Stock-Based Compensation - Stock-Based Compensation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	$ 2,479	$ 4,133
Cost of Revenues [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	272	408
Research and Development [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	530	652
Sales and Marketing [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	559	672
General and Administrative [Member]
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock compensation expense	$ 1,118	$ 2,401