Postretirement Benefits - Pension Plan Cost (Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Retirement Benefits [Abstract]
Service cost for benefits earned	$ 8,862	$ 8,651
Interest cost on benefit obligation	14,675	13,145
Expected return on plan assets	(20,069)	(20,198)
Prior service cost amortization	422	389
Net actuarial gain amortization	(654)	(1,751)
Settlement gain	(477)	(249)
Pension plan cost (income)	$ 2,759	$ (13)
Defined benefit plan, net periodic benefit cost (credit) excluding service cost, statement of income or comprehensive income	Other income