Derivative Instruments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2010	Dec. 31, 2011
Derivative Instruments
Forward contracts, designated as cash flow hedges, fair value assets		$ 5,105
Total derivatives designated as cash flow hedging instruments		5,105
Cash flow hedge gain recognized in accumulated other comprehensive income (loss) associated with interest rate contracts	(2,363)
Cash flow hedge gain (loss) recognized in accumulated other comprehensive income (loss) associated with foreign exchange rate forward contracts		$ (287)

Accumulated adjustment, net of tax, that results from the process of translating subsidiary financial statements and foreign equity investments into the reporting currency from the functional currency of the reporting entity, net of reclassification of realized foreign currency translation gains or losses.

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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+ Details