Income Taxes (Details 2) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Income Tax Disclosure [Line Items]
Foreign earnings before tax	$ (40,465)	$ (33,072)	$ 3,728
Differences on international earnings and remittances	29,000	26,400
Income Tax Expense (Benefit)	17,066	30,866	4,856
Total international income tax expense	24,884	23,801	16,428
Operating loss carryforwards	128,412	118,309
Valuation Allowance	192,745	177,888
Interest and penalties recognized	0	(100)	400
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	1,300	1,300	1,300
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	600
Current Foreign Tax Expense (Benefit)	22,100	26,900
Impaired asset write-downs	5,259	88	736
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions	2,100
Increase (decrease) in valuation allowance	(5,400)
Harsco Environmental
Income Tax Disclosure [Line Items]
Impaired asset write-downs	2,771	88	582
Clean Earth
Income Tax Disclosure [Line Items]
Impaired asset write-downs	567	0	59
Altek Group
Income Tax Disclosure [Line Items]
Impaired asset write-downs			$ 15,000
HE Sites
Income Tax Disclosure [Line Items]
Income Tax Expense (Benefit)	3,700	0
Impaired asset write-downs	14,100
International operations
Income Tax Disclosure [Line Items]
Operating loss carryforwards	116,000
Operating loss carryforwards not subject to expiration	107,900
Operating losses subject to expiration	8,100
U.S. state
Income Tax Disclosure [Line Items]
Operating loss carryforwards	12,400
United States
Income Tax Disclosure [Line Items]
Differences on international earnings and remittances	$ 300	$ 300