Goodwill and Intangible Assets - Summary of Other Intangible Assets (Detail) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Cost	$ 34,334	$ 34,334
Accumulated Amortization	33,545	33,305
Net Book Value	789	1,029
Customer Contracts and Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Cost	16,880	16,880
Accumulated Amortization	16,880	16,880
Net Book Value	0	0
Patents and Technology [Member]
Finite Lived Intangible Assets [Line Items]
Cost	10,114	10,114
Accumulated Amortization	9,503	9,336
Net Book Value	611	778
Trademarks and Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Cost	4,834	4,834
Accumulated Amortization	4,656	4,607
Net Book Value	178	227
Other [Member]
Finite Lived Intangible Assets [Line Items]
Cost	2,506	2,506
Accumulated Amortization	2,506	2,482
Net Book Value	$ 0	$ 24