Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Net revenue:
Revenue from Contract with Customer, Including Assessed Tax	$ 181,712	$ 162,720		$ 151,493
Cost of revenue:
Cost of revenue	83,549	82,338		65,383
Gross profit	98,163	80,382		86,110
Operating expenses:
Sales and marketing	71,109	58,420		52,070
Research and development	15,085	14,359		12,874
General and administrative	24,033	20,995		14,090
Lease termination income				(4,000)
Total operating expenses	110,227	93,774		75,034
Income (loss) from operations	(12,064)	(13,392)		11,076
Interest and other income(expense), net	(199)	(123)	[1]	884
Income (loss) before income taxes	(12,263)	(13,515)		11,960
Income tax (benefit) provision	85	17,255		(18,033)
Net income (loss)	$ (12,348)	$ (30,770)		$ 29,993
Net loss per share:
Basic (in dollars per share)	$ (0.88)	$ (2.23)		$ 2.16
Diluted (in dollars per share)	$ (0.88)	$ (2.23)		$ 2.04
Weighted-average number of shares used in per share calculations:
Basic (in shares)	14,096	13,771		13,873
Diluted (in shares)	14,096	13,771		14,728
Product [Member]
Net revenue:
Revenue from Contract with Customer, Including Assessed Tax	$ 158,638	$ 142,535		$ 132,660
Cost of revenue:
Cost of revenue	64,693	66,843		56,363
Operating expenses:
Sales and marketing		58,420
Service [Member]
Net revenue:
Revenue from Contract with Customer, Including Assessed Tax	23,074	20,185		18,833
Cost of revenue:
Cost of revenue	$ 18,856	$ 15,495		$ 9,020

[1] Included in interest and other income, net, is the estimated interest expense for advance payment related to service contracts under the new revenue standard.