Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021		Jun. 30, 2020		Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenue, net	$ 14,051		$ 9,253		$ 23,321	$ 23,027
Cost of revenue	6,940	[1]	4,204	[1]	12,485	11,203
Gross profit	7,111		5,049		10,836	11,824
Operating expenses:
Research and development	6,671	[2]	6,314	[2]	13,456	12,581
Selling, general and administrative	4,896	[3]	5,156	[3]	9,750	10,349
Restructuring	0		0		0	592
Total operating expenses	11,567		11,470		23,206	23,522
Loss from operations	(4,456)		(6,421)		(12,370)	(11,698)
Interest income (expense) and other, net	181		(24)		237	30
Total other income (expense), net	181		(24)		237	30
Loss before income taxes	(4,275)		(6,445)		(12,133)	(11,668)
Provision for income taxes	107		107		324	283
Net loss	$ (4,382)		$ (6,552)		$ (12,457)	$ (11,951)
Net loss per share - basic and diluted	$ (0.08)		$ (0.17)		$ (0.24)	$ (0.31)
Weighted average shares outstanding - basic and diluted	52,283		39,444		51,980	39,156

[1] (1) Includes:Amortization of acquired intangible assets218 298 463 596 Stock-based compensation76 127 155 228 

[2] (2) Includes stock-based compensation610 806 1,191 1,454 

[3] (3) Includes:Stock-based compensation820 1,310 1,592 2,383 Amortization of acquired intangible assets53 76 113 152