Two-Year Summary of Quarterly Results (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Quarterly Financial Information Disclosure [Abstract]
Product revenues	$ 462,100	$ 470,400	$ 468,700	$ 447,300	$ 431,500	$ 416,600	$ 365,600	$ 320,400	$ 1,848,399	$ 1,534,033	$ 1,204,369
Gross Profit	79,700	95,000	93,200	89,900	86,800	80,500	62,100	62,300
Net income (loss) attributable to Harsco Corporation common stockholders	$ (24,400)	$ 7,600	$ 13,400	$ 100	$ (6,300)	$ (9,600)	$ (10,600)	$ 100	$ (3,249)	$ (26,341)	$ 503,919
Continuing operations (in dollars per share)	$ 0.13	$ 0.06	$ 0.11	$ (0.02)	$ (0.09)	$ (0.12)	$ (0.25)	$ (0.17)	$ 0.28	$ (0.63)	$ 0.13
Discontinued operations (in dollars per share)	(0.43)	0.03	0.06	0.02	0.01	0	0.12	0.17	(0.32)	0.30	6.20
Earnings per share, basic (in dollars per share)	(0.31)	0.10	0.17	0	(0.08)	(0.12)	(0.13)	0	(0.04)	(0.33)	6.33
Continuing operations (in dollars per share)	0.13	0.06	0.11	(0.02)	(0.09)	(0.12)	(0.25)	(0.17)	0.28	(0.63)	0.13
Discontinued operations (in dollars per share)	(0.43)	0.03	0.06	0.02	0.01	0	0.12	0.17	(0.32)	0.30	6.07
Earnings per share, diluted (in dollars per share)	$ (0.30)	$ 0.09	$ 0.17	$ 0	$ (0.08)	$ (0.12)	$ (0.13)	$ 0	$ (0.04)	$ (0.33)	$ 6.19	[1]

[1] Does not total due to rounding.