Convertible notes payable (Details)				12 Months Ended
	Feb. 11, 2016 USD ($) item $ / shares shares	Jan. 19, 2016 item $ / shares	Oct. 27, 2015 USD ($) item $ / shares	Dec. 31, 2015 USD ($)
Interest expense associated to amortization of loan costs				$ 54,000
Convertible note payable (Note 11)				3,702,000
Derivative liability				488,000
Sentient Loan
Fair value of imbedded derivative			$ 1,100,000	500,000
Gain (loss) on imbedded derivative				600,000
Sentient Loan | Convertible loan
Principal amount of loan			$ 5,000,000
Stock price trigger (in dollars per share) | $ / shares			$ 0.29
Consecutive trading days, period | item			15
Interest rate (as a percent)			9.00%
Legal and other associated costs			$ 300,000
Interest expense associated to amortization of loan costs				$ 54,000
Maximum penalty for not registering the issued shares (as a percent)			3.00%
Effective interest rate (as a percent)				21.00%
Subsequent Event | Sentient Loan | Convertible loan
Stock price trigger (in dollars per share) | $ / shares		$ 0.29
Stock price trigger (as a percent)	90.00%	90.00%
Consecutive trading days, period | item	15	15
Amount of debt converted to equity	$ 3,900,000
Amount of accrued interest converted to equity	$ 100,000
Equity shares issued upon conversion of debt | shares	23,335,000
Exercise price per share of shares converted from debt | $ / shares	$ 0.172
Debt outstanding	$ 1,100,000
Period Preceding Loan Closure Date | Sentient Loan | Convertible loan
Stock price trigger (as a percent)			90.00%
Period Preceding Loan Conversion Date | Sentient Loan | Convertible loan
Stock price trigger (as a percent)			90.00%
Period Preceding Loan Conversion Date | Subsequent Event | Sentient Loan | Convertible loan
Stock price trigger (as a percent)	90.00%
Consecutive trading days, period | item	15