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Supplemental Information on Oil and Gas Producing Activities (Details 5) (USD $)
In Thousands, unless otherwise specified |
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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| Changes in Standardized Measure of Discounted Future Net Cash Flows: | |||
| BALANCE AT BEGINNING OF PERIOD | $ 166,187 | $ 124,824 | $ 102,518 |
| Sales of oil and gas, net of production costs | (168,563) | (183,705) | (112,360) |
| Net changes in prices and production costs | (11,223) | 194,633 | 139,810 |
| Revisions of previous quantity estimates | (155,111) | 75,713 | 71,600 |
| Additions | 69,092 | 7,742 | |
| Changes in estimated future development costs | (67,834) | (5,831) | (5,337) |
| Development costs incurred during the period | 34,944 | 31,913 | 37,531 |
| Accretion of discount | 16,619 | 12,482 | 10,252 |
| Net change of income taxes | 7,445 | 4,455 | (31,482) |
| Change in production rates (timing) and other | (48,876) | (96,039) | (87,708) |
| BALANCE AT END OF PERIOD | $ 152,902 | $ 166,187 | $ 124,824 |
| X | ||||||||||
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- Definition
The increase in the net discounted value of the proved oil and gas reserves due only to the passage of time. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) in the evaluation or calculation of the costs that will be required in future periods to make it possible to extract or process proved oil and gas reserves. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) in the estimate of future income taxes that will be due on future pretax net cash flows relating to the enterprise's proved oil and gas reserves. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
The increase (decrease) in sales and transfer prices and in production (lifting) costs related to future production. The effects of changes in prices and costs are computed before the effects of changes in quantities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The actual costs incurred during the reporting period to make it possible to extract or process proved oil and gas reserves. These costs were previously estimated and reduced the estimate of discounted future cash flows from oil and gas reserves. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Any changes made during the period to the evaluation or calculation of the estimated quantity of oil or gas in proved reserves. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The amount of sales or transfers of oil gas that was previously included in proved oil and gas reserves. This amount is net of production costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Changes in the standardized measure of discounted future net cash flows relating to proved oil and gas reserves that are not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) as a result of changes in the elements used to estimate the discounted future net cash flow relating to proved oil and gas reserves. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The balance as of the balance sheet date of the standardized measure of discounted future net cash flow relating to proved oil and gas reserves. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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