v3.26.1
Other investments (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Other investments    
Investments, Current $ 43,249 $ 45,408
Investments, non-current 19,013 $ 16,415
3.875% US treasury bills    
Other investments    
Investments, Current 5,162  
Interest rate   3.875%
0% US treasury bills | Financial assets at amortized cost    
Other investments    
Investments, Current $ 12,891 $ 15,440
Interest rate 0.00% 0.00%
0.75% US treasury bills | Financial assets at amortized cost    
Other investments    
Investments, Current $ 19,957 $ 24,815
Interest rate 0.75% 0.75%
iShares USD Treasury Bond 0-1yr UCITS ETF    
Other investments    
Investments, Current $ 5,239 $ 5,153
1.7% federal bonds German Government | Fair value through other comprehensive income    
Other investments    
Investments, non-current $ 3,243 $ 3,341
Interest rate 1.70% 1.70%
iShares 20+ Year Treasury Bond ETF (TLT) | Financial assets measured at fair value    
Other investments    
Investments, non-current $ 12,963 $ 13,074
iShares Treasury Bond 1-3yr Acc UCITS ETF    
Other investments    
Investments, non-current $ 2,807