Goodwill and Intangible Assets - Intangible Assets - Finite Life (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Cost	$ 93,972	$ 92,908
Accumulated Amortization	38,523	32,180
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	15,867	15,867
Accumulated Amortization	7,472	6,360
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	77,497	77,497
Accumulated Amortization	30,524	26,041
Non-compete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	1,118	1,118
Accumulated Amortization	588	478
Tradename [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	1,390	1,390
Accumulated Amortization	371	301
Foreign Currency Adjustments [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	(1,900)	(2,964)
Accumulated Amortization	$ (432)	$ (1,000)