Goodwill and Intangible Assets - Finite Lived Intangible Assets Amortization Expense (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Intangible assets - finite life, Beginning of period			$ 74,957	$ 58,398
Amortization expense	$ (3,500)	$ (3,300)	(11,123)	(8,513)
Acquisitions and purchase accounting adjustments				34,900
Foreign currency adjustments			142	(810)
Intangible assets - finite life, End of period	$ 63,976	$ 83,975	$ 63,976	$ 83,975