Benefit Plans - Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 306,711	$ 269,912
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	238,665	204,531
Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	68,046	65,381
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	188,579	159,575
Equity securities | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	188,579	159,575
Equity securities | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Equity securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,038	14,093
Cash and equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11,038	14,093
Cash and equivalents | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Cash and equivalents | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Fixed income
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	107,094	96,244
Fixed income | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	39,048	30,863
Fixed income | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	68,046	65,381
Fixed income | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	0
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	285,504	251,960	$ 310,176
Pension Benefits | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 101,498	$ 90,914
Actual plan asset allocations as a percent of total plan assets	36.00%	36.00%
Pension Benefits | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 174,155	$ 147,864
Actual plan asset allocations as a percent of total plan assets	61.00%	59.00%
Pension Benefits | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 9,851	$ 13,182
Actual plan asset allocations as a percent of total plan assets	3.00%	5.00%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 21,207	$ 17,952	$ 21,767
Other Postretirement Benefits | Debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 5,596	$ 5,330
Actual plan asset allocations as a percent of total plan assets	26.00%	30.00%
Other Postretirement Benefits | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 14,424	$ 11,711
Actual plan asset allocations as a percent of total plan assets	68.00%	65.00%
Other Postretirement Benefits | Cash and equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,187	$ 911
Actual plan asset allocations as a percent of total plan assets	6.00%	5.00%