Review of Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Operations by segment
Revenues	$ 509,398	$ 423,155	$ 1,355,520	$ 1,103,955
Operating income from continuing operations	5,064	46,745	9,813	84,368	$ 84,368
Interest income	604	445	1,613	1,569
Interest expense	(15,794)	(12,819)	(43,396)	(24,429)
Unused debt commitment and amendment fees	0	(158)	(1,920)	(7,593)
Defined benefit pension income (expense)	(1,859)	1,356	(5,171)	4,166
Income (loss) from continuing operations before income taxes and equity income	(8,267)	32,857	(28,719)	49,749
Capital Expenditures	27,883	54,941	78,990	140,920
Depreciation	32,353	29,824	93,864	89,681
Depreciation Excluding Industrial Segment			93,656	86,941
Amortization			24,721	11,941
Amortization Excluding Deferred Financing Costs	9,049	6,150	24,721	11,380
Operating Segments
Operations by segment
Operating income from continuing operations	25,278	56,217	68,507	123,123
Corporate
Operations by segment
Operating income from continuing operations	(20,214)	(9,472)	(58,694)	(38,755)
Capital Expenditures	62	109	444	1,549
Depreciation	497	716	1,531	2,094
Amortization	776	481	2,179	1,872
Harsco Environmental Segment \| Operating Segments
Operations by segment
Revenues	222,507	260,883	668,057	791,533
Operating income from continuing operations	12,317	32,794	36,400	84,868
Capital Expenditures	21,700	48,348	65,102	122,606
Depreciation	25,588	25,557	75,626	79,074
Amortization	1,970	1,751	5,827	5,436
Harsco Clean Earth Segment \| Operating Segments
Operations by segment
Revenues	194,098	87,639	434,489	87,639
Operating income from continuing operations	8,902	11,308	12,945	11,308
Capital Expenditures	2,647	3,204	7,134	3,204
Depreciation	5,010	2,359	12,769	2,359
Amortization	6,218	3,834	16,463	3,834
Harsco Rail Segment \| Operating Segments
Operations by segment
Revenues	92,793	74,633	252,974	224,783
Operating income from continuing operations	4,059	12,115	19,162	26,947
Capital Expenditures	3,474	3,280	6,310	13,561
Depreciation	1,258	1,192	3,730	3,414
Amortization	$ 85	$ 84	$ 252	$ 238

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