Business Segments, Geographic Data, and Sales by Major Customers - Information by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 20,156		$ 20,902
Net sales	70,826	$ 93,004
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	15,489		15,825
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	4,526		4,920
Net sales	57,558	71,373
Hong Kong
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	141		$ 157
Net sales	255	227
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	7,191	8,629
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	2,560	3,761
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 3,262	$ 9,014