Subsequent events (Details Textual) (USD $)	9 Months Ended				3 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011		Sep. 30, 2012 S-3 Registration Statement [Member]	Sep. 30, 2012 S-3 Registration Statement [Member] Series Convertible Preferred Shares and Warrants [Member]	Sep. 30, 2012 S-3 Registration Statement [Member] Common Stock [Member]	Sep. 30, 2012 Senior Secured Convertible Notes [Member]
Extinguishment of Debt, Amount								$ 3,500,000
Extinguishment of Debt, Shares Issued								100,000
Value of Shares Issued for Extinguishment of Debt								318,000
Deferred Finance Costs, Net	472,000		0	[1]				472,000
Warrant Discount								409,000
Debt Instrument, Convertible, Beneficial Conversion Feature	500,000	0						409,000
Subsequent Event, Date					Nov. 02, 2012			Nov. 06, 2012
Stock Issued During Period, Value, Issued for Cash					5,900,000		1,400,000
Stock and Warrants Issued During Period, Value, Preferred Stock and Warrants						$ 4,500,000
Stock Issued During Period, Shares, Issued for Cash						1,380,362	453,000
Number of Warrants Issued During Period						2,760,724
Conversion Price						$ 3.26
Preferred Stock, Dividend Rate, Percentage						6.00%
Exercise Price of Warrants						$ 3.85
Stock Issued During Period Price Per Share							$ 3.01

[1] Derived from audited financial information