Pension Plans and Other Postretirement Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3,762	$ 4,894
Interest cost	8,365	7,232
Expected return on plan assets	(11,228)	(10,922)
Amortization of prior service cost (credit)	123	123
Net loss recognition	790	839
Net periodic benefit cost	1,812	2,166
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	620	818
Interest cost	1,746	1,044
Expected return on plan assets	(974)	(891)
Amortization of prior service cost (credit)	(263)	(263)
Net loss recognition	91	533
Net periodic benefit cost	$ 1,220	$ 1,241