Goodwill and Intangible Assets - Schedule of Changes in Intangible Assets, Net of Accumulated Amortization (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Finite-lived Intangible Assets [Roll Forward]
Net balance at January 1	$ 90,068	$ 31,323
Additions	4,420	67,645
Amortization expense	(7,885)	(4,811)
Impairment losses	0	(723)	$ 0
Currency translation	(9,588)	(3,366)
Net balance at December 31	$ 77,015	$ 90,068	$ 31,323