Total Net Sales Based on Disaggregation Criteria (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Total net sales	$ 78,142	$ 60,219
Point-in-Time
Disaggregation Of Revenue [Line Items]
Total net sales	73,714	58,663
Over Time
Disaggregation Of Revenue [Line Items]
Total net sales	4,428	1,556
Americas
Disaggregation Of Revenue [Line Items]
Total net sales	60,153	40,018
Americas | Point-in-Time
Disaggregation Of Revenue [Line Items]
Total net sales	55,906	38,502
Americas | Over Time
Disaggregation Of Revenue [Line Items]
Total net sales	4,247	1,516
Europe and the Middle East
Disaggregation Of Revenue [Line Items]
Total net sales	9,943	7,887
Europe and the Middle East | Point-in-Time
Disaggregation Of Revenue [Line Items]
Total net sales	9,785	7,847
Europe and the Middle East | Over Time
Disaggregation Of Revenue [Line Items]
Total net sales	158	40
Asia-Pacific
Disaggregation Of Revenue [Line Items]
Total net sales	8,046	12,314
Asia-Pacific | Point-in-Time
Disaggregation Of Revenue [Line Items]
Total net sales	8,023	$ 12,314
Asia-Pacific | Over Time
Disaggregation Of Revenue [Line Items]
Total net sales	$ 23