Components of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances	$ 310,803	$ 351,910	$ 597,555
Other comprehensive income (loss) before reclassifications	(141,106)	16,271
Other comprehensive income (loss) from equity method investee	1,844	(22,586)
Amounts reclassified from accumulated other comprehensive loss, net of tax	16,905	20,243
Realized (gains) losses reclassified from accumulated other comprehensive loss in connection with loss on dilution of equity method investment	(28,743)
Total other comprehensive income (loss)	(93,614)	13,928	(163,243)
Less: Other comprehensive loss attributable to noncontrolling interests	2,580	2,640
Other comprehensive income (loss) attributable to Harsco Corporation	(91,034)	16,568
Balances	137,563	310,803	351,910
Cumulative Foreign Exchange Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances	(125,561)	(39,938)
Other comprehensive income (loss) before reclassifications	(53,301)	(66,305)
Other comprehensive income (loss) from equity method investee	1,943	(21,950)
Amounts reclassified from accumulated other comprehensive loss, net of tax	1,157	0
Realized (gains) losses reclassified from accumulated other comprehensive loss in connection with loss on dilution of equity method investment	(28,641)
Total other comprehensive income (loss)	(21,560)	(88,255)
Less: Other comprehensive loss attributable to noncontrolling interests	2,587	2,632
Other comprehensive income (loss) attributable to Harsco Corporation	(18,973)	(85,623)
Balances	(144,534)	(125,561)	(39,938)
Effective Portion of Derivatives Designated as Hedging Instruments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances	(400)	(9,025)
Other comprehensive income (loss) before reclassifications	(1,650)	9,796
Other comprehensive income (loss) from equity method investee	(405)	(1,232)
Amounts reclassified from accumulated other comprehensive loss, net of tax	(263)	53
Realized (gains) losses reclassified from accumulated other comprehensive loss in connection with loss on dilution of equity method investment	(1,636)
Total other comprehensive income (loss)	(682)	8,617
Less: Other comprehensive loss attributable to noncontrolling interests	(7)	8
Other comprehensive income (loss) attributable to Harsco Corporation	(689)	8,625
Balances	(1,089)	(400)	(9,025)
Cumulative Unrecognized Actuarial Losses on Pension Obligations
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances	(389,696)	(483,278)
Other comprehensive income (loss) before reclassifications	(86,181)	72,796
Other comprehensive income (loss) from equity method investee	306	596
Amounts reclassified from accumulated other comprehensive loss, net of tax	16,011	20,190
Realized (gains) losses reclassified from accumulated other comprehensive loss in connection with loss on dilution of equity method investment	1,534
Total other comprehensive income (loss)	(71,398)	93,582
Less: Other comprehensive loss attributable to noncontrolling interests	0	0
Other comprehensive income (loss) attributable to Harsco Corporation	(71,398)	93,582
Balances	(461,094)	(389,696)	(483,278)
Unrealized Loss on Marketable Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances	(31)	(15)
Other comprehensive income (loss) before reclassifications	26	(16)
Other comprehensive income (loss) from equity method investee	0	0
Amounts reclassified from accumulated other comprehensive loss, net of tax	0	0
Realized (gains) losses reclassified from accumulated other comprehensive loss in connection with loss on dilution of equity method investment	0
Total other comprehensive income (loss)	26	(16)
Less: Other comprehensive loss attributable to noncontrolling interests	0	0
Other comprehensive income (loss) attributable to Harsco Corporation	26	(16)
Balances	(5)	(31)	(15)
Total
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Balances	(515,688)	(532,256)	(370,615)
Total other comprehensive income (loss)	(91,034)	16,568	(161,641)
Balances	$ (606,722)	$ (515,688)	$ (532,256)