands of cubic feet of gas produced. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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