Major Customers and Foreign Sales - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Major Customers [Line Items]
Sales outside Country, percentage	32.00%	37.00%	38.00%
Europe [Member]
Major Customers [Line Items]
Sales outside Country, percentage	6.00%
Long lived assets located outside Country	$ 19.6
Outside United States [Member]
Major Customers [Line Items]
Long lived assets located outside Country	$ 35.4	$ 34.8
Asia [Member]
Major Customers [Line Items]
Sales outside Country, percentage	12.00%
Long lived assets located outside Country	$ 13.6
Net Sales [Member] | Customer Concentration Risk [Member]
Major Customers [Line Items]
Major customer	10.00%	10.00%	10.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Major Customers [Line Items]
Major customer	10.00%	10.00%	10.00%