Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Income Statement [Abstract]
Revenues	$ 5,644	$ 14,254	$ 16,362	$ 27,465
Cost of sales	3,215	7,088	8,296	13,058
Gross margin	2,429	7,166	8,066	14,407
Operating expenses:
Sales and marketing	2,265	7,803	8,595	15,500
General and administrative	2,157	3,343	5,496	7,060
Research and development	1,815	2,689	3,962	6,117
Amortization of intangible assets	490	528	986	1,081
Settlement gain	0	0	0	(5,609)
Total operating expenses	6,727	14,363	19,039	24,149
Loss from operations	(4,298)	(7,197)	(10,973)	(9,742)
Other expenses:
Interest expense, net	1,316	669	2,560	1,628
Other expense, net	633	908	2,927	157
Net loss before income taxes	(6,247)	(8,774)	(16,460)	(11,527)
Income tax expense	6	0	49	51
Net loss	(6,253)	(8,774)	(16,509)	(11,578)
Other comprehensive income:
Foreign currency translation	591	919	2,403	31
Comprehensive loss	$ (5,662)	$ (7,855)	$ (14,106)	$ (11,547)
Net loss per share, basic and diluted (USD per share)	$ (0.30)	$ (0.40)	$ (0.78)	$ (0.53)
Shares used in computing net loss per share, basic and diluted (shares)	21,152,937	21,926,891	21,135,032	21,917,140