Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Comprehensive income
Net (loss) income	$ (1,190)	$ 9,782
Other comprehensive income (loss)
Reclassification adjustment for hedge gains included in gain from oil hedging activities in the consolidated statements of operations	(10,003)	(12,423)
Income tax benefit related to other comprehensive loss	3,818	4,744
Other comprehensive loss, net of tax	(6,185)	(7,679)
Comprehensive (loss) income	$ (7,375)	$ 2,103

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

- Definition

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

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- Definition

Before tax amount of the income statement impact of the reclassification adjustment of accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges realized in net income. Also includes reclassification adjustments of an entity's share of an equity investee's deferred hedging gain (loss) realized in net income.

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+ Details

- Definition

Tax effect of the income statement impact of the reclassification adjustment of accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges realized in net income. Also includes reclassification adjustments of an entity's share of an equity investee's deferred hedging gain (loss) realized in net income.

+ References+ Details