Review of Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Operations by segment
Revenues	$ 350,898	$ 339,907	$ 680,800	$ 664,347
Operating income from continuing operations	17,799	38,064	37,623	60,792
Interest income	591	577	1,124	1,070
Interest expense	(6,103)	(5,681)	(11,610)	(11,271)
Unused debt commitment and amendment fees	(7,435)	0	(7,435)	0
Gain (Loss) on Extinguishment of Debt	0	(1,034)	0	(1,034)
Defined benefit pension income (expense)	1,472	(904)	2,810	(1,743)
Income from continuing operations before income taxes and equity income	3,380	32,830	16,892	51,300
Depreciation and Amortization	31,123	31,336	62,347	62,834
Capital Expenditures	51,747	26,683	85,979	52,493
Operating Segments
Operations by segment
Operating income from continuing operations	37,020	44,279	66,906	73,966
Corporate
Operations by segment
Revenues	0	35	0	74
Operating income from continuing operations	(19,221)	(6,215)	(29,283)	(13,174)
Depreciation and Amortization	1,417	1,665	2,769	3,014
Capital Expenditures	287	172	1,440	376
Harsco Environmental Segment | Operating Segments
Operations by segment
Revenues	269,338	272,320	530,650	537,043
Operating income from continuing operations	27,577	35,661	52,074	63,396
Depreciation and Amortization	28,497	28,632	57,202	57,717
Capital Expenditures	45,095	24,423	74,258	49,599
Harsco Clean Earth Segment | Operating Segments
Operations by segment
Revenues	0	0	0	0
Operating income from continuing operations	0	0	0	0
Depreciation and Amortization	0	0	0	0
Capital Expenditures	0	0	0	0
Harsco Rail Segment | Operating Segments
Operations by segment
Revenues	81,560	67,552	150,150	127,230
Operating income from continuing operations	9,443	8,618	14,832	10,570
Depreciation and Amortization	1,209	1,039	2,376	2,103
Capital Expenditures	$ 6,365	$ 2,088	$ 10,281	$ 2,518