CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues, net	$ 6,796	$ 11,728	$ 22,731	$ 37,652
Cost of revenues	4,323	5,567	14,253	17,307
Gross profit	2,473	6,161	8,478	20,345
Operating expenses
Sales and marketing	1,491	3,732	5,683	12,453
Research and development	3,106	3,872	9,881	13,427
General and administrative	2,131	2,631	6,123	8,129
Total operating expenses	6,728	10,235	21,687	34,009
Loss from operations	(4,255)	(4,074)	(13,209)	(13,664)
Other income, net	111	640	1,117	1,712
Loss before benefit from income taxes	(4,144)	(3,434)	(12,092)	(11,952)
Benefit from income taxes	(72)	(161)	(568)	(70)
Net loss	(4,072)	(3,273)	(11,524)	(11,882)
Foreign currency translation adjustments	(41)	(54)	47	(49)
Comprehensive loss	$ (4,113)	$ (3,327)	$ (11,477)	$ (11,931)
Net loss per share available to common stockholders, basic and diluted (Note 11)	$ (0.58)	$ (0.49)	$ (1.67)	$ (1.90)
Weighted-average shares used to compute net loss per share available to common stockholders, basic and diluted	7,017	6,631	6,916	6,262
Stock-based compensation expense	$ 195	$ 653	$ 1,208	$ 2,100
Amortization of intangible assets			95	1,468
Cost of Revenues [Member]
Operating expenses
Stock-based compensation expense	(19)	127	204	394
Amortization of intangible assets	0	234	47	702
Restructuring related expenses	529	0	522	6
Sales and Marketing [Member]
Operating expenses
Stock-based compensation expense	24	155	283	540
Amortization of intangible assets	0	0	0	64
Restructuring related expenses	214	0	264	223
Research and Development [Member]
Operating expenses
Stock-based compensation expense	123	266	507	816
Amortization of intangible assets	0	234	48	702
Restructuring related expenses	185	0	185	0
General and Administrative [Member]
Operating expenses
Stock-based compensation expense	67	105	214	350
Restructuring related expenses	$ 123	$ 0	$ 123	$ 0