v3.26.1
Provisions for pensions - Canada Provisions (Details)
 12 Months Ended
Dec. 31, 2025
USD ($)
plan
Dec. 31, 2024
USD ($)
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Provisions for pensions $ 28,903,000 $ 27,618,000
Pension Plans | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discount rate   3.40%
Discretionary contributions to the defined benefit pension and postretirement plans 625,000  
CANADA    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Provisions for pensions 5,036,000 $ 5,181,000
CANADA | Underfunded    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation 24,476,000 23,805,000
Fair value of plan assets (19,254,000) (18,456,000)
Provisions for pensions 5,222,000 5,349,000
Changes in net defined benefit liability (asset) [abstract]    
Obligations at beginning of year 23,805,000 25,938,000
Service cost 261,000 389,000
Borrowing cost 1,143,000 1,177,000
Actuarial differences (640,000) (328,000)
Benefits paid (1,303,000) (1,324,000)
Exchange differences 1,210,000 (2,047,000)
Obligations at end of year 24,476,000 $ 23,805,000
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discretionary contributions to the defined benefit pension and postretirement plans $ 467,000  
Weighted average duration of defined benefit obligation 11 years 10 months 6 days 12 years 4 months 13 days
CANADA | Actuarial assumption of medical cost trend rates [member] | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Health care cost trend rate 4.70%  
CANADA | Pension Plans | Underfunded    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation $ 19,228,000 $ 18,479,000
Fair value of plan assets (19,254,000) (18,456,000)
Provisions for pensions   23,000
Non-current net defined benefit asset 26,000  
Changes in net defined benefit liability (asset) [abstract]    
Obligations at beginning of year 18,479,000 20,196,000
Service cost 54,000 93,000
Borrowing cost 882,000 914,000
Actuarial differences (18,000) (14,000)
Benefits paid (1,109,000) (1,123,000)
Exchange differences 940,000 (1,587,000)
Obligations at end of year $ 19,228,000 $ 18,479,000
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discount rate 4.90% 4.68%
CANADA | Post Retirement Plans | Underfunded    
Reconciliation Of Benefit Obligation Plan Assets And Funded Status [Abstract]    
Benefit obligation $ 5,248,000 $ 5,326,000
Provisions for pensions 5,248,000 5,326,000
Changes in net defined benefit liability (asset) [abstract]    
Obligations at beginning of year 5,326,000 5,742,000
Service cost 207,000 296,000
Borrowing cost 261,000 263,000
Actuarial differences (622,000) (314,000)
Benefits paid (194,000) (201,000)
Exchange differences 270,000 (460,000)
Obligations at end of year $ 5,248,000 $ 5,326,000
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Discount rate 5.05% 4.75%
CANADA | Post Retirement Plans | Actuarial assumption of medical cost trend rates [member] | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Percentage of reasonably possible increase in actuarial assumption 1.00% 1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible increase in actuarial assumption $ 783,000 $ 852,000
Percentage of reasonably possible decrease in actuarial assumption 1.00% 1.00%
Increase (decrease) in defined benefit obligation due to reasonably possible decrease in actuarial assumption $ (634,000) $ (685,000)
Minimum | CANADA | Pension Plans | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Salary increase 2.75% 2.75%
Retirement age 58 years 58 years
Minimum | CANADA | Post Retirement Plans | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Retirement age 58 years 58 years
Maximum | CANADA | Pension Plans | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Salary increase 3.00% 3.00%
Retirement age 60 years 60 years
Maximum | CANADA | Post Retirement Plans | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Retirement age 60 years 60 years
Later Than fifteen Years And Not Later Than Sixteen Years [Member] | Actuarial assumption of medical cost trend rates [member] | Underfunded    
Actuarial Assumptions Used To Calculate Defined Benefit Obligation [Abstract]    
Health care cost trend rate 4.00%  
Quebec Silicon Limited Partnership | CANADA    
Disclosure of defined benefit plans [line items]    
Number of defined benefit plans sponsored | plan 2