Stockholders' Equity and Stock-based Compensation Expense - Stock-based Compensation Expense By Department (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 3,742	$ 1,982	$ 8,507	$ 8,057
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	330	326	908	1,359
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	711	648	1,954	2,618
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,020	254	1,628	1,344
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,681	$ 754	$ 4,017	$ 2,736