Intangible Assets and Liabilities - Summary of Intangible Asset Account Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Intangible Assets, Net (Excluding Goodwill) [Abstract]
Beginning balance, Finite-lived intangible assets, gross	$ 769,851	$ 669,896
Intangible assets acquired	242,039	36,500
Effect of change in exchange rates	(30,730)	63,455
Ending balance, Finite-lived intangible assets, gross	978,060	769,851
Finite-lived intangible liabilities, gross	(23,900)	0	$ 0
Customer contracts and relationships	(23,900)	0
Effect of change in exchange rates	0	0
Intangible assets, gross (excluding goodwill)	$ 981,160	$ 769,851