Business Segments, Geographic Data, and Sales by Major Customers - Information by Geographic Area (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	$ 21,107		$ 21,107		$ 20,902
Net sales	95,182	$ 105,781	166,008	$ 198,785
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	16,758		16,758		15,825
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	4,121		4,121		4,920
Net sales	82,409	79,673	139,967	151,046
Hong Kong
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived Assets	228		228		$ 157
Net sales	937	300	1,192	527
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	6,546	15,307	13,737	23,936
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	2,182	3,811	4,742	7,572
Other
Revenues from External Customers and Long-Lived Assets [Line Items]
Net sales	$ 3,108	$ 6,690	$ 6,370	$ 15,704