Reconciliation of Basic and Diluted Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share [Abstract]
Income (loss) from continuing operations, net of tax	$ (32,612)	$ (8,254)	$ (71,156)	$ 13,719
Weighted-average shares outstanding - basic (in shares)	80,379	80,238	80,318	80,233
Dilutive effect of stock-based compensation (in shares)	0	0	0	130
Weighted-average shares outstanding - diluted (in shares)	80,379	80,238	80,318	80,363
Earnings (loss) from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic (in dollars per share)	$ (0.41)	$ (0.10)	$ (0.89)	$ 0.17
Diluted (in dollars per share)	$ (0.41)	$ (0.10)	$ (0.89)	$ 0.17