Summary of Revenues Disaggregated by Timing of Goods and Services Transferred (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Net revenue	$ 2,938	$ 8,645	$ 7,721	$ 18,971
Revenue Recognized Over Time
Disaggregation Of Revenue [Line Items]
Net revenue	985	1,646	2,006	3,415
Revenue Recognized at a Point in Time
Disaggregation Of Revenue [Line Items]
Net revenue	$ 1,953	$ 6,999	$ 5,715	$ 15,556