v3.26.1
Pension Plan and Other Postretirement Benefits - Schedule of Components of Net Periodic Benefit Costs for the Pension Plans and Other Postretirement Benefits (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Pension Plan        
Pension Plan and Other Postretirement Benefits        
Service cost $ 5,782 $ 5,207 $ 11,564 $ 10,414
Interest cost 10,231 9,553 20,463 19,106
Expected return on plan assets (14,275) (12,793) (28,551) (25,586)
Amortization of prior service cost 131 131 262 262
Recognized net actuarial loss (gain) 606 194 1,212 388
Net periodic benefit cost (credit) 2,475 2,292 4,950 4,584
Other Benefits        
Pension Plan and Other Postretirement Benefits        
Service cost 1,331 1,408 2,661 2,816
Interest cost 1,641 1,773 3,283 3,546
Expected return on plan assets (3,680) (3,197) (7,359) (6,394)
Amortization of prior service cost 39 39 78 78
Recognized net actuarial loss (gain) (962) (522) (1,925) (1,044)
Net periodic benefit cost (credit) $ (1,631) $ (499) $ (3,262) $ (998)