Debt and Credit Agreements (Details 2)	1 Months Ended		12 Months Ended
	Nov. 30, 2016	Sep. 30, 2016 USD ($)	Dec. 31, 2021	Dec. 31, 2018	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Jan. 31, 2017 USD ($)	Dec. 02, 2015 USD ($)	Dec. 01, 2015 USD ($)
Line of Credit Facility [Line Items]
Net sales proceeds		$ 145,000,000			$ 0	$ 165,640,000	$ 0
Repayment of debt					108,280,000	979,567,000	399,533,000
Loss on early extinguishment of debt					(2,265,000)	(35,337,000)	0
Total debt obligations					593,659,000	673,410,000
Current maturities of long-term debt					11,208,000	25,574,000
Short-term borrowings					$ 8,621,000	$ 4,259,000
Weighted average interest rate					4.30%	6.20%
Interest paid					$ 44,300,000	$ 49,600,000	$ 44,400,000
Minimum consolidated interest coverage ratio, numerator					3.0
Harsco Infrastructure | Infrastructure Transaction Strategic Venture
Line of Credit Facility [Line Items]
Percentage of ownership in equity method investments						26.00%
Term Loan
Line of Credit Facility [Line Items]
Interest rate floor					1.00%
Quarterly payment, percentage of original principal amount					0.25%
Total debt obligations					$ 545,875,000	$ 550,000,000
Term Loan | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.00%
Term Loan | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	3.00%
Term Loan | Term Loan Facility 2015
Line of Credit Facility [Line Items]
Principle amount									$ 250,000,000
Repayment of debt						85,000,000
Total debt obligations						550,000,000
Term Loan | New Credit Facility
Line of Credit Facility [Line Items]
Principle amount					$ 550,000,000
Term Loan | Fixed-Rate Term Loan
Line of Credit Facility [Line Items]
Principle amount								$ 300,000,000
Term Loan | Fixed-Rate Term Loan | LIBOR | Forecast
Line of Credit Facility [Line Items]
Basis spread on variable rate			2.71%	1.65%
Senior Notes | 5.75% notes due May 15,2018
Line of Credit Facility [Line Items]
Stated interest rate					5.75%
Secured Debt | Senior Secured Credit Facilities
Line of Credit Facility [Line Items]
Long-term and Short-term, combined amount					$ 586,900,000	648,000,000
Total debt obligations					581,400,000	642,500,000
Current maturities of long-term debt					5,500,000	5,500,000
Credit Agreement
Line of Credit Facility [Line Items]
Facility limit					$ 400,000,000				$ 600,000,000	$ 500,000,000
Debt issuance cost						1,100,000
Minimum consolidated interest coverage ratio, numerator					3.75
Credit Agreement | Forecast
Line of Credit Facility [Line Items]
Minimum consolidated interest coverage ratio, numerator				3.5
Revolving Credit Facility
Line of Credit Facility [Line Items]
Facility limit										$ 350,000,000
Current borrowing capacity					$ 400,000,000
Long-term and Short-term, combined amount					41,000,000	98,000,000
Total debt obligations					$ 41,000,000	98,000,000
Revolving Credit Facility | Minimum | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	0.875%
Revolving Credit Facility | Minimum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	1.875%
Revolving Credit Facility | Maximum | Base Rate
Line of Credit Facility [Line Items]
Basis spread on variable rate	2.00%
Revolving Credit Facility | Maximum | LIBOR
Line of Credit Facility [Line Items]
Basis spread on variable rate	3.00%
Revolving Credit Facility | New Credit Facility
Line of Credit Facility [Line Items]
Repayment of debt						$ 60,000,000