v3.26.1
Income taxes - Income tax reconciliation (Details) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Taxes in amount    
U.S. federal statutory tax rate $ (0.4) $ 5.4
Effect of cross-border tax laws:    
Net controlled-foreign-corporation tested income 0.1 0.7
Incremental tax benefit on losses of subsidiary (0.1) (1.6)
Changes in unrecognized tax benefits 2.5 0.1
Income tax expense (benefit) $ 2.8 7.6
Taxes in percent    
U.S. Federal statutory income tax rate 21.00%  
Tax positions taken in current period $ 2.0  
Germany    
Taxes in amount    
Other 0.1 0.9
Belgium    
Taxes in amount    
Changes in valuation allowance 0.5 0.1
Other foreign jurisdictions    
Taxes in amount    
Other $ 0.1 0.6
United States    
Taxes in amount    
Changes in valuation allowance   $ 1.4