Benefit Plans - Components of Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Company Service Cost	$ 0	$ 7,153	$ 7,569
Interest Cost	13,787	12,461	11,276
Expected Return on Assets	(13,517)	(18,064)	(20,657)
Amortization of Net Transition Obligation/(Asset)	0	0	0
Amortization of Net Prior Service Cost/(Credit)	345	(163)	(239)
Amortization of Net Losses/(Gains)	2,185	5,726	5,490
Cost of Settlements and Curtailments	9,749	13,801	6,012
Net Periodic Benefit Cost (Benefit)	12,549	20,914	9,451
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Company Service Cost	1,497	1,307	1,508
Interest Cost	1,633	694	648
Expected Return on Assets	(8,235)	(10,502)	(8,863)
Amortization of Net Transition Obligation/(Asset)	0	0	0
Amortization of Net Prior Service Cost/(Credit)	1,861	489	213
Amortization of Net Losses/(Gains)	(150)	(3,103)	(1,697)
Cost of Settlements and Curtailments	0	0	0
Net Periodic Benefit Cost (Benefit)	$ (3,394)	$ (11,115)	$ (8,191)