Enviri (NVRI) 10-Q 9 May 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 30, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	HARSCO CORP
Entity Central Index Key	0000045876
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock, Shares Outstanding		80,189,569

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 84,743	$ 64,260
Restricted cash	2,942	2,886
Trade accounts receivable, net	296,795	291,213
Other receivables	51,130	54,182
Inventories	147,696	133,111
Current portion of contract assets	17,478	24,254
Other current assets	45,219	35,128
Total current assets	646,003	605,034
Property, plant and equipment, net	483,448	469,900
Right-of-use assets, net	49,584
Goodwill	412,449	411,552
Intangible assets, net	78,753	79,825
Deferred income tax assets	50,051	49,114
Other assets	17,273	17,442
Total assets	1,737,561	1,632,867
Current liabilities:
Short-term borrowings	6,426	10,078
Current maturities of long-term debt	6,538	6,489
Accounts payable	159,037	149,410
Accrued compensation	37,483	57,586
Income taxes payable	1,598	2,634
Insurance liabilities	40,830	40,774
Current portion of advances on contracts	37,014	31,317
Current portion of operating lease liabilities	12,936
Other current liabilities	122,721	118,708
Total current liabilities	424,583	416,996
Long-term debt	642,375	585,662
Insurance liabilities	20,384	19,575
Retirement plan liabilities	201,572	213,578
Advances on contracts	27,478	37,675
Operating lease liabilities	37,037
Other liabilities	48,860	46,005
Total liabilities	1,402,289	1,319,491
COMMITMENTS AND CONTINGENCIES
HARSCO CORPORATION STOCKHOLDERS' EQUITY
Preferred stock	0	0
Common stock	143,178	141,842
Additional paid-in capital	192,912	190,597
Accumulated other comprehensive loss	(584,425)	(567,107)
Retained earnings	1,340,878	1,298,752
Treasury stock	(805,520)	(795,821)
Total Harsco Corporation stockholders' equity	287,023	268,263
Noncontrolling interests	48,249	45,113
Total equity	335,272	313,376
Total liabilities and equity	$ 1,737,561	$ 1,632,867

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019		Mar. 31, 2018
Revenues from continuing operations:
Total revenues	$ 447,288		$ 408,038
Costs and expenses from continuing operations:
Selling, general and administrative costs	67,029		57,083
Research and development expenses	1,262		1,239
Other expenses, net	1,876		1,822
Total costs and expenses	409,042		371,497
Operating income from continuing operations	38,246		36,541
Interest income	534		498
Interest expense	(9,739)		(9,583)
Defined benefit pension income (expense)	(1,337)		839
Income from continuing operations before income taxes and equity income	27,704		28,295
Income tax expense	(4,855)		(8,266)
Equity income of unconsolidated entities, net	20		0
Income from continuing operations	22,869		20,029
Discontinued operations:
Loss on disposal of discontinued business	(440)		(580)
Income tax benefit related to discontinued business	108		128
Loss from discontinued operations	(332)		(452)
Net income	22,537		19,577
Less: Net income attributable to noncontrolling interests	(1,840)		(1,769)
Net income attributable to Harsco Corporation	20,697		17,808
Amounts attributable to Harsco Corporation common stockholders:
Income from continuing operations, net of tax	21,029		18,260
Loss from discontinued operations	(332)		(452)
Net income attributable to Harsco Corporation	$ 20,697		$ 17,808
Weighted-average shares of common stock outstanding (in shares)	79,907		80,650
Basic earnings (loss) per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	$ 0.26		$ 0.23
Discontinued operations (in dollars per share)	0		(0.01)
Basic earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	$ 0.26		$ 0.22
Diluted weighted-average shares of common stock outstanding (in shares)	81,653		83,544
Diluted earnings (loss) per common share attributable to Harsco Corporation common stockholders:
Continuing operations (in dollars per share)	$ 0.26		$ 0.22
Discontinued operations (in dollars per share)	0		(0.01)
Diluted earnings (loss) per share attributable to Harsco Corporation common stockholders (in dollars per share)	$ 0.25	[1]	$ 0.21
Service Revenues [Member]
Revenues from continuing operations:
Total revenues	$ 229,520		$ 244,209
Costs and expenses from continuing operations:
Cost of services and products sold	181,871		191,675
Product Revenues
Revenues from continuing operations:
Total revenues	217,768		163,829
Costs and expenses from continuing operations:
Cost of services and products sold	$ 157,004		$ 119,678
[1]	Does not total due to rounding

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 22,537	$ 19,577
Other comprehensive income (loss):
Foreign currency translation adjustments, net of deferred income taxes of $1,131 and $1,627 for the three months ended March 31, 2019 and 2018, respectively	9,454	12,501
Net gain (loss) on cash flow hedging instruments, net of deferred income taxes of $945 and $(839) for the three months ended March 31, 2019 and 2018, respectively	(3,147)	2,677
Pension liability adjustments, net of deferred income taxes of $(342) and $(325) for the three months ended March 31, 2019 and 2018, respectively	(1,791)	(9,001)
Unrealized gain (loss) on marketable securities, net of deferred income taxes of $(5) and $4 for the three months ended March 31, 2019 and 2018, respectively	15	(14)
Total other comprehensive income	4,531	6,163
Total comprehensive income	27,068	25,740
Less: Comprehensive (income) loss attributable to noncontrolling interests	(2,260)	(3,047)
Comprehensive income attributable to Harsco Corporation	$ 24,808	$ 22,693

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustments, deferred income taxes	$ 1,131	$ 1,627
Net gain (loss) on cash flow hedging instruments, deferred income taxes	945	(839)
Pension liability adjustments, deferred income taxes	(342)	(325)
Unrealized gain (loss) on marketable securities, deferred income taxes	$ (5)	$ 4

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities:
Net income	$ 22,537	$ 19,577
Adjustments to reconcile net income to net cash provided (used) by operating activities:
Depreciation	30,204	31,418
Amortization	3,045	1,934
Deferred income tax expense	595	4,635
Equity income of unconsolidated entities, net	(20)	0
Other, net	(279)	1,944
Changes in assets and liabilities:
Accounts receivable	(3,270)	(4,848)
Inventories	(14,448)	(11,490)
Contract assets	6,770	(5,698)
Right-of-use assets	3,895
Accounts payable	3,099	7,340
Accrued compensation	(19,924)	(26,131)
Advances on contracts	(3,406)	(7,348)
Operating lease liabilities	(3,913)
Retirement plan liabilities, net	(9,403)	(12,252)
Other assets and liabilities	(644)	(7,324)
Net cash provided (used) by operating activities	14,838	(8,243)
Cash flows from investing activities:
Purchases of property, plant and equipment	(36,407)	(26,897)
Purchase of business, net of cash acquired	680	0
Proceeds from sales of assets	1,177	377
Net payments from settlement of foreign currency forward exchange contracts	(4,091)	(3,822)
Net cash used by investing activities	(38,641)	(30,342)
Cash flows from financing activities:
Short-term borrowings, net	(3,578)	(3,659)
Current maturities and long-term debt:
Additions	56,998	46,000
Reductions	(1,700)	(2,944)
Sale of noncontrolling interests	876	477
Stock-based compensation - Employee taxes paid	(8,237)	(709)
Net cash provided by financing activities	44,359	39,165
Effect of exchange rate changes on cash and cash equivalents, including restricted cash	(17)	738
Net increase in cash and cash equivalents, including restricted cash	20,539	1,318
Cash and cash equivalents, including restricted cash, at beginning of period	67,146	66,209
Cash and cash equivalents, including restricted cash, at end of period	$ 87,685	$ 67,527

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock Issued	Common Stock Treasury	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Noncontrolling Interests
Balances at Dec. 31, 2017	$ 215,165	$ 141,110	$ (762,079)	$ 180,201	$ 1,157,801	$ (546,582)	$ 44,714
Increase (Decrease) in Stockholders' Equity
Net income	19,577				17,808		1,769
Sale of subsidiary shares to noncontrolling interest	477						477
Total other comprehensive income (loss), net of deferred income taxes of $1,729 and $467 in 2019 and 2018, respectively	6,163					4,885	1,278
Stock Appreciation Rights exercised, net 927 shares and 2,560 shares in 2019 and 2018, respectively	(26)	5	(26)	(5)
Vesting of restricted stock units and other stock grants, net 94,229 shares and 102,695 shares in 2019 and 2018, respectively	(683)	171	(683)	(171)
Amortization of unearned portion of stock-based compensation, net of forfeitures	3,285			3,285
Balances at Mar. 31, 2018	246,345	141,286	(762,788)	183,310	1,179,516	(543,217)	48,238
Increase (Decrease) in Stockholders' Equity
Adoption of new accounting standards (See Note 2)	0					(21,429)
Balances at Dec. 31, 2018	313,376	141,842	(795,821)	190,597	1,298,752	(567,107)	45,113
Increase (Decrease) in Stockholders' Equity
Net income	22,537				20,697		1,840
Sale of subsidiary shares to noncontrolling interest	876						876
Total other comprehensive income (loss), net of deferred income taxes of $1,729 and $467 in 2019 and 2018, respectively	4,531					4,111	420
Stock Appreciation Rights exercised, net 927 shares and 2,560 shares in 2019 and 2018, respectively	(8)	2	(8)	(2)
Vesting of restricted stock units and other stock grants, net 94,229 shares and 102,695 shares in 2019 and 2018, respectively	(1,456)	198	(1,456)	(198)
Vesting of performance share unites, net 529,213 shares in 2019	(8,248)	1,136	(8,235)	(1,149)
Amortization of unearned portion of stock-based compensation, net of forfeitures	3,664			3,664
Balances at Mar. 31, 2019	$ 335,272	$ 143,178	$ (805,520)	$ 192,912	$ 1,340,878	$ (584,425)	$ 48,249

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (Unaudited) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Other Comprehensive Income (Loss), Tax	$ 1,729	$ 467
Vesting of restricted stock units and other (in shares)	94,229	102,695
Stock Appreciation Rights exercise (in shares)	927	2,560
Vesting of performance share units (in shares)	529,213	0

Basis of Presentation

Basis of Presentation	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation Harsco Corporation (the "Company") has prepared these unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the U.S. (“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 Securities and Exchange Commission (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, 2018 Condensed Consolidated Balance Sheet information contained in this Quarterly Report on Form 10-Q was derived from the 2018 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, 2018 . 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. Reclassifications

Recently Adopted and Recently I

Recently Adopted and Recently Issued Accounting Standards	3 Months Ended
	Mar. 31, 2019
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 2019: On January 1, 2019, the Company adopted changes issued by the Financial Accounting Standards Board (“FASB”) related to 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 Company elected the package of practical expedients permitted under the transition, which among other items, allowed the carry forward of the historical lease classification. The Company has elected to apply the transition requirements at the January 1, 2019 effective date and therefore, comparative information has not been restated and continues to be reported under U.S. GAAP in effect for those periods. The changes had a significant impact on the Condensed Consolidated Balance Sheets upon adoption and the Company recorded Right-of-use ("ROU") assets and lease liabilities of $53.0 million and $53.4 million , respectively. The difference between the ROU assets and lease liabilities was recorded primarily as adjustments to other assets and liabilities where prepaid rent and deferred expenses were previously recorded. Additionally, the Company's accounting for finance leases remained consistent. The changes did not have an impact on the Company’s Condensed Consolidated Statements of Operations or Condensed Consolidated Statements of Cash Flows. The discount rates used to calculate the ROU assets and lease liabilities as of the effective date were based on the remaining lease terms as of the effective date. See Note 6, Leases for additional information. On January 1, 2019, the Company adopted changes issued by the FASB 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. Upon adoption, the Company’s recognition model for the excluded component was modified from a mark-to-market approach to an amortization approach for hedging relationships. Hedging relationships entered into on or after January 1, 2019 will be under the amortization approach while those entered into before January 1, 2019 will continue to be recognized under the mark-to-market approach. As such, there was no effect of applying this election reflected as an adjustment to Accumulated other comprehensive loss with a corresponding adjustment to the opening balance of Retained earnings. Presentation and disclosure amendments are required to be applied prospectively. Other than required expanded disclosures, the adoption of these changes did not have a material impact on the Company's condensed consolidated financial statements. On January 1, 2019, the Company adopted changes issued by the FASB which allow entities to reclassify stranded income tax effects resulting from the Tax Cuts and Jobs Act (the “Tax Act”) from accumulated other comprehensive income to retained earnings in the consolidated financial statements. Under the Tax Act, deferred taxes were adjusted to reflect the reduction of the historical corporate income tax rate to the newly enacted corporate income tax rate, which left the tax effects on items within accumulated other comprehensive income stranded at historical tax rates. The adoption of these changes resulted in the Company reclassifying approximately $21 million of stranded income tax effects into Retained earnings. The following accounting standards have been issued and become effective for the Company at a future date: In June 2016, the FASB issued changes which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses rather than incurred losses to estimate credit losses on certain types of financial instruments, including trade receivables. This may result in the earlier recognition of allowances for losses. The changes become effective for the Company on January 1, 2020, with early adoption permitted. Management has not yet completed the assessment of the impact of the new standard on the Company’s 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 August 2018, the FASB issued changes which modify the disclosure requirements for fair value measurements. The amendments in this update remove the requirement to disclose the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy; the policy for timing of transfers between levels; and the valuation processes for Level 3 fair value measurements. The changes require disclosure of changes in unrealized gains and losses for the period included in other comprehensive income (loss) for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The changes become effective for the Company on January 1, 2020. Other than required expanded disclosures, the adoption of these changes will not have a material impact on the Company's condensed consolidated financial statements.

Acquisitions

Acquisitions	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Acquisitions	Acquisitions In May 2018, the Company acquired Altek Europe Holdings Limited and its affiliated entities (collectively, "Altek"), a U.K.-based manufacturer of market-leading products that enable aluminum producers and recyclers to manage and efficiently extract value from critical byproduct streams, reduce byproduct generation and improve operating productivity. The Company acquired Altek, on a debt and cash free basis, for a purchase price of £45 million (approximately $60 million ) in cash, with the potential for up to £25 million (approximately $33 million ) in additional contingent consideration through 2021 subject to the future financial performance of Altek. The cash consideration transferred included payments of $59.4 million , net of cash acquired and normal working capital adjustments. In addition, the Company recognized contingent consideration with an initial fair value of $12.1 million as of the acquisition date. Altek's revenues and operating results have been included in the results of the Harsco Metals & Minerals Segment. Inclusion of pro forma financial information for this transaction is not necessary as the acquisition is immaterial to the Company's results of operations. The initial fair value of contingent consideration was estimated using a probability simulation model, which uses assumptions and estimates to forecast a range of outcomes for the contingent consideration. Key inputs to the model include projected earnings before interest, tax, depreciation and amortization; the discount rate; the projection risk neutralization rate; and volatility, which are Level 3 data. The Company will assess these assumptions and estimates on a quarterly basis as additional data impacting the assumptions is obtained. Any changes in the fair value of contingent consideration related to updated assumptions and estimates will be recognized in the Consolidated Statements of Operations during the period in which the change occurs. The fair value recorded for the assets acquired and liabilities assumed for Altek is as follows: Final Valuation (In millions) June 30 2018 Measurement Period Adjustments (a) March 31 Cash and cash equivalents $ 1.7 $ — $ 1.7 Net working capital (1.5 ) 0.2 (1.3 ) Property, plant and equipment 3.3 — 3.3 Intangible assets 52.5 0.2 52.7 Goodwill 20.9 1.6 22.5 Net deferred tax liabilities (8.5 ) — (8.5 ) Other liabilities (0.3 ) — (0.3 ) Total identifiable net assets of Altek $ 68.1 $ 2.0 $ 70.1 (a) The measurement period adjustments did not have a material impact on the Company's previously reported operating results. The following table reflects the changes in the fair value of contingent consideration: (In thousands) Contingent Consideration Balance, December 31, 2018 $ 8,420 Fair value adjustment (b) 369 Foreign currency translation 186 Balance, March 31, 2019 $ 8,975

Accounts Receivable and Invento

Accounts Receivable and Inventories	3 Months Ended
	Mar. 31, 2019
Accounts Receivable And Inventories
Accounts Receivable and Inventories	Accounts Receivable and Inventories Accounts receivable consist of the following: (In thousands) March 31 December 31 Trade accounts receivable $ 301,439 $ 295,847 Less: Allowance for doubtful accounts (4,644 ) (4,634 ) Trade accounts receivable, net $ 296,795 $ 291,213 Other receivables (a) $ 51,130 $ 54,182 (a) Other receivables include insurance claims, employee receivables, tax claims and other miscellaneous items not included in Trade accounts receivable, net. The provision (benefit) for doubtful accounts related to trade accounts receivable was as follows: Three Months Ended March 31 (In thousands) 2019 2018 Provision (benefit) for doubtful accounts related to trade accounts receivable $ 26 $ (46 ) Inventories consist of the following: (In thousands) March 31 December 31 Finished goods $ 19,089 $ 17,223 Work-in-process 21,715 21,787 Raw materials and purchased parts 82,983 72,194 Stores and supplies 23,909 21,907 Total inventories $ 147,696 $ 133,111 The Company recognized an initial estimated forward loss provision related to the contracts with the federal railway system of Switzerland ("SBB") of $45.1 million for the year ended December 31, 2016 . The Company recorded an additional forward loss provision of $1.8 million for the year ended December 31, 2018 . At March 31, 2019 , the entire remaining estimated forward loss provision of $6.8 million is included in the caption Other current liabilities on the Condensed Consolidated Balance Sheets. The estimated forward loss provision represents the Company's best estimate based on currently available information. It is possible that the Company's overall estimate of costs to complete these contracts may increase, which would result in an additional estimated forward loss provision at such time, but the Company is unable to estimate any further possible loss or range of loss at this time. There are a number of key events expected to occur in 2019, including the finalization of the manufacturing designs for certain of the vehicles, and which could affect the cost estimates. Any adjustment to the cost estimates would be recorded when new information becomes available and could have a material impact on the Company’s results of operations in that period. The Company recognized $4.7 million and $7.9 million of revenues for the contracts with SBB at zero margin, on an over time basis, utilizing a cost-to-cost method for the three months ended March 31, 2019 and 2018 , respectively. For the three months ended March 31, 2019 and 2018 , consolidated product revenue gross margins were not significantly impacted by the revenue recognized under the SBB contracts. The Company has substantially completed the first contract and is approximately 30% complete on the second contract with SBB as of March 31, 2019

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment consists of the following: (In thousands) March 31 December 31 Land $ 10,515 $ 10,621 Land improvements 15,932 16,156 Buildings and improvements 190,715 191,072 Machinery and equipment 1,566,706 1,538,166 Uncompleted construction 42,493 37,713 Gross property, plant and equipment 1,826,361 1,793,728 Less: Accumulated depreciation (1,342,913 ) (1,323,828 ) Property, plant and equipment, net $ 483,448 $ 469,900

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	Leases The Company leases certain property and equipment under noncancelable lease agreements. The Company determines if a contract or arrangement contains a lease at inception. All leases are evaluated and classified as either an operating or finance lease. A lease is classified as a finance lease if any of the following criteria are met: (i) ownership of the underlying asset transfers to the Company by the end of the lease term; (ii) the lease contains an option to purchase the underlying asset that the Company is reasonably expected to exercise; (iii) the lease term is for a major part of the remaining economic life of the underlying asset; (iv) the present value of the sum of lease payments and any residual value guaranteed by the Company equals or exceeds substantially all of the fair value of the underlying asset; or (v) the underlying asset is of a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. A lease that does not meet any of the criteria to be classified as a finance lease is classified as an operating lease. Operating leases are included in the captions Right-of-use assets, net, Current portion of operating lease liabilities, and Operating lease liabilities on the Condensed Consolidated Balance Sheets. ROU assets and operating lease liabilities are recognized based on the present value of the future lease payments over the lease term at the commencement date. As most of the Company’s leases do not provide an implicit rate for use in determining the present value of future payments, the Company uses an incremental borrowing rate that reflects the creditworthiness of the Company for a lending period commensurate to the term of the lease and the standard lending practices related to such loans in the respective jurisdiction where the underlying assets are located. This incremental borrowing rate reflects the creditworthiness of the Company for a lending period commensurate to the term of the lease and the standard lending practices related to such loans in the respective jurisdiction where the underlying assets are located. ROU assets also include any lease payments made and exclude any lease incentives and initial direct costs incurred. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term, including rent abatement periods and rent holidays. Finance leases are included in the captions Property, plant and equipment, net; Current maturities of long-term debt and Long-term debt on the Condensed Consolidated Balance Sheets. Finance lease costs are split between depreciation expense related to the asset and interest expense on the lease liability, using the effective rate charged by the lessor. The Company has lease agreements with lease and non-lease components, which the Company has elected to account for as a single lease component. Additionally, the Company has elected not to record short-term leases, those with expected terms of twelve months or less, on the Condensed Consolidated Balance Sheets. Certain lease agreements include fixed escalations, while others include rental payments adjusted periodically for inflation. There are no material residual value guarantees or material restrictive covenants. The Company's leases, excluding short-term leases, have remaining terms of less than one year to 24.5 years , some of which include options to extend for up to 10 years, and some of which include options to terminate within one year . The components of lease expense were as follows: Three Months Ended (In thousands) March 31 Finance leases: Amortization expense $ 310 Interest on lease liabilities 4 Operating leases 4,608 Short-term leases 4,669 Variable lease expense 314 Total lease expense $ 9,905 Supplemental cash flow information related to leases was as follows: Three Months Ended (In thousands) March 31 Cash paid for amounts included in the measurement of lease liabilities: Cash flows from operating activities - Operating leases $ 4,670 Cash flows from financing activities - Finance leases 363 Right-of-use assets obtained in exchange for lease obligations: Operating leases (a) $ 53,750 Finance leases 373 (a) Includes ROU assets of $53.0 million that were recorded upon adoption at January 1, 2019. Supplemental balance sheet information related to leases was as follows: (In thousands) March 31 Operating Leases: Operating lease right-of-use assets $ 49,584 Other current liabilities 12,936 Operating lease liabilities 37,037 Finance Leases: Property, plant and equipment, net $ 1,286 Current maturities of long-term debt 1,054 Long-term debt 945 Supplemental additional information related to leases is as follows: March 31 Other information: Weighted average remaining lease term - Operating leases (in years) 4.42 Weighted average remaining lease term - Finance leases (in years) 2.01 Weighted average discount rate - Operating leases 6.9 % Weighted average discount rate - Finance leases 4.1 % Maturities of lease liabilities were as follows: (In thousand) Operating Leases Finance Leases Year Ending December 31 st : 2019 (excluding the three months ended March 31, 2019) $ 12,210 $ 1,027 2020 12,943 631 2021 9,775 295 2022 7,563 117 2023 6,254 16 After 2023 21,576 2 Total lease payments 70,321 2,088 Less imputed interest (20,348 ) (89 ) Total $ 49,973 $ 1,999 As previously disclosed, under then in effect lease accounting in accordance with U.S. GAAP, future minimum payments under operating leases with noncancelable terms were as follows as of December 31, 2018: (In thousands) 2019 $ 13,985 2020 12,204 2021 9,448 2022 7,706 2023 6,201 After 2023 28,442 As of March 31, 2019, the Company has an additional operating lease for property that has not yet commenced with an estimated ROU asset and lease liability of approximately $5.0 million
Leases	Leases The Company leases certain property and equipment under noncancelable lease agreements. The Company determines if a contract or arrangement contains a lease at inception. All leases are evaluated and classified as either an operating or finance lease. A lease is classified as a finance lease if any of the following criteria are met: (i) ownership of the underlying asset transfers to the Company by the end of the lease term; (ii) the lease contains an option to purchase the underlying asset that the Company is reasonably expected to exercise; (iii) the lease term is for a major part of the remaining economic life of the underlying asset; (iv) the present value of the sum of lease payments and any residual value guaranteed by the Company equals or exceeds substantially all of the fair value of the underlying asset; or (v) the underlying asset is of a specialized nature that it is expected to have no alternative use to the lessor at the end of the lease term. A lease that does not meet any of the criteria to be classified as a finance lease is classified as an operating lease. Operating leases are included in the captions Right-of-use assets, net, Current portion of operating lease liabilities, and Operating lease liabilities on the Condensed Consolidated Balance Sheets. ROU assets and operating lease liabilities are recognized based on the present value of the future lease payments over the lease term at the commencement date. As most of the Company’s leases do not provide an implicit rate for use in determining the present value of future payments, the Company uses an incremental borrowing rate that reflects the creditworthiness of the Company for a lending period commensurate to the term of the lease and the standard lending practices related to such loans in the respective jurisdiction where the underlying assets are located. This incremental borrowing rate reflects the creditworthiness of the Company for a lending period commensurate to the term of the lease and the standard lending practices related to such loans in the respective jurisdiction where the underlying assets are located. ROU assets also include any lease payments made and exclude any lease incentives and initial direct costs incurred. Lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for minimum lease payments is recognized on a straight-line basis over the lease term, including rent abatement periods and rent holidays. Finance leases are included in the captions Property, plant and equipment, net; Current maturities of long-term debt and Long-term debt on the Condensed Consolidated Balance Sheets. Finance lease costs are split between depreciation expense related to the asset and interest expense on the lease liability, using the effective rate charged by the lessor. The Company has lease agreements with lease and non-lease components, which the Company has elected to account for as a single lease component. Additionally, the Company has elected not to record short-term leases, those with expected terms of twelve months or less, on the Condensed Consolidated Balance Sheets. Certain lease agreements include fixed escalations, while others include rental payments adjusted periodically for inflation. There are no material residual value guarantees or material restrictive covenants. The Company's leases, excluding short-term leases, have remaining terms of less than one year to 24.5 years , some of which include options to extend for up to 10 years, and some of which include options to terminate within one year . The components of lease expense were as follows: Three Months Ended (In thousands) March 31 Finance leases: Amortization expense $ 310 Interest on lease liabilities 4 Operating leases 4,608 Short-term leases 4,669 Variable lease expense 314 Total lease expense $ 9,905 Supplemental cash flow information related to leases was as follows: Three Months Ended (In thousands) March 31 Cash paid for amounts included in the measurement of lease liabilities: Cash flows from operating activities - Operating leases $ 4,670 Cash flows from financing activities - Finance leases 363 Right-of-use assets obtained in exchange for lease obligations: Operating leases (a) $ 53,750 Finance leases 373 (a) Includes ROU assets of $53.0 million that were recorded upon adoption at January 1, 2019. Supplemental balance sheet information related to leases was as follows: (In thousands) March 31 Operating Leases: Operating lease right-of-use assets $ 49,584 Other current liabilities 12,936 Operating lease liabilities 37,037 Finance Leases: Property, plant and equipment, net $ 1,286 Current maturities of long-term debt 1,054 Long-term debt 945 Supplemental additional information related to leases is as follows: March 31 Other information: Weighted average remaining lease term - Operating leases (in years) 4.42 Weighted average remaining lease term - Finance leases (in years) 2.01 Weighted average discount rate - Operating leases 6.9 % Weighted average discount rate - Finance leases 4.1 % Maturities of lease liabilities were as follows: (In thousand) Operating Leases Finance Leases Year Ending December 31 st : 2019 (excluding the three months ended March 31, 2019) $ 12,210 $ 1,027 2020 12,943 631 2021 9,775 295 2022 7,563 117 2023 6,254 16 After 2023 21,576 2 Total lease payments 70,321 2,088 Less imputed interest (20,348 ) (89 ) Total $ 49,973 $ 1,999 As previously disclosed, under then in effect lease accounting in accordance with U.S. GAAP, future minimum payments under operating leases with noncancelable terms were as follows as of December 31, 2018: (In thousands) 2019 $ 13,985 2020 12,204 2021 9,448 2022 7,706 2023 6,201 After 2023 28,442 As of March 31, 2019, the Company has an additional operating lease for property that has not yet commenced with an estimated ROU asset and lease liability of approximately $5.0 million

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets The following table reflects the changes in carrying amounts of goodwill by segment for the three months ended March 31, 2019 : (In thousands) Harsco Metals & Minerals Segment Harsco Industrial Segment Harsco Rail Segment Consolidated Totals Balance at December 31, 2018 $ 391,687 $ 6,839 $ 13,026 $ 411,552 Foreign currency translation 897 — — 897 Balance at March 31, 2019 $ 392,584 $ 6,839 $ 13,026 $ 412,449 The Company tests for goodwill impairment annually, or more frequently if indicators of impairment exist, or if a decision is made to dispose of a business. The Company performs the annual goodwill impairment test as of October 1 and monitors for triggering events on an ongoing basis. The Company determined that, as of March 31, 2019 , no interim goodwill impairment testing was necessary. Intangible assets included in the caption, Intangible assets, net, on the Condensed Consolidated Balance Sheets consist of the following: March 31, 2019 December 31, 2018 (In thousands) Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer related $ 137,242 $ 101,090 $ 136,307 $ 99,383 Patents 2,597 2,505 2,598 2,503 Technology related 36,572 3,599 35,831 2,681 Trade names 9,298 2,051 9,212 1,897 Other 5,929 3,640 5,865 3,524 Total $ 191,638 $ 112,885 $ 189,813 $ 109,988 Amortization expense for intangible assets was as follows: Three Months Ended March 31 (In thousands) 2019 2018 Amortization expense for intangible assets $ 2,352 $ 1,282 The estimated amortization expense for the next five fiscal years based on current intangible assets is as follows: (In thousands) 2019 2020 2021 2022 2023 Estimated amortization expense (a) $ 9,000 $ 8,750 $ 8,500 $ 8,250 $ 8,250

Employee Benefit Plans

Employee Benefit Plans	3 Months Ended
	Mar. 31, 2019
Retirement Benefits [Abstract]
Employee Benefit Plans	Employee Benefit Plans Three Months Ended March 31 Defined Benefit Pension Plans Net Periodic Pension Cost (Benefit) U.S. Plans International Plans (In thousands) 2019 2018 2019 2018 Service costs $ 10 $ 10 $ 356 $ 386 Interest costs 2,651 2,391 5,664 5,672 Expected return on plan assets (2,593 ) (3,017 ) (9,517 ) (11,145 ) Recognized prior service costs — — 66 (39 ) Recognized loss 1,405 1,302 3,653 3,840 Settlement/curtailment losses — 166 — — Defined benefit pension plans net periodic pension cost (benefit) $ 1,473 $ 852 $ 222 $ (1,286 ) Three Months Ended Company Contributions March 31 (In thousands) 2019 2018 Defined benefit pension plans (U.S.) $ 1,479 $ 1,284 Defined benefit pension plans (International) 9,270 9,734 Multiemployer pension plans 521 501 Defined contribution pension plans 3,390 2,835 The Company's estimate of expected contributions to be paid during the remainder of 2019 for the U.S. and international defined benefit pension plans are $7.0 million and $11.5 million

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income tax expense related to continuing operations for the three months ended March 31, 2019 and March 31, 2018 was $4.9 million and $8.3 million , respectively. An income tax benefit from an uncertain tax position may be recognized when it is more likely than not that the position will be sustained upon examination, based on technical merits, including resolutions of any related appeals or litigation processes. The reserve for uncertain tax positions at March 31, 2019 was $3.5 million , including interest and penalties. Within the next twelve months, it is reasonably possible that up to $0.1 million

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Environmental The Company is involved in a number of environmental remediation investigations and cleanups and, along with other companies, has been identified as a “potentially responsible party” for certain byproduct disposal sites. While each of these matters is subject to various uncertainties, it is probable that the Company will agree to make payments toward funding certain of these activities, and it is possible that some of these matters will be decided unfavorably to the Company. The Company has evaluated its potential liability, and its financial exposure is dependent upon such factors as the continuing evolution of environmental laws and regulatory requirements, the availability and application of technology, the allocation of cost among potentially responsible parties, the years of remedial activity required and the remediation methods selected. Other than set forth herein the Company did not have any material accruals or record any material expenses related to environmental matters during the periods presented. The Company evaluates its liability for future environmental remediation costs on a quarterly basis. Although actual costs to be incurred at identified sites in future periods may vary from the estimates (given inherent uncertainties in evaluating environmental exposures), the Company does not expect that any costs that are reasonably possible to be incurred by the Company in connection with environmental matters in excess of the amounts accrued would have a material adverse effect on the Company's financial condition, results of operations or cash flows. As previously disclosed, the Company has had ongoing meetings with the Supreme Council for Environment in Bahrain (“SCE”) over processing a byproduct (“salt cakes”) stored at the Al Hafeerah site. The Company’s Bahrain operations that produced the salt cakes has ceased operations and are owned under a strategic venture for which its strategic venture partner owns a 35% minority interest. An Environmental Impact Assessment and Technical Feasibility Study were approved by the SCE during the first quarter of 2018. The Company has previously established a reserve of $7.0 million , which represents the Company's best estimate of the ultimate costs to be incurred to resolve this matter. The Company continues to evaluate this reserve and any future change in estimated costs could be material to the Company’s results of operations in any one period. On July 27, 2018, Brazil’s Federal and Rio de Janeiro State Public Prosecution Offices (MPF and MPE) filed a Civil Public Action against one of the Company's customers (CSN), the Company’s Brazilian subsidiary, the Municipality of Volta Redonda, Brazil, and the Instituto Estadual do Ambiente (local environmental protection agency) seeking the implementation of various measures to limit and reduce the accumulation of customer-owned slag at the site in Brazil. On August 6, 2018, the 3rd Federal Court in Volta Redonda granted the MPF and MPE an injunction against the same parties requiring, among other things, CSN and the Company’s Brazilian subsidiary to limit the volume of slag sent to the site. Because the customer owns the site and the slag located on the site, the Company believes that complying with this injunction is the steel producer’s responsibility. On March 18, 2019, the Court issued an order fining the Company 5,000 Brazilian real per day (or approximately $1,300 per day) and CSN 20,000 Brazilian real per day until the requirements of the injunction are met. This fine is not yet currently being enforced, and the Company is appealing the fine and the underlying injunction. Both the Company and CSN continue to have discussions with the governmental authorities on the injunction and the possible resolution of the underlying case. The Company does not believe that a loss relating to this matter is probable or estimable at this point. On October 19, 2018, local environmental authorities issued an enforcement action against the Company concerning the Company’s operations at a customer site in Ijmuiden, Netherlands. The enforcement action alleges violations of the Company’s environmental permit at the site, which restricts the release of any visible dust emissions. The enforcement action ordered the Company to cease all violations of the permit by October 31, 2018. The authorities have issued fines of approximately $0.3 million , with the possibility of additional fines for any future violations. The Company is vigorously contesting the enforcement action and fines and is also working with its customer to ensure the control of emissions. The Company has contractual indemnity rights from its customer, should it be required to pay the assessed fines. Brazilian Tax Disputes The Company is involved in a number of tax disputes with federal, state and municipal tax authorities in Brazil. These disputes are at various stages of the legal process, including the administrative review phase and the collection action phase, and include assessments of fixed amounts of principal and penalties, plus interest charges that increase at statutorily determined amounts per month and are assessed on the aggregate amount of the principal and penalties. In addition, the losing party, at the collection action or court of appeals phase, could be subject to a charge to cover statutorily mandated legal fees, which are generally calculated as a percentage of the total assessed amounts due, inclusive of penalty and interest. Many of the claims relate to value-added ("ICMS"), services and social security tax disputes. The largest proportion of the assessed amounts relate to ICMS claims filed by the State Revenue Authorities from the State of São Paulo, Brazil (the "SPRA"), encompassing the period from January 2002 to May 2005. In October 2009, the Company received notification of the SPRA’s final administrative decision regarding the levying of ICMS in the State of São Paulo in relation to services provided to a customer in the State between January 2004 and May 2005. As of March 31, 2019 , the principal amount of the tax assessment from the SPRA with regard to this case is approximately $2 million , with penalty, interest and fees assessed to date increasing such amount by an additional $21 million . On June 4, 2018, the Appellate Court of the State of Sao Paulo ruled in favor of the SPRA, but ruled that the assessed penalty should be reduced to approximately $2 million . After calculating the interest accrued on the penalty, the Company estimates that this ruling reduces the current overall liability for this case to approximately $9 million . The Company has appealed the ruling in favor of the SPRA to the Superior Court of Justice. Due to multiple court precedents in the Company’s favor, as well as the Company’s ability to appeal, the Company does not believe a loss is probable. Another ICMS tax case involving the SPRA refers to the tax period from January 2002 to December 2003. In December 2018, the administrative tribunal hearing the case upheld the Company's liability. The Company plans to appeal to the judicial phase. The aggregate amount assessed by the tax authorities in August 2005 was $6.5 million (the amounts with regard to this claim are valued as of the date of the assessment since it has not yet reached the collection phase), composed of a principal amount of $1.5 million , with penalty and interest assessed through that date increasing such amount by an additional $4.9 million . On December 6, 2018, the administrative tribunal reduced the applicable penalties to $1.2 million . After calculating the interest accrued on the current penalty, the Company estimates that this ruling reduces the current overall liability for this case to approximately $10 million . All such amounts include the effect of foreign currency translation. Due to multiple court precedents in the Company's favor the Company does not believe a loss is probable. The Company continues to believe that sufficient coverage for these claims exists as a result of the indemnification obligations of the Company's customer and such customer’s pledge of assets in connection with the October 2009 notice, as required by Brazilian law. The Company intends to continue its practice of vigorously defending itself against these tax claims under various alternatives, including judicial appeal. The Company will continue to evaluate its potential liability with regard to these claims on a quarterly basis; however, it is not possible to predict the ultimate outcome of these tax-related disputes in Brazil. No loss provision has been recorded in the Company's condensed consolidated financial statements for the disputes described above because the loss contingency is not deemed probable, and the Company does not expect that any costs that are reasonably possible to be incurred by the Company in connection with Brazilian tax disputes would have a material adverse effect on the Company's financial condition, results of operations or cash flows. Brazilian Labor Disputes The Company is subject to ongoing collective bargaining and individual labor claims in Brazil through the Harsco Metals & Minerals Segment which allege, among other things, the Company's failure to pay required amounts for overtime and vacation at certain sites. The Company is vigorously defending itself against these claims; however, litigation is inherently unpredictable, particularly in foreign jurisdictions. While the Company does not currently expect that the ultimate resolution of these claims will have a material adverse effect on the Company’s financial condition, results of operations or cash flows, it is not possible to predict the ultimate outcome of these labor-related disputes. As of March 31, 2019 and December 31, 2018 , the Company has established reserves of $7.0 million and $7.1 million , respectively, on the Company's Condensed Consolidated Balance Sheets for amounts considered to be probable and estimable. Customer Disputes The Company may, in the normal course of business, become involved in commercial disputes with subcontractors or customers. Although results of operations and cash flows for a given period could be adversely affected by a negative outcome in these or other lawsuits, claims or proceedings, management believes that the ultimate outcome of any ongoing matters will not have a material adverse effect on the Company's financial condition, results of operations or cash flows. Lima Refinery Litigation On April 8, 2016, Lima Refining Company filed a lawsuit against the Company in the District Court of Harris County, Texas related to a January 2015 explosion at an oil refinery operated by Lima Refining Company. The action seeks approximately $317 million plus interest in property damages, lost profits and business interruption damages. The action alleges the explosion occurred because of a defect in a heat exchange cooler manufactured by Hammco Corporation ("Hammco") in 2009, prior to the Company’s acquisition of Hammco in 2014. The Company is vigorously contesting the allegations against it. The Company has both an indemnity right from the sellers of Hammco and liability insurance coverage under various primary and excess policies that the Company believes will be available, if necessary, to cover substantially all such liability that might ultimately be incurred in the above action. As a result, the Company believes the situation will not result in a net unreimbursed loss. Other The Company is named as one of many defendants (approximately 90 or more in most cases) in legal actions in the U.S. alleging personal injury from exposure to airborne asbestos over the past several decades. In their suits, the plaintiffs have named as defendants, among others, many manufacturers, distributors and installers of numerous types of equipment or products that allegedly contained asbestos. The Company believes that the claims against it are without merit. The Company has never been a producer, manufacturer or processor of asbestos fibers. Any asbestos-containing part of a Company product used in the past was purchased from a supplier and the asbestos encapsulated in other materials such that airborne exposure, if it occurred, was not harmful and is not associated with the types of injuries alleged in the pending actions. At March 31, 2019 , there were approximately 17,127 pending asbestos personal injury actions filed against the Company. Of those actions, approximately 16,586 were filed in the New York Supreme Court (New York County), approximately 119 were filed in other New York State Supreme Court Counties and approximately 422 were filed in courts located in other states. The complaints in most of those actions generally follow a form that contains a standard damages demand of $20 million or $25 million , regardless of the individual plaintiff’s alleged medical condition, and without identifying any specific Company product. At March 31, 2019 , approximately 16,550 of the actions filed in New York Supreme Court (New York County) were on the Deferred/Inactive Docket created by the court in December 2002 for all pending and future asbestos actions filed by persons who cannot demonstrate that they have a malignant condition or discernible physical impairment. The remaining approximately 36 cases in New York County are pending on the Active or In Extremis Docket created for plaintiffs who can demonstrate a malignant condition or physical impairment. The Company has liability insurance coverage under various primary and excess policies that the Company believes will be available, if necessary, to substantially cover any liability that might ultimately be incurred in the asbestos actions referred to above. The costs and expenses of the asbestos actions are being paid by the Company's insurers. In view of the persistence of asbestos litigation in the U.S., the Company expects to continue to receive additional claims in the future. The Company intends to continue its practice of vigorously defending these claims and cases. At March 31, 2019 , the Company has obtained dismissal in approximately 28,189 cases by stipulation or summary judgment prior to trial. It is not possible to predict the ultimate outcome of asbestos-related actions in the U.S. due to the unpredictable nature of this litigation, and no loss provision has been recorded in the Company's condensed consolidated financial statements because a loss contingency is not deemed probable or estimable. Despite this uncertainty, and although results of operations and cash flows for a given period could be adversely affected by asbestos-related actions, the Company does not expect that any costs that are reasonably possible to be incurred by the Company in connection with asbestos litigation would have a material adverse effect on the Company's financial condition, results of operations or cash flows. The Company is subject to various other claims and legal proceedings covering a wide range of matters that arose in the ordinary course of business. In the opinion of management, all such matters are adequately covered by insurance or by established reserves, and, if not so covered, are without merit or are of such kind, or involve such amounts, as would not have a material adverse effect on the financial position, results of operations or cash flows of the Company. Insurance liabilities are recorded when it is probable that a liability has been incurred for a particular event and the amount of loss associated with the event can be reasonably estimated. Insurance reserves have been estimated based primarily upon actuarial calculations and reflect the undiscounted estimated liabilities for ultimate losses, including claims incurred but not reported. Inherent in these estimates are assumptions that are based on the Company's history of claims and losses, a detailed analysis of existing claims with respect to potential value, and current legal and legislative trends. If actual claims differ from those projected by management, changes (either increases or decreases) to insurance reserves may be required and would be recorded through income in the period the change was determined. When a recognized liability is covered by third-party insurance, the Company records an insurance claim receivable to reflect the covered liability. Insurance claim receivables are included in Other receivables on the Company's Condensed Consolidated Balance Sheets. See Note 1, Summary of Significant Accounting Policies, to the Consolidated Financial Statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2018

Reconciliation of Basic and Dil

Reconciliation of Basic and Diluted Shares	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Shares	Reconciliation of Basic and Diluted Shares Three Months Ended March 31 (In thousands, except per share amounts) 2019 2018 Income from continuing operations attributable to Harsco Corporation common stockholders $ 21,029 $ 18,260 Weighted-average shares outstanding - basic 79,907 80,650 Dilutive effect of stock-based compensation 1,746 2,894 Weighted-average shares outstanding - diluted 81,653 83,544 Earnings from continuing operations per common share, attributable to Harsco Corporation common stockholders: Basic $ 0.26 $ 0.23 Diluted $ 0.26 $ 0.22 The following average outstanding stock-based compensation units were not included in the computation of diluted earnings per share because the effect was antidilutive: Three Months Ended March 31 (In thousands) 2019 2018 Stock appreciation rights 608 696 Performance share units 233 —

Derivative Instruments, Hedging

Derivative Instruments, Hedging Activities and Fair Value	3 Months Ended
	Mar. 31, 2019
Derivative Instruments, Hedging Activities And Fair Value Disclosure [Abstract]
Derivative Instruments, Hedging Activities and Fair Value	Derivative Instruments, Hedging Activities and Fair Value Derivative Instruments and Hedging Activities The Company uses derivative instruments, including foreign currency exchange forward contracts, interest rate swaps and cross-currency interest rate swaps ("CCIRs"), to manage certain foreign currency and interest rate exposures. Derivative instruments are viewed as risk management tools by the Company and are not used for trading or speculative purposes. All derivative instruments are recorded on the Condensed Consolidated Balance Sheets at fair value. The accounting for changes in the fair value of derivatives depends on the intended use of the derivative, whether the Company has elected to designate a derivative in a hedging relationship and apply hedge accounting and whether the hedging relationship has satisfied the criteria necessary to apply hedge accounting. Derivatives designated and qualifying as a hedge of the exposure to variability in expected future cash flows, or other types of forecasted transactions, are considered cash flow hedges. Hedge accounting generally provides for the matching of the timing of gain or loss recognition on the hedging instrument with the recognition of the earnings effect of the hedged forecasted transactions in a cash flow hedge. The Company may enter into derivative contracts that are intended to economically hedge certain of its risk, even though hedge accounting does not apply or the Company elects not to apply hedge accounting. Fair value is the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (an exit price). The Company utilizes market data or assumptions that the Company believes market participants would use in valuing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. The fair value hierarchy distinguishes between (1) market participant assumptions developed based on market data obtained from independent sources (observable inputs), and (2) an entity’s own assumptions about market participant assumptions based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which give the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3). The three levels of the fair value hierarchy are described below: • Level 1—Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities. • Level 2—Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, including quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in markets that are not active; inputs other than quoted prices that are observable for the asset or liability (e.g., interest rates); and inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3—Inputs that are both significant to the fair value measurement and unobservable. In instances in which multiple levels of inputs are used to measure fair value, hierarchy classification is based on the lowest level input that is significant to the fair value measurement in its entirety. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. The Company primarily applies the market approach for recurring fair value measurements and endeavors to utilize the best available information. Accordingly, the Company utilizes valuation techniques that maximize the use of observable inputs, such as forward rates, interest rates, the Company’s credit risk and counterparties’ credit risks, and which minimize the use of unobservable inputs. The Company is able to classify fair value balances based on the ability to observe those inputs. Foreign currency exchange forward contracts, interest rate swaps and CCIRs are based upon pricing models using market-based inputs (Level 2). Model inputs can be verified and valuation techniques do not involve significant management judgment. The fair value of outstanding derivative contracts recorded as assets and liabilities on the Condensed Consolidated Balance Sheets was as follows: (In thousands) Balance Sheet Location Fair Value of Derivatives Designated as Hedging Instruments Fair Value of Derivatives Not Designated as Hedging Instruments Total Fair Value March 31, 2019 Asset derivatives (Level 2): Foreign currency exchange forward contracts Other current assets $ 2,275 $ 5,520 $ 7,795 Interest rate swaps Other current assets 736 — 736 Total $ 3,011 $ 5,520 $ 8,531 Liability derivatives (Level 2): Foreign currency exchange forward contracts Other current liabilities $ 121 $ 1,426 $ 1,547 Interest rate swaps Other current liabilities 96 — 96 Interest rate swaps Other liabilities 4,639 — 4,639 Total $ 4,856 $ 1,426 $ 6,282 December 31, 2018 Asset derivatives (Level 2): Foreign currency exchange forward contracts Other current assets $ 2,970 $ 589 $ 3,559 Interest rate swaps Other current assets 1,331 — 1,331 Interest rate swaps Other assets 128 — $ 128 Total $ 4,429 $ 589 $ 5,018 Liability derivatives (Level 2): Foreign currency exchange forward contracts Other current liabilities $ 24 $ 2,910 $ 2,934 Interest rate swaps Other liabilities 1,849 — 1,849 Total $ 1,873 $ 2,910 $ 4,783 All of the Company's derivatives are recorded on the Condensed Consolidated Balance Sheets at gross amounts and not offset. All of the Company's interest rate swaps, CCIRs and certain foreign currency exchange forward contracts are transacted under International Swaps and Derivatives Association ("ISDA") documentation. Each ISDA master agreement permits the net settlement of amounts owed in the event of default. The Company's derivative assets and liabilities subject to enforceable master netting arrangements resulted in a net liability of $1.0 million and $0.1 million at March 31, 2019 and December 31, 2018 , respectively. The effect of derivative instruments on the Condensed Consolidated Statements of Operations and the Condensed Consolidated Statements of Comprehensive Income: Derivatives Designated as Hedging Instruments Amount Recognized in Other Comprehensive Income (“OCI”) on Derivatives Location of Amount Reclassified from Accumulated OCI into Income Amount Reclassified from Accumulated OCI into Income - Effective Portion or Equity Three Months Ended Three Months Ended March 31 March 31 (In thousands) 2019 2018 2019 2018 Foreign currency exchange forward contracts $ (712 ) $ 240 Product revenues $ (32 ) $ (212 ) Foreign currency exchange forward contracts (a) — — Retained earnings — (1,520 ) Interest rate swaps (3,309 ) 3,310 Interest expense (301 ) — Cross-currency interest rate swaps (b) (52 ) (93 ) Interest expense 314 271 (4,073 ) 3,457 $ (19 ) $ (1,461 ) (a) The Company has adopted the new revenue recognition standard utilizing the modified retrospective transition method, including use of practical expedients. See Note 2, Recently Adopted and Recently Issued Accounting Standards for additional information. (b) Amounts represent changes in foreign currency translation related to balances in Accumulated other comprehensive loss. The location and amount of gain (loss) recognized on the Condensed Consolidated Statements of Operations: Three Months Ended March 31 2019 2018 (in thousands) Product Revenues Interest Expense Product Revenues Cost of Products Sold Interest Expense Total amounts of income and expense line items presented in the statement of financial performance in which the effects of cash flow hedges are recorded $ 217,768 $ (9,739 ) $ 163,829 $ 119,678 $ (9,583 ) Interest rate swaps: Amount of gain or (loss) reclassified from accumulated other comprehensive income into income — 301 — — — Foreign exchange contracts: Amount of gain or (loss) reclassified from accumulated other comprehensive income into income 32 — 212 — — Amount excluded from effectiveness testing recognized in earnings based on changes in fair value 78 — — (19 ) — Cross-currency interest rate swaps: Amount of gain or (loss) reclassified from accumulated other comprehensive income into income — (314 ) — — (271 ) Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31(c) (In thousands) 2019 2018 Foreign currency exchange forward contracts Cost of services and products sold $ 2,323 $ (5,466 ) (c) These gains (losses) offset amounts recognized in cost of services and products sold principally as a result of intercompany or third party foreign currency exposures. Foreign Currency Exchange Forward Contracts The Company conducts business in multiple currencies and, accordingly, is subject to the inherent risks associated with foreign exchange rate movements. Foreign currency-denominated assets and liabilities are translated into U.S. dollars at the exchange rates existing at the respective balance sheet dates, and income and expense items are translated at the average exchange rates during the respective periods. The Company uses derivative instruments to hedge cash flows related to foreign currency fluctuations. Foreign currency exchange forward contracts outstanding are part of a worldwide program to minimize foreign currency exchange operating income and balance sheet exposure by offsetting foreign currency exposures of certain future payments between the Company and various subsidiaries, suppliers or customers. The unsecured contracts are with major financial institutions. The Company may be exposed to credit loss in the event of non-performance by the contract counterparties. The Company evaluates the creditworthiness of the counterparties and does not expect default by them. Foreign currency exchange forward contracts are used to hedge commitments, such as foreign currency debt, firm purchase commitments and foreign currency cash flows for certain export sales transactions. Changes in the fair value of derivatives used to hedge foreign currency denominated balance sheet items are reported directly in earnings, along with offsetting transaction gains and losses on the items being hedged. Derivatives used to hedge forecasted cash flows associated with foreign currency commitments may be accounted for as cash flow hedges, as deemed appropriate, if the criteria for hedge accounting are met. Gains and losses on derivatives designated as cash flow hedges are deferred in Accumulated other comprehensive loss, a separate component of equity, and reclassified to earnings in a manner that matches the timing of the earnings impact of the hedged transactions. The ineffective portion of all hedges, if any, is recognized currently in earnings. The recognized gains and losses offset amounts recognized in cost of services and products sold principally as a result of intercompany or third party foreign currency exposures. At March 31, 2019 and December 31, 2018 , the notional amounts of foreign currency exchange forward contracts were $444.3 million and $423.9 million , respectively. These contracts are primarily denominated in British pounds sterling and Euros and mature through October 2021 . In addition to foreign currency exchange forward contracts, the Company designates certain loans as hedges of net investments in international subsidiaries. The Company recorded pre-tax net gains of $4.8 million and $9.5 million for the three months ended March 31, 2019 and March 31, 2018 , respectively, in Accumulated other comprehensive loss . Interest Rate Swaps The Company uses interest rate swaps in conjunction with certain debt issuances in order to secure a fixed interest rate. Changes in the fair value attributed to the effect of the swaps’ interest spread and changes in the credit worthiness of the counter-parties are recorded in Accumulated other comprehensive loss. In January 2017 and February 2018, the Company entered into a series of interest rate swaps that cover the period from 2018 through 2022 and had the effect of converting $300.0 million of the Term Loan Facility from floating-rate to fixed-rate. The fixed rates provided by the swaps replace the adjusted LIBOR rate in the interest calculation, ranging from 2.12% for 2019 to 3.12% for 2022. The total notional of the Company's interest rate swaps was $300.0 million as of March 31, 2019 . Cross-Currency Interest Rate Swaps The Company may use CCIRs in conjunction with certain debt issuances in order to secure a fixed local currency interest rate. Under these CCIRs, the Company receives interest based on a fixed or floating U.S. dollar rate and pays interest on a fixed local currency rate based on the contractual amounts in dollars and the local currency, respectively. At maturity, there is also the payment of principal amounts between currencies. Changes in the fair value attributed to the effect of the swaps' interest spread and changes in the credit worthiness of the counter-parties are recorded in Accumulated other comprehensive loss. Changes in value attributed to the effect of foreign currency fluctuations are recorded in the Condensed Consolidated Statements of Operations and offset currency fluctuation effects on the debt principal. The Company had no outstanding CCIRs at March 31, 2019 . Fair Value of Other Financial Instruments The carrying amounts of cash and cash equivalents, accounts receivable, accounts payable, accrued liabilities and short-term borrowings approximate fair value due to the short-term maturities of these assets and liabilities. At March 31, 2019 and December 31, 2018 , the total fair value of long-term debt (excluding deferred financing costs), including current maturities, was $657.4 million and $592.0 million , respectively, compared with a carrying value of $661.5 million and $605.4 million

Review of Operations by Segment

Review of Operations by Segment	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Review of Operations by Segment	Review of Operations by Segment Three Months Ended March 31 (In thousands) 2019 2018 Revenues From Continuing Operations Harsco Metals & Minerals $ 261,312 $ 264,723 Harsco Industrial 117,385 83,598 Harsco Rail 68,591 59,678 Corporate — 39 Total Revenues From Continuing Operations $ 447,288 $ 408,038 Operating Income (Loss) From Continuing Operations Harsco Metals & Minerals $ 24,497 $ 27,735 Harsco Industrial 17,030 12,421 Harsco Rail 5,389 1,952 Corporate (8,670 ) (5,567 ) Total Operating Income From Continuing Operations $ 38,246 $ 36,541 Depreciation and Amortization Harsco Metals & Minerals $ 28,705 $ 29,085 Harsco Industrial 2,025 1,855 Harsco Rail 1,167 1,064 Corporate 1,352 1,348 Total Depreciation and Amortization $ 33,249 $ 33,352 Three Months Ended March 31 (In thousands) 2019 2018 Capital Expenditures Harsco Metals & Minerals $ 29,163 $ 25,176 Harsco Industrial 2,175 1,087 Harsco Rail 3,916 430 Corporate 1,153 204 Total Capital Expenditures $ 36,407 $ 26,897 Reconciliation of Segment Operating Income to Income From Continuing Operations Before Income Taxes and Equity Income Three Months Ended March 31 (In thousands) 2019 2018 Segment operating income $ 46,916 $ 42,108 General Corporate expense (8,670 ) (5,567 ) Operating income from continuing operations 38,246 36,541 Interest income 534 498 Interest expense (9,739 ) (9,583 ) Defined benefit pension income (expense) (1,337 ) 839 Income from continuing operations before income taxes and equity income $ 27,704 $ 28,295

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition The Company recognizes revenues to depict the transfer of promised services and products to customers in an amount that reflects the consideration the Company expects to receive in exchange for those services or products. Service revenues include the service components of the Harsco Metals & Minerals and Harsco Rail Segments. Product revenues include the Harsco Industrial Segment and the product revenues of the Harsco Metals & Minerals and Harsco Rail Segments. A summary of the Company's revenues by primary geographical markets as well as by key product and service groups is as follows: Three Months Ended March 31, 2019 (In thousands) Harsco Metals & Minerals Segment Harsco Industrial Segment Harsco Rail Segment Corporate Consolidated Totals Primary Geographical Markets (a) : North America $ 73,349 $ 112,099 $ 50,366 $ — $ 235,814 Western Europe 98,221 — 10,013 — 108,234 Latin America (b) 36,991 5,286 591 — 42,868 Asia-Pacific 34,138 — 7,621 — 41,759 Middle East and Africa 13,915 — — — 13,915 Eastern Europe 4,698 — — — 4,698 Total Revenues $ 261,312 $ 117,385 $ 68,591 $ — $ 447,288 Key Product and Service Groups: On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems $ 261,312 $ — $ — $ — $ 261,312 Railway track maintenance services and equipment — — 68,591 — 68,591 Air-cooled heat exchangers — 76,203 — — 76,203 Industrial grating and fencing products — 33,376 — — 33,376 Heat transfer products — 7,806 — — 7,806 Total Revenues $ 261,312 $ 117,385 $ 68,591 $ — $ 447,288 Three Months Ended March 31, 2018 (In thousands) Harsco Metals & Minerals Segment Harsco Industrial Segment Harsco Rail Segment Corporate Consolidated Totals Primary Geographical Markets (a) : North America $ 71,065 $ 78,858 $ 40,405 $ 39 $ 190,367 Western Europe 96,921 — 14,720 — 111,641 Latin America (b) 41,458 4,740 833 — 47,031 Asia-Pacific 36,221 — 3,720 — 39,941 Middle East and Africa 11,553 — — — 11,553 Eastern Europe 7,505 — — — 7,505 Total Revenues $ 264,723 $ 83,598 $ 59,678 $ 39 $ 408,038 Key Product and Service Groups: On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems $ 264,723 $ — $ — $ — $ 264,723 Railway track maintenance services and equipment — — 59,678 — 59,678 Air-cooled heat exchangers — 44,267 — — 44,267 Industrial grating and fencing products — 30,097 — — 30,097 Heat transfer products — 9,234 — — 9,234 General Corporate — — — 39 39 Total Revenues $ 264,723 $ 83,598 $ 59,678 $ 39 $ 408,038 (a) Revenues are attributed to individual countries based on the location of the facility generating the revenue. (b) Includes Mexico. The Company may receive payments in advance of earning revenue, which are treated as Advances on contracts on the Condensed Consolidated Balance Sheets. The Company may recognize revenue in advance of being able to contractually invoice the customer, which is treated as Contract assets on the Condensed Consolidated Balance Sheets. Contract assets are transferred to Trade accounts receivable, net when right to payment becomes unconditional. Contract assets and Contract liabilities are reported as a net position, on a contract-by-contract basis, at the end of each reporting period. These instances are primarily related to the Harsco Rail Segment and air-cooled heat exchangers business of the Harsco Industrial Segment. The Company had Contract assets totaling $17.5 million and $24.3 million at March 31, 2019 and December 31, 2018 , respectively. The decrease is due principally to the transfer of contract assets to accounts receivable in excess of additional contract assets recognized during the three months ended March 31, 2019, primarily in the Harsco Rail Segment. The Company had Advances on contracts totaling $64.5 million and $69.0 million at March 31, 2019 and December 31, 2018 , respectively. The decrease is due principally to the recognition of revenue on previously received advances on contracts in excess of receipts of new advances on contracts during the period and the impact of foreign currency translation during the three months ended March 31, 2019, primarily in the Harsco Rail Segment. During the three months ended March 31, 2019, the Company recognized $21.5 million of revenue related to amounts included in Advances on contracts at December 31, 2018. At March 31, 2019 , the Harsco Metals & Minerals Segment had remaining, fixed, unsatisfied performance obligations, where the expected contract duration exceeds one year totaling $136.7 million . Of this amount, $43.6 million is expected to be fulfilled by March 31, 2020, $35.4 million by March 31, 2021, $24.9 million by March 31, 2022, $22.9 million by March 31, 2023 and the remainder thereafter. These amounts exclude any variable fees, fixed fees subject to indexation and any performance obligations expected to be satisfied within one year. The decrease from December 31, 2018 is primarily due to changes in foreign currency exchange rates. At March 31, 2019 , the Harsco Rail Segment had remaining, fixed, unsatisfied performance obligations, where the expected contract duration exceeds one year totaling $209.8 million . Of this amount, $94.3 million is expected to be fulfilled by March 31, 2020, $64.5 million by March 31, 2021, $36.7 million by March 31, 2022, $14.2 million

Other (Income) Expenses, Net

Other (Income) Expenses, Net	3 Months Ended
	Mar. 31, 2019
Other Income and Expenses [Abstract]
Other (Income) Expenses	Other Expenses, Net The major components of this Condensed Consolidated Statements of Operations caption are as follows: Three Months Ended March 31 (In thousands) 2019 2018 Employee termination benefit costs $ 2,598 $ 1,443 Other costs to exit activities 1,165 364 Impaired asset write-downs 214 9 Contingent consideration adjustments 369 — Net gains (2,271 ) — Other (199 ) 6 Other expenses, net $ 1,876 $ 1,822

Components of Accumulated Other

Components of Accumulated Other Comprehensive Loss	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Components of Accumulated Other Comprehensive Loss	Components of Accumulated Other Comprehensive Loss Accumulated other comprehensive loss is included in the Condensed Consolidated Statements of Equity. The components of Accumulated other comprehensive loss, net of the effect of income taxes, and activity for the three months ended March 31, 2018 and 2019 was as follows: Components of Accumulated Other Comprehensive Income (Loss) - Net of Tax (In thousands) Cumulative Foreign Exchange Translation Adjustments Effective Portion of Derivatives Designated as Hedging Instruments Cumulative Unrecognized Actuarial Losses on Pension Obligations Unrealized Gain (Loss) on Marketable Securities Total Balance at December 31, 2017 $ (111,567 ) $ 808 $ (435,840 ) $ 17 $ (546,582 ) Adoption of new accounting standard (a) — (1,520 ) — — (1,520 ) Other comprehensive income (loss) before reclassifications 12,501 (b) 2,768 (c) (13,945 ) (b) (14 ) 1,310 Amounts reclassified from accumulated other comprehensive loss, net of tax — (91 ) 4,944 — 4,853 Total other comprehensive income (loss) 12,501 2,677 (9,001 ) (14 ) 6,163 Other comprehensive income attributable to noncontrolling interests (1,278 ) — — — (1,278 ) Other comprehensive income (loss) attributable to Harsco Corporation 11,223 2,677 (9,001 ) (14 ) 4,885 Balance at March 31, 2018 $ (100,344 ) $ 1,965 $ (444,841 ) $ 3 $ (543,217 ) Components of Accumulated Other Comprehensive Income (Loss) - Net of Tax (In thousands) Cumulative Foreign Exchange Translation Adjustments Effective Portion of Derivatives Designated as Hedging Instruments Cumulative Unrecognized Actuarial Losses on Pension Obligations Unrealized Gain (Loss) on Marketable Securities Total Balance at December 31, 2018 $ (159,810 ) $ 1,389 $ (408,655 ) $ (31 ) $ (567,107 ) Adoption of new accounting standard (c) — — (21,429 ) (d) — (21,429 ) Other comprehensive income (loss) before reclassifications 11,725 (b) (3,084 ) (c) (6,573 ) (b) 15 2,083 Amounts reclassified from accumulated other comprehensive loss, net of tax (2,271 ) (63 ) 4,782 — 2,448 Total other comprehensive income (loss) 9,454 (3,147 ) (1,791 ) 15 4,531 Other comprehensive income attributable to noncontrolling interests (420 ) — — — (420 ) Other comprehensive income (loss) attributable to Harsco Corporation 9,034 (3,147 ) (1,791 ) 15 4,111 Balance at March 31, 2019 $ (150,776 ) $ (1,758 ) $ (431,875 ) $ (16 ) $ (584,425 ) (a) Represents the opening balance sheet adjustment to retained earnings related to the adoption of the revenue recognition standard adopted by the Company on January 1, 2018. (b) Principally foreign currency fluctuation. (c) Net change from periodic revaluations. (d) Represents the adoption of the new accounting standard on January 1, 2019 related to stranded tax effects from the Tax Act. See Note 2, Recently Adopted and Recently Issued Accounting Standards for more information. Amounts reclassified from accumulated other comprehensive loss are as follows: (In thousands) Three Months Ended Affected Caption in the Condensed Consolidated Statements of Operations March 31 March 31 Recognition of cumulative foreign currency translation adjustments: Gain on substantial liquidation of subsidiary (e) $ (2,271 ) $ — Other expenses, net Amortization of cash flow hedging instruments: Foreign currency exchange forward contracts $ (32 ) $ (212 ) Product revenues Cross-currency interest rate swaps 314 271 Interest expense Interest rate swaps (301 ) — Interest expense Total before tax (19 ) 59 Tax expense (44 ) (150 ) Total reclassification of cash flow hedging instruments, net of tax $ (63 ) $ (91 ) Amortization of defined benefit pension items (f) : Recognized losses $ 5,058 $ 5,142 Defined benefit pension income (expense) Recognized prior-service costs 66 (39 ) Defined benefit pension income (expense) Settlement/curtailment losses — 166 Defined benefit pension income (expense) Total before tax 5,124 5,269 Tax benefit (342 ) (325 ) Total reclassification of defined benefit pension items, net of tax $ 4,782 $ 4,944 (e) No tax impact. (f)

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2019
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On May 9, 2019 the Company announced two separate strategic transactions that accelerate the transformation of the Company’s portfolio of businesses into a leading provider of environmental solutions and aligns with the Company’s strategy to decrease the complexity of the Company’s business portfolio by focusing on less cyclical and higher-growth businesses. The Company has entered into a definitive agreement to acquire CEHI Acquisition Corporation and Subsidiaries (“Clean Earth”), a leader in processing special waste and hazardous and non-hazardous waste, from Compass Diversified Holdings for approximately $625 million in cash, subject to post-closing adjustments. The transaction has been approved by the Company's Board of Directors ("Board") and is expected to close during the next few months, subject to customary closing conditions, including receipt of certain regulatory approvals. There are no material financial or other contingencies to close the transaction. In addition, the Company has entered into a definitive agreement to sell the Harsco Industrial Air-X-Changers business to Chart Industries, Inc. for $592 million in cash, subject to post-closing adjustments. The transaction has been approved by the Company's Board and is expected to close during the next few months, subject to customary closing conditions, including receipt of certain regulatory approvals. There are no material financial or other contingencies to close the transaction.

Basis of Presentation (Policies

Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation Harsco Corporation (the "Company") has prepared these unaudited condensed consolidated financial statements in accordance with accounting principles generally accepted in the U.S. (“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 Securities and Exchange Commission (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, 2018 Condensed Consolidated Balance Sheet information contained in this Quarterly Report on Form 10-Q was derived from the 2018 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, 2018 . 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. Reclassifications Certain reclassifications have been made to prior year amounts to conform with current year classifications.
Recently Adopted and Recently Issued Accounting Standards	Recently Adopted and Recently Issued Accounting Standards The following accounting standards have been adopted in 2019: On January 1, 2019, the Company adopted changes issued by the Financial Accounting Standards Board (“FASB”) related to 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 Company elected the package of practical expedients permitted under the transition, which among other items, allowed the carry forward of the historical lease classification. The Company has elected to apply the transition requirements at the January 1, 2019 effective date and therefore, comparative information has not been restated and continues to be reported under U.S. GAAP in effect for those periods. The changes had a significant impact on the Condensed Consolidated Balance Sheets upon adoption and the Company recorded Right-of-use ("ROU") assets and lease liabilities of $53.0 million and $53.4 million , respectively. The difference between the ROU assets and lease liabilities was recorded primarily as adjustments to other assets and liabilities where prepaid rent and deferred expenses were previously recorded. Additionally, the Company's accounting for finance leases remained consistent. The changes did not have an impact on the Company’s Condensed Consolidated Statements of Operations or Condensed Consolidated Statements of Cash Flows. The discount rates used to calculate the ROU assets and lease liabilities as of the effective date were based on the remaining lease terms as of the effective date. See Note 6, Leases for additional information. On January 1, 2019, the Company adopted changes issued by the FASB 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. Upon adoption, the Company’s recognition model for the excluded component was modified from a mark-to-market approach to an amortization approach for hedging relationships. Hedging relationships entered into on or after January 1, 2019 will be under the amortization approach while those entered into before January 1, 2019 will continue to be recognized under the mark-to-market approach. As such, there was no effect of applying this election reflected as an adjustment to Accumulated other comprehensive loss with a corresponding adjustment to the opening balance of Retained earnings. Presentation and disclosure amendments are required to be applied prospectively. Other than required expanded disclosures, the adoption of these changes did not have a material impact on the Company's condensed consolidated financial statements. On January 1, 2019, the Company adopted changes issued by the FASB which allow entities to reclassify stranded income tax effects resulting from the Tax Cuts and Jobs Act (the “Tax Act”) from accumulated other comprehensive income to retained earnings in the consolidated financial statements. Under the Tax Act, deferred taxes were adjusted to reflect the reduction of the historical corporate income tax rate to the newly enacted corporate income tax rate, which left the tax effects on items within accumulated other comprehensive income stranded at historical tax rates. The adoption of these changes resulted in the Company reclassifying approximately $21 million of stranded income tax effects into Retained earnings. The following accounting standards have been issued and become effective for the Company at a future date: In June 2016, the FASB issued changes which amends the impairment model by requiring entities to use a forward-looking approach based on expected losses rather than incurred losses to estimate credit losses on certain types of financial instruments, including trade receivables. This may result in the earlier recognition of allowances for losses. The changes become effective for the Company on January 1, 2020, with early adoption permitted. Management has not yet completed the assessment of the impact of the new standard on the Company’s 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 August 2018, the FASB issued changes which modify the disclosure requirements for fair value measurements. The amendments in this update remove the requirement to disclose the amount of, and reasons for, transfers between Level 1 and Level 2 of the fair value hierarchy; the policy for timing of transfers between levels; and the valuation processes for Level 3 fair value measurements. The changes require disclosure of changes in unrealized gains and losses for the period included in other comprehensive income (loss) for recurring Level 3 fair value measurements held at the end of the reporting period and the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements. The changes become effective for the Company on January 1, 2020. Other than required expanded disclosures, the adoption of these changes will not have a material impact on the Company's condensed consolidated financial statements.

Acquisitions (Tables)

Acquisitions (Tables)	3 Months Ended
	Mar. 31, 2019
Business Combinations [Abstract]
Summary of assets acquired and liabilities assumed	The fair value recorded for the assets acquired and liabilities assumed for Altek is as follows: Final Valuation (In millions) June 30 2018 Measurement Period Adjustments (a) March 31 Cash and cash equivalents $ 1.7 $ — $ 1.7 Net working capital (1.5 ) 0.2 (1.3 ) Property, plant and equipment 3.3 — 3.3 Intangible assets 52.5 0.2 52.7 Goodwill 20.9 1.6 22.5 Net deferred tax liabilities (8.5 ) — (8.5 ) Other liabilities (0.3 ) — (0.3 ) Total identifiable net assets of Altek $ 68.1 $ 2.0 $ 70.1
Summary of changes in fair value of contingent consideration	The following table reflects the changes in the fair value of contingent consideration: (In thousands) Contingent Consideration Balance, December 31, 2018 $ 8,420 Fair value adjustment (b) 369 Foreign currency translation 186 Balance, March 31, 2019 $ 8,975 (b) These amounts are recorded in the caption Other expenses, net on the Condensed Consolidated Statements of Operations.

Accounts Receivable and Inven_2

Accounts Receivable and Inventories (Tables)	3 Months Ended
	Mar. 31, 2019
Accounts Receivable And Inventories
Schedule of accounts receivable	Accounts receivable consist of the following: (In thousands) March 31 December 31 Trade accounts receivable $ 301,439 $ 295,847 Less: Allowance for doubtful accounts (4,644 ) (4,634 ) Trade accounts receivable, net $ 296,795 $ 291,213 Other receivables (a) $ 51,130 $ 54,182
Schedule of provision for doubtful accounts related to trade accounts receivable	The provision (benefit) for doubtful accounts related to trade accounts receivable was as follows: Three Months Ended March 31 (In thousands) 2019 2018 Provision (benefit) for doubtful accounts related to trade accounts receivable $ 26 $ (46 )
Schedule of inventories	Inventories consist of the following: (In thousands) March 31 December 31 Finished goods $ 19,089 $ 17,223 Work-in-process 21,715 21,787 Raw materials and purchased parts 82,983 72,194 Stores and supplies 23,909 21,907 Total inventories $ 147,696 $ 133,111

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2019
Property, Plant and Equipment [Abstract]
Schedule of property, plant and equipment	Property, plant and equipment consists of the following: (In thousands) March 31 December 31 Land $ 10,515 $ 10,621 Land improvements 15,932 16,156 Buildings and improvements 190,715 191,072 Machinery and equipment 1,566,706 1,538,166 Uncompleted construction 42,493 37,713 Gross property, plant and equipment 1,826,361 1,793,728 Less: Accumulated depreciation (1,342,913 ) (1,323,828 ) Property, plant and equipment, net $ 483,448 $ 469,900

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Components of Lease Expense and Supplemental Cash Flow and Additional Information	The components of lease expense were as follows: Three Months Ended (In thousands) March 31 Finance leases: Amortization expense $ 310 Interest on lease liabilities 4 Operating leases 4,608 Short-term leases 4,669 Variable lease expense 314 Total lease expense $ 9,905 Supplemental cash flow information related to leases was as follows: Three Months Ended (In thousands) March 31 Cash paid for amounts included in the measurement of lease liabilities: Cash flows from operating activities - Operating leases $ 4,670 Cash flows from financing activities - Finance leases 363 Right-of-use assets obtained in exchange for lease obligations: Operating leases (a) $ 53,750 Finance leases 373 (a) Includes ROU assets of $53.0 million March 31 Other information: Weighted average remaining lease term - Operating leases (in years) 4.42 Weighted average remaining lease term - Finance leases (in years) 2.01 Weighted average discount rate - Operating leases 6.9 % Weighted average discount rate - Finance leases 4.1 %
Supplemental Balance Sheet Information Related to Leases	Supplemental balance sheet information related to leases was as follows: (In thousands) March 31 Operating Leases: Operating lease right-of-use assets $ 49,584 Other current liabilities 12,936 Operating lease liabilities 37,037 Finance Leases: Property, plant and equipment, net $ 1,286 Current maturities of long-term debt 1,054 Long-term debt 945
Maturities of Operating Lease Liabilities	Maturities of lease liabilities were as follows: (In thousand) Operating Leases Finance Leases Year Ending December 31 st : 2019 (excluding the three months ended March 31, 2019) $ 12,210 $ 1,027 2020 12,943 631 2021 9,775 295 2022 7,563 117 2023 6,254 16 After 2023 21,576 2 Total lease payments 70,321 2,088 Less imputed interest (20,348 ) (89 ) Total $ 49,973 $ 1,999
Maturities of Finance Lease Liabilities	Maturities of lease liabilities were as follows: (In thousand) Operating Leases Finance Leases Year Ending December 31 st : 2019 (excluding the three months ended March 31, 2019) $ 12,210 $ 1,027 2020 12,943 631 2021 9,775 295 2022 7,563 117 2023 6,254 16 After 2023 21,576 2 Total lease payments 70,321 2,088 Less imputed interest (20,348 ) (89 ) Total $ 49,973 $ 1,999
Future Minimum Payments Under Operating Leases with Noncancelable Terms	As previously disclosed, under then in effect lease accounting in accordance with U.S. GAAP, future minimum payments under operating leases with noncancelable terms were as follows as of December 31, 2018: (In thousands) 2019 $ 13,985 2020 12,204 2021 9,448 2022 7,706 2023 6,201 After 2023 28,442

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in carrying amounts of goodwill by segment	The following table reflects the changes in carrying amounts of goodwill by segment for the three months ended March 31, 2019 : (In thousands) Harsco Metals & Minerals Segment Harsco Industrial Segment Harsco Rail Segment Consolidated Totals Balance at December 31, 2018 $ 391,687 $ 6,839 $ 13,026 $ 411,552 Foreign currency translation 897 — — 897 Balance at March 31, 2019 $ 392,584 $ 6,839 $ 13,026 $ 412,449
Schedule of intangible assets by class	Intangible assets included in the caption, Intangible assets, net, on the Condensed Consolidated Balance Sheets consist of the following: March 31, 2019 December 31, 2018 (In thousands) Gross Carrying Amount Accumulated Amortization Gross Carrying Amount Accumulated Amortization Customer related $ 137,242 $ 101,090 $ 136,307 $ 99,383 Patents 2,597 2,505 2,598 2,503 Technology related 36,572 3,599 35,831 2,681 Trade names 9,298 2,051 9,212 1,897 Other 5,929 3,640 5,865 3,524 Total $ 191,638 $ 112,885 $ 189,813 $ 109,988
Schedule of amortization expense	Amortization expense for intangible assets was as follows: Three Months Ended March 31 (In thousands) 2019 2018 Amortization expense for intangible assets $ 2,352 $ 1,282
Schedule of estimated amortization expense	The estimated amortization expense for the next five fiscal years based on current intangible assets is as follows: (In thousands) 2019 2020 2021 2022 2023 Estimated amortization expense (a) $ 9,000 $ 8,750 $ 8,500 $ 8,250 $ 8,250

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	3 Months Ended
	Mar. 31, 2019
Retirement Benefits [Abstract]
Schedule of net benefit costs	Three Months Ended March 31 Defined Benefit Pension Plans Net Periodic Pension Cost (Benefit) U.S. Plans International Plans (In thousands) 2019 2018 2019 2018 Service costs $ 10 $ 10 $ 356 $ 386 Interest costs 2,651 2,391 5,664 5,672 Expected return on plan assets (2,593 ) (3,017 ) (9,517 ) (11,145 ) Recognized prior service costs — — 66 (39 ) Recognized loss 1,405 1,302 3,653 3,840 Settlement/curtailment losses — 166 — — Defined benefit pension plans net periodic pension cost (benefit) $ 1,473 $ 852 $ 222 $ (1,286 )
Schedule of contributions to pension plans	Three Months Ended Company Contributions March 31 (In thousands) 2019 2018 Defined benefit pension plans (U.S.) $ 1,479 $ 1,284 Defined benefit pension plans (International) 9,270 9,734 Multiemployer pension plans 521 501 Defined contribution pension plans 3,390 2,835

Reconciliation of Basic and D_2

Reconciliation of Basic and Diluted Shares (Tables)	3 Months Ended
	Mar. 31, 2019
Earnings Per Share [Abstract]
Reconciliation of basic and diluted shares	Three Months Ended March 31 (In thousands, except per share amounts) 2019 2018 Income from continuing operations attributable to Harsco Corporation common stockholders $ 21,029 $ 18,260 Weighted-average shares outstanding - basic 79,907 80,650 Dilutive effect of stock-based compensation 1,746 2,894 Weighted-average shares outstanding - diluted 81,653 83,544 Earnings from continuing operations per common share, attributable to Harsco Corporation common stockholders: Basic $ 0.26 $ 0.23 Diluted $ 0.26 $ 0.22
Schedule of antidilutive securities excluded from computation of earnings per share	The following average outstanding stock-based compensation units were not included in the computation of diluted earnings per share because the effect was antidilutive: Three Months Ended March 31 (In thousands) 2019 2018 Stock appreciation rights 608 696 Performance share units 233 —

Derivative Instruments, Hedgi_2

Derivative Instruments, Hedging Activities and Fair Value (Tables)	3 Months Ended
	Mar. 31, 2019
Derivative Instruments, Hedging Activities And Fair Value Disclosure [Abstract]
Schedule of fair value of outstanding derivative contracts	(In thousands) Balance Sheet Location Fair Value of Derivatives Designated as Hedging Instruments Fair Value of Derivatives Not Designated as Hedging Instruments Total Fair Value March 31, 2019 Asset derivatives (Level 2): Foreign currency exchange forward contracts Other current assets $ 2,275 $ 5,520 $ 7,795 Interest rate swaps Other current assets 736 — 736 Total $ 3,011 $ 5,520 $ 8,531 Liability derivatives (Level 2): Foreign currency exchange forward contracts Other current liabilities $ 121 $ 1,426 $ 1,547 Interest rate swaps Other current liabilities 96 — 96 Interest rate swaps Other liabilities 4,639 — 4,639 Total $ 4,856 $ 1,426 $ 6,282 December 31, 2018 Asset derivatives (Level 2): Foreign currency exchange forward contracts Other current assets $ 2,970 $ 589 $ 3,559 Interest rate swaps Other current assets 1,331 — 1,331 Interest rate swaps Other assets 128 — $ 128 Total $ 4,429 $ 589 $ 5,018 Liability derivatives (Level 2): Foreign currency exchange forward contracts Other current liabilities $ 24 $ 2,910 $ 2,934 Interest rate swaps Other liabilities 1,849 — 1,849 Total $ 1,873 $ 2,910 $ 4,783
Schedule of effect of derivative instruments	Derivatives Designated as Hedging Instruments Amount Recognized in Other Comprehensive Income (“OCI”) on Derivatives Location of Amount Reclassified from Accumulated OCI into Income Amount Reclassified from Accumulated OCI into Income - Effective Portion or Equity Three Months Ended Three Months Ended March 31 March 31 (In thousands) 2019 2018 2019 2018 Foreign currency exchange forward contracts $ (712 ) $ 240 Product revenues $ (32 ) $ (212 ) Foreign currency exchange forward contracts (a) — — Retained earnings — (1,520 ) Interest rate swaps (3,309 ) 3,310 Interest expense (301 ) — Cross-currency interest rate swaps (b) (52 ) (93 ) Interest expense 314 271 (4,073 ) 3,457 $ (19 ) $ (1,461 ) (a) The Company has adopted the new revenue recognition standard utilizing the modified retrospective transition method, including use of practical expedients. See Note 2, Recently Adopted and Recently Issued Accounting Standards for additional information. (b) Amounts represent changes in foreign currency translation related to balances in Accumulated other comprehensive loss. The location and amount of gain (loss) recognized on the Condensed Consolidated Statements of Operations: Three Months Ended March 31 2019 2018 (in thousands) Product Revenues Interest Expense Product Revenues Cost of Products Sold Interest Expense Total amounts of income and expense line items presented in the statement of financial performance in which the effects of cash flow hedges are recorded $ 217,768 $ (9,739 ) $ 163,829 $ 119,678 $ (9,583 ) Interest rate swaps: Amount of gain or (loss) reclassified from accumulated other comprehensive income into income — 301 — — — Foreign exchange contracts: Amount of gain or (loss) reclassified from accumulated other comprehensive income into income 32 — 212 — — Amount excluded from effectiveness testing recognized in earnings based on changes in fair value 78 — — (19 ) — Cross-currency interest rate swaps: Amount of gain or (loss) reclassified from accumulated other comprehensive income into income — (314 ) — — (271 ) Derivatives Not Designated as Hedging Instruments Location of Gain (Loss) Recognized in Income on Derivatives Amount of Gain (Loss) Recognized in Income on Derivatives for the Three Months Ended March 31(c) (In thousands) 2019 2018 Foreign currency exchange forward contracts Cost of services and products sold $ 2,323 $ (5,466 ) (c) These gains (losses) offset amounts recognized in cost of services and products sold principally as a result of intercompany or third party foreign currency exposures.

Review of Operations by Segme_2

Review of Operations by Segment (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Schedule of operations by segment	Three Months Ended March 31 (In thousands) 2019 2018 Revenues From Continuing Operations Harsco Metals & Minerals $ 261,312 $ 264,723 Harsco Industrial 117,385 83,598 Harsco Rail 68,591 59,678 Corporate — 39 Total Revenues From Continuing Operations $ 447,288 $ 408,038 Operating Income (Loss) From Continuing Operations Harsco Metals & Minerals $ 24,497 $ 27,735 Harsco Industrial 17,030 12,421 Harsco Rail 5,389 1,952 Corporate (8,670 ) (5,567 ) Total Operating Income From Continuing Operations $ 38,246 $ 36,541 Depreciation and Amortization Harsco Metals & Minerals $ 28,705 $ 29,085 Harsco Industrial 2,025 1,855 Harsco Rail 1,167 1,064 Corporate 1,352 1,348 Total Depreciation and Amortization $ 33,249 $ 33,352 Three Months Ended March 31 (In thousands) 2019 2018 Capital Expenditures Harsco Metals & Minerals $ 29,163 $ 25,176 Harsco Industrial 2,175 1,087 Harsco Rail 3,916 430 Corporate 1,153 204 Total Capital Expenditures $ 36,407 $ 26,897
Reconciliation of segment operating income to income from continuing operations before income taxes and equity income	Reconciliation of Segment Operating Income to Income From Continuing Operations Before Income Taxes and Equity Income Three Months Ended March 31 (In thousands) 2019 2018 Segment operating income $ 46,916 $ 42,108 General Corporate expense (8,670 ) (5,567 ) Operating income from continuing operations 38,246 36,541 Interest income 534 498 Interest expense (9,739 ) (9,583 ) Defined benefit pension income (expense) (1,337 ) 839 Income from continuing operations before income taxes and equity income $ 27,704 $ 28,295

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2019
Revenue from Contract with Customer [Abstract]
Summary of revenues by primary geographical markets	A summary of the Company's revenues by primary geographical markets as well as by key product and service groups is as follows: Three Months Ended March 31, 2019 (In thousands) Harsco Metals & Minerals Segment Harsco Industrial Segment Harsco Rail Segment Corporate Consolidated Totals Primary Geographical Markets (a) : North America $ 73,349 $ 112,099 $ 50,366 $ — $ 235,814 Western Europe 98,221 — 10,013 — 108,234 Latin America (b) 36,991 5,286 591 — 42,868 Asia-Pacific 34,138 — 7,621 — 41,759 Middle East and Africa 13,915 — — — 13,915 Eastern Europe 4,698 — — — 4,698 Total Revenues $ 261,312 $ 117,385 $ 68,591 $ — $ 447,288 Key Product and Service Groups: On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems $ 261,312 $ — $ — $ — $ 261,312 Railway track maintenance services and equipment — — 68,591 — 68,591 Air-cooled heat exchangers — 76,203 — — 76,203 Industrial grating and fencing products — 33,376 — — 33,376 Heat transfer products — 7,806 — — 7,806 Total Revenues $ 261,312 $ 117,385 $ 68,591 $ — $ 447,288 Three Months Ended March 31, 2018 (In thousands) Harsco Metals & Minerals Segment Harsco Industrial Segment Harsco Rail Segment Corporate Consolidated Totals Primary Geographical Markets (a) : North America $ 71,065 $ 78,858 $ 40,405 $ 39 $ 190,367 Western Europe 96,921 — 14,720 — 111,641 Latin America (b) 41,458 4,740 833 — 47,031 Asia-Pacific 36,221 — 3,720 — 39,941 Middle East and Africa 11,553 — — — 11,553 Eastern Europe 7,505 — — — 7,505 Total Revenues $ 264,723 $ 83,598 $ 59,678 $ 39 $ 408,038 Key Product and Service Groups: On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems $ 264,723 $ — $ — $ — $ 264,723 Railway track maintenance services and equipment — — 59,678 — 59,678 Air-cooled heat exchangers — 44,267 — — 44,267 Industrial grating and fencing products — 30,097 — — 30,097 Heat transfer products — 9,234 — — 9,234 General Corporate — — — 39 39 Total Revenues $ 264,723 $ 83,598 $ 59,678 $ 39 $ 408,038 (a) Revenues are attributed to individual countries based on the location of the facility generating the revenue. (b) Includes Mexico.

Other (Income) Expenses, Net (T

Other (Income) Expenses, Net (Tables)	3 Months Ended
	Mar. 31, 2019
Other Income and Expenses [Abstract]
Schedule of other (income) expenses	The major components of this Condensed Consolidated Statements of Operations caption are as follows: Three Months Ended March 31 (In thousands) 2019 2018 Employee termination benefit costs $ 2,598 $ 1,443 Other costs to exit activities 1,165 364 Impaired asset write-downs 214 9 Contingent consideration adjustments 369 — Net gains (2,271 ) — Other (199 ) 6 Other expenses, net $ 1,876 $ 1,822

Components of Accumulated Oth_2

Components of Accumulated Other Comprehensive Loss (Tables)	3 Months Ended
	Mar. 31, 2019
Equity [Abstract]
Schedule of accumulated other comprehensive loss	The components of Accumulated other comprehensive loss, net of the effect of income taxes, and activity for the three months ended March 31, 2018 and 2019 was as follows: Components of Accumulated Other Comprehensive Income (Loss) - Net of Tax (In thousands) Cumulative Foreign Exchange Translation Adjustments Effective Portion of Derivatives Designated as Hedging Instruments Cumulative Unrecognized Actuarial Losses on Pension Obligations Unrealized Gain (Loss) on Marketable Securities Total Balance at December 31, 2017 $ (111,567 ) $ 808 $ (435,840 ) $ 17 $ (546,582 ) Adoption of new accounting standard (a) — (1,520 ) — — (1,520 ) Other comprehensive income (loss) before reclassifications 12,501 (b) 2,768 (c) (13,945 ) (b) (14 ) 1,310 Amounts reclassified from accumulated other comprehensive loss, net of tax — (91 ) 4,944 — 4,853 Total other comprehensive income (loss) 12,501 2,677 (9,001 ) (14 ) 6,163 Other comprehensive income attributable to noncontrolling interests (1,278 ) — — — (1,278 ) Other comprehensive income (loss) attributable to Harsco Corporation 11,223 2,677 (9,001 ) (14 ) 4,885 Balance at March 31, 2018 $ (100,344 ) $ 1,965 $ (444,841 ) $ 3 $ (543,217 ) Components of Accumulated Other Comprehensive Income (Loss) - Net of Tax (In thousands) Cumulative Foreign Exchange Translation Adjustments Effective Portion of Derivatives Designated as Hedging Instruments Cumulative Unrecognized Actuarial Losses on Pension Obligations Unrealized Gain (Loss) on Marketable Securities Total Balance at December 31, 2018 $ (159,810 ) $ 1,389 $ (408,655 ) $ (31 ) $ (567,107 ) Adoption of new accounting standard (c) — — (21,429 ) (d) — (21,429 ) Other comprehensive income (loss) before reclassifications 11,725 (b) (3,084 ) (c) (6,573 ) (b) 15 2,083 Amounts reclassified from accumulated other comprehensive loss, net of tax (2,271 ) (63 ) 4,782 — 2,448 Total other comprehensive income (loss) 9,454 (3,147 ) (1,791 ) 15 4,531 Other comprehensive income attributable to noncontrolling interests (420 ) — — — (420 ) Other comprehensive income (loss) attributable to Harsco Corporation 9,034 (3,147 ) (1,791 ) 15 4,111 Balance at March 31, 2019 $ (150,776 ) $ (1,758 ) $ (431,875 ) $ (16 ) $ (584,425 ) (a) Represents the opening balance sheet adjustment to retained earnings related to the adoption of the revenue recognition standard adopted by the Company on January 1, 2018. (b) Principally foreign currency fluctuation. (c) Net change from periodic revaluations.
Reclassification out of accumulated other comprehensive income	Amounts reclassified from accumulated other comprehensive loss are as follows: (In thousands) Three Months Ended Affected Caption in the Condensed Consolidated Statements of Operations March 31 March 31 Recognition of cumulative foreign currency translation adjustments: Gain on substantial liquidation of subsidiary (e) $ (2,271 ) $ — Other expenses, net Amortization of cash flow hedging instruments: Foreign currency exchange forward contracts $ (32 ) $ (212 ) Product revenues Cross-currency interest rate swaps 314 271 Interest expense Interest rate swaps (301 ) — Interest expense Total before tax (19 ) 59 Tax expense (44 ) (150 ) Total reclassification of cash flow hedging instruments, net of tax $ (63 ) $ (91 ) Amortization of defined benefit pension items (f) : Recognized losses $ 5,058 $ 5,142 Defined benefit pension income (expense) Recognized prior-service costs 66 (39 ) Defined benefit pension income (expense) Settlement/curtailment losses — 166 Defined benefit pension income (expense) Total before tax 5,124 5,269 Tax benefit (342 ) (325 ) Total reclassification of defined benefit pension items, net of tax $ 4,782 $ 4,944 (e) No tax impact. (f)

Recently Adopted and Recently_2

Recently Adopted and Recently Issued Accounting Standards (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets, net	$ 49,584
Lease liabilities	49,973
Stranded income tax effects in accumulated other comprehensive income	$ 21,000
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets, net		$ 53,000
Lease liabilities		$ 53,400

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - 1 months ended May 31, 2018 - Altek £ in Millions, $ in Millions	GBP (£)	USD ($)	USD ($)
Business Acquisition [Line Items]
Purchase price	£ 45	$ 60
Additional contingent consideration	£ 25		$ 33
Payments to Acquire Businesses, Net of Cash Acquired		$ 59.4
Estimated preliminary fair value			$ 12.1

Acquisitions - Assets Acquired

Acquisitions - Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	9 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Jun. 30, 2018
Business Acquisition [Line Items]
Goodwill	$ 412,449	$ 411,552
Altek
Business Acquisition [Line Items]
Cash and cash equivalents	1,700		$ 1,700
Net working capital	(1,300)		(1,500)
Property, plant and equipment	3,300		3,300
Intangible assets	52,700		52,500
Goodwill	22,500		20,900
Net deferred tax liabilities	(8,500)		(8,500)
Other liabilities	(300)		(300)
Total identifiable net assets of Altek	70,100		$ 68,100
Measurement Period Adjustments
Net working capital	200
Intangible assets	200
Goodwill	1,600
Total identifiable net assets of Altek	$ 2,000

Acquisitions - Changes in Fair

Acquisitions - Changes in Fair Value of Contingent Consideration (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Contingent Consideration
Balance, December 31, 2018	$ 8,420
Fair value adjustment	369	$ 0
Foreign currency translation	186
Balance, March 31, 2019	$ 8,975

Accounts Receivable and Inven_3

Accounts Receivable and Inventories (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Dec. 31, 2016
Accounts receivable
Trade accounts receivable	$ 301,439		$ 295,847
Less: Allowance for doubtful accounts	(4,644)		(4,634)
Trade accounts receivable, net	296,795		291,213
Other receivables	51,130		54,182
Provision for doubtful accounts related to trade accounts receivable	26	$ (46)
Inventories
Finished goods	19,089		17,223
Work-in-process	21,715		21,787
Raw materials and purchased parts	82,983		72,194
Stores and supplies	23,909		21,907
Inventories	147,696		133,111
Inventory for Contracts
Loss provision that exceeds accumulated contract costs	6,800
Net customer advances	64,500		69,000
Contract estimated forward loss provision for Harsco Rail Segment			$ 1,800	$ 45,100
Revenues	447,288	408,038
SBB [Member]
Inventory for Contracts
Revenues	$ 4,700	$ 7,900
Contract 2 [Member] | SBB [Member]
Inventory for Contracts
Percentage complete	30.00%

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment
Gross property, plant and equipment	$ 1,826,361	$ 1,793,728
Less: Accumulated depreciation	(1,342,913)	(1,323,828)
Property, plant and equipment, net	483,448	469,900
Land
Property, Plant and Equipment
Gross property, plant and equipment	10,515	10,621
Land improvements
Property, Plant and Equipment
Gross property, plant and equipment	15,932	16,156
Buildings and improvements
Property, Plant and Equipment
Gross property, plant and equipment	190,715	191,072
Machinery and equipment
Property, Plant and Equipment
Gross property, plant and equipment	1,566,706	1,538,166
Construction in progress
Property, Plant and Equipment
Gross property, plant and equipment	$ 42,493	$ 37,713

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term - Operating leases (in years)	4 years 5 months 1 day
Termination period	1 year
Operating lease not yet commenced	$ 5
Minimum
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term - Operating leases (in years)	1 year
Maximum
Lessee, Lease, Description [Line Items]
Weighted average remaining lease term - Operating leases (in years)	24 years 6 months
Extension period	10 years

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Finance leases:
Amortization expense	$ 310
Interest on lease liabilities	4
Operating leases	4,608
Short-term leases	4,669
Variable lease expense	314
Total lease expense	$ 9,905

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Thousands	Jan. 01, 2019	Mar. 31, 2019
Cash paid for amounts included in the measurement of lease liabilities:
Cash flows from operating activities - Operating leases		$ 4,670
Cash flows from financing activities - Finance leases		363
Right-of-use assets obtained in exchange for lease obligations:
Operating leases	$ 53,000	53,750
Finance leases		$ 373

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information Related to Leases (Details) $ in Thousands	Mar. 31, 2019USD ($)
Operating Leases:
Right-of-use assets, net	$ 49,584
Other current liabilities	12,936
Operating lease liabilities	37,037
Finance Leases:
Property, plant and equipment, net	1,286
Current maturities of long-term debt	1,054
Long-term debt	$ 945

Leases - Supplemental Additiona

Leases - Supplemental Additional Information (Details)	Mar. 31, 2019
Other information:
Weighted average remaining lease term - Operating leases (in years)	4 years 5 months 1 day
Weighted average remaining lease term - Finance leases (in years)	2 years 3 days
Weighted average discount rate - Operating leases	6.90%
Weighted average discount rate - Finance leases	4.10%

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Mar. 31, 2019USD ($)
Operating Leases
2019 (excluding the three months ended March 31, 2019)	$ 12,210
2020	12,943
2021	9,775
2022	7,563
2023	6,254
After 2023	21,576
Total lease payments	70,321
Less imputed interest	(20,348)
Total	49,973
Finance Leases
2019 (excluding the three months ended March 31, 2019)	1,027
2020	631
2021	295
2022	117
2023	16
After 2023	2
Total lease payments	2,088
Less imputed interest	(89)
Total	$ 1,999

Leases - Future Minimum Payment

Leases - Future Minimum Payments Under Operating Leases with Noncancelable Terms (Details) $ in Thousands	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 13,985
2020	12,204
2021	9,448
2022	7,706
2023	6,201
After 2023	$ 28,442

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Changes in Carrying Amounts of Goodwill by Segment (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019USD ($)
Changes in carrying amounts of goodwill
Balance at December 31, 2018	$ 411,552
Foreign currency translation	897
Balance at March 31, 2019	412,449
Harsco Metals & Minerals Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2018	391,687
Foreign currency translation	897
Balance at March 31, 2019	392,584
Harsco Industrial Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2018	6,839
Foreign currency translation	0
Balance at March 31, 2019	6,839
Harsco Rail Segment
Changes in carrying amounts of goodwill
Balance at December 31, 2018	13,026
Foreign currency translation	0
Balance at March 31, 2019	$ 13,026

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Intangible Assets, by category
Gross Carrying Amount	$ 191,638		$ 189,813
Accumulated Amortization	112,885		109,988
Amortization expense for intangible assets	2,352	$ 1,282
Estimated amortization expense for next 5 years
2019	9,000
2020	8,750
2021	8,500
2022	8,250
2023	8,250
Customer related
Intangible Assets, by category
Gross Carrying Amount	137,242		136,307
Accumulated Amortization	101,090		99,383
Patents
Intangible Assets, by category
Gross Carrying Amount	2,597		2,598
Accumulated Amortization	2,505		2,503
Technology related
Intangible Assets, by category
Gross Carrying Amount	36,572		35,831
Accumulated Amortization	3,599		2,681
Trade names
Intangible Assets, by category
Gross Carrying Amount	9,298		9,212
Accumulated Amortization	2,051		1,897
Other
Intangible Assets, by category
Gross Carrying Amount	5,929		5,865
Accumulated Amortization	$ 3,640		$ 3,524

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Defined benefit plans:
Multiemployer pension plans	$ 521	$ 501
Defined contribution pension plans	3,390	2,835
Pension Plan | U.S. Plans
Defined benefit plans:
Service cost	10	10
Interest cost	2,651	2,391
Expected return on plan assets	(2,593)	(3,017)
Recognized prior service costs	0	0
Recognized loss	1,405	1,302
Settlement/curtailment losses	0	(166)
Defined benefit pension plans net periodic pension cost (benefit)	1,473	852
Defined benefit pension plan	1,479	1,284
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year	7,000
Pension Plan | International Plans
Defined benefit plans:
Service cost	356	386
Interest cost	5,664	5,672
Expected return on plan assets	(9,517)	(11,145)
Recognized prior service costs	66	(39)
Recognized loss	3,653	3,840
Settlement/curtailment losses	0	0
Defined benefit pension plans net periodic pension cost (benefit)	222	(1,286)
Defined benefit pension plan	9,270	$ 9,734
Anticipated contributions to defined benefit pension plans during the remainder of the fiscal year	$ 11,500

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Tax Disclosure [Abstract]
Income tax expense	$ 4,855	$ 8,266
Unrecognized income tax benefits including interest and penalties	3,500
Portion of unrecognized income tax benefits, expected to be recognized upon settlement of tax examinations and the expiration of various statutes of limitations within next twelve months	$ 100

Commitments and Contingencies (

Commitments and Contingencies (Details)	1 Months Ended	3 Months Ended
	Aug. 31, 2005USD ($)	Mar. 31, 2019USD ($)claimdefendantcase	Mar. 31, 2019BRL (R$)claimcase	Dec. 31, 2018USD ($)	Apr. 08, 2016USD ($)
Commitments and Contingencies
Minority interest		35.00%	35.00%
Reserve for loss contingencies		$ 7,000,000
Penalties per day		1,300	R$ 5000
Lima Refinery Litigation
Commitments and Contingencies
Loss contingency damages sought					$ 317,000,000
NETHERLANDS
Commitments and Contingencies
Damages sought - interest, penalties and fees		300,000
Brazilian Tax Disputes - Jan 2004 through May 2005 | Sao Paulo State Revenue Authority
Commitments and Contingencies
Damages sought - principal		2,000,000
Damages sought - interest, penalties and fees		21,000,000
Loss Contingency, Reduced Penalty		2,000,000
Amount of damages sought		9,000,000
Brazilian Tax Disputes - Jan 2002 through Dec 2003 | Sao Paulo State Revenue Authority
Commitments and Contingencies
Damages sought - principal	$ 1,500,000
Damages sought - interest, penalties and fees	4,900,000
Loss Contingency, Reduced Penalty	1,200,000
Loss Contingency, Reduced Penalty, Including Interest	10,000,000
Amount of damages sought	$ 6,500,000
Brazilian Labor Claims
Commitments and Contingencies
Loss contingency reserves		$ 7,000,000		$ 7,100,000
Other
Commitments and Contingencies
Approximate number of defendants that includes the company named in legal actions | defendant		90
Number of pending claims | claim		17,127	17,127
Number of claims dismissed to date by stipulation or summary judgment prior to trial | case		28,189
Other | Active or In Extremis docket
Commitments and Contingencies
Number of pending claims | claim		36	36
Other | Minimum
Commitments and Contingencies
Amount of damages sought		$ 20,000,000
Other | Maximum
Commitments and Contingencies
Amount of damages sought		$ 25,000,000
Other | New York County as managed by the New York Supreme Court
Commitments and Contingencies
Number of pending claims | case		16,586	16,586
Other | New York County as managed by the New York Supreme Court | Pending And Future Litigation, Deferred Or Inactive Docket
Commitments and Contingencies
Number of pending claims | claim		16,550	16,550
Other | New York State Supreme Court, Counties Excluding New York County
Commitments and Contingencies
Number of pending claims | case		119	119
Other | Courts Located In States Other Than New York
Commitments and Contingencies
Number of pending claims | case		422	422
CSN [Member]
Commitments and Contingencies
Penalties per day | R$			R$ 20000

Reconciliation of Basic and D_3

Reconciliation of Basic and Diluted Shares - Reconciliation of Basic and Diluted Shares (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Income from continuing operations, net of tax	$ 21,029	$ 18,260
Weighted-average shares outstanding - basic (in shares)	79,907	80,650
Dilutive effect of stock-based compensation (in shares)	1,746	2,894
Weighted-average shares outstanding - diluted (in shares)	81,653	83,544
Earnings (loss) from continuing operations per common share, attributable to Harsco Corporation common stockholders:
Basic (in dollars per share)	$ 0.26	$ 0.23
Diluted (in dollars per share)	$ 0.26	$ 0.22

Reconciliation of Basic and D_4

Reconciliation of Basic and Diluted Shares - Antidilutive Securities Excluded from Computation of Earnings per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Stock appreciation rights
Antidilutive securities
Number of securities not included in computation of diluted earnings per share (in shares)	608	696
Performance share units
Antidilutive securities
Number of securities not included in computation of diluted earnings per share (in shares)	233	0

Derivative Instruments, Hedgi_3

Derivative Instruments, Hedging Activities and Fair Value - Fair Value of Outstanding Derivative Contracts (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Derivative contracts
Asset derivatives	$ 8,531	$ 5,018
Liability derivatives	6,282	4,783
Foreign currency exchange forward contracts | Other current assets
Derivative contracts
Asset derivatives	7,795	3,559
Foreign currency exchange forward contracts | Other current liabilities
Derivative contracts
Liability derivatives	1,547	2,934
Interest rate swaps | Other current assets
Derivative contracts
Asset derivatives	736	1,331
Interest rate swaps | Other assets
Derivative contracts
Asset derivatives		128
Interest rate swaps | Other current liabilities
Derivative contracts
Liability derivatives	96
Interest rate swaps | Other liabilities
Derivative contracts
Liability derivatives	4,639	1,849
Fair Value of Derivatives Designated as Hedging Instruments
Derivative contracts
Asset derivatives	3,011	4,429
Liability derivatives	4,856	1,873
Fair Value of Derivatives Designated as Hedging Instruments | Foreign currency exchange forward contracts | Other current assets
Derivative contracts
Asset derivatives	2,275	2,970
Fair Value of Derivatives Designated as Hedging Instruments | Foreign currency exchange forward contracts | Other current liabilities
Derivative contracts
Liability derivatives	121	24
Fair Value of Derivatives Designated as Hedging Instruments | Interest rate swaps | Other current assets
Derivative contracts
Asset derivatives	736	1,331
Fair Value of Derivatives Designated as Hedging Instruments | Interest rate swaps | Other assets
Derivative contracts
Asset derivatives		128
Fair Value of Derivatives Designated as Hedging Instruments | Interest rate swaps | Other current liabilities
Derivative contracts
Liability derivatives	96
Fair Value of Derivatives Designated as Hedging Instruments | Interest rate swaps | Other liabilities
Derivative contracts
Liability derivatives	4,639	1,849
Fair Value of Derivatives Not Designated as Hedging Instruments
Derivative contracts
Asset derivatives	5,520	589
Liability derivatives	1,426	2,910
Fair Value of Derivatives Not Designated as Hedging Instruments | Foreign currency exchange forward contracts | Other current assets
Derivative contracts
Asset derivatives	5,520	589
Fair Value of Derivatives Not Designated as Hedging Instruments | Foreign currency exchange forward contracts | Other current liabilities
Derivative contracts
Liability derivatives	1,426	2,910
Fair Value of Derivatives Not Designated as Hedging Instruments | Interest rate swaps | Other current assets
Derivative contracts
Asset derivatives	0	0
Fair Value of Derivatives Not Designated as Hedging Instruments | Interest rate swaps | Other assets
Derivative contracts
Asset derivatives		0
Fair Value of Derivatives Not Designated as Hedging Instruments | Interest rate swaps | Other current liabilities
Derivative contracts
Liability derivatives	0
Fair Value of Derivatives Not Designated as Hedging Instruments | Interest rate swaps | Other liabilities
Derivative contracts
Liability derivatives	$ 0	$ 0

Derivative Instruments, Hedgi_4

Derivative Instruments, Hedging Activities and Fair Value - Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2022	Dec. 31, 2018
Foreign Currency Derivatives
Liabilities	$ 1,402,289,000			$ 1,319,491,000
Pre-tax net gains (losses) on certain loans designated as hedges of net investments in foreign subsidiaries	4,800,000	$ 9,500,000
Fair value of long-term debt	657,400,000			592,000,000
Carrying value of long-term debt	661,500,000			605,400,000
Subject to Master Netting Agreements [Member]
Foreign Currency Derivatives
Liabilities	1,000,000			100,000
Foreign currency exchange forward contracts
Foreign Currency Derivatives
U.S. Dollar Equivalent	444,300,000			$ 423,900,000
Term Loan Facility, Fixed-Rate | Term Loan
Foreign Currency Derivatives
Principal amount	$ 300,000,000
LIBOR | Term Loan Facility, Fixed-Rate | Term Loan
Foreign Currency Derivatives
Variable rate basis spread	2.12%
LIBOR | Scenario, Forecast | Term Loan Facility, Fixed-Rate | Term Loan
Foreign Currency Derivatives
Variable rate basis spread			3.12%

Derivative Instruments, Hedgi_5

Derivative Instruments, Hedging Activities and Fair Value - Effect of Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018	Jan. 01, 2018
Effect of derivative instruments
Amount of Gain (Loss) Recognized in Other Comprehensive Income ("OCI") on Derivative - Effective Portion	$ (4,073)	$ 3,457
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income - Effective Portion	(19)	(1,461)
Accumulated other comprehensive loss	(584,425)		$ (567,107)
Foreign currency exchange forward contracts
Effect of derivative instruments
Amount of Gain (Loss) Recognized in Other Comprehensive Income ("OCI") on Derivative - Effective Portion	(712)	240
Foreign currency exchange forward contracts | Cost of services and products sold
Effect of derivative instruments
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income - Effective Portion	(32)	(212)
Derivatives Not Designated as Hedging Instruments
Amount of Gain (Loss) Recognized in Income on Derivative	2,323	(5,466)
Interest rate swaps
Effect of derivative instruments
Amount of Gain (Loss) Recognized in Other Comprehensive Income ("OCI") on Derivative - Effective Portion	(3,309)	3,310
Interest rate swaps | Interest Expense
Effect of derivative instruments
Amount of Gain (Loss) Recognized in Other Comprehensive Income ("OCI") on Derivative - Effective Portion	(301)	0
Cross currency interest rate swaps
Effect of derivative instruments
Amount of Gain (Loss) Recognized in Other Comprehensive Income ("OCI") on Derivative - Effective Portion	(52)	(93)
Cross currency interest rate swaps | Interest Expense
Effect of derivative instruments
Amount of Gain (Loss) Reclassified from Accumulated OCI into Income - Effective Portion	$ 314	271
Amount of Gain (Loss) Recognized in Income on Derivative - Ineffective Portion and Amount Excluded from Effectiveness Testing		$ (271)
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Effect of derivative instruments
Accumulated other comprehensive loss				$ (1,520)

Derivative Instruments, Hedgi_6

Derivative Instruments, Hedging Activities and Fair Value - Derivatives Designated as Hedging Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative [Line Items]
Product Revenues	$ 447,288	$ 408,038
Interest Expense	(9,739)	(9,583)
Product Revenues | Interest rate swaps
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	0
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Product Revenues | Foreign exchange contracts
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	32
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		212
Amount excluded from effectiveness testing recognized in earnings	78
Amount excluded from effectiveness testing recognized in earnings		0
Product Revenues | Cross currency interest rate swaps
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings	0
Amount excluded from effectiveness testing recognized in earnings		0
Cost of Goods, Total [Member] | Interest rate swaps
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Cost of Goods, Total [Member] | Foreign exchange contracts
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Amount excluded from effectiveness testing recognized in earnings		(19)
Cost of Goods, Total [Member] | Cross currency interest rate swaps
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings		0
Interest Expense | Interest rate swaps
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	301
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Interest Expense | Foreign exchange contracts
Derivative [Line Items]
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income	0
Amount of gain or (loss) reclassified from accumulated other comprehensive income into income		0
Amount excluded from effectiveness testing recognized in earnings	0
Amount excluded from effectiveness testing recognized in earnings		0
Interest Expense | Cross currency interest rate swaps
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings	(314)
Amount excluded from effectiveness testing recognized in earnings		(271)
Product Revenues
Derivative [Line Items]
Product Revenues	217,768	163,829
Cost of services and products sold	$ 157,004	$ 119,678

Review of Operations by Segme_3

Review of Operations by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Operations by segment
Revenues	$ 447,288	$ 408,038
Operating income from continuing operations	38,246	36,541
Interest income	534	498
Interest expense	(9,739)	(9,583)
Defined benefit pension income (expense)	1,337	(839)
Income from continuing operations before income taxes and equity income	27,704	28,295
Depreciation and Amortization	33,249	33,352
Capital Expenditures	36,407	26,897
Operating Segments
Operations by segment
Operating income from continuing operations	46,916	42,108
Corporate
Operations by segment
Revenues	0	39
Operating income from continuing operations	(8,670)	(5,567)
Depreciation and Amortization	1,352	1,348
Capital Expenditures	1,153	204
Harsco Metals & Minerals Segment | Operating Segments
Operations by segment
Revenues	261,312	264,723
Operating income from continuing operations	24,497	27,735
Depreciation and Amortization	28,705	29,085
Capital Expenditures	29,163	25,176
Harsco Industrial Segment | Operating Segments
Operations by segment
Revenues	117,385	83,598
Operating income from continuing operations	17,030	12,421
Depreciation and Amortization	2,025	1,855
Capital Expenditures	2,175	1,087
Harsco Rail Segment | Operating Segments
Operations by segment
Revenues	68,591	59,678
Operating income from continuing operations	5,389	1,952
Depreciation and Amortization	1,167	1,064
Capital Expenditures	$ 3,916	$ 430

Revenue Recognition - Narrative

Revenue Recognition - Narrative (Details) $ in Millions	Mar. 31, 2019USD ($)
Harsco Metals & Minerals Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 43.6
Harsco Metals & Minerals Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Period of expected timing of satisfaction	1 year
Harsco Metals & Minerals Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 35.4
Period of expected timing of satisfaction	1 year
Harsco Metals & Minerals Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 24.9
Period of expected timing of satisfaction	1 year
Harsco Metals & Minerals Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 22.9
Period of expected timing of satisfaction	1 year
Harsco Metals & Minerals Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Period of expected timing of satisfaction	1 year
Harsco Metals & Minerals Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 136.7
Harsco Rail Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 94.3
Harsco Rail Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Period of expected timing of satisfaction	1 year
Harsco Rail Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 64.5
Period of expected timing of satisfaction	1 year
Harsco Rail Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 36.7
Period of expected timing of satisfaction	1 year
Harsco Rail Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 14.2
Period of expected timing of satisfaction	1 year
Harsco Rail Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Period of expected timing of satisfaction	1 year
Harsco Rail Segment | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation	$ 209.8

Revenue Recognition - Revenues

Revenue Recognition - Revenues by Primary Geographical Markets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenues	$ 447,288	$ 408,038
On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems
Disaggregation of Revenue [Line Items]
Total revenues	261,312	264,723
Railway track maintenance services and equipment
Disaggregation of Revenue [Line Items]
Total revenues	68,591	59,678
Air-cooled heat exchangers
Disaggregation of Revenue [Line Items]
Total revenues	76,203	44,267
Industrial grating and fencing products
Disaggregation of Revenue [Line Items]
Total revenues	33,376	30,097
Heat transfer products
Disaggregation of Revenue [Line Items]
Total revenues	7,806	9,234
General Corporate
Disaggregation of Revenue [Line Items]
Total revenues		39
North America
Disaggregation of Revenue [Line Items]
Total revenues	235,814	190,367
Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	108,234	111,641
Latin America
Disaggregation of Revenue [Line Items]
Total revenues	42,868	47,031
Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	41,759	39,941
Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	13,915	11,553
Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,698	7,505
Harsco Metals & Minerals Segment
Disaggregation of Revenue [Line Items]
Total revenues	261,312	264,723
Harsco Metals & Minerals Segment | On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems
Disaggregation of Revenue [Line Items]
Total revenues	261,312	264,723
Harsco Metals & Minerals Segment | Railway track maintenance services and equipment
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Metals & Minerals Segment | Air-cooled heat exchangers
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Metals & Minerals Segment | Industrial grating and fencing products
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Metals & Minerals Segment | Heat transfer products
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Metals & Minerals Segment | General Corporate
Disaggregation of Revenue [Line Items]
Total revenues		0
Harsco Metals & Minerals Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	73,349	71,065
Harsco Metals & Minerals Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	98,221	96,921
Harsco Metals & Minerals Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	36,991	41,458
Harsco Metals & Minerals Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	34,138	36,221
Harsco Metals & Minerals Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	13,915	11,553
Harsco Metals & Minerals Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	4,698	7,505
Harsco Industrial Segment
Disaggregation of Revenue [Line Items]
Total revenues	117,385	83,598
Harsco Industrial Segment | On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Industrial Segment | Railway track maintenance services and equipment
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Industrial Segment | Air-cooled heat exchangers
Disaggregation of Revenue [Line Items]
Total revenues	76,203	44,267
Harsco Industrial Segment | Industrial grating and fencing products
Disaggregation of Revenue [Line Items]
Total revenues	33,376	30,097
Harsco Industrial Segment | Heat transfer products
Disaggregation of Revenue [Line Items]
Total revenues	7,806	9,234
Harsco Industrial Segment | General Corporate
Disaggregation of Revenue [Line Items]
Total revenues		0
Harsco Industrial Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	112,099	78,858
Harsco Industrial Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Industrial Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	5,286	4,740
Harsco Industrial Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Industrial Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Industrial Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Rail Segment
Disaggregation of Revenue [Line Items]
Total revenues	68,591	59,678
Harsco Rail Segment | On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Rail Segment | Railway track maintenance services and equipment
Disaggregation of Revenue [Line Items]
Total revenues	68,591	59,678
Harsco Rail Segment | Air-cooled heat exchangers
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Rail Segment | Industrial grating and fencing products
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Rail Segment | Heat transfer products
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Rail Segment | General Corporate
Disaggregation of Revenue [Line Items]
Total revenues		0
Harsco Rail Segment | North America
Disaggregation of Revenue [Line Items]
Total revenues	50,366	40,405
Harsco Rail Segment | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	10,013	14,720
Harsco Rail Segment | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	591	833
Harsco Rail Segment | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	7,621	3,720
Harsco Rail Segment | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Harsco Rail Segment | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate
Disaggregation of Revenue [Line Items]
Total revenues	0	39
Corporate | On-site services and material logistics, product quality improvement and resource recovery for iron, steel and metals manufacturing; value- added environmental solutions for industrial co-products; as well as aluminum dross and scrap processing systems
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Railway track maintenance services and equipment
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Air-cooled heat exchangers
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Industrial grating and fencing products
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Heat transfer products
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | General Corporate
Disaggregation of Revenue [Line Items]
Total revenues		39
Corporate | North America
Disaggregation of Revenue [Line Items]
Total revenues	0	39
Corporate | Western Europe
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Latin America
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Asia-Pacific
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Middle East and Africa
Disaggregation of Revenue [Line Items]
Total revenues	0	0
Corporate | Eastern Europe
Disaggregation of Revenue [Line Items]
Total revenues	$ 0	$ 0

Revenue Recognition - Contract

Revenue Recognition - Contract Assets and Advances on Contracts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Dec. 31, 2018
Contract assets:
Current portion of contract assets	$ 17,478	$ 24,254
Total contract assets	17,500	24,300
Advances on contracts:
Current portion of advances on contracts	37,014	31,317
Advances on contracts	27,478	37,675
Total advances on contracts	64,500	$ 69,000
Contract with Customer, Liability, Revenue Recognized	$ 21,500

Other (Income) Expenses, Net (D

Other (Income) Expenses, Net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Other Income and Expenses [Abstract]
Employee termination benefit costs	$ 2,598	$ 1,443
Net gains	(2,271)	0
Other costs to exit activities	1,165	364
Impaired asset write-downs	214	9
Contingent consideration adjustments	369	0
Other	(199)	6
Other expenses, net	$ 1,876	$ 1,822

Components of Accumulated Oth_3

Components of Accumulated Other Comprehensive Loss - Accumulated Other Comprehensive Income Loss (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019	Jan. 01, 2018
Components of Accumulated Other Comprehensive Income [Roll Forward]
Balances	$ 313,376	$ 215,165
Accumulated other comprehensive loss		0		$ (2,387)
Other comprehensive income (loss) before reclassifications	2,083	1,310
Amounts reclassified from accumulated other comprehensive loss	2,448	4,853
Total other comprehensive income	4,531	6,163
Other comprehensive income attributable to noncontrolling interests	(420)	(1,278)
Other comprehensive income (loss) attributable to Harsco Corporation	4,111	4,885
Balances	335,272	246,345
Cumulative Foreign Exchange Translation Adjustments
Components of Accumulated Other Comprehensive Income [Roll Forward]
Balances	(159,810)	(111,567)
Accumulated other comprehensive loss			$ 0
Other comprehensive income (loss) before reclassifications	11,725	12,501
Amounts reclassified from accumulated other comprehensive loss	(2,271)	0
Total other comprehensive income	9,454	12,501
Other comprehensive income attributable to noncontrolling interests	(420)	(1,278)
Other comprehensive income (loss) attributable to Harsco Corporation	9,034	11,223
Balances	(150,776)	(100,344)
Effective Portion of Deriviatives Designated as Hedging Instruments
Components of Accumulated Other Comprehensive Income [Roll Forward]
Balances	1,389	808
Accumulated other comprehensive loss			0
Other comprehensive income (loss) before reclassifications	(3,084)	2,768
Amounts reclassified from accumulated other comprehensive loss	(63)	(91)
Total other comprehensive income	(3,147)	2,677
Other comprehensive income attributable to noncontrolling interests	0	0
Other comprehensive income (loss) attributable to Harsco Corporation	(3,147)	2,677
Balances	(1,758)	1,965
Cumulative Unrecognized Actuarial Losses on Pension Obligations
Components of Accumulated Other Comprehensive Income [Roll Forward]
Balances	(408,655)	(435,840)
Accumulated other comprehensive loss			(21,429)
Other comprehensive income (loss) before reclassifications	(6,573)	(13,945)
Amounts reclassified from accumulated other comprehensive loss	4,782	4,944
Total other comprehensive income	(1,791)	(9,001)
Other comprehensive income attributable to noncontrolling interests	0	0
Other comprehensive income (loss) attributable to Harsco Corporation	(1,791)	(9,001)
Balances	(431,875)	(444,841)
Unrealized Loss on Marketable Securities
Components of Accumulated Other Comprehensive Income [Roll Forward]
Balances	(31)	17
Accumulated other comprehensive loss			0
Other comprehensive income (loss) before reclassifications	15	(14)
Amounts reclassified from accumulated other comprehensive loss	0	0
Total other comprehensive income	15	(14)
Other comprehensive income attributable to noncontrolling interests	0	0
Other comprehensive income (loss) attributable to Harsco Corporation	15	(14)
Balances	(16)	3
Accumulated Other Comprehensive Loss
Components of Accumulated Other Comprehensive Income [Roll Forward]
Balances	(567,107)	(546,582)
Accumulated other comprehensive loss		21,429	$ (21,429)	(1,520)
Total other comprehensive income	4,111	4,885
Balances	$ (584,425)	(543,217)
Accounting Standards Update 2014-09 | Accumulated Other Comprehensive Loss
Components of Accumulated Other Comprehensive Income [Roll Forward]
Accumulated other comprehensive loss		$ (1,520)
Accounting Standards Update 2014-09 | Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Components of Accumulated Other Comprehensive Income [Roll Forward]
Accumulated other comprehensive loss				$ (1,520)

Components of Accumulated Oth_4

Components of Accumulated Other Comprehensive Loss - Reclassification out of Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Realized upon Sale or Liquidation, before Tax	$ (2,271)	$ 0
Product revenues	447,288	408,038
Interest expense	9,739	9,583
Income from continuing operations before income taxes	27,704	28,295
Income tax expense (benefit)	4,855	8,266
Net income	22,537	19,577
Amount Reclassified from Accumulated Other Comprehensive Loss | Cumulative Unrecognized Actuarial Losses on Pension Obligations
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations before income taxes	5,124	5,269
Income tax expense (benefit)	(342)	(325)
Net income	4,782	4,944
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations before income taxes	(19)	59
Income tax expense (benefit)	(44)	(150)
Net income	(63)	(91)
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments | Foreign currency exchange forward contracts
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Product revenues	(32)	(212)
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments | Cross currency interest rate swaps
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	314	271
Amount Reclassified from Accumulated Other Comprehensive Loss | Effective Portion of Deriviatives Designated as Hedging Instruments | Interest rate swaps
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Interest expense	(301)	0
Amount Reclassified from Accumulated Other Comprehensive Loss | Actuarial losses
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income (expense)	5,058	5,142
Amount Reclassified from Accumulated Other Comprehensive Loss | Prior service costs (benefits)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income (expense)	66	(39)
Amount Reclassified from Accumulated Other Comprehensive Loss | Settlement/curtailment losses
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Defined benefit pension income (expense)	$ 0	$ 166

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - Scenario, Forecast $ in Millions	2 Months Ended
	Jun. 30, 2019USD ($)
Disposal Group, Held-for-sale, Not Discontinued Operations | Harsco Industrial Air-X-Changers Business
Subsequent Event [Line Items]
Selling price	$ 592
Clean Earth
Subsequent Event [Line Items]
Acquisition price	$ 625

Uncategorized Items - hsc-03312

Label	Element	Value
Retained Earnings [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 21,429,000
Cumulative Effect of New Accounting Principle in Period of Adoption	us-gaap_CumulativeEffectOfNewAccountingPrincipleInPeriodOfAdoption	$ 3,907,000