Summary of Revenues Disaggregated by Timing of Goods and Services Transferred (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Net revenue	$ 37,799	$ 46,155	$ 46,926
Revenue Recognized Over Time
Disaggregation Of Revenue [Line Items]
Net revenue	7,174	6,441	7,123
Revenue Recognized at a Point in Time
Disaggregation Of Revenue [Line Items]
Net revenue	$ 30,625	$ 39,714	$ 39,803