Goodwill and Intangible Assets - Intangible Assets - Finite Life (Detail) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Cost	$ 91,846	$ 86,825
Accumulated Amortization	60,369	55,542
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	14,457	14,457
Accumulated Amortization	12,425	10,686
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	73,199	68,943
Accumulated Amortization	47,754	44,484
Tradename [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	6,578	5,294
Accumulated Amortization	1,582	1,154
Foreign Currency Adjustments [Member]
Finite-Lived Intangible Assets [Line Items]
Cost	(2,388)	(1,869)
Accumulated Amortization	$ (1,392)	$ (782)