Derivative liability - Summary of derivative liability (Details) (USD $)
12 Months Ended 45 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2013
Schedule Of Derivative Liabilities [Roll Forward]        
Opening balance $ 121,000 $ 106,146    
Issuance of units 3,681,372 333,356    
Dividend warrant liability acquired on reverse acquisition 2,041,680       
Warrants issued for services 124,020 49,379    
Change in fair value of derivative liability (1,324,051) (318,502)    (1,642,553)
Reclassification to equity upon exercise of warrants (241,715)       
Closing balance $ 4,402,306 $ 121,000 $ 106,146 $ 4,402,306