Consolidated statements of operations (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Income Statement [Abstract]
Revenue	$ 10,555	$ 17,003	$ 18,862	$ 27,210
Cost of goods sold	16,972	16,992	28,654	30,607
Gross (loss) profit	(6,417)	11	(9,792)	(3,397)
Operating expenses:
General and administrative	2,215	2,044	4,405	4,350
Sales and marketing	414	473	763	929
Research and development	495	597	877	1,073
Loss (gain) on disposal of assets	427	(5)	427	(5)
Loss from operations	(9,968)	(3,098)	(16,264)	(9,744)
Other income:
Interest income	13	23	26	56
Interest expense	(24)		(47)
Realized (loss) gain on foreign currency translation	(194)	(311)	(306)	31
Total other (expense) income	(205)	(288)	(327)	87
Loss before income taxes	(10,173)	(3,386)	(16,591)	(9,657)
Income tax benefit	4,279	2,074	7,321	4,978
Net loss	$ (5,894)	$ (1,312)	$ (9,270)	$ (4,679)
Net loss per common share
Basic	$ (0.26)	$ (0.06)	$ (0.41)	$ (0.21)
Diluted	$ (0.26)	$ (0.06)	$ (0.41)	$ (0.21)
Weighted average common shares outstanding used in computing net loss per common share	22,560,603	22,518,364	22,555,490	22,516,451