Intangibles, Net - Schedule of Intangibles, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Cost	$ 155,453	$ 155,246
Accumulated Amortization	(143,655)	(140,128)
Net	11,798	15,118
Trademarks
Finite-Lived Intangible Assets [Line Items]
Cost	13,540	13,540
Accumulated Amortization	(9,304)	(8,752)
Net	4,236	4,788
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Cost	99,133	98,926
Accumulated Amortization	(92,072)	(89,705)
Net	7,061	9,221
Patents
Finite-Lived Intangible Assets [Line Items]
Cost	42,780	42,780
Accumulated Amortization	(42,279)	(41,671)
Net	$ 501	$ 1,109