Intangible Assets Summary of Intangible Asset Account Activity (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013
Intangible Assets [Line Items]
Beginning balance, intangible assets, gross	$ 804,281	$ 802,540
Intangible assets acquired	497	(1,500)
Effect of change in exchange rates	(4,075)	(16,894)
Ending balance, intangible assets, gross	$ 800,703	$ 784,146