Summary of Significant Accounting Policies (Details 11) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Significant Accounting Policies
Beginning balance	$ (90,900)
Other comprehensive income (loss) before reclassifications	7,217
Amounts reclassified from accumulated other comprehensive income (loss)	7,888
Other comprehensive income (loss)	15,105
Ending balance	(75,795)
Currency translation adjustments
Significant Accounting Policies
Beginning balance	(26,220)
Other comprehensive income (loss) before reclassifications	2,439
Other comprehensive income (loss)	2,439
Ending balance	(23,781)
Accumulated derivative losses, net
Significant Accounting Policies
Beginning balance	(66,917)
Other comprehensive income (loss) before reclassifications	6,044
Amounts reclassified from accumulated other comprehensive income (loss)	7,888
Other comprehensive income (loss)	13,932
Ending balance	(52,985)
Net unrealized gains on marketable securities
Significant Accounting Policies
Beginning balance	2,237
Other comprehensive income (loss) before reclassifications	(1,266)
Other comprehensive income (loss)	(1,266)
Ending balance	$ 971