Consolidated Statement of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue
Subscription	$ 155,417	$ 130,061	$ 99,924
Professional services	33,102	30,508	29,327
Total revenue	188,519	160,569	129,251
Cost of revenue
Subscription	29,650	27,298	23,457
Professional services	28,903	26,862	25,720
Total cost of revenue	58,553	54,160	49,177
Gross profit	129,966	106,409	80,074
Operating expenses
Research and development	40,550	35,475	30,553
Sales and marketing	87,949	75,856	71,337
General and administrative	27,706	23,229	17,763
Total operating expenses	156,205	134,560	119,653
Loss from operations	(26,239)	(28,151)	(39,579)
Other income (expense)
Interest income (expense) and other, net	1,204	(1,533)	(18)
Foreign exchange loss	(25)	(1,417)	(1,301)
Loss before provision for income taxes	(25,060)	(31,101)	(40,898)
Provision for income taxes	(561)	(452)	(109)
Net loss	$ (25,621)	$ (31,553)	$ (41,007)
Net loss per share attributable to common stockholders, basic and diluted	$ (0.64)	$ (1.61)	$ (3.24)
Weighted-average shares used to compute net loss per share attributable to common stockholders, basic and diluted	39,754	19,595	12,653