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Cost Incurred in Oil and Gas Property Acquisition Exploration and Development Activities (Parenthetical) (Detail) (USD $)
In Millions, 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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| Reserve Quantities [Line Items] | |||
| Additions (reductions) of asset retirement obligations | $ 86.9 | $ 32.8 | $ 106.1 |
| Seismic costs | 6.2 | 8.0 | 5.8 |
| Geological and geophysical costs | $ 6.2 | $ 6.8 | $ 4.3 |
| X | ||||||||||
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- Details
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| X | ||||||||||
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- Definition
Asset retirement obligation period increase decrease due to acquisitions, incurred and revisions No definition available.
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| X | ||||||||||
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- Definition
Geological And Geophysical Costs No definition available.
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| X | ||||||||||
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- Definition
Seismic costs No definition available.
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