Benefit Plans - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension and Supplemental Executive Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain)/Loss	$ 89,711	$ 84,045
Net Prior Service Cost/(Credit)	3,245	(747)
Net Transition Obligation/(Asset)	0	0
Total at Year End	92,956	83,298	$ 97,911
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Net Actuarial (Gain)/Loss	(13,781)	(47,352)
Net Prior Service Cost/(Credit)	13,249	2,461
Net Transition Obligation/(Asset)	0	0
Total at Year End	$ (532)	$ (44,891)	$ (27,892)