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		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 18,770	$ 13,732	$ 35,327	$ 23,381	$ 52,416
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	559	595	1,149	1,021	2,231
Research, development and clinical trials
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	3,779	1,813	7,173	3,001	7,570
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	4,769	3,255	8,385	5,217	11,897
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total share-based compensation expense	$ 9,663	$ 8,069	$ 18,620	$ 14,142	$ 30,718