CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Software subscriptions	$ 463,163	$ 355,850	$ 271,245
Other	38,363	23,874	24,983
Total revenues	501,526	379,724	296,228
Cost of revenues
Software subscriptions	89,193	73,470	66,354
Other	32,078	18,741	20,917
Total cost of revenues	121,271	92,211	87,271
Gross profit	380,255	287,513	208,957
Operating expenses
Research and development	75,148	65,514	52,924
Sales and marketing	260,069	192,497	139,851
General and administrative	72,313	55,454	47,114
Total operating expenses	407,530	313,465	239,889
Loss from operations	(27,275)	(25,952)	(30,932)
Other income (expense), net
Interest expense	(99)	(746)	(1,123)
Other income (expense), net	1,491	(2,375)	(1,307)
Other income (expense), net	1,392	(3,121)	(2,430)
Loss before provision (benefit) for income taxes	(25,883)	(29,073)	(33,362)
Provision (benefit) for income taxes	258	236	(1,263)
Net loss	$ (26,141)	$ (29,309)	$ (32,099)
Net loss per common share
Basic and diluted	$ (0.34)	$ (0.40)	$ (0.46)
Weighted-average number of shares used in computing net loss per share
Basic and diluted	76,281	72,994	70,069