Review of Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Operations by segment
Total revenues	$ 431,972	$ 394,898	$ 840,010	$ 767,439
Operating income from continuing operations	53,625	43,149	90,166	71,756
Interest income	577	493	1,075	1,005
Interest expense	(9,993)	(12,405)	(19,576)	(24,058)
Defined benefit pension income (expense)	(904)	675	(1,743)	1,374
Gain (Loss) on Extinguishment of Debt	(1,034)	0	(1,034)	0
Income from continuing operations before income taxes	44,079	30,562	72,374	47,329
Depreciation and Amortization	33,219	32,275	66,571	64,503
Capital Expenditures	29,599	23,711	56,496	40,700
Operating Segments
Operations by segment
Operating income from continuing operations	58,449	48,896	100,557	83,764
Corporate
Operations by segment
Total revenues	35	35	74	69
Operating income from continuing operations	(4,824)	(5,747)	(10,391)	(12,008)
Depreciation and Amortization	1,666	1,479	3,014	2,950
Capital Expenditures	172	233	376	778
Harsco Metals & Minerals Segment | Operating Segments
Operations by segment
Total revenues	272,320	259,306	537,043	506,340
Operating income from continuing operations	35,661	31,464	63,396	57,221
Depreciation and Amortization	28,632	27,928	57,717	55,808
Capital Expenditures	24,423	21,599	49,599	37,071
Harsco Industrial Segment | Operating Segments
Operations by segment
Total revenues	92,065	73,563	175,663	139,448
Operating income from continuing operations	14,170	9,240	26,591	12,134
Depreciation and Amortization	1,882	1,843	3,737	3,683
Capital Expenditures	2,916	796	4,003	1,548
Harsco Rail Segment | Operating Segments
Operations by segment
Total revenues	67,552	61,994	127,230	121,582
Operating income from continuing operations	8,618	8,192	10,570	14,409
Depreciation and Amortization	1,039	1,025	2,103	2,062
Capital Expenditures	$ 2,088	$ 1,083	$ 2,518	$ 1,303