Postretirement Benefits - Pension Liability (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
PBO	$ 562,567	$ 778,934
ABO	526,286	689,562
Defined Benefit Plan, Pension Plan with Project Benefit Obligation in Excess of Plan Assets [Abstract]
Funded benefit pension plans PBO	492,103	686,917
Funded benefit pension plans fair value of plan assets	499,775	597,547
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets [Abstract]
Funded benefit pension plans ABO	458,510	601,647
Funded benefit pension plans fair value of plan assets	499,775	597,547
Pension plans
Defined Benefit Plan Disclosure [Line Items]
PBO	562,567	778,934	$ 763,313
Qualified Plan | Pension plans | Funded defined benefit pension
Defined Benefit Plan Disclosure [Line Items]
PBO	492,103	686,917
ABO	458,510	601,647
Nonqualified Plan | SERP
Defined Benefit Plan Disclosure [Line Items]
PBO	70,464	92,017
ABO	$ 67,776	$ 87,915