Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Pension and SERPA Benefits:
Defined Benefit Plan Disclosure
Service cost	$ 963	$ 1,175
Interest cost	20,501	20,118
Expected return on plan assets	(32,799)	(33,143)
Amortization of unrecognized: Prior service cost (credit)	380	188
Amortization of unrecognized: Net (gain) loss	(174)	(163)
Net periodic benefit income	(11,129)	(11,825)
Postretirement Healthcare Benefits:
Defined Benefit Plan Disclosure
Service cost	643	723
Interest cost	2,618	2,694
Expected return on plan assets	(4,675)	(4,424)
Amortization of unrecognized: Prior service cost (credit)	149	149
Amortization of unrecognized: Net (gain) loss	(1,369)	(1,250)
Net periodic benefit income	$ (2,634)	$ (2,108)