Nature of business, basis of presentation and summary of significant accounting policies (Details Textual) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended								1 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Apr. 23, 2012 April 2012 Note And Warrant Purchase Agreement [Member]	Sep. 14, 2012 September 2012 Note Purchase Agreement [Member]	Sep. 02, 2011 Unsecured Demand Notes One And Two [Member]	Feb. 17, 2012 Unsecured Demand Note Three [Member]	Mar. 05, 2012 Unsecured Demand Note Four [Member]	Nov. 30, 2012 Series D Financing [Member]	Dec. 31, 2012 Series D Two Preferred Stock For Cash [Member]	Dec. 31, 2010 Series D Two Preferred Stock For Cash [Member]
Nature Of Business Basis Of Presentation And Summary Of Significant Accounting Policies Textual Abstract
Cash and Cash Equivalents, at Carrying Value	$ 486	$ 307	$ 1,879
Accumulated deficit	(114,420)	(111,305)
Ownership percentage of company's Joint Venture in the People's Rebublic of China	90.00%
Subsidiary, Sale of Stock [Line Items]
Purchase price per share for the shares sold in private placement					$ 1.00						$ 1.00
Aggregate amount of loans borrowed					1,103	100	25	100
Stated percentage of loans borrowed				10.00%	10.00%	10.00%	10.00%	10.00%
Conversion of short-term debt and accrued interest, net of offering costs									3,099
Series D-2 Preferred Shares issued in a private placement for cash, net of offering expenses, shares	1,082
Net proceeds from issuance of Series D-2 preferred shares	967
Offering expenses									$ 190	$ 115