Employee and Retiree Benefit Plans - Components of Net Periodic Benefit Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,683	$ 1,706
Interest cost	8,398	8,391
Expected return on plan assets	(8,871)	(8,357)
Estimated defined contribution provision	60	55
Amortization of prior service cost (credit)	491	579
Recognized actuarial loss (gain)	1,891	2,360
Total net periodic benefit expense	3,652	4,734
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	84	135
Interest cost	708	782
Expected return on plan assets	0	0
Estimated defined contribution provision	0	0
Amortization of prior service cost (credit)	(133)	(133)
Recognized actuarial loss (gain)	(1,056)	(812)
Total net periodic benefit expense	$ (397)	$ (28)