Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Comprehensive income
Net income	$ 40,463	$ 47,394	$ 50,245	$ 7,130
Other comprehensive income (loss)
Reclassification adjustment for hedge (gains) losses included in net income	(11,886)	6,806	(24,309)	13,561
Income tax expense (benefit) related to other comprehensive income (loss)	5,844	(2,588)	10,588	(5,156)
Other comprehensive income (loss), net of tax	(6,042)	4,218	(13,721)	8,405
Comprehensive income (loss)	$ 34,421	$ 51,612	$ 36,524	$ 15,535

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.

+ References

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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