Equity Incentive Plans and ESPP - Schedule of Non-cash Share-Based Compensation Expenses Related to Company's Equity-Based Awards (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 20,121	$ 14,338	$ 55,448	$ 37,719	$ 52,416
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	767	605	1,916	1,626	2,231
Research, development and clinical trials
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	5,101	2,202	12,275	5,203	7,570
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	4,677	3,368	13,061	8,585	11,897
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 9,576	$ 8,163	$ 28,196	$ 22,305	$ 30,718