Finite-Lived Intangible Assets and Liabilities and Goodwill - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2018	Mar. 31, 2018
Goodwill [Roll Forward]
Beginning balance of goodwill	$ 60,300	$ 0
Net additions during the period		60,300
Foreign currency translation adjustment	(2,600)
Ending balance of goodwill	$ 57,736	$ 60,300