Basis of Presentation	9 Months Ended
Basis of Presentation	Sep. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The Company has prepared these unaudited condensed consolidated financial statements in accordance with U.S. GAAP for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X of the SEC. Accordingly, the unaudited condensed consolidated financial statements do not include all information and disclosure required by U.S. GAAP for annual financial statements. The December 31, 2019 Condensed Consolidated Balance Sheet information contained in this Quarterly Report on Form 10-Q was derived from the 2019 audited consolidated financial statements. The unaudited condensed consolidated financial statements should be read in conjunction with the audited consolidated financial statements, including the notes thereto, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. In the opinion of management, all adjustments (all of which are of a normal recurring nature) that are necessary for a fair statement are reflected in the unaudited condensed consolidated financial statements. Restricted Cash The Company had restricted cash of $2.3 million and $2.5 million at September 30, 2020 and December 31, 2019, respectively, and the restrictions are primarily related to collateral provided for certain guarantees of the Company's performance. Acquisition of ESOL On April 6, 2020 the Company completed the previously announced acquisition of ESOL, an established waste transportation, processing and services provider with a comprehensive portfolio of disposal solutions for customers primarily across the industrial, retail and healthcare markets, from Stericycle, Inc. for $429.0 million in cash, inclusive of post-closing adjustments. See Note 3, Acquisitions and Dispositions, for additional information. Segment Reporting The Company reports information about operating segments using the "management approach," which is based on the way management organizes and reports the segments within the enterprise for making operating decisions and assessing performance. The Company's reportable segments are identified based upon differences in products, service and markets served. The operations of ESOL are combined and included as part of the Harsco Clean Earth Segment. Impact of COVID-19 Beginning in early 2020, overall global economic conditions were significantly impacted by COVID-19. The continuing impact of COVID-19 on the Company varies by end market as well as local conditions (including applicable government mandates) and is continually evolving. The ultimate duration and impact of COVID-19 on the Company and its customers' operations is presently unclear, though the Company continues to operate as a provider of certain essential services in the U.S. and other countries. The Company continues to take significant and proactive actions to protect all stakeholders and to minimize the operational and financial impacts of COVID-19 where possible. The Company did not record any long-lived asset impairments, indefinite-lived asset impairments, goodwill impairments, significant inventory write-downs or incremental accounts receivable reserves for current expected credit losses during the three months or nine months ended September 30, 2020, however such charges are possible in future periods, which could have an adverse effect on the Company's future results of operations, cash flows, or financial condition. Discontinued Operations In January 2020 the Company sold IKG and, together with the 2019 sales of AXC and PK, this completed the divestiture of the former Harsco Industrial Segment originally announced in May 2019. These disposals represent a strategic shift and accelerated the transformation of the Company's portfolio of businesses into a leading provider of environmental solutions and services. As a result of these disposals (i) the carrying value of the remaining assets and liabilities of the Harsco Industrial Segment were classified as Assets held-for-sale and Liabilities of assets held-for-sale on the Company's December 31, 2019 Condensed Consolidated Balance Sheet; (ii) the operating results of the Harsco Industrial Segment, costs directly related to the disposals, an allocation of interest expense associated with mandatory debt repayments required as a result of the disposals and the write-off of deferred financing costs resulting from the mandatory repayment have been reflected in the Company's Condensed Consolidated Statements of Operations as discontinued operations for all periods presented; and (iii) all disclosures have been updated to reflect these changes. See Note 3, Acquisitions and Dispositions, for additional information. Reclassifications Certain reclassifications have been made to prior year amounts to conform with current year classifications.