v3.21.2
Warrant derivative liability (Warrant activity) (Details) - $ / shares
 1 Months Ended 12 Months Ended
Jan. 31, 2018
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Warrant derivative liability        
Number of Warrants, Outstanding at Beginning   817,489 817,489  
Number of Warrants, Exercisable at Beginning   817,489 817,489  
Number of Warrants, Exercised 174,903 (298,914)    
Number of Warrants, Outstanding at Ending     817,489 817,489
Number of Warrants, Exercisable at Ending   518,575 817,489 817,489
Average Exercise Price, Outstanding at Beginning   $ 1.00 $ 1.00  
Average Exercise Price, Exercisable at Beginning   1.00 1.00  
Average Exercise Price, Exercised   1.00    
Average Exercise Price, Outstanding at Ending     1.00 $ 1.00
Average Exercise Price, Exercisable at Ending   $ 1.00 $ 1.00 $ 1.00
Weighted Average Remaining Contractual Contractual Term in Years, Granted     0 years  
Weighted Average Remaining Contractual Contractual Term in Years, Outstanding     1 year 3 months 4 days 2 years 3 months 4 days
Weighted Average Remaining Contractual Contractual Term in Years, Exercisable   3 months 4 days 0 years 0 years