Information by Segment and Geographic Area (Details 3) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total revenues	$ 1,607,062	$ 1,451,223	$ 1,723,092
Operating income from continuing operations	142,799	63,469	88,536
Total assets	1,578,685	1,581,338	2,051,887
Depreciation and Amortization	129,937	141,486	156,475
Capital Expenditures	98,314	69,340	123,552
Interest income	2,469	2,475	1,574
Interest expense	(47,552)	(51,584)	(46,804)
Loss on early extinguishment of debt	(2,265)	(35,337)	0
Change in fair value to unit adjustment liability	0	(58,494)	(8,491)
Income (loss) from continuing operations before income taxes and equity income	95,451	(79,471)	34,815
Operating segments
Segment Reporting Information [Line Items]
Operating income from continuing operations	172,522	87,289	134,205
Operating segments | Harsco Metals & Minerals
Segment Reporting Information [Line Items]
Total revenues	1,011,328	965,540	1,106,162
Operating income from continuing operations	105,257	81,634	26,289
Total assets	1,184,280	1,181,602	1,286,336
Depreciation and Amortization	112,329	120,611	136,579
Capital Expenditures	87,526	62,322	99,563
Operating segments | Harsco Industrial
Segment Reporting Information [Line Items]
Total revenues	299,592	247,542	357,256
Operating income from continuing operations	35,174	23,182	57,020
Total assets	113,410	107,987	119,830
Depreciation and Amortization	7,360	7,223	6,266
Capital Expenditures	6,895	5,118	17,382
Operating segments | Harsco Rail
Segment Reporting Information [Line Items]
Total revenues	295,999	238,107	259,674
Operating income from continuing operations	32,091	(17,527)	50,896
Total assets	237,135	204,477	219,753
Depreciation and Amortization	4,221	5,383	6,093
Capital Expenditures	2,403	1,696	1,957
Corporate
Segment Reporting Information [Line Items]
Total revenues	143	34	0
Operating income from continuing operations	(29,723)	(23,820)	(45,669)
Total assets	43,860	87,272	425,968
Depreciation and Amortization	6,027	8,269	7,537
Capital Expenditures	$ 1,490	$ 204	$ 4,650