Significant Accounting Policies (Details 6) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Significant Accounting Policies
Beginning balance	$ (90,900)
Other comprehensive income (loss) before reclassifications	8,511
Amounts reclassified from accumulated other comprehensive income (loss)	5,687
Other comprehensive income (loss)	14,198
Ending balance	(76,702)
Currency translation adjustments
Significant Accounting Policies
Beginning balance	(26,220)
Other comprehensive income (loss) before reclassifications	9,085
Other comprehensive income (loss)	9,085
Ending balance	(17,135)
Accumulated derivative losses, net
Significant Accounting Policies
Beginning balance	(66,917)
Other comprehensive income (loss) before reclassifications	786
Amounts reclassified from accumulated other comprehensive income (loss)	5,687
Other comprehensive income (loss)	6,473
Ending balance	(60,444)
Net unrealized gains on marketable securities
Significant Accounting Policies
Beginning balance	2,237
Other comprehensive income (loss) before reclassifications	(1,360)
Other comprehensive income (loss)	(1,360)
Ending balance	$ 877