Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment
Gross property, plant and equipment	$ 1,246,072	$ 1,108,427
Less: accumulated depreciation	(810,933)	(775,334)
Net property, plant and equipment	435,139	333,093
Land
Property, Plant and Equipment
Gross property, plant and equipment	18,165	17,287
Buildings and leasehold improvements
Property, Plant and Equipment
Gross property, plant and equipment	129,513	120,506
Operating equipment
Property, Plant and Equipment
Gross property, plant and equipment	784,826	683,027
Computer software
Property, Plant and Equipment
Gross property, plant and equipment	19,535	22,194
Furniture and fixtures
Property, Plant and Equipment
Gross property, plant and equipment	5,298	5,480
Vehicles
Property, Plant and Equipment
Gross property, plant and equipment	$ 288,735	$ 259,933