Intangible Assets Summary of Intangible Asset Account Activity (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Beginning balance, intangible assets, gross	$ 804,281	$ 802,540
Intangible assets acquired	1,453	(1,500)
Effect of change in exchange rates	(57,586)	3,241
Ending balance, intangible assets, gross	$ 748,148	$ 804,281