Discontinued Operations and Dispositions - Schedule of Income (Loss) from Discontinued Operations Harsco Rail (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues	$ 600,317	$ 560,705
Selling, general and administrative expenses	87,126	81,861
Research and development expenses	861	520
Other expense (income)	2,440	5,648
Total costs and expenses	574,504	528,790
Operating income from continuing operations	25,813	31,915
Interest income	1,697	1,480
Interest expense	28,122	24,995
Defined benefit pension income	4,176	5,329
Income (loss) from continuing operations before income taxes	(7,577)	708
Income tax benefit (expense) from continuing operations	7,915	8,017
Income (loss) from continuing operations	(15,741)	(7,442)
Revision of Prior Period, Adjustment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cost of services and products sold	51,369
Harsco Rail Segment | Revision of Prior Period, Adjustment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues		65,052
Selling, general and administrative expenses		9,926
Research and development expenses		344
Other expense (income)		503
Total costs and expenses		62,142
Operating income from continuing operations		2,910
Interest income		25
Interest expense		(667)
Defined benefit pension income		6
Income (loss) from continuing operations before income taxes		2,274
Income tax benefit (expense) from continuing operations		(1,094)
Income (loss) from continuing operations		1,180
Service revenues | Harsco Rail Segment | Revision of Prior Period, Adjustment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues		7,720
Cost of services and products sold		5,626
Product Revenues
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues	101,163	99,145
Cost of services and products sold	$ 85,410	82,549
Product Revenues | Harsco Rail Segment | Revision of Prior Period, Adjustment
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Total revenues		57,332
Cost of services and products sold		$ 45,743