Employee Postretirement Benefits - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Defined Benefit Plan Disclosure [Line Items]
Net Periodic Benefit Cost (Income)	$ (1,724)	$ 1,479
Pension Benefits (Pension Plan)
Defined Benefit Plan Disclosure [Line Items]
Service Cost	925	1,644
Interest Cost	4,109	3,086
Expected Return on Assets	(6,479)	(5,921)
Amortization of Prior Service Cost	0	0
Amortization of Net Actuarial Loss	0	1,966
Net Periodic Benefit Cost (Income)	(1,445)	775
Pension Benefits (ESSRP)
Defined Benefit Plan Disclosure [Line Items]
Service Cost	18	49
Interest Cost	314	335
Expected Return on Assets	0	0
Amortization of Prior Service Cost	0	0
Amortization of Net Actuarial Loss	0	142
Net Periodic Benefit Cost (Income)	332	526
Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service Cost	153	335
Interest Cost	669	510
Expected Return on Assets	0	0
Amortization of Prior Service Cost	(1,433)	(1,433)
Amortization of Net Actuarial Loss	0	766
Net Periodic Benefit Cost (Income)	$ (611)	$ 178