Other Comprehensive Income (Details) (USD $) In Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Statement of Income and Comprehensive Income [Abstract]
Net Income	$ 14,895	$ 14,379	$ 58,440	$ 54,788
Other Comprehensive Income (loss), Net of Tax [Abstract]
Reclassification of net gains on hedging instruments from OCI to net income	(183)	(297)	(777)	(891)
Foreign currency translation	(168)	62	(99)	35
Comprehensive Income	$ 14,544	$ 14,144	$ 57,564	$ 53,932

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.

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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

Adjustment that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency of the reporting entity, net of tax.

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Net of tax effect of the reclassification adjustment for accumulated gains and losses from derivative instrument designated and qualifying as the effective portion of cash flow hedges included in accumulated comprehensive income that was realized in net income during the period.

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+ Details