Retirement Plans and Other Postretirement Benefits - Schedule of Net Periodic Benefit Costs and Portion including Portion Charged to Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Amortization of:
Portion of costs (credits) charged to expense	$ (3,982)	$ (2,958)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the period	12,099	10,949
Non-service costs (credits):
Interest cost on benefit obligation	37,612	38,976
Expected return on plan assets	(44,096)	(44,547)
Amortization of:
Prior service cost (credit)	151	0
Net actuarial loss (gain)	11,153	12,118
Net periodic benefit costs (credits)	16,919	17,496
Portion of costs (credits) charged to expense	9,518	10,461
Other Benefits Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost-benefits earned during the period	2,237	1,982
Non-service costs (credits):
Interest cost on benefit obligation	4,979	5,102
Expected return on plan assets	(12,719)	(12,142)
Amortization of:
Prior service cost (credit)	0	(1,265)
Net actuarial loss (gain)	(2,700)	(2,899)
Net periodic benefit costs (credits)	(8,203)	(9,222)
Portion of costs (credits) charged to expense	$ (6,509)	$ (6,873)