Intangible Assets Summary of Intangible Asset Account Activity (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Beginning balance, intangible assets, gross	$ 802,540	$ 749,194
Intangible assets acquired	(1,500)	43,400
Assets no longer in use written-off	0	(100)
Effect of change in exchange rates	3,241	10,046
Ending balance, intangible assets, gross	$ 804,281	$ 802,540