Recently Adopted and Recently Issued Accounting Standards - Consolidated Statements of Operation (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenues from continuing operations:
Total revenues		$ 1,722,380	$ 1,607,062	$ 1,451,223
Costs and expenses from continuing operations:
Selling, general and administrative costs		238,690	229,792	196,871
Total costs and expenses		1,531,453	1,461,668	1,386,340
Operating income from continuing operations		190,927	145,394	64,883
Interest expense		(38,148)	(47,552)	(51,584)
Income from continuing operations before income taxes		157,254	95,451	(79,471)
Income tax expense		(12,899)	(83,803)	(6,637)
Income from continuing operations		144,739	11,648	(80,422)
Net income		145,013	11,844	(79,753)
Less: Net income attributable to noncontrolling interests		(7,956)	(4,022)	(5,914)
Net income (loss) attributable to Harsco Corporation		137,057	7,822	(85,667)
Income (loss) from continuing operations, net of tax		136,783	7,626	(86,336)
Net income (loss) attributable to Harsco Corporation common stockholders		$ 137,057	$ 7,822	$ (85,667)
Basic earnings per share attributable to Harsco Corporation common stockholders (a):
Continuing operations (in dollars per share)		$ 1.69	$ 0.09	$ (1.07)
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	[1]	1.70	0.10	(1.07)
Diluted earnings per share attributable to Harsco Corporation common stockholders (a):
Continuing operations (in dollars per share)		1.64	0.09	(1.07)
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)		$ 1.64	$ 0.09	$ (1.07)	[1]
Services
Revenues from continuing operations:
Total revenues		$ 1,007,239	$ 981,672	$ 939,129
Costs and expenses from continuing operations:
Cost of Goods and Services Sold		780,930	770,268	762,431
Product
Revenues from continuing operations:
Total revenues		715,141	625,390	512,094
Costs and expenses from continuing operations:
Cost of Goods and Services Sold		507,807	$ 452,740	$ 410,138
As Reported
Revenues from continuing operations:
Total revenues		1,733,385
Costs and expenses from continuing operations:
Selling, general and administrative costs		238,807
Total costs and expenses		1,548,512
Operating income from continuing operations		184,873
Interest expense		(36,219)
Income from continuing operations before income taxes		153,129
Income tax expense		(11,453)
Income from continuing operations		142,060
Net income		142,334
Less: Net income attributable to noncontrolling interests		(7,977)
Net income (loss) attributable to Harsco Corporation		134,357
Income (loss) from continuing operations, net of tax		134,083
Net income (loss) attributable to Harsco Corporation common stockholders		$ 134,357
Basic earnings per share attributable to Harsco Corporation common stockholders (a):
Continuing operations (in dollars per share)		$ 1.66
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)		1.66
Diluted earnings per share attributable to Harsco Corporation common stockholders (a):
Continuing operations (in dollars per share)		1.60
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)		$ 1.61
As Reported | Services
Revenues from continuing operations:
Total revenues		$ 1,012,160
Costs and expenses from continuing operations:
Cost of Goods and Services Sold		786,230
As Reported | Product
Revenues from continuing operations:
Total revenues		721,225
Costs and expenses from continuing operations:
Cost of Goods and Services Sold		519,449
Accounting Standards Update 2014-09 | Impact of Adoption
Revenues from continuing operations:
Total revenues		11,005
Costs and expenses from continuing operations:
Selling, general and administrative costs		117
Total costs and expenses		17,059
Operating income from continuing operations		(6,054)
Interest expense		1,929
Income from continuing operations before income taxes		(4,125)
Income tax expense		1,446
Income from continuing operations		(2,679)
Net income		(2,679)
Less: Net income attributable to noncontrolling interests		(21)
Net income (loss) attributable to Harsco Corporation		(2,700)
Income (loss) from continuing operations, net of tax		(2,700)
Net income (loss) attributable to Harsco Corporation common stockholders		$ (2,700)
Basic earnings per share attributable to Harsco Corporation common stockholders (a):
Continuing operations (in dollars per share)		$ (0.03)
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)		(0.03)
Diluted earnings per share attributable to Harsco Corporation common stockholders (a):
Continuing operations (in dollars per share)		(0.03)
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)		$ (0.03)
Accounting Standards Update 2014-09 | Impact of Adoption | Services
Revenues from continuing operations:
Total revenues		$ 4,921
Costs and expenses from continuing operations:
Cost of Goods and Services Sold		5,300
Accounting Standards Update 2014-09 | Impact of Adoption | Product
Revenues from continuing operations:
Total revenues		6,084
Costs and expenses from continuing operations:
Cost of Goods and Services Sold		$ 11,642

[1] Does not total due to rounding.