Reconciliation of Basic and Diluted Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Earnings Per Share [Abstract]
Income (loss) from continuing operations, net of tax	$ 18,635	$ (27,994)	$ 27,902	$ (38,544)
Weighted-average shares outstanding - basic (in shares)	80,535	80,337	80,460	80,288
Dilutive effect of stock-based compensation (in shares)	2,315	0	2,098	0
Weighted-average shares outstanding - diluted (in shares)	82,850	80,337	82,558	80,288
Earnings (loss) from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic (in dollars per share)	$ 0.23	$ (0.35)	$ 0.35	$ (0.48)
Diluted (in dollars per share)	$ 0.22	$ (0.35)	$ 0.34	$ (0.48)