v3.25.1
Organization and description of business - Acquisition of Vision Lane (Details) - Vision Lane Limited - USD ($)
12 Months Ended
Mar. 08, 2019
Feb. 05, 2019
Dec. 31, 2018
Business combination consideration transferred $ 12,740,000 $ 12,420,000  
Cash   $ 7,460,000 $ 6,410,000
Paris Sky Limited      
Percentage of voting interests acquired   100.00%  
Business combination consideration transferred $ 12,700,000 $ 12,428,205  
Business acquisition, equity interest issued or issuable (in shares) 4,519,347 4,519,347  
Sale of stock, price per share $ 1.16 $ 1.1  
Cash   $ 7,500,000  
Fair value of equity issued in business acquisition $ 5,240,000