Summary of Disaggregation of Revenues Related to Geographic Areas (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Net revenue	$ 22,780	$ 37,799	$ 46,155
United States
Disaggregation Of Revenue [Line Items]
Net revenue	16,195	22,814	28,661
International
Disaggregation Of Revenue [Line Items]
Net revenue	$ 6,585	$ 14,985	$ 17,494