Goodwill and Intangible Assets - Finite Lived Intangible Assets Amortization Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible assets – finite life, net at beginning of period	$ 49,956	$ 60,728
Amortization expense	(2,555)	(2,890)
Divestitures	(2,372)
Foreign currency adjustments	259	68
Intangible assets – finite life, net at end of period	$ 45,288	$ 57,906