Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Income Statement [Abstract]
Revenue	$ 84,074	$ 85,214
Cost of revenue	44,516	49,009
Gross profit	39,558	36,205
Operating expenses:
Research and development	23,795	22,775
Selling, general and administrative	20,636	21,220
Total operating expenses	44,431	43,995
Loss from operations	(4,873)	(7,790)
Interest expense	(1,714)	(1,512)
Other expense, net	(28)	(66)
Loss before income taxes	(6,615)	(9,368)
Income tax benefit	8	26
Net loss	(6,607)	(9,342)
Net loss attributable to common stockholder and comprehensive loss	$ (6,607)	$ (9,342)
Net loss per share attributable to common stockholder, basic and diluted	$ (0.63)	$ (0.93)
Weighted-average shares used to compute basic and diluted net loss per share	10,558	10,000