Consolidated statements of operations (unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Revenue	$ 14,469	$ 10,555	$ 28,737	$ 18,862
Cost of goods sold	21,743	16,972	43,505	28,654
Gross loss	(7,274)	(6,417)	(14,768)	(9,792)
Operating expenses:
General and administrative	2,197	2,215	4,585	4,405
Sales and marketing	332	414	799	763
Research and development	391	495	967	877
(Gain) loss on disposal of assets	(15)	427	(15)	427
Loss from operations	(10,179)	(9,968)	(21,104)	(16,264)
Other income:
Interest income	23	13	44	26
Interest expense	(24)	(24)	(47)	(47)
Realized gain (loss) on foreign currency translation	196	(194)	235	(306)
Total other income (expense)	195	(205)	232	(327)
Loss before income taxes	(9,984)	(10,173)	(20,872)	(16,591)
Income tax benefit (expense)		4,279	(6)	7,321
Net loss	$ (9,984)	$ (5,894)	$ (20,878)	$ (9,270)
Net loss per common share
Basic	$ (0.39)	$ (0.26)	$ (0.82)	$ (0.41)
Diluted	$ (0.39)	$ (0.26)	$ (0.82)	$ (0.41)
Weighted average common shares outstanding used in computing net loss per common share	25,706,797	22,560,603	25,511,972	22,555,490