Summary of Intangible Asset Account Activity (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Total Intangible Assets [Abstract]
Beginning balance, intangible assets, gross	$ 669,896	$ 702,507
Finite-lived Intangible Assets Acquired	36,500	0
Effect of change in exchange rates	57,640	2,309
Intangible Assets, Gross (Excluding Goodwill)	$ 764,036	$ 704,816