Reconciliation of Basic and Diluted Shares Reconciliation of Basic and Diluted Shares (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]
Income from continuing operations attributable to Harsco Corporation common stockholders	$ 26,208	$ 32,207	$ 10,278	$ 82,648
Weighted-average shares outstanding - basic	80,659	80,767	80,623	80,737
Dilutive effect of stock-based compensation	251	270	240	260
Weighted-average shares outstanding - diluted	80,910	81,037	80,863	80,997
Earnings from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic	$ 0.32	$ 0.40	$ 0.13	$ 1.02
Diluted	$ 0.32	$ 0.40	$ 0.13	$ 1.02