Condensed Consolidated Statements of Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenues		$ 92,380	$ 71,296
Cost of revenues	[1]	53,107	37,184
Gross profit		39,273	34,112
Operating expenses:
Sales and marketing	[1]	19,884	15,805
Research and development	[1]	24,958	17,657
General and administrative	[1]	19,110	13,860
Acquisition related costs		(1,967)	2,718
Amortization of acquired intangibles		4,491	1,215
Total operating expenses		66,476	51,255
Loss from operations		(27,203)	(17,143)
Other income (expense):
Interest and other income		456	807
Interest and other expense		(6,921)	(3,014)
Total other income (expense), net		(6,465)	(2,207)
Loss before income taxes		(33,668)	(19,350)
Benefit from (provision for) income taxes		(440)	39
Net loss		(34,108)	(19,311)
Other comprehensive loss:
Unrealized gain (loss) on available-for-sale investments		(122)	113
Foreign currency translation adjustment		(55)	12
Comprehensive loss		$ (34,285)	$ (19,186)
Net loss per common share, basic and diluted (usd per share)		$ (0.70)	$ (0.44)
Weighted average common shares outstanding:
Basic and diluted (in shares)		48,581	43,773

[1] Includes stock-based compensation expenses as follows:     Three Months Ended March 31,     2020   2019 Cost of revenues   $ 3,408
  $ 1,548
Sales and marketing   2,754
  1,806
Research and development   3,770
  2,012
General and administrative   4,604
  3,530
Total stock-based compensation expenses   $ 14,536
  $ 8,896