v3.25.4
Employee benefit plans - Amounts Recognized in AOCI, Benefit Expense (Income), and OCI (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Pension plans      
Amounts recognized in accumulated other comprehensive income (loss) consist of:      
Net actuarial gain (loss), excluding deferred taxes $ (45,707) $ (48,969) $ (51,165)
Net prior service credit (cost) (253) (313) (398)
Deferred income taxes assets (liabilities) (1,157) 0 0
Net amount recognized in accumulated other comprehensive income (loss) (47,117) (49,282) (51,563)
Expense component      
Service cost 0 0 0
Interest cost 5,235 5,134 5,367
Expected return on plan assets (6,399) (6,240) (6,117)
Amortization of net actuarial (gains) losses 2,341 2,358 2,284
Amortization of prior service (credit) loss 82 79 79
Defined benefit (income) expense 1,259 1,331 1,613
Defined contribution expense 8,380 8,363 8,525
Total benefit (income) expense 9,639 9,694 10,138
Other changes recognized in other comprehensive income (loss)      
Net gain (loss) arising during the year 1,439 (288) (5,762)
Amortization of net actuarial (gains) losses 2,341 2,358 2,284
Amortization of prior service (credit) cost 82 79 79
Change in deferred taxes (1,135) 0 0
Foreign exchange adjustment (562) 132 (259)
Total changes recognized in other comprehensive income (loss) 2,165 2,281 (3,658)
Post- retirement medical benefit plan      
Amounts recognized in accumulated other comprehensive income (loss) consist of:      
Net actuarial gain (loss), excluding deferred taxes 22,291 22,022 18,114
Net prior service credit (cost) (5,246) (5,770) (6,294)
Deferred income taxes assets (liabilities) 0 0 0
Net amount recognized in accumulated other comprehensive income (loss) 17,045 16,252 11,820
Expense component      
Service cost 43 54 76
Interest cost 4,369 4,385 4,786
Expected return on plan assets 0 0 0
Amortization of net actuarial (gains) losses (602) 524 524
Amortization of prior service (credit) loss 524 (2,311) (1,333)
Defined benefit (income) expense 4,334 2,652 4,053
Defined contribution expense 0 0 0
Total benefit (income) expense 4,334 2,652 4,053
Other changes recognized in other comprehensive income (loss)      
Net gain (loss) arising during the year 871 6,219 4,919
Amortization of net actuarial (gains) losses (602) 524 524
Amortization of prior service (credit) cost 524 (2,311) (1,333)
Change in deferred taxes 0 0 0
Foreign exchange adjustment 0 0 0
Total changes recognized in other comprehensive income (loss) $ 793 $ 4,432 $ 4,110