Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance at Dec. 31, 2012	$ 825	$ 0	$ 80,989	$ 460	$ (80,624)
Beginning balance (in shares) at Dec. 31, 2012		4,470
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, including under registered follow-on offering, net	2		2
Issuance of common stock under employee stock option and stock purchase plans	45		45
Issuance of common stock under employee stock option and stock purchase plans (in shares)		20
Convertible debt issued for financing	2,697		2,697
Issuance of common stock for conversion of convertible debt	1,501	$ 1	1,500
Issuance of common stock for conversion of convertible debt (in shares)		652
Stock-based compensation	201		201
Warrants issued	12		12
Foreign currency translation adjustment	2			2
Net income (loss)	(2,361)				(2,361)
Ending balance at Dec. 31, 2013	2,924	$ 1	85,446	462	(82,985)
Ending balance (in shares) at Dec. 31, 2013		5,142
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, including under registered follow-on offering, net	5,090		5,090
Issuance of common stock, including under registered follow-on offering, net (in shares)		1,343
Issuance of common stock under employee stock option and stock purchase plans	58		58
Issuance of common stock under employee stock option and stock purchase plans (in shares)		18
Issuance of common stock for conversion of convertible debt	6,145		6,145
Issuance of common stock for conversion of convertible debt (in shares)		2,672
Stock-based compensation	532		532
Warrants exercised	862		862
Warrants exercised (in shares)		249
Foreign currency translation adjustment	7			7
Net income (loss)	(5,845)				(5,845)
Ending balance at Dec. 31, 2014	9,773	$ 1	98,133	469	(88,830)
Ending balance (in shares) at Dec. 31, 2014		9,424
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, including under registered follow-on offering, net	23,574		23,574
Issuance of common stock, including under registered follow-on offering, net (in shares)		1,500
Issuance of common stock under employee stock option and stock purchase plans	346		346
Issuance of common stock under employee stock option and stock purchase plans (in shares)		77
Stock-based compensation	813		813
Stock-based compensation (shares)		10
Warrants exercised	2,503		2,503
Warrants exercised (in shares)		638
Foreign currency translation adjustment	(469)			(469)
Net income (loss)	8,780				8,780
Ending balance at Dec. 31, 2015	$ 45,320	$ 1	$ 125,369	$ 0	$ (80,050)
Ending balance (in shares) at Dec. 31, 2015		11,649