Goodwill and Other Intangible Assets - Changes in Carrying Amounts of Goodwill by Segment (Details) $ in Thousands	9 Months Ended
Sep. 30, 2019 USD ($)
Changes in carrying amounts of goodwill
Balance at December 31, 2018	$ 404,713
Goodwill, Other Increase (Decrease)	328,215
Foreign currency translation	(7,822)
Balance at September 30, 2019	725,106
Harsco Environmental Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2018	391,687
Goodwill, Other Increase (Decrease)	0
Foreign currency translation	(7,822)
Balance at September 30, 2019	383,865
Harsco Clean Earth Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2018	0
Goodwill, Other Increase (Decrease)	328,215
Foreign currency translation	0
Balance at September 30, 2019	328,215
Harsco Rail Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2018	13,026
Goodwill, Other Increase (Decrease)	0
Foreign currency translation	0
Balance at September 30, 2019	$ 13,026

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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- Definition

Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of increase (decrease), classified as other, of an asset representing the future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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No definition available.

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