Capital Stock (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Common Stock
Shares outstanding at the beginning of the period	111,611,102	111,387,185
Stock Options Exercised (in shares)	157,058	91,485	76,605
Vested Restricted Stock Units (in shares)	92,630	69,515	101,918
Treasury shares purchased	286,577
Shares outstanding at the end of the period	111,931,267	111,611,102	111,387,185
Reconciliation of the average shares of common stock used to compute basic earnings per common share to the shares used to compute diluted earnings per common share
Income (loss) from continuing operations attributable to Harsco Corporation common stockholders (in dollars)	$ (9,447)	$ 10,885	$ 133,838
Weighted average shares outstanding - basic	80,736,000	80,569,000	80,295,000
Dilutive effect of stock-based compensation (in shares)		192,000	291,000
Weighted average shares outstanding - diluted	80,736,000	80,761,000	80,586,000
Earnings (loss) from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic (in dollars per share)	$ (0.12)	$ 0.14	$ 1.67
Diluted (in dollars per share)	$ (0.12)	$ 0.13	$ 1.66
Shares Issued
Common Stock
Shares outstanding at the beginning of the period	111,611,102	111,387,185	111,139,988
Stock Options Exercised (in shares)	199,032	115,493	92,250
Vested Restricted Stock Units (in shares)	121,133	108,424	154,947
Shares outstanding at the end of the period	111,931,267	111,611,102	111,387,185
Common Stock Treasury
Common Stock
Shares outstanding at the beginning of the period	31,097,043	31,034,126	30,965,452
Stock Options Exercised (in shares)	41,974	24,008	15,645
Vested Restricted Stock Units (in shares)	28,503	38,909	53,029
Treasury shares purchased	286,577
Shares outstanding at the end of the period	31,454,097	31,097,043	31,034,126
Outstanding Shares
Common Stock
Shares outstanding at the beginning of the period	80,514,059	80,353,059	80,174,536
Stock Options Exercised (in shares)	157,058	91,485	76,605
Vested Restricted Stock Units (in shares)	92,630	69,515	101,918
Treasury shares purchased	(286,577)
Shares outstanding at the end of the period	80,477,170	80,514,059	80,353,059