Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 3,082	$ 5,172	$ 6,259	$ 9,831
Cost of sales	3,191	3,876	6,270	7,719
Gross profit (loss)	(109)	1,296	(11)	2,112
Operating expenses:
Product development	318	673	844	1,302
Selling, general, and administrative	1,594	2,421	3,835	5,068
Restructuring	128	3	262	(47)
Total operating expenses	2,040	3,097	4,941	6,323
Loss from operations	(2,149)	(1,801)	(4,952)	(4,211)
Other expenses (income):
Interest expense	26	1	69	2
Other expenses (income)	79	2	98	(19)
Net loss	$ (2,254)	$ (1,804)	$ (5,119)	$ (4,194)
Net loss per share - basic and diluted (in dollars per share)	$ (0.18)	$ (0.15)	$ (0.42)	$ (0.35)
Weighted average shares used in computing net loss per share:
Basic and diluted (in shares)	12,336	11,949	12,231	11,925