Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue:
Total revenue	$ 674,860	$ 512,980	$ 375,612
Cost of Revenue:
Total cost of revenue	129,958	100,357	75,729
Gross profit	544,902	412,623	299,883
Operating expenses:
Research and development	158,237	117,603	70,373
Sales and marketing	340,685	267,444	212,859
General and administrative	92,971	75,834	56,787
Total operating expenses	591,893	460,881	340,019
Loss from operations	(46,991)	(48,258)	(40,136)
Other expense:
Interest income	19,429	9,176	3,837
Interest expense	(22,818)	(21,386)	(13,181)
Other expense	(393)	(1,492)	(559)
Total other expense	(3,782)	(13,702)	(9,903)
Loss before income tax (expense) benefit	(50,773)	(61,960)	(50,039)
Income tax (expense) benefit	(2,973)	(1,868)	10,325
Net loss	$ (53,746)	$ (63,828)	$ (39,714)
Net loss per common share, basic and diluted	$ (1.28)	$ (1.66)	$ (1.08)
Weighted average common shares used in computing basic and diluted net loss per common share:	42,025	38,529	36,827
Subscription [Member]
Revenue:
Total revenue	$ 646,266	$ 487,450	$ 356,727
Cost of Revenue:
Total cost of revenue	98,510	69,718	51,563
Professional Services and Other [Member]
Revenue:
Total revenue	28,594	25,530	18,885
Cost of Revenue:
Total cost of revenue	$ 31,448	$ 30,639	$ 24,166