Revenue Recognition - Revenues by Primary Geographical Markets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Total revenues	$ 486,914	$ 470,385	$ 1,420,763	$ 1,386,324
Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Total revenues	220,578	230,340	684,432	688,923
Ecoproducts
Disaggregation of Revenue [Line Items]
Total revenues	40,274	36,091	110,322	100,706
Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Total revenues	3,865	3,470	9,613	10,804
Waste processing, recycling, reuse and transportation solutions
Disaggregation of Revenue [Line Items]
Total revenues	222,197	200,484	616,396	585,891
North America
Disaggregation of Revenue [Line Items]
Total revenues	297,426	271,963	843,413	794,286
Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	92,757	106,859	294,427	336,011
Latin America
Disaggregation of Revenue [Line Items]
Total revenues	40,574	35,072	115,581	99,524
Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	31,402	30,228	91,420	80,520
Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	20,195	20,804	60,843	60,798
Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,560	5,459	15,079	15,185
Operating Segments | Harsco Environmental Segment
Disaggregation of Revenue [Line Items]
Total revenues	264,717	269,901	804,367	800,433
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	220,578	230,340	684,432	688,923
Operating Segments | Harsco Environmental Segment | Ecoproducts
Disaggregation of Revenue [Line Items]
Total revenues	40,274	36,091	110,322	100,706
Operating Segments | Harsco Environmental Segment | Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Total revenues	3,865	3,470	9,613	10,804
Operating Segments | Harsco Environmental Segment | Waste processing, recycling, reuse and transportation solutions
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Harsco Environmental Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	75,229	71,479	227,017	208,395
Operating Segments | Harsco Environmental Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	92,757	106,859	294,427	336,011
Operating Segments | Harsco Environmental Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	40,574	35,072	115,581	99,524
Operating Segments | Harsco Environmental Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	31,402	30,228	91,420	80,520
Operating Segments | Harsco Environmental Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	20,195	20,804	60,843	60,798
Operating Segments | Harsco Environmental Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,560	5,459	15,079	15,185
Operating Segments | Harsco Clean Earth Segment
Disaggregation of Revenue [Line Items]
Total revenues	222,197	200,484	616,396	585,891
Operating Segments | Harsco 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	0	0
Operating Segments | Harsco Clean Earth Segment | Ecoproducts
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Harsco Clean Earth Segment | Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Harsco Clean Earth Segment | Waste processing, recycling, reuse and transportation solutions
Disaggregation of Revenue [Line Items]
Total revenues	222,197	200,484	616,396	585,891
Operating Segments | Harsco Clean Earth Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	222,197	200,484	616,396	585,891
Operating Segments | Harsco Clean Earth Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Harsco Clean Earth Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Harsco Clean Earth Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Harsco Clean Earth Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	0	0	0	0
Operating Segments | Harsco Clean Earth Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 0	$ 0	$ 0