Recently Adopted and Recently Issued Accounting Standards (Details 2) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Revenues from continuing operations:
Total revenues	$ 431,972	$ 394,898		$ 840,010	$ 767,439
Costs and expenses from continuing operations:
Selling, general and administrative costs	58,927	54,385		116,010	108,322
Total costs and expenses	378,347	351,749		749,844	695,683
Operating income from continuing operations	53,625	43,149		90,166	71,756
Interest expense	(9,993)	(12,405)		(19,576)	(24,058)
Income from continuing operations before income taxes	44,079	30,562		72,374	47,329
Income tax expense	(1,944)	(11,234)		(10,210)	(17,487)
Income from continuing operations	42,135	19,328		62,164	29,842
Net income	42,711	19,731		62,288	29,868
Net Income (Loss) Attributable to Noncontrolling Interest	(2,222)	(693)		(3,991)	(1,940)
Amounts attributable to Harsco Corporation common stockholders:
Income from continuing operations, net of tax	39,913	18,635		58,173	27,902
Net income attributable to Harsco Corporation common stockholders	$ 40,489	$ 19,038		$ 58,297	$ 27,928
Basic earnings per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	$ 0.49	$ 0.23		$ 0.72	$ 0.35
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	0.50	0.24		0.72	0.35
Diluted earnings per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	0.48	0.22		0.70	0.34
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	$ 0.48	$ 0.23	[1]	$ 0.70	$ 0.34
Service Revenues [Member]
Revenues from continuing operations:
Total revenues	$ 257,963	$ 251,306		$ 512,925	$ 491,915
Costs and expenses from continuing operations:
Cost of services and products sold	195,906	193,235		395,279	382,717
Product Revenues [Member]
Revenues from continuing operations:
Total revenues	174,009	143,592		327,085	275,524
Costs and expenses from continuing operations:
Cost of services and products sold	122,976	$ 100,728		234,956	$ 199,518
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Revenues from continuing operations:
Total revenues	(6,085)			(15,187)
Costs and expenses from continuing operations:
Selling, general and administrative costs	21			37
Total costs and expenses	(6,812)			(15,368)
Operating income from continuing operations	727			181
Interest expense	451			903
Income from continuing operations before income taxes	1,178			1,084
Income tax expense	12			4
Income from continuing operations	1,190			1,088
Net income	1,190			1,088
Net Income (Loss) Attributable to Noncontrolling Interest	2			2
Amounts attributable to Harsco Corporation common stockholders:
Income from continuing operations, net of tax	1,192			1,090
Net income attributable to Harsco Corporation common stockholders	$ 1,192			$ 1,090
Basic earnings per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	$ 0.01			$ 0.01
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	0.01			0.01
Diluted earnings per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	0.01			0.01
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	$ 0.01			$ 0.01
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Service Revenues [Member]
Revenues from continuing operations:
Total revenues	$ 2,321			$ 3,671
Costs and expenses from continuing operations:
Cost of services and products sold	1,349			2,707
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Product Revenues [Member]
Revenues from continuing operations:
Total revenues	(8,406)			(18,858)
Costs and expenses from continuing operations:
Cost of services and products sold	(8,182)			(18,112)
Calculated under Revenue Guidance in Effect before Topic 606 [Member]
Revenues from continuing operations:
Total revenues	425,887			824,823
Costs and expenses from continuing operations:
Selling, general and administrative costs	58,948			116,047
Total costs and expenses	371,535			734,476
Operating income from continuing operations	54,352			90,347
Interest expense	(9,542)			(18,673)
Income from continuing operations before income taxes	45,257			73,458
Income tax expense	(1,932)			(10,206)
Income from continuing operations	43,325			63,252
Net income	43,901			63,376
Net Income (Loss) Attributable to Noncontrolling Interest	(2,220)			(3,989)
Amounts attributable to Harsco Corporation common stockholders:
Income from continuing operations, net of tax	41,105			59,263
Net income attributable to Harsco Corporation common stockholders	$ 41,681			$ 59,387
Basic earnings per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	$ 0.50			$ 0.73
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	0.51			0.73
Diluted earnings per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	0.49			0.71
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	$ 0.49			$ 0.71
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Service Revenues [Member]
Revenues from continuing operations:
Total revenues	$ 260,284			$ 516,596
Costs and expenses from continuing operations:
Cost of services and products sold	197,255			397,986
Calculated under Revenue Guidance in Effect before Topic 606 [Member] | Product Revenues [Member]
Revenues from continuing operations:
Total revenues	165,603			308,227
Costs and expenses from continuing operations:
Cost of services and products sold	$ 114,794			$ 216,844

[1] Does not total due to rounding