Annual report pursuant to Section 13 and 15(d)

Commitments and contingencies - Operating Lease Obligations (Details)

v3.3.1.900
Commitments and contingencies - Operating Lease Obligations (Details)
 12 Months Ended
Dec. 31, 2015
USD ($)
Dec. 31, 2014
USD ($)
Jan. 31, 2012
vehicle
Operating Leased Assets [Line Items]      
Future minimum payments receivable $ 65,748    
Office space and warehouse facilities      
Operating Leased Assets [Line Items]      
Rent expense, gross 637,588 $ 615,602  
Rent expense, sublease rent offset 113,472 201,440  
Rent expense, net 524,116 414,162  
Vehicles      
Operating Leased Assets [Line Items]      
Rent expense, net $ 7,547 $ 1,839  
Operating Leased Assets, Number of Assets | vehicle     2