Goodwill and Other Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 404,713	$ 394,919
Changes to goodwill	330,230	22,518
Foreign currency translation	3,426	(12,724)
Balance at the end of the period	738,369	404,713
Harsco Environmental
Goodwill [Roll Forward]
Balance at the beginning of the period	391,687	381,893
Changes to goodwill	0	22,518
Foreign currency translation	3,426	(12,724)
Balance at the end of the period	395,113	391,687
Clean Earth
Goodwill [Roll Forward]
Balance at the beginning of the period	0	0
Changes to goodwill	330,230	0
Foreign currency translation	0	0
Balance at the end of the period	330,230	0
Harsco Rail
Goodwill [Roll Forward]
Balance at the beginning of the period	13,026	13,026
Changes to goodwill	0	0
Foreign currency translation	0	0
Balance at the end of the period	$ 13,026	$ 13,026