Capital Stock (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Common Stock
Shares outstanding at the beginning of the period	112,063,938	111,931,267	111,611,102	111,387,185
Treasury Stock, Number of Shares Held	31,479,310	31,454,097	31,097,043	31,034,126
Common Stock, Shares, Outstanding	80,584,628	80,477,170	80,514,059	80,353,059
Stock Options Exercised (in shares)	38,900	199,032	115,493
Vested Restricted Stock Units (in shares)	45,898	121,133	108,424
Treasury shares purchased (in shares)	0	286,577	0
Other Stock Grants (in shares)	47,873
Shares outstanding at the end of the period	112,063,938	111,931,267	111,611,102	111,387,185
Treasury Stock, Number of Shares Held	31,479,310	31,454,097	31,097,043	31,034,126
Common Stock, Shares, Outstanding	80,584,628	80,477,170	80,514,059	80,353,059
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)	$ (253,693)	$ (9,447)	$ 10,885
Weighted average number of shares outstanding - basic	80,632,000	80,736,000	80,569,000
Dilutive effect of stock-based compensation (in shares)	0	0	192,000
Weighted average number of shares outstanding - diluted	80,632,000	80,736,000	80,761,000
Earnings (loss) from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic (in dollars per share)	$ (3.15)	$ (0.12)	$ 0.14
Diluted (in dollars per share)	$ (3.15)	$ (0.12)	$ 0.13
Common Stock Treasury
Common Stock
Stock Options Exercised (in shares)	0	41,974	24,008
Vested Restricted Stock Units (in shares)	14,677	28,503	38,909
Treasury shares purchased (in shares)	286,577
Other Stock Grants (in shares)	10,536
Outstanding Shares
Common Stock
Stock Options Exercised (in shares)	38,900	157,058	91,485
Vested Restricted Stock Units (in shares)	31,221	92,630	69,515
Treasury shares purchased (in shares)	(286,577)
Other Stock Grants (in shares)	37,337