CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (unaudited) - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue		$ 65,205	$ 55,309	$ 186,392	$ 161,761
Cost of revenue	[1]	23,213	16,241	58,967	47,083
Gross profit		41,992	39,068	127,425	114,678
Operating expenses:
Research and development	[1]	51,765	14,910	85,997	39,890
Sales and marketing	[1],[2]	34,309	18,878	71,609	55,791
General and administrative	[1]	50,391	11,169	76,809	35,298
Restructuring		0	2	33	147
Total operating expenses		136,465	44,959	234,448	131,126
Loss from operations		(94,473)	(5,891)	(107,023)	(16,448)
Interest expense		7,496	6,714	22,181	20,030
Other non-operating income (expense), net		(219)	774	132	7,950
Loss before income taxes		(102,188)	(11,831)	(129,072)	(28,528)
Provision for income taxes		174	1,151	470	3,551
Net loss		$ (102,362)	$ (12,982)	$ (129,542)	$ (32,079)
Net loss per share, basic and diluted		$ (0.99)	$ (0.13)	$ (1.27)	$ (0.32)
Weighted-average shares used in computing basic and diluted net loss per share		103,096	100,584	101,984	100,056

[1] Includes stock-based compensation, net of amounts capitalized as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Cost of revenue $6,472 $634 $7,776 $1,870 Research and development 37,490 2,799 43,903 7,065 Sales and marketing 14,496 1,322 16,411 6,622 General and administrative 40,354 3,667 48,014 10,806 Stock-based compensation, net of amounts capitalized $98,812 $8,422 $116,104 $26,363

[2] Includes amortization of acquisition intangible assets as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Cost of revenue $488 $488 $1,464 $1,552 Sales and marketing 565 604 1,773 1,817 Amortization of acquisition intangible assets $1,053 $1,092 $3,237 $3,369