Revenue Recognition - Revenues by Primary Geographical Markets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Disaggregation of Revenue [Line Items]
Total revenues	$ 600,317	$ 560,705
Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Total revenues	258,128	229,361
Ecoproducts
Disaggregation of Revenue [Line Items]
Total revenues	36,264	38,402
Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Total revenues	4,727	5,426
Railway Track Maintenance Equipment
Disaggregation of Revenue [Line Items]
Total revenues	29,918	29,444
After-market Parts and Services; Safety and Diagnostic Technology
Disaggregation of Revenue [Line Items]
Total revenues	30,876	27,793
Railway Contracting Services
Disaggregation of Revenue [Line Items]
Total revenues	14,374	7,815
Hazardous waste processing solutions
Disaggregation of Revenue [Line Items]
Total revenues	191,910	186,112
Soil and dredged materials processing and reuse solutions
Disaggregation of Revenue [Line Items]
Total revenues	34,120	36,352
North America
Disaggregation of Revenue [Line Items]
Total revenues	354,671	345,099
Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	131,647	114,573
Latin America
Disaggregation of Revenue [Line Items]
Total revenues	43,961	41,559
Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	37,240	36,060
Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	28,349	18,405
Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,449	5,009
Operating Segments | Harsco Environmental Segment
Disaggregation of Revenue [Line Items]
Total revenues	299,119	273,189
Operating Segments | Harsco Environmental Segment | Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Total revenues	258,128	229,361
Operating Segments | Harsco Environmental Segment | Ecoproducts
Disaggregation of Revenue [Line Items]
Total revenues	36,264	38,402
Operating Segments | Harsco Environmental Segment | Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Total revenues	4,727	5,426
Operating Segments | Harsco Environmental Segment | Railway Track Maintenance Equipment
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Environmental Segment | After-market Parts and Services; Safety and Diagnostic Technology
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Environmental Segment | Railway Contracting Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Environmental Segment | Hazardous waste processing solutions
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Environmental Segment | Soil and dredged materials processing and reuse solutions
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Environmental Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	84,210	78,473
Operating Segments | Harsco Environmental Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	110,275	101,386
Operating Segments | Harsco Environmental Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	42,921	40,955
Operating Segments | Harsco Environmental Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	28,915	28,961
Operating Segments | Harsco Environmental Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	28,349	18,405
Operating Segments | Harsco Environmental Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,449	5,009
Operating Segments | Clean Earth Segment
Disaggregation of Revenue [Line Items]
Total revenues	226,030	222,464
Operating Segments | Clean Earth Segment | Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Ecoproducts
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Railway Track Maintenance Equipment
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | After-market Parts and Services; Safety and Diagnostic Technology
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Railway Contracting Services
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Hazardous waste processing solutions
Disaggregation of Revenue [Line Items]
Total revenues	191,910	186,112
Operating Segments | Clean Earth Segment | Soil and dredged materials processing and reuse solutions
Disaggregation of Revenue [Line Items]
Total revenues	34,120	36,352
Operating Segments | Clean Earth Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	226,030	222,464
Operating Segments | Clean Earth Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Clean Earth Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Rail Segment
Disaggregation of Revenue [Line Items]
Total revenues	75,168	65,052
Operating Segments | Harsco Rail Segment | Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Rail Segment | Ecoproducts
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Rail Segment | Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Rail Segment | Railway Track Maintenance Equipment
Disaggregation of Revenue [Line Items]
Total revenues	29,918	29,444
Operating Segments | Harsco Rail Segment | After-market Parts and Services; Safety and Diagnostic Technology
Disaggregation of Revenue [Line Items]
Total revenues	30,876	27,793
Operating Segments | Harsco Rail Segment | Railway Contracting Services
Disaggregation of Revenue [Line Items]
Total revenues	14,374	7,815
Operating Segments | Harsco Rail Segment | Hazardous waste processing solutions
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Rail Segment | Soil and dredged materials processing and reuse solutions
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Rail Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	44,431	44,162
Operating Segments | Harsco Rail Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	21,372	13,187
Operating Segments | Harsco Rail Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	1,040	604
Operating Segments | Harsco Rail Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	8,325	7,099
Operating Segments | Harsco Rail Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Operating Segments | Harsco Rail Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 0