Equity Incentive Plans - Summary of Stock Based Compensation Expenses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based Compensation	$ 4,357	$ 2,487	$ 11,667	$ 6,902
Cost of Revenue Subscription
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based Compensation	330	232	927	564
Cost of Revenue Professional Services
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based Compensation	294	190	842	557
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based Compensation	1,179	698	3,332	1,965
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based Compensation	1,239	735	3,316	2,176
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based Compensation	$ 1,315	$ 632	$ 3,250	$ 1,640