Postretirement Benefits - Pension Plan Cost (Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Retirement Benefits [Abstract]
Service cost for benefits earned	$ 8,862	$ 8,641	$ 17,724	$ 17,292
Interest cost on benefit obligation	14,676	13,163	29,351	26,308
Expected return on plan assets	(20,069)	(20,198)	(40,138)	(40,396)
Prior service cost amortization	422	397	844	786
Net actuarial gain amortization	(655)	(1,734)	(1,309)	(3,485)
Settlement gain	0	(1,030)	(477)	(1,279)
Pension plan cost (income)	$ 3,236	$ (761)	$ 5,995	$ (774)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]			Other Nonoperating Income (Expense)