Intangible Assets Summary of Intangible Asset Account Activity (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Intangible Assets [Line Items]
Beginning balance, intangible assets, gross	$ 748,148	$ 804,281
Intangible assets impaired	(497)	0
Effect of change in exchange rates	(42,038)	(2,073)
Ending balance, intangible assets, gross	$ 705,613	$ 802,208