Review of Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operations by segment
Revenues	$ 573,627	$ 596,968	$ 1,783,937	$ 1,766,689
Operating income (loss) from continuing operations	37,372	28,760	94,440	94,362
Interest income	981	1,722	6,113	4,796
Interest expense	(28,813)	(27,552)	(84,869)	(78,956)
Facility fees and debt-related income (expense)	(2,978)	(2,806)	(8,687)	(7,899)
Defined benefit pension income (expense)	(4,257)	(5,430)	(12,599)	(16,159)
Income (loss) from continuing operations before income taxes and equity income	2,305	(5,306)	(5,602)	(3,856)
Depreciation	37,579	35,397	111,525	102,893
Amortization	7,909	8,295	24,089	24,327
Capital Expenditures	41,574	27,289	102,094	93,630
Operating Segments
Operations by segment
Operating income (loss) from continuing operations	45,913	38,365	118,112	124,157
Operating Segments | Harsco Environmental Segment
Operations by segment
Revenues	279,148	285,877	871,196	848,659
Operating income (loss) from continuing operations	33,181	17,867	73,055	52,885
Depreciation	27,554	28,793	83,793	84,707
Amortization	532	1,013	2,525	3,020
Capital Expenditures	24,905	20,735	69,674	75,826
Operating Segments | Clean Earth Segment
Operations by segment
Revenues	236,791	238,711	698,926	691,750
Operating income (loss) from continuing operations	26,833	21,497	71,308	61,002
Depreciation	8,685	6,054	24,347	16,528
Amortization	5,991	6,330	18,147	18,472
Capital Expenditures	13,020	6,186	27,084	15,990
Operating Segments | Harsco Rail Segment
Operations by segment
Revenues	57,688	72,380	213,815	226,280
Operating income (loss) from continuing operations	(14,101)	(999)	(26,251)	10,270
Depreciation	1,040	0	2,424	0
Amortization	68	0	157	0
Capital Expenditures	3,567	279	5,154	1,515
Corporate
Operations by segment
Operating income (loss) from continuing operations	(8,541)	(9,605)	(23,672)	(29,795)
Depreciation	300	550	961	1,658
Amortization	1,318	952	3,260	2,835
Capital Expenditures	$ 82	$ 89	$ 182	$ 299