Pension and Other Post-Retirement Benefit Plans - Net Periodic Benefit Costs (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 0	$ 0	$ 0
Interest cost	34,526	24,173	22,387
Expected return on plan assets	(40,767)	(46,954)	(47,502)
Settlements	24,145	0	0
Amortization of prior service cost	0	0	0
Amortization of net loss	18,981	2,630	7,058
Net periodic benefit cost (income)	36,885	(20,151)	(18,057)
Post-retirement Healthcare Plans
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	53	76	95
Interest cost	132	59	42
Expected return on plan assets	0	0	0
Settlements	0	0	0
Amortization of prior service cost	0	0	0
Amortization of net loss	0	45	186
Net periodic benefit cost (income)	$ 185	$ 180	$ 323