Balance Sheet Components - Schedule of Deferred Revenue (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Deferred Revenue [Line Items]
Total deferred revenue	$ 13,054	$ 14,010
Less: current portion of deferred revenue	(9,861)	(10,457)
Noncurrent portion of deferred revenue	3,193	3,553
Product
Deferred Revenue [Line Items]
Total deferred revenue	3,026	3,141
Service
Deferred Revenue [Line Items]
Total deferred revenue	7,751	8,473
Distribution Rights
Deferred Revenue [Line Items]
Total deferred revenue	$ 2,277	$ 2,396