Significant Accounting Policies (Details 5) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ (106,146)
Other comprehensive income (loss) before reclassifications	9,912
Amounts reclassified from accumulated other comprehensive income (loss)	6,642
Net current-period other comprehensive income (loss)	16,554
Ending balance	(89,592)
Currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(30,620)
Other comprehensive income (loss) before reclassifications	10,603
Net current-period other comprehensive income (loss)	10,603
Ending balance	(20,017)
Accumulated derivative losses, net
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	(78,139)
Other comprehensive income (loss) before reclassifications	897
Amounts reclassified from accumulated other comprehensive income (loss)	6,642
Net current-period other comprehensive income (loss)	7,539
Ending balance	(70,600)
Net unrealized gains on marketable securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	2,613
Other comprehensive income (loss) before reclassifications	(1,588)
Net current-period other comprehensive income (loss)	(1,588)
Ending balance	$ 1,025