Subsequent events (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	Oct. 08, 2015	Sep. 30, 2015	Dec. 31, 2014
Common stock, par value (in dollars per share)		$ 0.001	$ 0.001
Subsequent Event [Member]
Proceeds from Sale of Units	$ 700
Units Issued price per unit	$ 0.25
Class of Warrant or Right, Exercise Price of Warrants or Rights	0.25
Warrants Exercisable Price per share	$ 0.25
Proceeds from Issuance of Warrants	$ 7,500
Class of Warrant or Right, Title of Security Warrants or Rights Outstanding	The Company is prohibited from effecting an exercise of any Warrant to the extent that, as a result of any such exercise, the holder would beneficially own more than 4.99% of the number of shares of Common Stock outstanding immediately after giving effect to the issuance of shares of Common Stock upon exercise of such Warrant, which beneficial ownership limitation may be increased by the holder up to, but not exceeding, 9.99%. The Warrants are also subject to certain adjustments upon certain actions by the Company as outlined in the Warrants. Prior to receipt of shareholder approval, the warrants, when aggregated with the shares of common stock issued in the offering, shall not be exercisable into more than 19.99% of the number of shares of Common Stock outstanding as of the closing date.
Common stock, par value (in dollars per share)	$ 0.001