Recently Adopted and Recently Issued Accounting Standards	9 Months Ended
Sep. 30, 2017
Accounting Changes and Error Corrections [Abstract]
Recently Adopted and Recently Issued Accounting Standards	Recently Adopted and Recently Issued Accounting Standards The following accounting standards have been adopted in 2017: On January 1, 2017, the Company adopted changes issued by the Financial Accounting Standards Board ("FASB") related to the simplification of the measurement of inventory. The changes required entities to measure most inventory at the lower of cost and net realizable value, thereby simplifying the previous guidance under which an entity must measure inventory at the lower of cost or market. The changes did not apply to inventories that are measured using either the last-in, first-out method or the retail inventory method. The adoption of these changes did not have an impact on the Company's condensed consolidated financial statements. On January 1, 2017, the Company adopted changes issued by the FASB that required deferred tax assets and liabilities to be classified as non-current in a classified statement of financial position. The changes applied to all entities that present a classified statement of financial position. The requirement that deferred tax assets and liabilities of a tax-paying component of an entity be offset and presented as a single amount was not affected. The adoption of these changes resulted in the Company reclassifying approximately $27 million from reported current assets to Deferred income tax assets based on balances at December 31, 2016. On January 1, 2017, the Company adopted changes issued by the FASB amending the accounting for stock-based compensation and requiring excess tax benefits and shortfalls to be recognized as a component of income tax expense rather than equity. These changes also required excess tax benefits and shortfalls to be presented as an operating activity on the Condensed Consolidated Statement of Cash Flows and allowed an entity to make an accounting policy election to either estimate expected forfeitures or to account for them as they occur. These changes resulted in the Company recording the cumulative impact of approximately $1 million pre-tax on January 1, 2017 to retained earnings, related to the Company electing to not estimate forfeitures on stock compensation plans but rather recognize forfeitures as they occur. The inclusion of excess tax benefits and shortfalls as a component of the Company’s income tax expense will increase volatility within the provision for income taxes as the amount of excess tax benefits or deficiencies from stock-based compensation awards are dependent on the Company's stock price at the date an award vests. The impact to income tax expense resulting from this change was tax expense of $0.1 million and a tax benefit of $0.4 million for the three and nine months ended September 30, 2017, respectively. During the second quarter of 2017, the Company early-adopted changes issued by the FASB that added and clarified guidance related to the classification, presentation and disclosure of restricted cash in the statement of cash flows. The adoption of these changes did not have an impact on the Company's condensed consolidated statement of cash flows for the current and prior periods. The following accounting standards have been issued and become effective for the Company at a future date: In May 2014, the FASB issued changes related to the recognition of revenue from contracts with customers. The changes clarify the principles for recognizing revenue and develop a common revenue standard. The core principle of the changes is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The changes also require additional disclosures related to revenue recognition. In July 2015, the FASB deferred the effective date of these changes by one year, but will permit entities to adopt one year earlier. During 2016, the FASB clarified the implementation guidance for principal versus agent considerations; identifying performance obligations; accounting for intellectual property licenses; collectability; non-cash consideration; and the presentation of sales and other similar taxes. The FASB also introduced practical expedients related to disclosures of remaining performance obligations and other technical corrections and improvements. These changes become effective for the Company on January 1, 2018. Management has determined that the most significant impact will be with regard to the timing of revenue recognition associated with the air-cooled heat exchanger business of the Harsco Industrial Segment and certain equipment sales in the Harsco Rail Segment. The Company currently recognizes revenues on such arrangements upon the completion of the efforts associated with these arrangements, but as a result of these changes, revenue from these arrangements will be recognized over time and increase revenue in earlier periods. Management has determined that there will not be any significant impact with regards to the timing of revenue recognition associated with the Harsco Metals & Minerals Segment or the industrial grating and fencing or heat transfer businesses of the Harsco Industrial Segment. Management is currently quantifying the impact of these changes, including the impact of income taxes, training those with responsibilities related to revenue recognition and evaluating impacts on the Company's internal controls over financial reporting. The Company will adopt the standard using the modified retrospective method of implementation with the cumulative effect of initially applying the changes recognized in retained earnings at the date of initial application and continues to progress with regard to the quantification of the above identified differences. In February 2016, the FASB issued changes in accounting for leases. The changes introduce a lessee model that brings most leases onto the balance sheet. The changes also align many of the underlying principles of the new lessor model with those in the FASB’s new revenue recognition standard. Furthermore, the changes address other concerns related to the current leases model such as eliminating the requirement in current guidance for an entity to use bright-line tests in determining lease classification. The changes also require lessors to increase the transparency of their exposure to changes in value of their residual assets and how they manage that exposure. The changes become effective for the Company on January 1, 2019. Management is currently evaluating the impact of these changes on its condensed consolidated financial statements. In January 2017, the FASB issued changes that remove the second step of the annual goodwill impairment test, which requires a hypothetical purchase price allocation. The changes provide that the amount of goodwill impairment will be equal to the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. All other goodwill impairment guidance remains largely unchanged. The same one-step impairment test will be applied to goodwill at all reporting units, even those with zero or negative carrying amounts. Entities will be required to disclose the amount of goodwill at reporting units with zero or negative carrying amounts. The changes become effective for the Company on January 1, 2020. Management has determined that these changes will not have a material impact on the Company's condensed consolidated financial statements. However, should the Company be required to record a goodwill impairment charge in future periods, the amount recorded may differ compared to any amounts that might be recorded under current practice. In March 2017, the FASB issued changes to how employers that sponsor defined benefit pension plans and other postretirement plans present the net periodic pension cost ("NPPC") in the statement of operations. An employer will be required to report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. Other components of NPPC are required to be presented in the statement of operations separately from the service cost component and outside of the subtotal of income from operations. The changes also allow only the service cost component to be eligible for capitalization. The changes become effective for the Company on January 1, 2018. Management is currently evaluating the impact of these changes on its condensed consolidated financial statements. In May 2017, the FASB issued changes to clarify when revisions to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The changes require modification accounting only in circumstances when the terms or conditions result in changes to the fair value, vesting conditions or classification of the award as an equity instrument or a liability. The changes become effective for the Company on January 1, 2018. Management does not believe these changes will impact its condensed consolidated financial statements. In August 2017, the FASB issued changes which expand and refine hedge accounting for both financial and non-financial risk components, aligns the recognition and presentation of the effects of hedging instruments and hedged items in the financial statements, and includes certain targeted improvements to ease the application of current guidance related to the assessment of hedge effectiveness. The amendments in this update should be applied to hedging relationships existing on the date of adoption, which includes a cumulative-effect adjustment to eliminate any ineffectiveness recorded to accumulated other comprehensive income or loss with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year in which adoption occurred. Presentation and disclosure amendments are required to be applied prospectively. The changes become effect for the Company on January 1, 2019. Management is currently evaluating the impact of these changes on its condensed consolidated financial statements.

Recently Adopted and Recently Issued Accounting Standards

The following accounting standards have been adopted in 2017:

On January 1, 2017, the Company adopted changes issued by the Financial Accounting Standards Board ("FASB") related to the simplification of the measurement of inventory. The changes required entities to measure most inventory at the lower of cost and net realizable value, thereby simplifying the previous guidance under which an entity must measure inventory at the lower of cost or market. The changes did not apply to inventories that are measured using either the last-in, first-out method or the retail inventory method. The adoption of these changes did not have an impact on the Company's condensed consolidated financial statements.

On January 1, 2017, the Company adopted changes issued by the FASB that required deferred tax assets and liabilities to be classified as non-current in a classified statement of financial position. The changes applied to all entities that present a classified statement of financial position. The requirement that deferred tax assets and liabilities of a tax-paying component of an entity be offset and presented as a single amount was not affected. The adoption of these changes resulted in the Company reclassifying approximately $27 million from reported current assets to Deferred income tax assets based on balances at December 31, 2016.

On January 1, 2017, the Company adopted changes issued by the FASB amending the accounting for stock-based compensation and requiring excess tax benefits and shortfalls to be recognized as a component of income tax expense rather than equity. These changes also required excess tax benefits and shortfalls to be presented as an operating activity on the Condensed Consolidated Statement of Cash Flows and allowed an entity to make an accounting policy election to either estimate expected forfeitures or to account for them as they occur. These changes resulted in the Company recording the cumulative impact of approximately $1 million pre-tax on January 1, 2017 to retained earnings, related to the Company electing to not estimate forfeitures on stock compensation plans but rather recognize forfeitures as they occur. The inclusion of excess tax benefits and shortfalls as a component of the Company’s income tax expense will increase volatility within the provision for income taxes as the amount of excess tax benefits or deficiencies from stock-based compensation awards are dependent on the Company's stock price at the date an award vests. The impact to income tax expense resulting from this change was tax expense of $0.1 million and a tax benefit of $0.4 million for the three and nine months ended September 30, 2017, respectively.

During the second quarter of 2017, the Company early-adopted changes issued by the FASB that added and clarified guidance related to the classification, presentation and disclosure of restricted cash in the statement of cash flows. The adoption of these changes did not have an impact on the Company's condensed consolidated statement of cash flows for the current and prior periods.

The following accounting standards have been issued and become effective for the Company at a future date:

In May 2014, the FASB issued changes related to the recognition of revenue from contracts with customers. The changes clarify the principles for recognizing revenue and develop a common revenue standard. The core principle of the changes is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The changes also require additional disclosures related to revenue recognition. In July 2015, the FASB deferred the effective date of these changes by one year, but will permit entities to adopt one year earlier. During 2016, the FASB clarified the implementation guidance for principal versus agent considerations; identifying performance obligations; accounting for intellectual property licenses; collectability; non-cash consideration; and the presentation of sales and other similar taxes. The FASB also introduced practical expedients related to disclosures of remaining performance obligations and other technical corrections and improvements. These changes become effective for the Company on January 1, 2018. Management has determined that the most significant impact will be with regard to the timing of revenue recognition associated with the air-cooled heat exchanger business of the Harsco Industrial Segment and certain equipment sales in the Harsco Rail Segment. The Company currently recognizes revenues on such arrangements upon the completion of the efforts associated with these arrangements, but as a result of these changes, revenue from these arrangements will be recognized over time and increase revenue in earlier periods. Management has determined that there will not be any significant impact with regards to the timing of revenue recognition associated with the Harsco Metals & Minerals Segment or the industrial grating and fencing or heat transfer businesses of the Harsco Industrial Segment. Management is currently quantifying the impact of these changes, including the impact of income taxes, training those with responsibilities related to revenue recognition and evaluating impacts on the Company's internal controls over financial reporting. The Company will adopt the standard using the modified retrospective method of implementation with the cumulative effect of initially applying the changes recognized in retained earnings at the date of initial application and continues to progress with regard to the quantification of the above identified differences.

In February 2016, the FASB issued changes in accounting for leases. The changes introduce a lessee model that brings most leases onto the balance sheet. The changes also align many of the underlying principles of the new lessor model with those in the FASB’s new revenue recognition standard. Furthermore, the changes address other concerns related to the current leases model such as eliminating the requirement in current guidance for an entity to use bright-line tests in determining lease classification. The changes also require lessors to increase the transparency of their exposure to changes in value of their residual assets and how they manage that exposure. The changes become effective for the Company on January 1, 2019. Management is currently evaluating the impact of these changes on its condensed consolidated financial statements.

In January 2017, the FASB issued changes that remove the second step of the annual goodwill impairment test, which requires a hypothetical purchase price allocation. The changes provide that the amount of goodwill impairment will be equal to the amount by which a reporting unit’s carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. All other goodwill impairment guidance remains largely unchanged. The same one-step impairment test will be applied to goodwill at all reporting units, even those with zero or negative carrying amounts. Entities will be required to disclose the amount of goodwill at reporting units with zero or negative carrying amounts. The changes become effective for the Company on January 1, 2020. Management has determined that these changes will not have a material impact on the Company's condensed consolidated financial statements. However, should the Company be required to record a goodwill impairment charge in future periods, the amount recorded may differ compared to any amounts that might be recorded under current practice.

In March 2017, the FASB issued changes to how employers that sponsor defined benefit pension plans and other postretirement plans present the net periodic pension cost ("NPPC") in the statement of operations. An employer will be required to report the service cost component in the same line item or items as other compensation costs arising from services rendered by the pertinent employees during the period. Other components of NPPC are required to be presented in the statement of operations separately from the service cost component and outside of the subtotal of income from operations. The changes also allow only the service cost component to be eligible for capitalization. The changes become effective for the Company on

January 1, 2018. Management is currently evaluating the impact of these changes on its condensed consolidated financial statements.

In May 2017, the FASB issued changes to clarify when revisions to the terms or conditions of a share-based payment award require an entity to apply modification accounting. The changes require modification accounting only in circumstances when the terms or conditions result in changes to the fair value, vesting conditions or classification of the award as an equity instrument or a liability. The changes become effective for the Company on January 1, 2018. Management does not believe these changes will impact its condensed consolidated financial statements.

In August 2017, the FASB issued changes which expand and refine hedge accounting for both financial and non-financial risk components, aligns the recognition and presentation of the effects of hedging instruments and hedged items in the financial statements, and includes certain targeted improvements to ease the application of current guidance related to the assessment of hedge effectiveness. The amendments in this update should be applied to hedging relationships existing on the date of adoption, which includes a cumulative-effect adjustment to eliminate any ineffectiveness recorded to accumulated other comprehensive income or loss with a corresponding adjustment to the opening balance of retained earnings as of the beginning of the fiscal year in which adoption occurred. Presentation and disclosure amendments are required to be applied prospectively. The changes become effect for the Company on January 1, 2019. Management is currently evaluating the impact of these changes on its condensed consolidated financial statements.