Goodwill and Intangible Assets - Goodwill / Tradename (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill, beginning balance	$ 152,156	$ 166,951
Goodwill, divestitures		(14,317)
Goodwill, foreign currency translation	43	(478)
Goodwill, ending balance	152,199	152,156
Tradename, beginning balance	18,258	19,691
Tradename, transfers to finite life classification	3,904
Tradename, divestitures		(1,340)
Tradename, foreign currency translation	(12)	(93)
Tradename, ending balance	$ 14,342	$ 18,258