CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019		Jun. 30, 2020	Jun. 30, 2019
Revenues from continuing operations:
Total revenues	$ 447,281		$ 350,898		$ 846,122	$ 680,800
Costs and expenses from continuing operations:
Selling, general and administrative costs	80,771		67,501		153,270	123,907
Research and development expenses	792		1,120		2,052	1,869
Other (income) expenses, net	(292)		(1,717)		5,441	26
Total costs and expenses	445,413		333,099		841,373	643,177
Operating income from continuing operations	1,868		17,799		4,749	37,623
Interest income	816		591		1,009	1,124
Interest expense	(14,953)		(6,103)		(27,602)	(11,610)
Unused debt commitment and amendment fees	(1,432)		(7,435)		(1,920)	(7,435)
Defined benefit pension income (expense)	1,723		(1,472)		3,312	(2,810)
Income (loss) from continuing operations before income taxes and equity income	(11,978)		3,380		(20,452)	16,892
Income tax benefit (expense)	2,304		(3,994)		2,986	(5,213)
Equity income of unconsolidated entities, net	71		49		167	70
Income (loss) from continuing operations	(9,603)		(565)		(17,299)	11,749
Discontinued Operation, Gain (Loss) from Disposal of Discontinued Operation, before Income Tax	(91)		0		18,371	0
Discontinued operations:
Income from discontinued businesses	524		9,936		299	23,686
Income tax benefit (expense) related to discontinued businesses	(285)		1,558		(9,599)	(1,969)
Income from discontinued operations	148		11,494		9,071	21,717
Net income (loss)	(9,455)		10,929		(8,228)	33,466
Less: Net income attributable to noncontrolling interests	(1,147)		(2,287)		(2,233)	(4,127)
Net income (loss) attributable to Harsco Corporation	(10,602)		8,642		(10,461)	29,339
Amounts attributable to Harsco Corporation common stockholders:
Income (loss) from continuing operations, net of tax	(10,750)		(2,852)		(19,532)	7,622
Income from discontinued operations	148		11,494		9,071	21,717
Net income (loss) attributable to Harsco Corporation	$ (10,602)		$ 8,642		$ (10,461)	$ 29,339
Weighted-average shares of common stock outstanding (in shares)	78,987		80,328		78,874	80,119
Basic earnings (loss) per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	$ (0.14)		$ (0.04)		$ (0.25)	$ 0.10
Discontinued operations (in dollars per share)	0		0.14		0.12	0.27
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	$ (0.13)	[1]	$ 0.11	[1]	$ (0.13)	$ 0.37
Diluted weighted-average shares of common stock outstanding (in shares)	78,987		80,328		78,874	82,074
Diluted earnings (loss) per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	$ (0.14)		$ (0.04)		$ (0.25)	$ 0.09
Discontinued operations (in dollars per share)	0		0.14		0.12	0.26
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	$ (0.13)	[1]	$ 0.11	[1]	$ (0.13)	$ 0.36	[1]
Products And Services, Service Revenue [Member]
Revenues from continuing operations:
Total revenues	$ 345,578		$ 238,003		$ 636,917	$ 467,523
Costs and expenses from continuing operations:
Cost of services sold	285,822		186,840		522,141	368,711
Product Revenues
Revenues from continuing operations:
Total revenues	101,703		112,895		209,205	213,277
Costs and expenses from continuing operations:
Cost of services sold	$ 78,320		$ 79,355		$ 158,469	$ 148,664

[1]  Does not total due to rounding