Description of Operations and Summary of Significant Accounting Policies - Summary of Select Unaudited Condensed Consolidated Statement of Operations Reflect Adoption of Accounting Standards (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating expenses
Sales and marketing	$ 22,678	$ 19,617
Loss from operations	(8,073)	(7,297)
Foreign exchange loss	114	(53)
Net loss	$ (8,099)	$ (7,139)	[1]
Net loss per share attributable to common stockholders, basic and diluted	$ (0.19)	$ (0.19)
ASU 2014-09 | As Previously Reported
Operating expenses
Sales and marketing		$ 19,026
Loss from operations		(6,706)
Foreign exchange loss		(52)
Net loss		$ (6,547)
Net loss per share attributable to common stockholders, basic and diluted		$ (0.17)
ASU 2014-09 | Adjustments
Operating expenses
Sales and marketing		$ 591
Loss from operations		(591)
Foreign exchange loss		(1)
Net loss		$ (592)
Net loss per share attributable to common stockholders, basic and diluted		$ (0.02)

[1] See Note 1 for a summary of adjustments