Information by Segment and Geographic Area (Details 3) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenues		$ 1,503,742,000	$ 1,347,672,000	$ 1,307,470,000
Operating income from continuing operations		104,279,000	130,695,000	104,655,000
Total assets	$ 1,578,685,000	2,367,467,000	1,632,867,000	1,578,685,000
Depreciation and Amortization		135,094,000	125,056,000	122,577,000
Capital Expenditures		176,600,000	124,607,000	91,419,000
Interest income		1,975,000	2,155,000	2,469,000
Interest expense		(36,586,000)	(21,531,000)	(26,862,000)
Defined benefit pension income (expense)		(5,493,000)	3,457,000	(2,595,000)
Loss on early extinguishment of debt	2,300,000	(7,704,000)	(1,127,000)	(2,265,000)
Income from continuing operations before income taxes and equity income		56,471,000	113,649,000	75,402,000
Clean Earth
Segment Reporting Information [Line Items]
Operating income from continuing operations		20,009,000	0	0
Total assets	0	745,410,000	0	0
Depreciation and Amortization		12,855,000	0	0
Capital Expenditures		5,870,000	0	0
Operating segments
Segment Reporting Information [Line Items]
Operating income from continuing operations		156,015,000	158,536,000	135,315,000
Operating segments | Harsco Environmental
Segment Reporting Information [Line Items]
Revenues		1,034,847,000	1,068,304,000	1,011,328,000
Operating income from continuing operations		112,298,000	121,195,000	102,362,000
Total assets	1,184,280,000	1,296,061,000	1,230,152,000	1,184,280,000
Depreciation and Amortization		112,126,000	115,059,000	112,329,000
Capital Expenditures		153,694,000	114,142,000	87,526,000
Operating segments | Clean Earth
Segment Reporting Information [Line Items]
Revenues		169,522,000	0	0
Operating segments | Harsco Industrial
Segment Reporting Information [Line Items]
Total assets	113,410,000	53,582,000	163,324,000	113,410,000
Operating segments | Harsco Rail
Segment Reporting Information [Line Items]
Revenues		299,373,000	279,294,000	295,999,000
Operating income from continuing operations		23,708,000	37,341,000	32,953,000
Total assets	237,135,000	246,377,000	186,049,000	237,135,000
Depreciation and Amortization		4,875,000	4,287,000	4,221,000
Capital Expenditures		15,274,000	9,152,000	2,403,000
Corporate
Segment Reporting Information [Line Items]
Revenues		0	74,000	143,000
Operating income from continuing operations		(51,736,000)	(27,841,000)	(30,660,000)
Total assets	$ 43,860,000	26,037,000	53,342,000	43,860,000
Depreciation and Amortization		5,238,000	5,710,000	6,027,000
Capital Expenditures		$ 1,762,000	$ 1,313,000	$ 1,490,000