Employee pension (Additional Information) (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Percentage of monthly contributions made by the company to the state retirement plan | 20.00% | ||
| Percentage of monthly salaries for all Australia based employees to mandatory provident fund Schemes | 5.00% | ||
| Percentage of monthly salaries for all Australia based employees to Superannuation Schemes | 9.50% | ||
| Continuing Operations [Member] | |||
| Pension expense | $ 20 | $ 21 | $ 8 |
| Discontinued Operations [Member] | |||
| Pension expense | $ 4 | $ 4 | $ 5 |