v3.21.2
Summary of significant accounting policies (Revenue by major product line and Foreign Currency translation) (Details)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
USD ($)
Dec. 31, 2019
USD ($)
Dec. 31, 2018
USD ($)
Dec. 31, 2016
Dec. 31, 2015
Revenues $ 4,293 $ 5,115 $ 1,570    
Foreign exchange 6.52 6.98   1.00  
Foreign Currency Exchange Rate 6.90 6.89 6.64   1.00
Maximum [Member]          
Foreign exchange 0.77        
Foreign Currency Exchange Rate 0.73        
Minimum [Member]          
Foreign exchange 1.00        
Foreign Currency Exchange Rate 1.00        
Interest On Loans [Member]          
Revenues $ 1,667 $ 3,930 $ 980    
Property lease and management          
Revenues 1,130 $ 1,185 $ 590    
Financial technology solution and services (Member)          
Revenues $ 1,496