Consolidated Statements of Operations - USD ($) shares in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Net revenue:
Products	$ 99,028,000	$ 77,022,000	$ 60,299,000
Sales Revenue, Services, Net	19,028,000	17,739,000	17,839,000
Total net revenue	118,056,000	94,761,000	78,138,000
Cost of revenue:
Products	40,149,000	32,402,000	26,796,000
Service	9,772,000	8,076,000	7,969,000
Total cost of revenue	49,921,000	40,478,000	34,765,000
Gross profit	68,135,000	54,283,000	43,373,000
Operating expenses:
Sales and marketing	41,563,000	35,942,000	32,246,000
Research and development	11,232,000	10,733,000	10,543,000
General and administrative	12,943,000	12,129,000	11,203,000
Total operating expenses	65,738,000	58,804,000	53,992,000
Income (loss) from operations	2,397,000	(4,521,000)	(10,619,000)
Interest and other income, net	323,000	293,000	226,000
Income (loss) before income taxes	2,720,000	(4,228,000)	(10,393,000)
Income tax provision	143,000	212,000	219,000
Net income (loss)	$ 2,577,000	$ (4,440,000)	$ (10,612,000)
Net income (loss) per share:
Basic (in dollars per share)	$ 0.19	$ (0.32)	$ (0.74)
Diluted (in dollars per share)	$ 0.19	$ (0.32)	$ (0.74)
Weighted-average number of shares used in per share calculations:
Basic (in shares)	13,225	13,960	14,254
Diluted (in shares)	13,753	13,960	14,254