v3.25.2
Equity - Options valuation assumptions and additional information (Details) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Valuation assumptions      
Range of expected share price volatility, minimum   103.20% 103.20%
Range of expected share price volatility, maximum   121.85% 121.85%
Range of weighted average of risk-free interest rate, minimum   4.33% 4.33%
Range of weighted average of risk-free interest rate, maximum   4.50% 4.50%
Weighted average grant date fair value of options granted   $ 2.13 $ 2.41
Total intrinsic value of options exercised $ 1.4 $ 2.7 $ 4.8
Minimum      
Valuation assumptions      
Range of estimated life (years)   4 years 6 months 4 years 6 months
Maximum      
Valuation assumptions      
Range of estimated life (years)   8 years 8 years