Revenue Recognition - Revenues by Primary Geographical Markets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	$ 520,168	$ 481,052	$ 1,015,821	$ 933,849
Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Revenues	242,638	236,165	471,999	463,854
Ecoproducts
Disaggregation of Revenue [Line Items]
Revenues	40,504	38,083	78,906	70,048
Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Revenues	6,451	3,351	11,877	5,748
Hazardous waste processing solutions
Disaggregation of Revenue [Line Items]
Revenues	197,506	170,817	383,618	329,824
Soil and dredged materials processing and reuse solutions
Disaggregation of Revenue [Line Items]
Revenues	33,069	32,636	69,421	64,375
North America
Disaggregation of Revenue [Line Items]
Revenues	312,191	284,162	613,128	545,987
Western Europe
Disaggregation of Revenue [Line Items]
Revenues	107,318	99,591	208,704	201,670
Latin America
Disaggregation of Revenue [Line Items]
Revenues	42,180	39,202	83,135	75,007
Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	32,339	31,950	61,300	60,018
Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	21,117	20,762	39,522	40,648
Eastern Europe
Disaggregation of Revenue [Line Items]
Revenues	5,023	5,385	10,032	10,519
Operating Segments | Harsco Environmental Segment
Disaggregation of Revenue [Line Items]
Revenues	289,593	277,599	562,782	539,650
Operating Segments | Harsco Environmental Segment | Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Revenues	242,638	236,165	471,999	463,854
Operating Segments | Harsco Environmental Segment | Ecoproducts
Disaggregation of Revenue [Line Items]
Revenues	40,504	38,083	78,906	70,048
Operating Segments | Harsco Environmental Segment | Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Revenues	6,451	3,351	11,877	5,748
Operating Segments | Harsco Environmental Segment | Hazardous waste processing solutions
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Harsco Environmental Segment | Soil and dredged materials processing and reuse solutions
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Harsco Environmental Segment | North America
Disaggregation of Revenue [Line Items]
Revenues	81,616	80,709	160,089	151,788
Operating Segments | Harsco Environmental Segment | Western Europe
Disaggregation of Revenue [Line Items]
Revenues	107,318	99,591	208,704	201,670
Operating Segments | Harsco Environmental Segment | Latin America
Disaggregation of Revenue [Line Items]
Revenues	42,180	39,202	83,135	75,007
Operating Segments | Harsco Environmental Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	32,339	31,950	61,300	60,018
Operating Segments | Harsco Environmental Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	21,117	20,762	39,522	40,648
Operating Segments | Harsco Environmental Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Revenues	5,023	5,385	10,032	10,519
Operating Segments | Clean Earth Segment
Disaggregation of Revenue [Line Items]
Revenues	230,575	203,453	453,039	394,199
Operating Segments | Clean Earth Segment | Environmental services related to resource recovery for metals manufacturing and related logistical services
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Clean Earth Segment | Ecoproducts
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Clean Earth Segment | Environmental systems for aluminum dross and scrap processing
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Clean Earth Segment | Hazardous waste processing solutions
Disaggregation of Revenue [Line Items]
Revenues	197,506	170,817	383,618	329,824
Operating Segments | Clean Earth Segment | Soil and dredged materials processing and reuse solutions
Disaggregation of Revenue [Line Items]
Revenues	33,069	32,636	69,421	64,375
Operating Segments | Clean Earth Segment | North America
Disaggregation of Revenue [Line Items]
Revenues	230,575	203,453	453,039	394,199
Operating Segments | Clean Earth Segment | Western Europe
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Clean Earth Segment | Latin America
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Clean Earth Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Clean Earth Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Operating Segments | Clean Earth Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 0