v3.24.3
Pension and Other Postretirement Benefits - Pension Benefits - Net Periodic Pension (Income)/Cost (Details) - Pension Plan - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2024
Sep. 30, 2023
Sep. 30, 2024
Sep. 30, 2023
Pension Benefits        
Service cost $ 1,541 $ 1,417 $ 4,623 $ 4,252
Interest cost 15,582 16,494 46,747 49,482
Expected return on plan assets (18,109) (19,122) (54,327) (57,367)
Amortization of actuarial loss 3,600 1,553 10,800 4,660
Amortization of prior service credit (486) (486) (1,459) (1,459)
Effect of settlement     (27) 0
Net periodic pension (income)/cost or postretirement benefit cost 2,128 (144) 6,357 (432)
Qualified Plans        
Pension Benefits        
Service cost 1,541 1,417 4,623 4,252
Interest cost 13,376 14,198 40,128 42,595
Expected return on plan assets (18,109) (19,122) (54,327) (57,367)
Amortization of actuarial loss 2,603 663 7,809 1,991
Amortization of prior service credit (486) (486) (1,459) (1,459)
Effect of settlement     0 0
Net periodic pension (income)/cost or postretirement benefit cost (1,075) (3,330) (3,226) (9,988)
Non- Qualified Plans        
Pension Benefits        
Service cost 0 0 0 0
Interest cost 2,206 2,296 6,619 6,887
Expected return on plan assets 0 0 0 0
Amortization of actuarial loss 997 890 2,991 2,669
Amortization of prior service credit 0 0 0 0
Effect of settlement     (27) 0
Net periodic pension (income)/cost or postretirement benefit cost $ 3,203 $ 3,186 $ 9,583 $ 9,556