Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Income Tax Disclosure [Line Items]
Foreign earnings before tax	$ 10,108	$ 29,644	$ 71,968
Differences on international earnings and remittances	13,300	5,800
Income Tax Expense (Benefit)	28,185	10,381	9,089
Total international income tax expense	21,096	14,914	22,295
Operating loss carryforwards	54,935	54,237
Valuation Allowance	112,905	89,234
Interest and penalties recognized	0	400	(400)
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	1,300	1,300	1,700
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	400
Current Foreign Tax Expense (Benefit)	23,400	17,500
Impaired asset write-downs	88	641	1,005
Harsco Environmental
Income Tax Disclosure [Line Items]
Impaired asset write-downs	88	582	942
Clean Earth
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)	3,000
Impaired asset write-downs	0	59	$ 63
Altek Group
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)	0
Impaired asset write-downs	15,000
HE Sites
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)	3,700
Impaired asset write-downs	14,100
International operations
Income Tax Disclosure [Line Items]
Operating loss carryforwards	43,900
Operating loss carryforwards not subject to expiration	39,600
Operating losses subject to expiration	4,300
U.S. state
Income Tax Disclosure [Line Items]
Operating loss carryforwards	11,000
United States
Income Tax Disclosure [Line Items]
Differences on international earnings and remittances	$ 300	$ 100