Equity Incentive Plans - 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, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 8,629	$ 5,626	$ 20,760	$ 16,719	$ 21,441
Cost of Revenues
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	79	160	353	471	623
Research, Development and Clinical Trials
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	972	776	2,645	2,378	3,155
Sales and Marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	1,874	1,249	4,264	3,888	5,111
General and Administrative
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total share-based compensation expense	$ 5,704	$ 3,441	$ 13,498	$ 9,982	$ 12,552