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Exploration and Production Activities (Unaudited) Purchase and sale agreements (Details)	12 Months Ended
	Dec. 31, 2014
Discontinued operations, disposed of by sale
Entity Sector Industry Classifications [Line Items]
Percent of oil and natural gas production sold	93.00%

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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No definition available.

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- Definition

Percent of oil and natural gas production sold.

+ References

No definition available.

+ Details

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- Details

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