v3.26.1
Stockholders' equity - Schedule of Changes in Accumulated Other Comprehensive Loss (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income Loss        
Balance at beginning of period     $ 358,769  
Balance at end of period $ 363,033   363,033  
Currency translation        
Accumulated Other Comprehensive Income Loss        
Balance at beginning of period (177,512) $ (185,423) (176,497) $ (181,238)
Other comprehensive income (loss) (1,042) 3,437 (27) 7,622
Balance at end of period (177,539) (177,801) (177,539) (177,801)
Defined benefit pension plans | Defined benefit pension plans        
Accumulated Other Comprehensive Income Loss        
Balance at beginning of period (17,359) (36,666) (17,273) (36,349)
Other comprehensive income (loss) 85 323 171 640
Balance at end of period (17,188) (36,026) (17,188) (36,026)
Other | OPEB plans        
Accumulated Other Comprehensive Income Loss        
Balance at beginning of period (1,196) (1,267) (1,195) (1,300)
Other comprehensive income (loss) 2 (31) 3 (64)
Balance at end of period (1,193) (1,331) (1,193) (1,331)
Total accumulated other comprehensive loss        
Accumulated Other Comprehensive Income Loss        
Balance at beginning of period (196,067) (223,356) (194,965) (218,887)
Other comprehensive income (loss) (955) 3,729 147 8,198
Balance at end of period $ (195,920) $ (215,158) $ (195,920) $ (215,158)