Calgon Carbon 10-K 1 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2017	Feb. 05, 2018	Jun. 30, 2017
Document and Entity Information
Entity Registrant Name	CALGON CARBON Corp
Entity Central Index Key	812,701
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 750,784,306.50
Entity Common Stock, Shares Outstanding		50,812,679
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME
Net sales	$ 619,811	$ 514,246	$ 535,004
Cost of products sold (excluding depreciation and amortization)	430,896	346,398	343,522
Depreciation and amortization	46,667	38,070	35,453
Selling, general and administrative expenses	98,806	99,815	84,810
Research and development expenses	5,416	5,441	6,425
Other operating income	(4,148)
Total costs and expenses	577,637	489,724	470,210
Income from operations	42,174	24,522	64,794
Interest income	49	99	58
Interest expense	(7,842)	(2,385)	(773)
Other income (expense) - net	(818)	(2,163)	(693)
Income before income tax provision	33,563	20,073	63,386
Income tax provision (Note 14)	12,462	6,276	19,923
Net income	21,101	13,797	43,463
Other comprehensive income (loss), net of tax (Note 12)
Foreign currency translation	27,989	(10,956)	(13,013)
Defined benefit pension plans	1,292	(1,899)	(116)
Derivatives	(1,323)	886	(991)
Total other comprehensive income (loss)	27,958	(11,969)	(14,120)
Total comprehensive income	$ 49,059	$ 1,828	$ 29,343
Net income per common share
Basic (in dollars per share)	$ 0.42	$ 0.27	$ 0.84
Diluted (in dollars per share)	0.42	0.27	0.82
Dividends per common share (in dollars per share)	$ 0.20	$ 0.20	$ 0.20
Weighted average shares outstanding
Basic (in shares)	50,470	50,259	51,902
Diluted (in shares)	50,546	51,023	52,709

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 42,328	$ 37,984
Receivables (net of allowance of $1,820 and $1,416)	133,465	108,056
Revenue recognized in excess of billings on uncompleted contracts	7,601	6,998
Inventories	121,647	125,115
Other current assets	16,154	13,437
Total current assets	321,195	291,590
Property, plant and equipment, net	399,510	366,442
Intangibles, net	44,066	40,543
Goodwill	77,773	66,316
Deferred income taxes	9,515	7,957
Other assets	2,525	2,370
Total assets	854,584	775,218
Current liabilities:
Accounts payable and accrued liabilities	92,852	74,493
Billings in excess of revenue recognized on uncompleted contracts	4,097	4,063
Payroll and benefits payable	20,097	15,458
Accrued income taxes	2,713	1,641
Current portion of long-term debt	5,000	5,000
Total current liabilities	124,759	100,655
Long-term debt	228,500	220,000
Deferred income taxes	17,584	25,624
Accrued pension and other liabilities	59,320	47,796
Total liabilities	430,163	394,075
Commitments and contingencies (Notes 15 and 16)
Stockholders' equity:
Common stock, $.01 par value, 100,000,000 shares authorized, 61,729,948 and 61,531,025 shares issued	617	615
Additional paid-in capital	190,534	185,791
Retained earnings	413,198	402,286
Treasury stock, at cost, 10,804,009 and 10,781,001 shares	(154,287)	(153,950)
Accumulated other comprehensive loss	(25,641)	(53,599)
Total stockholders' equity	424,421	381,143
Total liabilities and stockholders' equity	$ 854,584	$ 775,218

CONDENSED CONSOLIDATED BALANCE4

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
CONSOLIDATED BALANCE SHEETS
Receivables allowance (in dollars)	$ 1,820	$ 1,416
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	61,729,948	61,531,025
Treasury stock, shares	10,804,009	10,781,001

CONDENSED CONSOLIDATED STATEME5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net income	$ 21,101	$ 13,797	$ 43,463
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	46,667	38,070	35,453
Employee benefit plan provisions	4,084	4,376	2,044
Gain on sale of property, plant and equipment	(4,148)
Stock-based compensation	4,338	4,058	3,761
Deferred income tax (benefit) expense	(9,339)	(5,392)	6,782
Changes in assets and liabilities — net of effects from foreign exchange:
Receivables	(19,358)	(3,665)	(4,751)
Inventories	5,458	3,692	(14,805)
Revenue in excess of billings on uncompleted contracts and other current assets	(3,987)	5,302	53
Accounts payable and other accrued liabilities	16,018	11,247	1,112
Transition tax payable	6,780
Pension contributions	(2,925)	(2,426)	(3,056)
Other items - net	(98)	(87)	(175)
Net cash provided by operating activities	64,591	68,972	69,881
Cash flows from investing activities
Purchase of business - net of cash	(1,234)
Purchase of businesses - net of cash		(153,599)
Capital expenditures	(57,379)	(31,870)	(62,264)
Proceeds from sale of assets	5,106	1,234
Other investing	348
Net cash used in investing activities	(53,159)	(184,235)	(62,264)
Cash flows from financing activities
Japanese working capital loan borrowings — short-term			1,643
Japanese working capital loan repayments — short-term			(2,490)
Credit agreement borrowings — long-term	151,411	328,249	111,400
Credit agreement repayments — long-term	(142,920)	(210,650)	(70,400)
Repayment of Japanese term loan - long-term		(4,002)
Treasury stock purchased	(337)	(8,655)	(35,634)
Common stock dividends paid	(10,189)	(10,138)	(10,430)
Proceeds from the exercise of stock options	407	286	1,095
Other financing	(10,916)	5,709
Net cash (used in) provided by financing activities	(12,544)	100,799	(4,816)
Effect of exchange rate changes on cash and cash equivalents	5,456	(1,181)	(2,305)
Net increase (decrease) increase in cash and cash equivalents	4,344	(15,645)	496
Cash and cash equivalents, beginning of period	37,984	53,629	53,133
Cash and cash equivalents, end of period	$ 42,328	$ 37,984	$ 53,629

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total
Balance (Note 11) at Dec. 31, 2014	$ 612	$ 176,438	$ 365,594	$ (27,510)	$ (109,661)	$ 405,473
Balance (in shares) (Note 11) at Dec. 31, 2014	61,123,259				8,196,372
Increase (Decrease) in Stockholders' Equity
Net income			43,463			43,463
Other comprehensive income (loss), net of tax (Note 12)				(14,120)		(14,120)
Cash dividends			(10,430)			(10,430)
Employee and director stock plans	$ 1	5,238				5,239
Employee and director stock plans (in shares)	177,294
Share repurchase (Note 11)					$ (34,952)	(34,952)
Share repurchase (Note 11) (in shares)					2,002,444
Treasury stock purchased					$ (682)	(682)
Treasury stock purchased (in shares)					33,796
Balance (Note 11) at Dec. 31, 2015	$ 613	181,676	398,627	(41,630)	$ (145,295)	393,991
Balance (in shares) at Dec. 31, 2015	61,300,553				10,232,612
Increase (Decrease) in Stockholders' Equity
Net income			13,797			13,797
Other comprehensive income (loss), net of tax (Note 12)				(11,969)		(11,969)
Cash dividends			(10,138)			(10,138)
Employee and director stock plans	$ 2	4,115				4,117
Employee and director stock plans (in shares)	230,472
Share repurchase (Note 11)					$ (8,201)	(8,201)
Share repurchase (Note 11) (in shares)					518,576
Treasury stock purchased					$ (454)	(454)
Treasury stock purchased (in shares)					29,813
Balance (Note 11) at Dec. 31, 2016	$ 615	185,791	402,286	(53,599)	$ (153,950)	381,143
Balance (in shares) at Dec. 31, 2016	61,531,025				10,781,001
Increase (Decrease) in Stockholders' Equity
Net income			21,101			21,101
Other comprehensive income (loss), net of tax (Note 12)				27,958		27,958
Cash dividends			(10,189)			(10,189)
Employee and director stock plans	$ 2	4,743				4,745
Employee and director stock plans (in shares)	198,923
Treasury stock purchased					$ (337)	(337)
Treasury stock purchased (in shares)					23,008
Balance (Note 11) at Dec. 31, 2017	$ 617	$ 190,534	$ 413,198	$ (25,641)	$ (154,287)	$ 424,421
Balance (in shares) at Dec. 31, 2017	61,729,948				10,804,009

Summary of Accounting Policies

Summary of Accounting Policies	12 Months Ended
	Dec. 31, 2017
Summary of Accounting Policies
Summary of Accounting Policies	1. Summary of Accounting Policies Operations Calgon Carbon Corporation (the Company) is a global leader in innovative solutions, high quality products and reliable services designed to protect human health and the environment from harmful contaminants in water and air. As a leading manufacturer of activated carbon, with broad capabilities in ultraviolet light disinfection, the Company provides purification solutions for drinking water, wastewater, pollution abatement, and a variety of industrial and commercial manufacturing processes. The Company’s operations are principally conducted in three business segments: Activated Carbon, Alternative Materials, and Advanced Water Purification. Each of these segments includes the production, design and marketing of products and services specifically developed for the purification, separation and concentration of liquids and gases and other media. The Activated Carbon segment relies on activated carbon as a base material, while the Advanced Water Purification segment relies on a variety of methods and materials which involve other products. The Alternative Materials segment supplies diatomaceous earth and perlite filtration media for use in applications for decolorization, purification, decontamination, and filtration of liquids in various applications including food and beverage, industrial and pharmaceuticals; as well as activated carbon cloth for use in military, industrial, and medical applications. The Company’s largest markets are in the United States (U.S.), Europe, and Japan. The Company also has markets in Africa, Canada, China, India, Latin America, and in other parts of Asia. On November 2, 2016, the Company completed the acquisition of the wood-based activated carbon, reactivation, and mineral-based filtration media business of CECA, a subsidiary of Arkema Group (New Business). With the complementary New Business located in Europe, the Company became an even more global and diverse industry leader in activated carbon and reactivation, as well as filtration media in the form of diatomaceous earth and perlites. Refer to Notes 18 and 20 for additional information regarding the acquisition. On September 21, 2017, the Company entered into a definitive merger agreement under which a subsidiary of the Japanese chemical manufacturer Kuraray Co., Ltd. (Kuraray) agreed to acquire the Company, by way of a reverse triangular merger (Pending Merger). Following the consummation of the Pending Merger, the Company would become a wholly owned subsidiary of Kuraray. Refer to Note 21 for additional information regarding the Pending Merger. Principles of Consolidation The consolidated financial statements include the accounts of majority-owned and controlled subsidiaries. Investments in business entities in which the Company does not have control, but has the ability to exercise significant influence over the operating and financial policies, are accounted for under the equity method. All intercompany transactions and accounts have been eliminated in consolidation. Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Foreign Currency Substantially all assets and liabilities of the Company’s international operations are translated at year-end exchange rates; income and expenses are translated at average exchange rates prevailing during the year. Translation adjustments represent other comprehensive income or loss and are accumulated in a separate component of stockholders’ equity. Transaction gains and losses are included in other income (expense) — net. Revenue Recognition Revenue and related costs are recognized when goods are shipped or services are rendered to customers provided that ownership and risk of loss have passed to the customer, the price to the customer is fixed or determinable, persuasive evidence of an arrangement exists and collection is reasonably assured. Revenue for major equipment projects is recognized under the percentage of completion method. The Company’s major equipment projects generally have a long project life cycle from bid solicitation to project completion. The nature of the contracts are generally fixed price with milestone billings. The Company recognizes revenue for these projects based on the fixed sales prices multiplied by the percentage of completion. In applying the percentage of completion method, a project’s percent complete as of any balance sheet date is computed as the ratio of total costs incurred to date divided by the total estimated costs at completion. As changes in the estimates of total costs at completion and/or estimated total losses on projects are identified, appropriate earnings adjustments are recorded during the period that the change is identified. The Company has a history of making reasonably dependable estimates of costs at completion on contracts that follow the percentage of completion method; however, due to uncertainties inherent in the estimation process, it is possible that actual project costs at completion could vary from estimates. The principal components of costs include material, direct labor, subcontracts, and allocated indirect costs. Indirect costs primarily consist of administrative labor and associated operating expenses, which are allocated to the respective projects on actual hours charged to the project utilizing a standard hourly rate. Cash and Cash Equivalents The Company considers all highly liquid, short-term investments made with an original maturity of three months or less to be cash equivalents. From time to time, the Company could have cash deposited with financial institutions in excess of federally insured limits. As of December 31, 2017 and 2016, the Company had $3.8 million and $4.8 million, respectively, of cash deposits with U.S. financial institutions in excess of federally insured limits. The Company’s foreign subsidiaries held cash and cash equivalents of $33.1 million and $27.4 million as of December 31, 2017 and 2016, respectively. Generally, cash and cash equivalents held by foreign subsidiaries are not readily available for use in the U.S. without adverse tax consequences. Concentration of Credit Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents and customer receivables. The Company places its cash with financial institutions and invests in low-risk, highly liquid instruments. With respect to customer receivables, the Company believes that it has no significant concentration of credit risk as no single customer accounted for more than 10 percent of gross annual revenues as of December 31, 2017. The Company closely monitors the credit risk associated with its customers and to date has not experienced material losses. Allowance for Doubtful Accounts The Company maintains allowances for doubtful accounts for estimated losses resulting from the inability of its customers to make required payments. The amount of allowance recorded is primarily based upon a periodic review of specific customer transactions that remain outstanding at least three months beyond their respective due dates. Inventories Inventories are carried at the lower of cost or net realizable value. Inventory costs are primarily determined using the first-in, first-out (FIFO) method. Property, Plant and Equipment Property, plant and equipment is recorded at cost. Repair and maintenance costs are expensed as incurred. Depreciation for financial reporting purposes is computed on the straight-line method over the estimated service lives of the assets, which are from 15 to 30 years for land improvements and buildings, 5 to 15 years for furniture, machinery and equipment, 5 to 10 years for customer capital, 5 years for vehicles, and 5 to 10 years for computer hardware and software. Depletion is computed for mineral rights for the diatomite ore deposits using the units-of-production method and is included in the Company’s depreciation expense. Expenditures for new facilities and improvements that substantially extend the capacity or useful life of an asset are capitalized. Asset Retirement Obligations The Company has asset retirement obligations (AROs) related to reclamation obligations associated with the normal operation of the diatomite mining facilities. These AROs consist primarily of costs associated with mine reclamation and landfill closures. The fair values of these AROs are recorded on a discounted basis at the time the obligation is incurred, and accreted over time for the change in present value. Additionally, the Company capitalizes asset retirement costs by increasing the carrying amount of the related long-lived assets and depreciating these assets over the remaining life of the active mining facilities. Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of an acquired business over the fair value of the identifiable tangible and intangible assets acquired and liabilities assumed in a business combination. Identifiable intangible assets acquired in business combinations are recorded based on their fair values at the date of acquisition. In accordance with guidance within Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 350 “Intangibles - Goodwill and Other,” goodwill and identifiable intangible assets with indefinite lives are not subject to amortization but must be evaluated for impairment. The Company evaluates goodwill and indefinite-lived intangible assets for impairment annually, or when events occur or circumstances change that may reduce the fair value of the asset below its carrying amount. The Company has elected to perform the annual impairment test of its goodwill and indefinite-lived intangible assets, as required, on December 31 of each year by initially comparing the fair value of each of the Company’s reporting units or indefinite-lived assets to its related carrying value. If the carrying amount of the intangible asset exceeds its fair value, the Company recognizes an impairment loss in the amount of the excess. If the fair value of the reporting unit is less than its carrying value, the Company performs an additional step to determine the implied fair value of the goodwill. The implied fair value of goodwill is determined by first allocating the fair value of the reporting unit to all of the assets and liabilities of the unit and then computing the excess of the unit’s fair value over the amounts assigned to the assets and liabilities. If the carrying value of goodwill exceeds the implied fair value of goodwill, such excess represents the amount of goodwill impairment, and the Company recognizes such impairment accordingly. Fair values are estimated using discounted cash flows and other valuation methodologies that are based on projections of the amounts and timing of future revenues and cash flows, assumed discount rates and other assumptions as deemed appropriate. The Company also considers such factors as historical performance, anticipated market conditions, operating expense trends and capital expenditure requirements. The Company’s identifiable intangible assets other than goodwill and trade names and trademarks have finite lives. Certain of these intangible assets are amortized using an accelerated methodology, while the majority are amortized on a straight-line basis over their estimated useful lives. In addition, intangible assets with finite lives are evaluated for impairment whenever events or circumstances indicate that their carrying amount may not be recoverable, as prescribed by guidance within ASC 360 “Property, Plant, and Equipment.” Long-Lived Assets The Company evaluates long-lived assets under the provisions of ASC 360 “Property, Plant, and Equipment” which addresses financial accounting and reporting for the impairment of long-lived assets and for long-lived assets to be disposed of. For assets to be held and used, the Company groups a long-lived asset or assets with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. An impairment loss for an asset group reduces only the carrying amounts of a long-lived asset or assets of the group being evaluated. The loss is allocated to the long-lived assets of the group on a pro-rata basis using the relative carrying amounts of those assets, except that the loss allocated to an individual long-lived asset of the group does not reduce the carrying amount of that asset below its fair value whenever that fair value is determinable without undue cost and effort. Estimates of future cash flows to test the recoverability of a long-lived asset group include only the future cash flows that are directly associated with and that are expected to arise as a direct result of the use and eventual disposition of the asset group. The future cash flow estimates used by the Company exclude interest charges. Fair Value Fair value is defined as 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. 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 developed based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which gives 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 — Quoted prices (unadjusted) in active markets for identical assets or liabilities; · Level 2 — Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and · Level 3 — Unobservable inputs that reflect the reporting entity’s own assumptions. The Company’s financial instruments, excluding derivative instruments, consist primarily of cash and cash equivalents, short and long-term debt as well as accounts receivable and accounts payable. The fair value of accounts receivable and accounts payable approximates their carrying value because of the short-term maturity of the instruments. Derivative Instruments The Company applies ASC 815 “Derivatives and Hedging” which establishes accounting and reporting standards for derivative instruments, including certain derivative instruments embedded in other contracts and for hedging activities. Derivative financial instruments are utilized by the Company to manage risk exposure to movements in foreign exchange rates, interest rates or the prices of natural gas. The Company enters into derivative financial instruments with high credit quality counterparties and diversifies its positions among such counterparties. In addition, various master netting arrangements are in place with counterparties to facilitate settlement of gains and losses on these contracts. The Company does not net its derivative positions by counterparty for purposes of balance sheet presentation and disclosure. Changes in the value of the derivative financial instruments are measured at the balance sheet date and recognized in current earnings or other comprehensive income depending on whether the derivative is designated as part of a hedge transaction and meets certain other criteria. The Company does not hold derivative financial instruments for trading purposes. Pensions The Company accounts for its pensions in accordance with ASC 715 “Compensation – Retirement Benefits.” Accounting for pensions involves estimating the cost of benefits to be provided well into the future and attributing that cost over the time period each employee works. To accomplish this, extensive use is made of assumptions about inflation, investment returns, mortality, turnover and discount rates. These assumptions are reviewed annually. In determining the expected return on plan assets, the Company evaluates long-term actual return information, the mix of investments that comprise plan assets and future estimates of long-term investment returns. The Company uses country specific mortality tables and updates them periodically as better information becomes available. In determining the discount rates for pension obligations, the Company evaluates long-term corporate bonds that receive one of the two highest ratings given by a recognized rating agency. Amortization of the actuarial net gain or loss as a result of experience differing from that assumed and from changes in assumptions is included as a component of net periodic pension cost for the year. The Company uses a 10% corridor such that if, as of the beginning of the year, the net gain or loss exceeds 10% of the greater of the projected benefit obligation or the market-related value of plan assets, the amortization is that excess divided by the average future working lifetime of participating employees expected to receive benefits under the plan or the average remaining life expectancy of the plan’s participants if the percentage of actives is less than 10% of the total population. As only the excess actuarial gain or loss is amortized, this approach will not fully amortize the net actuarial gain or loss. Stock-Based Compensation The Company applies ASC 718 “Compensation — Stock Compensation” and accordingly records compensation expense for stock options over the vesting period using the fair value on the date of grant, as calculated by the Company using the Black-Scholes model. For time vested restricted stock awards, the nonvested restricted stock grant date fair value, which is the market price of the underlying common stock, is expensed over the vesting period. For certain performance based stock awards that vest subject to a market condition, the initial grant date fair value is determined using a Monte Carlo simulation model and is expensed on a straight-line basis over the performance period. For certain performance based stock awards that vest subject to a performance condition, the initial grant date fair value is the market price of the underlying common stock. This fair value is expensed on a straight-line basis over the performance period when it is probable that the performance condition will be achieved. The Company’s stock-based compensation plans are more fully described in Note 10. Net Income per Common Share Basic net income per common share is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per common share is computed by dividing net income by the weighted average number of common shares outstanding plus all potentially dilutive common shares outstanding during the period. Potentially dilutive common shares are determined using the treasury stock method. Under the treasury stock method, the Company’s stock-based compensation awards are treated as if they had been exercised, with any proceeds used to repurchase common stock at the average market price during the period. Any incremental difference between the assumed number of shares issued and purchased is included in the diluted share computation. For the Company’s performance based stock awards, their contingent features result in an assessment for any potentially dilutive common stock by using the end of the reporting period as if it were the end of the contingency period for all awards granted. Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the book and tax basis of assets and liabilities based upon enacted tax rates. If it is more likely than not that some portion or all of a deferred tax asset will not be realized, a valuation allowance is recognized. The Company assesses its ability to realize deferred tax assets based on normalized historical performance and on projections of future taxable income in the relevant tax jurisdictions. Normalized historical performance for purposes of this assessment includes adjustments for those income and expense items that are unusual and non-recurring in nature and are not expected to affect results in future periods. Such unusual and non-recurring items include the effects of legal fees or settlements associated with specific litigation matters, acquisition and restructuring costs. The Company’s projections of future taxable income consider known events, such as the passage of legislation or expected occurrences, and do not reflect a general growth assumption. The Company’s estimates of future taxable income are reviewed annually or whenever events or changes in circumstances indicate that such projections should be modified. The Company utilizes guidance within ASC 740 “Income Taxes” regarding the accounting for uncertainty in income taxes. This guidance prescribes recognition and measurement standards for a tax position taken or expected to be taken in a tax return. According to this guidance, the evaluation of a tax position is a two step process. The first step is the determination of whether a tax position should be recognized in the financial statements. The benefit of a tax position taken or expected to be taken in a tax return is to be recognized only if the Company determines that it is more likely than not that the tax position will be sustained upon examination by the tax authorities based upon the technical merits of the position. In step two, for those tax positions which should be recognized, the measurement of a tax position is determined as being the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. Except for the estimated U.S. transition tax, no provision is made for U.S. income taxes on the undistributed earnings of non-U.S. subsidiaries because these earnings are intended to be indefinitely reinvested outside the U.S. These earnings would become subject to additional income tax if they were remitted as dividends, were loaned to the Company or a U.S. affiliate, or if the Company were to sell its ownership interest in the subsidiaries. Refer to Note 14 for additional information on the estimated U.S. transition tax. Leases The Company leases certain facilities, equipment and vehicles. Certain of the Company’s leases contain renewal options, rent escalation clauses and landlord incentives. Renewal terms generally reflect market rates at the time of renewal. Rent expense for noncancelable operating leases with scheduled rent increases or landlord incentives is recognized on a straight-line basis over the lease term, including any applicable rent holidays, beginning with the lease commencement date. The excess of straight-line rent expense over scheduled payment amounts and landlord incentives is recorded as a deferred liability. Contingencies The Company from time to time is subject to various legal proceedings, lawsuits and claims, including employment, product warranty and environmental matters of the nature considered normal to its business. It is the Company’s policy to accrue for amounts related to legal matters when it is probable that a liability has been incurred and the loss amount is reasonably estimable. Estimates are developed through consultation with legal counsel involved in the defense and are based upon an analysis of probable results, assuming a combination of litigation and settlement strategies. Legal fees associated with defending these various lawsuits and claims are expensed when incurred. Government Grants The Company’s policy for accounting for government grants, including non-monetary grants at fair value, is to recognize them only when there is reasonable assurance that (a) the Company will comply with the conditions attached to the grants and (b) the grants will be received. A grant will be recognized over the period necessary to match it to the related costs, for which it is intended to compensate, on a systematic basis. A grant related to assets is presented by deducting it from the asset’s depreciation expense and is reported within cash flows from investing activities. A grant related to income will be deducted from the related expense and reported within cash flows from operating activities. Labor Agreements Collective bargaining agreements cover approximately 48% of the Company’s full-time labor force as of December 31, 2017 and expire at various dates through 2021. Approximately 3% of the Company’s labor force is operating under a contract that expired on December 31, 2017, which is in the process of being renegotiated. The Company has certain contracts with national labor organizations in the U.S. and Europe that expire in July and December 2018, respectively, affecting 4% and 25% of the Company’s labor force, respectively. New Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update (ASU) 2014-09, “Revenue (Topic 606): Revenue from Contracts with Customers”, as amended, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The core principle of ASU 2014-09 is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services by applying five steps listed in the guidance. ASU 2014-09 also requires disclosure of both quantitative and qualitative information that enables users of the financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from customers. The new revenue standard is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. The Company will adopt the new revenue standard effective January 1, 2018 using the modified retrospective method. The Company will recognize the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of retained earnings, for those contracts not completed as of the adoption date, however this effect is not expected to be material. While certain assets and liabilities will also change upon adoption of this standard, the changes are again not expected to be material. There will be no restatement of comparative prior year information, as those periods will continue to be reported under the accounting standards in effect for those periods. Prospectively, the Company does not expect that the adoption of the new revenue standard will have a material impact to the Company’s net income on an ongoing basis. For the majority of the Company’s revenue which consists of product sales, the Company does not anticipate a material change to result from the adoption of the new standard, as the revenue recognition will continue to be at a point in time. Approximately 6% of the Company’s consolidated net sales for the year ended December 31, 2017 were recognized on a percentage of completion basis. For some of these contracts, the new guidance will instead require revenue to be recognized at a point in time due to the nature of the product, which in some cases has an alternative use to the Company. In 2017, these sales are reported in both the Activated Carbon and Advanced Water Purification reportable segments. In July 2015, the FASB issued Accounting Standards Update 2015-11, “Simplifying the Measurement of Inventory” which requires entities to measure most inventory at the lower of cost and net realizable value. This simplifies the current guidance under which an entity measures inventory at the lower of cost or market. Market in this context is defined as one of three different measures, one of which is net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The Company adopted this ASU on a prospective basis as of January 1, 2017 and it did not have a material impact on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” which introduces a lessee model that brings most leases on the balance sheet, requiring lessees to recognize the right to use assets and lease obligations that arise from lease arrangements exceeding a twelve month term. Lessees will also need to disclose qualitative and quantitative information about lease transactions, such as information about variable lease payments and options to renew and terminate leases. For income statement purposes, the FASB retained a dual model, requiring leases to be classified as either operating or finance. Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright lines. Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model and the new revenue recognition standard. The new guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. Entities are required to use a modified retrospective transition for existing leases. The Company is evaluating the provisions of this ASU and assessing the impact it may have on the Company’s consolidated financial statements and related disclosures. At a minimum, total assets and total liabilities will increase in the period the ASU is adopted. As of December 31, 2017, the Company’s undiscounted future minimum payments outstanding for lease obligations were approximately $41 million. In March 2016, the FASB issued ASU 2016-09, “Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting” which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. The Company adopted the provisions of this ASU effective January 1, 2017 and it did not have a material impact on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” which adds a Current Expected Credit Loss (CECL) model that is based on expected losses rather than incurred losses, which is applicable to trade receivables. The new guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods. Entities are required to use the modified retrospective approach. The Company is evaluating the provisions of this ASU and assessing the impact it may have on the Company’s consolidated financial statements and related disclosures. In August and November 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” and ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash” to add or clarify guidance on the classification of certain cash receipts and payments and restricted cash in the statement of cash flows. Entities must apply the guidance retrospectively to all periods presented, but may apply it prospectively from the earliest date practicable if retrospective application would be impracticable. The Company is planning to adopt the provisions of this ASU, effective January 1, 2018. The adoption of this ASU is not expected to have a material impact on the Company’s consolidated financial statements. In March 2017, the FASB issued ASU 2017-07, “Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” which requires that employers disclose components of their pension service cost in the same line item as other compensation costs related to relevant employees. The ASU also

Inventories

Inventories	12 Months Ended
	Dec. 31, 2017
Inventories
Inventories	2. Inventories December 31 2017 2016 Raw materials $ 29,940 $ 24,831 Finished goods 91,707 100,284 Total $ 121,647 $ 125,115 Inventories are recorded net of reserves of $2.8 million and $2.6 million for obsolete and slow-moving items as of December 31, 2017 and 2016, respectively.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment
Property, Plant and Equipment	3. Property, Plant and Equipment December 31 2017 2016 Land and improvements $ 39,679 $ 37,479 Mineral rights 11,424 11,240 Buildings 96,694 90,385 Machinery, equipment and customer capital 524,162 494,722 Computer hardware and software 45,499 43,631 Furniture and vehicles 12,189 10,893 Construction-in-progress 61,459 30,525 791,106 718,875 Less accumulated depreciation (391,596) (352,433) Property, plant and equipment, net $ 399,510 $ 366,442 Depreciation expense for the years ended December 31, 2017, 2016, and 2015 totaled $44.4 million, $36.3 million, and $33.7 million, respectively. In 2017, the Company sold an idled plant in the United Kingdom (UK) and recorded a $4.1 million gain in earnings, within other operating income. Proceeds from the sale of assets of $4.7 million was reflected on the consolidated statements of cash flows. The Company's AROs are for legal obligations associated with the normal operations of the diatomite mining facilities up to the end of the quarries’ exploration. These AROs consist primarily of costs associated with mine reclamation and landfill closures related to the mineral rights. As of December 31, 2017 and 2016, the $2.8 million and $1.8 million liabilities were recorded as components of accrued pension and other liabilities.

Goodwill and Other Identifiable

Goodwill and Other Identifiable Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Identifiable Intangible Assets
Goodwill and Other Identifiable Intangible Assets	4. Goodwill and Other Identifiable Intangible Assets The Company has elected to perform the annual impairment test of its goodwill and indefinite-lived intangible assets, as required, on December 31 of each year. For purposes of the test, the Company has identified five reporting units as defined within ASC 350 “Intangibles – Goodwill and Other” and has allocated goodwill to these reporting units accordingly. These reporting units include (a) Activated Carbon segment, the Advanced Water Purification segment which includes (b) ultraviolet light and (c) ion exchange separation technologies, and the Alternative Materials segment which includes the (d) filtration media and (e) cloth reporting units. Goodwill and the changes in the carrying amount of goodwill by segment for the years ended December 31, 2017 and 2016 are as follows: Activated Alternative Advanced Carbon Materials Water Purification Segment Segment Segment Total Balance as of January 1, 2016 $ 19,604 $ 60 $ 6,113 $ 25,777 Goodwill acquired (Note 20) 26,415 16,429 — 42,844 Foreign currency translation (1,673) (679) 47 (2,305) Balance as of December 31, 2016 44,346 15,810 6,160 66,316 Measurement period adjustments 2,788 2,085 — 4,873 Foreign currency translation 4,054 2,427 103 6,584 Balance as of December 31, 2017 $ 51,188 $ 20,322 $ 6,263 $ 77,773 The following is a summary of the Company’s identifiable intangible assets as of December 31, 2017 and 2016, respectively: December 31, 2017 Weighted Average Gross Net Amortization Carrying Foreign Accumulated Carrying Period Amount Exchange Amortization Amount Amortized intangible assets : Customer relationships 18.9 Years $ 25,584 $ 1,250 $ (9,859) $ 16,975 Product certification 8.4 Years 8,453 (89) (4,427) 3,937 Unpatented technology 20.0 Years 14,174 1,273 (839) 14,608 Licenses 20.0 Years 964 (81) (394) 489 17.9 Years 49,175 2,353 (15,519) 36,009 Indefinite-lived intangible assets : Trade names and trademarks 7,362 695 — 8,057 Total $ 56,537 $ 3,048 $ (15,519) $ 44,066 December 31, 2016 Weighted Average Gross Net Amortization Carrying Foreign Accumulated Carrying Period Amount Exchange Amortization Amount Amortized intangible assets: Customer relationships 18.9 Years $ 25,035 $ (873) $ (8,900) $ 15,262 Product certification 7.4 Years 8,649 (90) (4,320) 4,239 Unpatented technology 20.0 Years 14,174 (586) (114) 13,474 Licenses 20.0 Years 964 (99) (354) 511 17.3 Years 48,822 (1,648) (13,688) 33,486 Indefinite-lived intangible assets: Trade names and trademarks 7,362 (305) — 7,057 Total $ 56,184 $ (1,953) $ (13,688) $ 40,543 For the years ended December 31, 2017, 2016 and 2015, the Company recognized $2.3 million, $1.8 million, and $1.7 million, respectively, of amortization expense related to intangible assets. The Company estimates amortization expense to be recognized during the next five years as follows: For the year ending December 31: 2018 $ 2,230 2019 2,477 2020 2,389 2021 2,344 2022 2,333

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements
Fair Value Measurements	5. Fair Value Measurements The following financial instrument assets (liabilities) are presented below at carrying amount, fair value, and classification within the fair value hierarchy (refer to Notes 6 and 8 for details relating to derivative instruments and borrowing arrangements). The only financial instruments measured at fair value on a recurring basis are derivative instruments and the acquisition earn-out liability: Fair Value December 31, 2017 December 31, 2016 Hierarchy Carrying Fair Carrying Fair Level Amount Value Amount Value Derivative assets 2 $ 560 $ 560 $ 1,168 $ 1,168 Derivative liabilities 2 (1,095) (1,095) (1,452) (1,452) Acquisition earn-out liability 2 — — (125) (125) Long-term debt, including current portion 2 (233,500) (233,500) (225,000) (225,000) Cash, accounts receivable and accounts payable included in the consolidated balance sheets approximate fair value and are excluded from the table above. The fair value of derivative assets and liabilities are measured based on inputs from market sources that aggregate data based upon market transactions. Fair value for the acquisition earn-out liability is based upon Level 2 inputs which are periodically re-evaluated for changes in future projections and the discount rate. This liability is recorded in accrued pension and other liabilities within the Company’s consolidated balance sheets. The Company’s debt bears interest based on market rates and, accordingly, the carrying value of this obligation approximates fair value.

Derivative Instruments

Derivative Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments
Derivative Instruments	6. Derivative Instruments The Company uses foreign currency forward exchange contracts and foreign exchange option contracts to limit the exposure of exchange rate fluctuations on certain foreign currency receivables, payables, and other known and forecasted transactional exposures for periods consistent with the expected cash flow of the underlying transactions. Management’s policy for managing risk is to use derivatives to hedge up to 75% of the value of the forecasted exposure. The foreign currency forward exchange contracts generally mature within eighteen months, while the natural gas contracts generally mature within twenty-four months. In May 2017, the Company entered into a $50.0 million interest rate swap contract (the Swap) with a 2023 termination date, to manage its exposure to its variable rate LIBOR-based borrowings. The Company accounts for its derivative instruments under ASC 815 “Derivatives and Hedging.” Hedge effectiveness is measured on a quarterly basis and any portion of ineffectiveness as well as hedge components excluded from the assessment of effectiveness are recorded directly to current earnings, in other income (expense) — net. The fair value of outstanding derivative contracts in the consolidated balance sheets was as follows: December 31 Asset Derivatives Balance Sheet Locations 2017 2016 Derivatives designated as hedging instruments: Foreign exchange contracts Other current assets $ 129 $ 670 Natural gas contracts Other current assets — 255 Foreign exchange contracts Other assets — 179 Natural gas contracts Other assets 1 43 Interest rate swap contract Other assets 121 — Derivatives not designated as hedging instruments: Foreign exchange contracts Other current assets 309 21 Total asset derivatives $ 560 $ 1,168 December 31 Liability Derivatives Balance Sheet Locations 2017 2016 Derivatives designated as hedging instruments: Foreign exchange contracts Accounts payable and accrued liabilities $ 639 $ 30 Natural gas contracts Accounts payable and accrued liabilities 143 — Foreign exchange contracts Accrued pension and other liabilities 52 1 Natural gas contracts Accrued pension and other liabilities 50 — Derivatives not designated as hedging instruments: Foreign exchange contracts Accounts payable and accrued liabilities 211 1,421 Total liability derivatives $ 1,095 $ 1,452 The Company had the following outstanding derivative contracts that were entered into to hedge forecasted transactions: December 31 (in thousands except for millions of British Thermal Units (mmbtu)) 2017 2016 2015 Natural gas contracts (mmbtu) 1,105,000 540,000 955,000 Foreign exchange contracts $ 75,006 $ 199,420 $ 37,016 Interest rate swap contract $ 50,000 $ — $ — The Company’s hedging associated with foreign exchange contracts increased significantly as of December 31, 2016 as a result of an intercompany loan relating to the acquisition of the New Business. The use of derivatives exposes the Company to the risk that a counterparty may default on a derivative contract. The Company enters into derivative financial instruments with high credit quality counterparties and diversifies its positions among such counterparties. The aggregate fair value of the Company’s derivative instruments in asset positions represents the maximum loss that the Company would recognize at that date if all counterparties failed to perform as contracted. The Company has entered into various master netting arrangements with counterparties to facilitate settlement of gains and losses on these contracts. These arrangements may allow for netting of exposures in the event of default or termination of the counterparty agreement due to breach of contract. The Company does not net its derivative positions by counterparty for purposes of balance sheet presentation and disclosure. December 31, 2017 December 31, 2016 Fair Value Fair Value Fair Value Fair Value of Assets of Liabilities of Assets of Liabilities Gross derivative amounts recognized in the balance sheet $ 560 $ 1,095 $ 1,168 $ 1,452 Gross derivative amounts not offset in the balance sheet (341) (341) (52) (52) Net amount $ 219 $ 754 $ 1,116 $ 1,400 Derivatives in Cash Flow Hedging Relationships For derivative instruments that are designated and qualify as cash flow hedges, the effective portion of the gain or loss on the derivative is reported as a component of other comprehensive income (loss) (OCI) and reclassified into earnings in the same period or periods during which the hedged transaction affects earnings. The location of the gain or (loss) reclassified into earnings (effective portion) for derivatives in cash flow hedging relationships is cost of products sold (excluding depreciation and amortization) except for the Swap, which is reclassified into earnings in interest expense. Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) Year Ended December 31 2017 2016 2015 Foreign exchange contracts $ (1,421) $ 399 $ 647 Natural gas contracts (467) 835 (984) Interest rate swap contract (190) — — Total $ (2,078) $ 1,234 $ (337) Amount of Gain or (Loss) Recognized from Accumulated OCI into Earnings (Effective Portion) (1) Year Ended December 31 2017 2016 2015 Foreign exchange contracts $ 102 $ 206 $ 2,077 Natural gas contracts 66 (339) (941) Interest rate swap contract (311) — — Total $ (143) $ (133) $ 1,136 (1) Assuming market rates remain constant with the rates as of December 31, 2017, a loss of $0.7 million is expected to be recognized in earnings over the next 12 months. During the years ended December 31, 2017, 2016, and 2015, there was no gain or (loss) recognized in earnings on derivatives related to the ineffective portion and the amount excluded from effectiveness testing. Derivatives Not Designated as Hedging Instruments The Company has also entered into certain derivatives to minimize its exposure of exchange rate fluctuations on certain foreign currency receivables, payables, and other known and forecasted transactional exposures. The Company has not qualified these contracts for hedge accounting treatment and therefore, the fair value gains and losses on these contracts are recorded in earnings, in other income (expense) — net as follows: Amount of Gain or (Loss) Recognized in Earnings on Derivatives Year Ended December 31 2017 2016 2015 Foreign exchange contracts $ (9,096) $ 4,425 $ (1,042) Total $ (9,096) $ 4,425 $ (1,042) For the years ended December 31, 2017 and 2016, non-designated contracts pertaining to an intercompany loan related to the acquisition of the New Business resulted in net losses of $9.6 million and a net gain of $4.4 million, respectively, which were offset by foreign exchange transaction gains of $10.3 million and losses of $5.0 million, respectively, both of which were recorded in earnings, within other income (expense) — net. The realized portion of this loss from the settlement of these contracts was reflected in other financing on the consolidated statements of cash flows.

Product Warranties

Product Warranties	12 Months Ended
	Dec. 31, 2017
Product Warranties
Product Warranties	7. Product Warranties The Company establishes a warranty reserve for equipment project sales and estimates the warranty accrual based on the history of warranty claims to total sales, adjusted for significant known claims in excess of established reserves. Warranty terms are based on the negotiated equipment project contract and typically are either 18 months from shipment date or 12 months from project startup date. The change in the warranty reserve, which is included in accounts payable and accrued liabilities in the consolidated balance sheets, is as follows: December 31 2017 2016 Balance as of January 1 $ 1,402 $ 1,252 Payments and replacement product (390) (1,495) Additions to warranty reserve for warranties issued during the period 618 1,647 Change in the warranty reserve for pre-existing warranties 6 (2) Balance as of December 31 $ 1,636 $ 1,402

Borrowing Arrangements

Borrowing Arrangements	12 Months Ended
	Dec. 31, 2017
Borrowing Arrangements
Borrowing Arrangements	8. Borrowing Arrangements December 31 2017 2016 Total long-term debt $ 233,500 $ 225,000 Less current portion of long-term debt (5,000) (5,000) Net long-term debt $ 228,500 $ 220,000 U.S. Credit Agreement On October 4, 2016, the Company entered into the First Amended and Restated Credit Agreement (Credit Agreement) which provides for total borrowing capacity of $400 million, comprised of a $300 million revolving credit facility (Revolver) that expires on October 4, 2021 and a $100 million term loan facility (Term Loan) that expires on October 4, 2023. The Revolver contains a $75 million sublimit for the issuance of letters of credit, and a $15 million sublimit for swing loans. The Company has the option to increase the Revolver by a maximum of $100 million with the consent of the Lenders. Availability under the Credit Agreement was conditioned upon various customary conditions. Upon entering into the Credit Agreement, the Company incurred issuance costs of $0.8 million of which approximately $0.1 million was expensed. The remainder of the issuance costs were deferred, and along with other previously deferred costs, are being amortized over the terms of the Revolver and Term Loan facilities. A quarterly nonrefundable commitment fee is payable by the Company based on the unused availability under the Revolver and was equal to 0.25% as of December 31, 2017. The interest rate on amounts owed under the Revolver and Term Loan will be, at the Company’s option, either (i) a fluctuating Base Rate or (ii) an adjusted LIBOR rate, plus, in each case, an applicable margin based on the Company’s leverage ratio as set forth in the Credit Agreement. The interest rate charged on amounts owed under swing loans will be either (i) a fluctuating Base Rate or (ii) such other interest rates as the lender and the Company may agree to from time to time. The interest rate per annum on outstanding borrowings ranged from 3.37% to 3.62% as of December 31, 2017. The Company borrowed the full $100 million under the Term Loan on October 4, 2016. During the fourth quarter of 2016, the Company borrowed $160 million under the Revolver to finance the acquisition of the New Business. Required quarterly repayments under the Term Loan began January 1, 2017, and are equal to 1.25% of the original outstanding balance of the Term Loan until January 1, 2019, at which time the quarterly repayments will increase to 2.0% until the remaining balance is due on the October 4, 2023 maturity date. As a result, $5.0 million is shown as the current portion of long-term debt within the consolidated balance sheets as of both December 31, 2017 and 2016. Total outstanding borrowings under the Revolver as of December 31, 2017 and 2016 were $138.5 million and $125.0 million respectively. Total availability under the Revolver as of December 31, 2017 and 2016 was $159.2 million and $172.5 million, respectively, after considering borrowings and outstanding letters of credit of $2.3 million and $2.5 million as of December 31, 2017 and 2016, respectively. Total outstanding borrowings under the Term Loan were $95.0 million and $100.0 million as of as of December 31, 2017 and 2016, respectively. There is no remaining availability under the Term Loan. Borrowings and repayments are presented on a gross basis within the Company’s consolidated statement of cash flows. Certain domestic subsidiaries of the Company unconditionally guarantee all indebtedness and obligations related to borrowings under the Credit Agreement. The Company’s obligations under the Credit Agreement are unsecured. The Credit Agreement contains customary affirmative and negative covenants for credit facilities of this type. As of a result of an amendment signed in February 2017, the Company is permitted to pay annual dividends of up to $14 million, so long as the sum of availability under the Credit Agreement and the amount of U.S. cash on hand is at least $50 million. In addition, the Credit Agreement includes limitations on the Company and its subsidiaries with respect to indebtedness, additional liens, disposition of assets or subsidiaries, and transactions with affiliates. The Company must comply with certain financial covenants including a minimum interest coverage ratio and a maximum leverage ratio as defined within the Credit Agreement. The Company was in compliance with all such covenants as of December 31, 2017. The Credit Agreement also provides for customary events of default, including failure to pay principal or interest when due, breach of representations and warranties, certain insolvency or receivership events affecting the Company and its subsidiaries and a change in control of the Company. If an event of default occurs, the lenders would be under no further obligation to make loans or issue letters of credit. Upon the occurrence of certain events of default, all outstanding obligations of the Company automatically would become immediately due and payable, and other events of default would allow the agent to declare all or any portion of the outstanding obligations of the Company to be immediately due and payable. Japanese Credit Agreement In 2016, Calgon Carbon Japan (CCJ) entered into a 2.0 billion Japanese Yen unsecured revolving loan facility agreement (Japanese Credit Agreement) which was scheduled to expire on March 24, 2019. As of both December 31, 2017 and 2016, there were no amounts outstanding under the Japanese Credit Agreement. Total availability was 2.0 billion Japanese yen, or $17.8 million as of December 31, 2017. Borrowings and repayments are presented on a gross basis within the Company’s consolidated statements of cash flows. A quarterly nonrefundable commitment fee was payable by CCJ based on the unused availability under the Japanese Credit Agreement and was equal to 0.25% as of December 31, 2017. The Japanese Credit Agreement bore interest based on the Tokyo Interbank Offered Rate of interest, plus an applicable margin based on the Company’s leverage ratio as defined in the U.S. Credit Agreement. The interest rate averaged 2.06% and 1.31% per annum as of December 31, 2017 and 2016, respectively. The Company was jointly and severally liable as the guarantor of CCJ’s obligations under the Japanese Credit Agreement. CCJ could make voluntary prepayments of principal and interest after providing prior written notice and before the full amount then outstanding was due and payable on the March 24, 2019 expiration date. In January 2018, the Company canceled the Japanese Credit Agreement. Prior to March 31, 2016, CCJ maintained a Japanese Term Loan and Japanese Working Capital Loan. These agreements were terminated on March 31, 2016 in conjunction with the repayment of the $4.0 million balance then outstanding. These agreements were replaced by the Japanese Credit Agreement described above. Other Credit Facilities The Company also maintains smaller credit facilities denominated in the local currencies of the various countries in which it operates. These facilities totaled approximately $7 million and $6 million as of December 31, 2017 and 2016, respectively. There are no financial covenants related to these facilities and the Company had no outstanding borrowings under them as of either December 31, 2017 and 2016. Bank guarantees totaling $5.1 million and $3.5 million were issued as of December 31, 2017 and 2016, respectively. In addition, the Company had surety bonds outstanding of $1.1 million as of both December 31, 2017 and 2016. Maturities of Debt The Company intends to make principal payments on debt outstanding as of December 31, 2017 of $5.0 million in 2018, $8.0 million in 2019, $8.0 million in 2020, $146.5 million in 2021, and $8.0 million in 2022. Interest Expense The Company’s interest expense for the years ended December 31, 2017, 2016, and 2015 totaled $7.8 million, $2.4 million, and $0.8 million, respectively. These amounts are net of interest costs capitalized of $0.8 million, $0.3 million, and $0.4 million for the years ended December 31, 2017, 2016, and 2015, respectively.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Employee Benefit Plans
Employee Benefit Plans	9. Employee Benefit Plans The Company sponsors defined benefit pension plans covering certain union and non-union employees in the U.S. and Europe. As of December 31, 2017, all of the U.S. plans are closed to new hires. In addition, future benefit accruals are frozen for a number of the plans. The Company uses a measurement date of December 31 for all of its pension plans. Some of the Company’s defined benefit plans allow for lump sum payments, which may trigger settlement accounting. The Company made lump sum payments from the U.S. and European plans totaling $4.2 million, $5.2 million and $3.8 million during the years ended December 31, 2017, 2016, and 2015 respectively. As a result of these lump sum payments, the Company incurred settlement charges in the U.S. and European plans totaling $1.0 million, $1.5 million, and $0.8 million, during the years ended December 31, 2017, 2016, and 2015, respectively. For the U.S. plans, the Company has used the same mortality tables, RP-2014 and a modified version of the projection scale MP-2014 since 2014. For the European defined benefit plans, the Company utilizes country-specific mortality tables and has used the same tables for the majority of its European plans since 2014. In 2016, the Company updated the mortality tables used for the UK plans which did not cause a significant increase to the projected benefit obligations for those plans. For the European defined benefit plans, the Company utilizes country-specific mortality tables and has used the same tables for the majority of its European plans since 2014. In 2016, the Company updated the mortality tables used for the UK plans which did not cause a significant increase to the projected benefit obligations for those plans. The following table provides a reconciliation of changes in the plans’ benefit obligations and fair value of assets over the two-year period ended December 31, 2017 and the funded status as of December 31 for both years: U.S. Plans European Plans 2017 2016 2017 2016 Change in projected benefit obligations Projected benefit obligations as of January 1 $ 110,732 $ 108,938 $ 43,495 $ 39,201 Service cost 959 957 524 395 Interest cost 4,413 4,589 972 1,142 Employee contributions — — 72 73 Actuarial loss 7,796 4,293 593 7,018 Benefits paid (4,327) (4,094) (1,055) (1,527) Acquisition — — — 3,899 Plan amendments — — — (91) Settlement (2,021) (3,951) (2,173) (1,224) Foreign currency exchange rate changes — — 4,836 (5,391) Projected benefit obligations as of December 31 $ 117,552 $ 110,732 $ 47,264 $ 43,495 Change in plan assets Fair value of plan assets as of January 1 $ 88,240 $ 89,382 $ 27,936 $ 29,351 Actual return on plan assets 12,547 6,221 2,012 4,212 Employer contributions 838 682 2,087 1,744 Employee contributions — — 72 73 Benefits paid (4,327) (4,094) (1,055) (1,527) Settlement (2,021) (3,951) (2,173) (1,224) Foreign currency exchange rate changes — — 2,775 (4,693) Fair value of plan assets as of December 31 $ 95,277 $ 88,240 $ 31,654 $ 27,936 Funded status as of December 31 $ (22,275) $ (22,492) $ (15,610) $ (15,559) Amounts recognized in the balance sheets consist of: Noncurrent asset — Other assets $ — $ — $ 710 $ 141 Current liability — Payroll and benefits payable (82) (82) (630) (493) Noncurrent liability — Accrued pension and other liabilities (22,193) (22,410) (15,690) (15,207) Net amount recognized $ (22,275) $ (22,492) $ (15,610) $ (15,559) Amounts recognized in accumulated other comprehensive income consist of: Accumulated prior service cost $ — $ — $ (91) $ (91) Accumulated net actuarial loss 36,273 38,694 10,720 10,549 Net amount recognized, before tax effect $ 36,273 $ 38,694 $ 10,629 $ 10,458 The assumptions used to determine benefit obligations are shown in the following table: U.S. Plans European Plans Weighted average actuarial assumptions as of December 31: 2017 2016 2017 2016 Discount rate 3.63 % 4.09 % 2.02 % 2.11 % Rate of increase in compensation levels 3.00 % 3.00 % 2.95 % 2.87 % The following tables set forth the fair values of the Company’s pension plans assets as of December 31, 2017 and 2016: U.S. Plans Fair Value Measurements Fair Value Measurements as of December 31, 2017 as of December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and cash equivalents $ 2,984 $ — $ — $ 2,984 $ 4,414 $ — $ — $ 4,414 Equity securities Large cap 17,260 — — 17,260 16,528 — — 16,528 Small/mid cap 11,485 — — 11,485 9,584 — — 9,584 International equity (a) 7,927 — — 7,927 6,377 — — 6,377 Emerging markets (b) 6,190 — — 6,190 5,333 — — 5,333 Fixed income securities Corporate bonds (c) — 25,906 — 25,906 — 23,034 — 23,034 Government bonds (d) 690 14,370 — 15,060 561 13,785 — 14,346 International bonds (e) — 5,001 — 5,001 — 3,966 — 3,966 Commodities (f) 1,737 — — 1,737 2,051 — — 2,051 Real estate (g) 1,727 — — 1,727 2,607 — — 2,607 Total $ 50,000 $ 45,277 $ — $ 95,277 $ 47,455 $ 40,785 $ — $ 88,240 (a) This category consists of international equity securities from Europe, Australia and Southeast Asia. (b) This category invests in global emerging markets outside the U.S. The strategy targets broad diversification across various economic sectors in emerging economies. (c) This category invests primarily in investment grade corporate securities. (d) This category includes securities and mutual funds which invest in a diversified portfolio of longer duration bonds. The funds typically invest primarily in U.S. investment grade securities. (e) This includes securities and mutual funds which invest in a diversified portfolio of longer duration foreign bonds. (f) This fund invests in assets of commodity linked derivative instruments and fixed income securities. (g) This fund primarily invests in equity related securities of real estate companies and other real estate securities. A significant portion of the total assets are typically in foreign securities. European Plans Fair Value Measurements Fair Value Measurements as of December 31, 2017 as of December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and cash equivalents $ 2,833 $ — $ — $ 2,833 $ 2,005 $ — $ — $ 2,005 Equity securities M&G PP UK equity passive fund (a) 1,092 — — 1,092 950 — — 950 M&G PP overseas equity passive fund (b) 5,062 — — 5,062 4,291 — — 4,291 LGIM dynamic diversified fund (c) 2,672 — — 2,672 3,758 — — 3,758 W. Blair dynamic diversified allocation fund (d) 2,418 — — 2,418 1,160 — — 1,160 Fixed income securities Delta Lloyd fixed income (e) — — 738 738 — — 1,158 1,158 Corporate bonds (f) 548 — — 548 428 — — 428 Government bonds (g) 12,823 — — 12,823 10,582 — — 10,582 Real estate (h) 2,581 — — 2,581 2,796 — — 2,796 Insurance reserves (i) — — 887 887 — — 808 808 Total $ 30,029 $ — $ 1,625 $ 31,654 $ 25,970 $ — $ 1,966 $ 27,936 (a) This fund invests in the shares of UK companies. (b) This fund invests in overseas companies with fixed proportions representing each region’s economic importance. (c) This fund invests in a range of different asset classes, including equities, bonds, properties, commodities, listed infrastructure, private equity, and global real estate companies. (d) This fund utilizes a combination of traditional assets (equities, bonds, currencies, etc.), and investment strategies based on advanced derivative techniques. (e) This category invests in fixed income investments with Delta Lloyd. (f) This category invests primarily in investment grade corporate bonds, and other debt instruments, including higher yielding corporate bonds, government debt, convertible and preferred stocks, money market instruments and equities. (g) This category invests mainly in long-term gilts. (h) This category invests in commercial properties in the UK and is well diversified in the retail, office, and industrial sectors. (i) This category invests in individual insurance policies in the name of the individual plan members. The European plans’ Level 3 investments were valued using significant unobservable inputs. Inputs to these valuations include characteristics and quantitative data relating to the assets and reserves, investment and insurance policy cost, position size, liquidity, current financial condition of the company/insurer and other relevant market data. The following table sets forth changes in the fair value measurements for the years ended December 31, 2017 and 2016: Delta Lloyd Insurance Fixed Income Reserves Balance as of January 1, 2016 $ 1,864 $ 1,259 Purchases — 101 Sales/Maturities (668) (525) Foreign currency translation (38) (27) Balance as of December 31, 2016 $ 1,158 $ 808 Purchases — 95 Sales/Maturities (554) (129) Foreign currency translation 134 113 Balance as of December 31, 2017 $ 738 $ 887 The following table provides information on the plans’ projected benefit obligations, accumulated benefit obligations, and the fair value of plan assets: U.S. Plans European Plans December 31 December 31 2017 2016 2017 2016 The projected benefit obligation and accumulated benefit obligation for all defined benefit plans was as follows: Projected benefit obligation $ 117,552 $ 110,732 $ 47,264 $ 43,495 Accumulated benefit obligation 114,322 107,037 43,940 40,886 Fair value of plan assets 95,277 88,240 31,654 27,936 The aggregate projected benefit obligation and fair value of plan assets for plans with projected benefit obligations in excess of plan assets was as follows: Projected benefit obligation $ 117,552 $ 110,732 $ 33,896 $ 31,570 Fair value of plan assets 95,277 88,240 17,575 15,872 The aggregate accumulated benefit obligation and fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets was as follows: Accumulated benefit obligation $ 114,322 $ 107,037 $ 30,572 $ 28,962 Fair value of plan assets 95,277 88,240 17,575 15,872 Information about the expected cash flows by year for the pension plans follows: U.S. Plans European Plans Employer contributions 2018 $ 2,126 $ 1,950 Benefit payments 2018 $ 6,188 $ 1,429 2019 6,551 1,291 2020 6,791 1,433 2021 6,756 1,377 2022 7,933 1,645 2023 - 2027 36,611 10,311 For the European plans, the total benefit payments include both the Company’s share of the benefit cost and the participants’ share of the cost, which is funded by participant contributions to the plans. U.S. Plans European Plans Year Ended December 31 Year Ended December 31 Net periodic pension cost 2017 2016 2015 2017 2016 2015 Service cost $ 959 $ 957 $ 1,136 $ 524 $ 395 $ 288 Interest cost 4,413 4,589 4,499 972 1,142 1,250 Expected return on assets (5,855) (6,040) (7,070) (1,322) (1,416) (1,705) Amortization of prior service cost (credit) — — 15 (9) — — Net actuarial loss amortization 2,987 3,010 2,606 452 229 219 Settlement 537 1,149 607 426 361 199 Net periodic pension cost $ 3,041 $ 3,665 $ 1,793 $ 1,043 $ 711 $ 251 U.S. Plans European Plans Year Ended December 31 Year Ended December 31 Amounts recognized in 2017 2016 2015 2017 2016 2015 Current year actuarial gain (loss) $ (1,103) $ (4,112) $ (3,348) $ 98 $ (4,222) $ (984) Amortization of actuarial loss 2,987 3,010 2,606 452 229 219 Current year prior service credit — — — — 91 — Amortization of prior service cost (credit) — — 15 (9) — — Settlement 537 1,149 607 426 361 199 Foreign currency exchange — — — (1,138) 1,122 603 Total recognized in other comprehensive income (loss) $ 2,421 $ 47 $ (120) $ (171) $ (2,419) $ 37 Total recognized in net periodic pension cost and other comprehensive income (loss) $ (620) $ (3,618) $ (1,913) $ (1,214) $ (3,130) $ (214) U.S. Plans European Plans Amounts expected to be recognized in net periodic pension cost 2018 2018 Prior service credit $ — $ (10) Net actuarial loss 2,825 367 Total as of December 31 $ 2,825 $ 357 The assumptions used in the measurement of net periodic pension cost are shown in the following table: U.S. Plans European Plans December 31 December 31 Weighted average actuarial assumptions 2017 2016 2015 2017 2016 2015 Discount rate 4.09 % 4.38 % 4.01 % 2.11 % 2.97 % 3.00 % Expected annual return on plan assets 6.87 % 7.00 % 7.50 % 4.46 % 5.28 % 5.54 % Rate of increase in compensation levels 3.00 % 3.00 % 3.00 % 2.87 % 3.07 % 3.38 % The discount rates that the Company utilizes to determine pension obligations for its U.S. plans are based on a review of long-term corporate bonds that receive one of the two highest ratings given by a recognized rating agency. The expected rate of return on plan assets was determined by the Company based on a review of asset class return expectations, as well as long-term inflation assumptions. Projected returns are based on broad equity and bond indices that the Company uses to benchmark its actual asset portfolio performance. The Company also considered historical returns on asset classes and investment mix. The expected long-term return on the U.S. plans’ assets is based on an asset allocation assumption of approximately 40%-50% equity securities, 45%-55% fixed income securities, and 5% with other investments. The expected long-term return on the European plans’ assets is based on its targeted portfolio mix of approximately 25%-35% equity securities, 40%-50% fixed income securities and 20%-30% other investments. The Company also takes into account the effect on its projected returns from any reasonably likely changes in its asset portfolio when applicable. The Company’s investment strategy is to earn the highest possible long-term total rate of return while minimizing the associated risk to ensure the preservation of the plan assets for the provision of benefits to participants and their beneficiaries. This is accomplished by managing a diversified portfolio of fund styles, asset types, risk characteristics and investment holdings. Multi-Employer Pension Plan In addition to the aforementioned European plans, the Company participates in a multi-employer pension plan in Europe. This multi-employer plan almost entirely relates to former employees of operations it has divested. Benefits are distributed by the multi-employer plan. The multi-employer plan reduced benefits to entitled parties, and the local Labor Court concluded that an employer was required to compensate its pensioners for the shortfall if benefits had been reduced. As a result, the Company has a liability for the past shortfall to its former employees, including a cost of living adjustment on the amounts paid by the multi-employer plan. As of December 31, 2017 and 2016, the Company had a $1.1 million and a $0.9 million liability recorded as a component of payroll and benefits payable within its consolidated balance sheets for the past shortfall adjustments to its former employees, respectively. The Company cannot predict if future benefit payments to entitled parties to be made by the multi-employer plan will continue to be reduced. Defined Contribution Plans The Company sponsors a defined contribution plan for certain U.S. employees. The plan allows for employee contributions, and the Company can make fixed, matching and discretionary contributions to the plan on behalf of its employees. The Company also makes contributions to the United Steelworkers 401(k) Plan for certain eligible employees. Total expenses related to the defined contribution plans were $3.6 million, $3.8 million, and $3.1 million for the years ended December 31, 2017, 2016, and 2015, respectively.

Stock Compensation Plans

Stock Compensation Plans	12 Months Ended
	Dec. 31, 2017
Stock Compensation Plans
Stock Compensation Plans	10. Stock Compensation Plans In 2008, the Company adopted an equity incentive plan for eligible employees, service providers, and non-employee directors of the Company and its subsidiaries. Since that time, the Company has amended and restated the 2008 Equity Incentive Plan to among other things, increase the aggregate number of shares available for issuance to 7.6 million, and to extend the term of the plan. The plan includes a 1.5 million share fixed sub-limit for the granting of incentive stock options. The awards may be stock options, restricted stock, performance units or other stock-based awards. Stock options may be non-statutory or incentive. The exercise price for options and stock appreciation rights shall not be less than the fair market value on the date of grant, except if an incentive stock option is granted to a “10% employee,” as defined by the plan, then the option price may not be less than 110% of such fair market value. Options and stock appreciation rights may be exercisable commencing with the grant date, and are no longer exercisable after the expiration of seven or ten years from the grant date. The former Employee Stock Option Plan and the Non-Employee Directors’ Stock Option Plan (Prior Plans) were terminated and superseded by the 2008 Equity Incentive Plan. The Prior Plans had stock-based awards outstanding as of December 31, 2017 and 2016. The Prior Plans granted stock options and restricted stock to officers, directors and other key employees of the Company. The stock options were granted at the fair market value on the grant date, became exercisable no less than six months after granted, and, in general, expire ten years after the date of grant. Stock Options The following tables show a summary of the status and activity of stock options for the year ended December 31, 2017: Weighted- Weighted- Average Average Remaining Exercise Price Contractual Term Aggregate Employee stock options: Shares (per share) (in years) Intrinsic Value Outstanding as of January 1, 2017 1,666,802 $ 17.67 4.69 $ 1,993 Granted 540,466 14.37 Exercised (18,199) 14.28 Forfeited (5,174) 14.27 Expired (137,355) 19.19 Outstanding as of December 31, 2017 2,046,540 $ 16.74 4.37 $ 9,421 Vested and expected to vest as of December 31, 2017 2,046,540 $ 16.74 4.37 $ 9,421 Exercisable as of December 31, 2017 1,279,612 $ 18.21 3.49 $ 4,001 Weighted- Weighted- Average Average Remaining Exercise Price Contractual Term Aggregate Non-employee director stock options: Shares (per share) (in years) Intrinsic Value Outstanding as of January 1, 2017 17,565 $ 8.37 0.42 $ 154 Exercised (17,565) 8.37 Outstanding, vested and exercisable — $ — — $ — The following assumptions were used to calculate the fair values of employee stock option grants in each year: Year Ended December 31 2017 2016 2015 Weighted-average grant date fair value per stock option $ $ $ Expected dividend yield % % % Expected volatility % % % Risk-free interest rates % % % Expected lives of options years years years The expected dividend yield is based on the latest annualized dividend rate and the current market price of the underlying common stock at the date of grant. The expected volatility is based on the historical volatility of the Company’s stock and the implied volatility calculated from traded options on the Company’s stock. The risk-free interest rates are based on the U.S. Treasury strip rate for the expected life of the option. For the 2011 through 2017 grants of stock options, the Company used the simplified method for determining the expected life. This method was used since the Company granted stock options to a different population of its employees, and decreased the term from 10 to 7 years. As a result of these changes, the Company does not believe that the historical stock option exercise data provides a reasonable basis upon which to estimate the expected life for the 2011 through 2017 grants. The total grant date fair value of options vested during the years ended December 31, 2017, 2016, and 2015 was $3.19 per share, $3.75 per share, and $4.49 per share, or $1.5 million, $1.5 million, and $1.5 million, respectively. During the years ended December 31, 2017, 2016 and 2015, the total intrinsic value of stock options exercised (i.e., the difference between the market price at exercise and the price paid by the employee or non-employee directors to exercise the option) was $0.3 million, $0.2 million, and $0.4 million, respectively. The total amount of cash received from the exercise of options was $0.4 million, $0.3 million, and $1.1 million, for the years ended December 31, 2017, 2016, and 2015, respectively. Restricted and Performance Based Stock Awards The grant date fair value of time vested restricted stock awards is the market price of the underlying common stock and is expensed over the vesting period of three years. Performance stock awards, based on Return on Capital (ROC), vest subject to the satisfaction of this performance condition, at the end of a three-year performance period. The Company’s actual ROC for the performance period is compared to the target set, and the actual award payout is interpolated. The ROC award can vest at between zero and 200 percent of the target award. The grant date fair value of the ROC performance stock is the market price of the underlying common stock. The fair value is expensed on a straight-line basis over the performance period when it is probable that the performance condition will be achieved. No expense was recognized for these awards in 2017, 2016, or 2015 as it was not considered probable that the performance condition would be achieved. Performance stock awards, based on Total Stockholder Return (TSR), vest subject to the satisfaction of this market condition, at the end of a three-year performance period. The Company’s actual TSR for the performance period is compared to the results of its peer companies for the same period with the Company’s relative position in the group determined by percentile rank. The actual award payout is determined by multiplying the target award by the performance factor percentage based upon the Company’s percentile ranking and can vest at between zero and 200 percent of the target award. The initial grant date fair value of the TSR performance stock is determined using a Monte Carlo simulation model. The grant date fair value is expensed on a straight-line basis over the three-year performance period. The following table shows a summary of the status and activity of employee and non-employee directors’ non-vested stock awards for the year ended December 31, 2017: Weighted- Weighted- Weighted- Average ROC Average TSR Average Restricted Grant Date Performance Grant Date Performance Grant Date Stock Fair Value Stock Fair Value Stock Fair Value Awards (per share) Awards (a) (per share) Awards (a) (per share) Nonvested as of January 1, 2017 250,540 $ 17.02 79,948 $ 17.56 93,044 $ 15.09 Granted 170,226 14.25 33,158 14.37 42,469 11.22 Vested (113,285) 18.01 — — — — Forfeited (5,784) 15.16 (24,890) 20.54 (23,900) 21.39 Nonvested as of December 31, 2017 301,697 $ 15.12 88,216 $ 15.52 111,613 $ 12.27 (a) The number of shares shown for the performance stock awards is based on the target number of share awards. The weighted-average grant date fair value of restricted stock awards granted during the years ended December 31, 2017, 2016, and 2015 was $14.25 per share, $14.65 per share, and $21.06 per share or $2.4 million, $2.3 million, and $2.4 million, respectively. The total fair value of restricted stock awards vested during the years ended December 31, 2017, 2016, and 2015 was $2.0 million in each of the years. The weighted-average grant date fair value of ROC performance stock awards granted during the years ended December 31, 2017, 2016, and 2015 was $14.37 per share, $13.76 per share, and $20.74 per share, respectively or $0.5 million in each of the years. There were no ROC performance stock awards that vested during the years ended December 31, 2017, 2016, and 2015. The weighted-average grant date fair value of TSR performance stock awards granted during the years ended December 31, 2017, 2016, and 2015, was $11.22 per share, $9.66 per share, and $21.96 per share, respectively, or $0.5 million in each of the years. There were no TSR performance stock awards vested during the year ended December 31, 2017. The total fair value of TSR performance stock awards vested during the years ended 2016 and 2015 was $0.5 million and $0.2 million, respectively. The following significant assumptions were used for the TSR performance stock awards: Year Ended December 31 2017 2016 2015 Dividend yield % % % Expected volatility 30.4 % 26.8 % 25.9 % Risk-free interest rates 1.31 % 0.83 % 0.93 % Performance period 3 years 3 years 3 years Total Stock-Based Compensation Compensation expense related to all stock-based compensation totaled $4.3 million, $4.1 million, and $3.8 million for the years ended December 31, 2017, 2016, and 2015, respectively, and was recognized as a component of selling, general and administrative expense. The related income tax benefit was $1.6 million, $1.3 million, and $1.2 million for the years ended December 31, 2017, 2016, and 2015, respectively. As of December 31, 2017, there was $4.3 million of total future compensation cost related to non-vested share-based compensation arrangements and the weighted-average period over which this cost is expected to be recognized is approximately 1.6 years.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2017
Stockholders' Equity
Stockholders' Equity	11. Stockholders’ Equity In December 2013, the Company’s Board of Directors approved a share repurchase program with a total of $150 million of purchases authorized. In April 2016, the Company suspended the activities of the share repurchase program. During 2015, the Company repurchased 2,002,444 shares at an average price of $17.45 per share. During 2016, the Company repurchased 518,576 shares at an average price of $15.81 per share. The repurchases were funded from operating cash flows, cash on hand, and borrowings and the shares are held as treasury stock. The Company’s remaining authorization to repurchase its common stock is approximately $64.1 million.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss)	12. Accumulated Other Comprehensive Income (Loss) The changes in the components of accumulated other comprehensive income (loss), net of tax, are as follows: Total Foreign Defined Accumulated Currency Benefit Other Translation Pension Plan Comprehensive Adjustments Adjustments Derivatives Income (Loss) Balance as of December 31, 2014, net of tax $ 1,943 $ (30,358) $ 905 $ (27,510) Other comprehensive loss before reclassifications (13,013) (2,446) (199) (15,658) Amounts reclassified from other comprehensive income (loss) — 2,330 (792) 1,538 Net current period other comprehensive loss (13,013) (116) (991) (14,120) Balance as of December 31, 2015, net of tax (11,070) (30,474) (86) (41,630) Other comprehensive income (loss) before reclassifications (10,956) (4,879) 809 (15,026) Amounts reclassified from other comprehensive income (loss) — 2,980 77 3,057 Net current period other comprehensive income (loss) (10,956) (1,899) 886 (11,969) Balance as of December 31, 2016, net of tax (22,026) (32,373) 800 (53,599) Other comprehensive income (loss) before reclassifications 27,989 (1,537) (1,409) 25,043 Amounts reclassified from other comprehensive income (loss) — 2,829 86 2,915 Net current period other comprehensive income (loss) 27,989 1,292 (1,323) 27,958 Balance as of December 31, 2017, net of tax $ 5,963 $ (31,081) $ (523) $ (25,641) Amount Reclassified from Accumulated Other Details about Accumulated Comprehensive Income (Loss) (1) Affected Line Item in the Other Comprehensive Year Ended December 31 Statement where Income (Loss) Components 2017 2016 2015 Net Income is Presented Defined Benefit Pension Plan Adjustments: Prior service credit $ 9 $ — $ (15) (2) Actuarial losses (4,402) (4,749) (3,631) (2) (4,393) (4,749) (3,646) Total before tax 1,564 1,769 1,316 Tax benefit (2,829) (2,980) (2,330) Net of tax Derivatives: Foreign exchange contracts 102 206 2,077 Cost of products sold (excluding depreciation and amortization) Natural gas contracts 66 (339) (941) Cost of products sold (excluding depreciation and amortization) Interest rate swap contract (311) — — Interest expense (143) (133) 1,136 Total before tax 57 56 (344) Tax benefit (expense) (86) (77) 792 Net of tax Total reclassifications for the period $ (2,915) $ (3,057) $ (1,538) Net of tax (1) Amounts in parentheses indicate expenses. (2) These accumulated other comprehensive (loss) components are included in the computation of net periodic pension cost. Foreign currency translation adjustments exclude income tax for the earnings of the Company’s non-U.S. subsidiaries as management believes these earnings will be reinvested for an indefinite period of time. Determination of the amount of unrecognized deferred U.S. income tax liability on these unremitted earnings is not practicable. The income tax benefit associated with ASC 715 “Compensation — Retirement Benefits” included in accumulated other comprehensive loss was $16.7 million, $17.7 million and $17.1 million as of December 31, 2017, 2016, and 2015, respectively. The income tax (benefit) expense associated with the Company’s derivatives included in accumulated other comprehensive income (loss) was $(0.2) million, $0.4 million, and $(0.1) million as of December 31, 2017, 2016, and 2015, respectively. The following table contains the components of income tax expense (benefit) included in other comprehensive income (loss): Year Ended December 31 2017 2016 2015 Defined benefit pension plan $ 1,239 $ (647) $ 183 Derivatives (615) 519 (521)

Basic and Diluted Net Income pe

Basic and Diluted Net Income per Common Share	12 Months Ended
	Dec. 31, 2017
Basic and Diluted Net Income Per Common Share
Basic and Diluted Net Income Per Common Share	13. Basic and Diluted Net Income Per Common Share Computation of basic and diluted net income per common share is performed as follows: Year Ended December 31 (In thousands, except per share amounts) 2017 2016 2015 Net income available to common stockholders $ 21,101 $ 13,797 $ 43,463 Weighted average shares outstanding Basic 50,470 50,259 51,902 Effect of dilutive securities 76 764 807 Diluted 50,546 51,023 52,709 Basic net income per common share $ 0.42 $ 0.27 $ 0.84 Diluted net income per common share $ 0.42 $ 0.27 $ 0.82 For the years ended December 31, 2017, 2016 and 2015, there were 1.0 million, 1.2 million, and 0.8 million stock based compensation awards, respectively, that were excluded from the dilutive calculations as the effect would have been antidilutive.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Taxes
Income Taxes	14. Income Taxes The components of the provision for income taxes were as follows: Year Ended December 31 2017 2016 2015 Current Federal $ 15,799 $ 6,481 $ 5,967 State and local 1,505 523 577 Foreign 4,497 4,664 6,597 21,801 11,668 13,141 Deferred Federal (9,860) (1,795) 5,471 State and local 52 435 563 Foreign 469 (4,032) 748 (9,339) (5,392) 6,782 Provision for income taxes $ 12,462 $ 6,276 $ 19,923 On December 22, 2017, the Tax Cuts and Jobs Act of 2017 (the Act), also commonly referred to as “U.S. tax reform” was enacted. The Act reduces the U.S. federal corporate tax rate from 35% to 21%, requires companies to pay a one-time transition tax on earnings of certain foreign subsidiaries that were previously tax deferred, and creates new taxes on certain foreign earnings. On December 22, 2017, Staff Accounting Bulletin No. 118 (SAB 118) was issued to address the application of U.S. Generally Accepted Accounting Principles in situations when a registrant does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain income tax effects of the Act. As of December 31, 2017, in accordance with SAB 118, the Company has made a reasonable estimate of: (i) the one-time transition tax, and (ii) the effects on the Company’s existing deferred tax balances, but has not completed its full accounting for the tax effects of enactment of the Act. The Company anticipates U.S. regulatory agencies will issue further regulations during 2018, which may alter this estimate. The Company is continuing to analyze its earnings and profits in foreign jurisdictions and its deferred tax balances. In January 2018, the FASB released guidance on the accounting for tax on the global intangible low-taxed income (GILTI) provisions of the Act. The GILTI provisions impose a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations. The guidance indicates that either accounting for deferred taxes related to GILTI inclusions or to treating any taxes on GILTI inclusions as period cost are both acceptable methods, subject to an accounting policy election. The Company is still evaluating the GILTI provisions and has not yet elected an accounting policy for GILTI. The final determination of the tax effects of enactment of the Act will be completed within the measurement period of up to one year from the enactment date as permitted by SAB 118, and any adjustments to provisional amounts that are identified during the measurement period will be recorded in the reporting period in which the adjustment is determined. The Company recognized income tax expense of $0.6 million during the year ended December 31, 2017 associated with the Act’s items it could reasonably estimate. This expense reflects (i) a one-time net transition tax of $6.8 million, which the Company will elect to pay over an eight-year period on unremitted foreign earnings and profits, partially offset by (ii) the revaluation of its net deferred tax liability based on a U.S. federal tax rate of 21%. The Company is still analyzing the Act and refining its provisional amounts, which could potentially impact the measurement of its tax balances. As of December 31, 2017, the Company estimates that it will make tax payments on its estimated long-term transition tax payable of $0.5 million in the years 2018 through 2022, $1.0 million in 2023, $1.4 million in 2024, and $1.7 million in 2025. Income before income tax provision includes income generated by operations outside the U.S. of $12.0 million, $9.6 million, and $28.1 million for the years ended December 31, 2017, 2016, and 2015, respectively. The Company previously considered the earnings in its non-U.S. subsidiaries to be indefinitely reinvested and, accordingly, recorded no deferred income taxes. Prior to the Act’s transition tax, the Company had aggregate undistributed foreign earnings of $100.1 million. While the transition tax subjected $79.9 million of undistributed foreign earnings to tax, an actual repatriation from the non-U.S. subsidiaries could still be subject to additional foreign withholding taxes and U.S. state taxes. The Company is currently analyzing its global working capital and cash requirements and the potential tax liabilities attributable to a repatriation but has yet to determine whether it plans to change its prior assertion and repatriate earnings. Accordingly, the Company has not recorded any deferred taxes attributable to its investments in foreign subsidiaries. The Company will record the tax effects of any change in the prior assertion in the period that it completes its analysis and is able to make a reasonable estimate, and disclose any unrecognized deferred tax liability for temporary differences related to its foreign investments, if practicable. In 2017, the Company completed the incorporation of its former U.S. Belgium branch to a Belgium controlled foreign corporation, which was part of an overall single integrated plan of reorganization that included the Company’s acquisition of the New Business in November 2016. This resulted in the Company recognizing tax expense of $2.4 million in 2017. In 2016, the U.S. Internal Revenue Code Section 987 Treasury Regulations were finalized and the Company recognized a benefit of $0.5 million. In 2015, the Company completed a U.S. research and development tax credit study for the prior years 2012—2014, and the Company recognized a benefit of $1.4 million. The differences between the U.S. federal statutory tax rate and the Company’s effective income tax rate are as follows: Year Ended December 31 2017 2016 2015 U.S. federal statutory rate 35.0 % 35.0 % 35.0 % State income taxes, net of federal income tax benefit 1.9 2.9 1.8 Tax rate differential on foreign income (9.8) (6.5) (3.1) Permanent tax differences (1.3) 3.2 (1.6) Valuation allowance (1.2) 0.8 0.3 Tax statute expiration (0.3) (0.3) (0.6) Change in uncertain tax positions 0.1 0.4 0.1 Deferred tax benefit for Section 987 — (2.7) — Corporate restructuring 9.4 — — U.S. tax reform 1.8 — — Other — net 1.5 (1.5) (0.5) Effective income tax rate 37.1 % 31.3 % 31.4 % The Company has the following gross operating loss carryforwards and tax credit carryforwards as of December 31, 2017: Type Amount Expiration Date Foreign tax credits $ 13 State tax credits (1) 2,231 2023 - 2027; unlimited Operating loss carryforwards — federal 421 Operating loss carryforwards — state (2) 6,619 2018 - 2037 Operating loss carryforwards — foreign (3) 15,692 2022 - unlimited (1) Of the total state tax credit carryforwards, approximately 44% begin to expire in 2023. (2) Of the total state operating loss-carryforwards, approximately 98% expire in 2025 or later. (3) Of the total foreign tax operating loss carryforwards, approximately 80% have no expiration. The components of deferred taxes consist of the following: December 31 2017 2016 Deferred tax assets Net operating loss and credit carryforwards (1) (2) $ 6,191 $ 7,763 Accruals and other timing items 10,653 15,824 Inventories 8,730 11,181 Pensions 9,156 12,186 Valuation allowance (2,063) (2,510) Total deferred tax assets 32,667 44,444 Deferred tax liabilities Property, plant and equipment 25,850 45,300 Goodwill and other intangible assets 14,374 15,716 U.S. liability on foreign deferred taxes 512 1,095 Total deferred tax liabilities 40,736 62,111 Net deferred tax liability $ (8,069) $ (17,667) (1) Uncertain tax liabilities of approximately $0.1 million and $0.2 million partially offset the net operating losses and credit carryforwards in 2017 and 2016, respectively. (2) Net indirect benefits on uncertain tax liabilities of approximately $12 thousand and $72 thousand are included in the U.S. net operating loss and credit carryforwards in 2017 and 2016, respectively. A valuation allowance is established when it is more likely than not that a portion of the deferred tax assets will not be realized. The valuation allowance is adjusted based on the changing facts and circumstances, such as the expected expiration of an operating loss carryforward. The Company’s valuation allowance as of December 31, 2017 of $2.1 million pertains to an uncertainty related to the realization of foreign and state net operating loss carryforwards, U.S. passive foreign tax credits, and state tax credits. The Company’s valuation allowance as of December 31, 2016 of $2.5 million pertained to an uncertainty related to the realization of foreign net operating loss carryforwards, domestic capital loss carryforwards, U.S. passive foreign tax credits, and state tax credits. The Company has classified uncertain tax positions as non-current income tax liabilities unless the amount is expected to be paid within one year. The following is a reconciliation of the unrecognized income tax benefits: Year Ended December 31 2017 2016 2015 Balance as of January 1 $ 785 $ 778 $ 1,187 Gross increases for tax positions of current year 112 108 78 Lapse of statute of limitations (135) (101) (417) Settlement of uncertain tax positions — — (70) Balance as of December 31 $ 762 $ 785 $ 778 The Company recognizes accrued interest and penalties related to unrecognized tax benefits in income tax expense. In 2017, the Company accrued interest and penalties of approximately $41 thousand on prior year uncertain tax positions and reversed approximately $65 thousand of interest and penalties due to the expiration of the statute of limitations. In 2016, the Company accrued interest and penalties of approximately $23 thousand on prior year uncertain tax positions and reversed approximately $3 thousand of interest and penalties due to the expiration of the statute of limitations. As of both December 31, 2017 and 2016, the amount accrued for the payment of interest and penalties is approximately $0.3 million. Total uncertain tax positions recorded as a component of accrued pension and other liabilities within its consolidated balance sheets were approximately $0.9 million as of both December 31, 2017 and 2016. As of December 31, 2017 and 2016, approximately $0.7 million and $0.6 million, respectively, of unrecognized tax benefits would reduce the Company’s effective tax rate if recognized. At this time, the Company believes that it is reasonably possible that approximately $0.3 million of the estimated unrecognized tax benefits as of December 31, 2017 will be recognized within the next twelve months based on the expiration of statutory review periods all of which will impact the effective tax rate. As of December 31, 2017, the following tax years remain subject to examination for the major jurisdictions where the Company conducts business: Jurisdiction Years United States 2012 - 2017 Kentucky 2013 - 2017 Pennsylvania 2014 - 2017 Belgium 2014 - 2017 China 2014 - 2017 Germany 2014 - 2017 United Kingdom 2014 - 2017 Japan 2012, 2016, 2017 Singapore 2014 - 2017 France 2016 - 2017 Italy 2013 - 2017

Commitments

Commitments	12 Months Ended
	Dec. 31, 2017
Commitments
Commitments	15. Commitments The Company has entered into leases covering principally office, research and warehouse space, office equipment and vehicles. Future minimum rental payments required under all operating leases that have remaining non-cancelable lease terms in excess of one year are $8.6 million in 2018, $6.0 million in 2019, $4.1 million in 2020, $3.2 million in 2021, $3.0 million in 2022, and $16.5 million thereafter. Total rental expense on all operating leases was $9.7 million, $8.0 million, and $8.9 million for the years ended December 31, 2017, 2016, and 2015, respectively. The Company has unconditional purchase obligations for raw materials and information systems and services under long-term supply contracts. Future minimum purchase requirements under the terms of the aforementioned contracts are as follows: Due 2018 2019 2020 2021 2022 Thereafter Raw and other materials $ 821 $ 821 $ 821 $ 821 $ — $ — Information systems and services 2,245 705 15 — — — Total contractual cash obligations $ 3,066 $ 1,526 $ 836 $ 821 $ — $ — Total payments made for purchases under these supply contracts were as follows: December 31 2017 (1) 2016 2015 Raw and other materials $ 815 $ 21,178 $ 27,832 Information systems and services 2,291 1,384 1,871 Total payments $ 3,106 $ 22,562 $ 29,703 (1) Decline in 2017 was a result of lower unconditional purchase obligations as of December 31, 2017 having a remaining term in excess of one year.

Contingencies

Contingencies	12 Months Ended
	Dec. 31, 2017
Contingencies
Contingencies	16. Contingencies Waterlink In conjunction with the February 2004 purchase of substantially all of Waterlink Inc.’s (Waterlink) operating assets and the stock of Waterlink’s UK subsidiary, environmental studies were performed on Waterlink’s Columbus, Ohio property by environmental consulting firms that provided an identification and characterization of certain areas of contamination. In addition, these firms identified alternative methods of remediating the property and prepared cost evaluations of the various alternatives. The Company concluded from the information in the studies that a loss at this property was probable and recorded the liability. As of both December 31, 2017 and 2016, the balance recorded was $0.3 million as a component of accrued pension and other liabilities, respectively. The Company determined that additional site characterization work is needed to establish the next steps. The potential costs of further remediation activities cannot be reasonably estimated until the additional site characterization work is finished. The additional characterization work is in progress and is expected to be completed during 2018. Implementation and timing of further remediation activity, if necessary, will depend on acceptance by the Ohio Voluntary Action Program administrators. Liability estimates are based on an evaluation of, among other factors, currently available facts, existing technology, presently enacted laws and regulations, and the experience of experts in groundwater and soil remediation. It is possible that a further change in the estimate of this obligation will occur as remediation progresses. Carbon Imports General Anti-Dumping Background : In March 2006, the Company and another U.S. producer of activated carbon (collectively, the “Petitioners”) requested that the U.S. Department of Commerce (Commerce Department) investigate unfair pricing of certain thermally activated carbon imported from the People’s Republic of China (China). In 2007, the Commerce Department found that imports of the subject merchandise from China were being unfairly priced (or “dumped”). Following a finding by the U.S. International Trade Commission (ITC) that the domestic industry was injured by unfairly traded imports of activated carbon from China, the Commerce Department issued an anti-dumping order imposing tariffs on Chinese imports to offset the amount of the unfair pricing. The Commerce Department published the anti-dumping order in the Federal Register in April 2007, and all imports from China remain subject to it. Importers of subject activated carbon from China are required to make cash deposits of estimated anti-dumping duties at the time the goods are entered into the U.S. customs territory. Final assessment of duties and duty deposits are subject to revision based on annual retrospective reviews conducted by the Commerce Department. The Company is a domestic producer, exporter from China (through its wholly-owned subsidiary Calgon Carbon (Tianjin) Co., Ltd. (Calgon Carbon Tianjin)), and a U.S. importer of the activated carbon that is subject to the anti-dumping order. As such, the Company’s involvement in the Commerce Department’s proceedings is both as a domestic producer (a “petitioner”) and as a foreign exporter (a “respondent”). The Company’s role as an importer, which has in the past (and may in the future) required it to pay anti-dumping duties, results in a contingent liability related to the final amount of tariffs that are ultimately assessed on the imported product following the Commerce Department’s annual review of relevant shipments and calculation of the anti-dumping duties due. As a result of proceedings before the Commerce Department that concluded in September 2016, the Company is currently required to post a duty of $0.616 per pound when importing activated carbon from Calgon Carbon Tianjin into the U.S. The impact of the tariffs to the Company’s financial results was not material for the years ended December 31, 2017, 2016, and 2015. However, the Company’s ultimate assessment rate and future cash deposit rate on such imports could change, as a result of on-going proceedings before the Commerce Department. In February 2013, the ITC determined that the anti-dumping order on certain thermally activated carbon from China should remain in effect for an additional five years. As a result, the Commerce Department has continued to conduct annual reviews of sales made to the first unaffiliated U.S. customer, typically over the prior 12-month period. The Commerce Department will continue to perform reviews from February 2018 to February 2019, dependent upon an affirmative outcome of the Second Sunset Review, which will be initiated in February 2018. If, as a result of the Second Sunset Review, the anti-dumping order is revoked, then the annual Periods of Review (POR) will cease, and any duty deposits made by the Company during the POR then in effect would be refunded. These annual reviews can result in changes to the anti-dumping tariff rate (either increasing or reducing the rate) applicable to any foreign exporter. Revision of tariff rates has two effects. First, it will alter the actual amount of tariffs that U.S. Customs and Border Protection (Customs) will collect for the period reviewed, by either collecting additional duties, plus interest above those deposited with Customs by the U.S. importer at the time of entry or refunding a portion of the duties, plus interest deposited at the time of importation to reflect a decline in the margin of dumping. Second, the revised anti-dumping rate becomes the cash deposit rate applied to future entries, and can either increase or decrease the amount of duty deposits an importer will be required to post at the time of importation. Some PORs have been finalized and are not subject to further review or appeal. Below is a discussion of the relevant PORs. Period of Review III: In October, 2011, the Commerce Department published the final results of its third annual administrative review (POR III), which covers imports that entered the U.S. between April 1, 2009 and March 31, 2010. The Company’s ongoing duty deposit rate was adjusted to zero, and the Company recorded a receivable of $1.1 million reflecting expected refunds for duty deposits made during POR III. The Commerce Department’s final results were appealed, and the litigation over POR III finally concluded in June 2017, but did not impact the receivable that had been recorded by the Company. The Company received $0.8 million of the duty deposits made during POR III during the fourth quarter of 2017, with the remaining amount received in 2018. Period of Review VII: The Commerce Department announced the final results for its seventh administrative review (POR VII) in October 2015, covering imports that entered the U.S. between April 1, 2013 and March 31, 2014. The Commerce Department calculated anti-dumping margins for the mandatory respondents it examined ranging from $0.00 per pound to $0.476 per pound, and it calculated an anti-dumping margin of $0.476 per pound for the separate rate respondents, including Calgon Carbon Tianjin. In October 2015, appeals were commenced challenging the final results. In April 2017, the Court remanded the matter to the Commerce Department to reconsider certain aspects of the final results. On August 10, 2017, the Commerce Department filed with the Court its remand determination, which did not make any modifications to the anti-dumping margins calculated in the final results for POR VII. A decision from the Court is possible in early to mid-2018. Any revision to the final results is not expected to have a material impact on the Company’s financial results. Period of Review VIII: In September 2016, the Commerce Department announced the final margins for its eighth administrative review (POR VIII), which covers imports that entered the U.S. between April 1, 2014 and March 31, 2015. The final anti-dumping margins for the mandatory respondents ranged from $0.009 per pound to $0.797 per pound, while the separate rate respondents, including Calgon Carbon Tianjin, were assigned $0.616 per pound. In October 2016, appeals were commenced challenging the final results. In June 2017, the Court remanded the matter to the Commerce Department to allow it to reconsider certain issues identified by the Court in the litigation over POR VII. On September 5, 2017, the Commerce Department filed with the Court its remand redetermination, which did not make any modifications to the anti-dumping margins calculated in the final results for POR VIII. A decision from the Court is possible in early to mid-2018. Any revision to the final results is not expected to have a material impact on the Company’s financial results. Period of Review IX: In November 2017, the Commerce Department published its final results for its ninth administrative review (POR IX) of the anti-dumping duty order covering the period April 1, 2015 through March 31, 2016. The final anti-dumping duties range from $0.00 per pound to $0.10 per pound for the Chinese entities subject to review. Calgon Carbon Tianjin was not subject to review under POR IX. Because no interested party pursued a challenge of the Commerce Department’s final results for POR IX, the anti-dumping margins calculated by the Commerce Department in that segment are final and conclusive. Period of Review X: In April 2017, the Commerce Department published a notice allowing parties to request a tenth administrative review (POR X) of the anti-dumping duty order covering the period April 1, 2016 through March 31, 2017. The Commerce Department has selected the two largest Chinese exporters of activated carbon to the U.S. during the relevant period for mandatory examination. The Commerce Department is likely to issue the final results of the review in the fourth quarter of 2018. Big Sandy Plant In 2007, the Company received from the Environmental Protection Agency (EPA) Region 4 a report of a hazardous waste facility inspection performed by the EPA and the Kentucky Department of Environmental Protection (KYDEP) of the Company’s Big Sandy plant in Kentucky. Accompanying the report was a Notice of Violation alleging multiple violations of the Federal Resource Conservation and Recovery Act (RCRA) and corresponding EPA and KYDEP hazardous waste regulations as well as the Clean Water Act. The Company was required to conduct testing of the portion of stockpiled material dredged from onsite wastewater treatment lagoons that had not previously been tested in accordance with a pre-approved work plan and installed two ground water monitoring wells at the Company’s permitted solid waste landfill where some lagoon solids had previously been disposed. The landfill is considered a non-hazardous facility and regulated by the KYDEP. The testing of the stockpile material was completed and the results have been reviewed by the EPA. The Company received comments from the EPA including a request for a health and safety risk assessment similar to that which the Company performed on other materials from the lagoons. The Company has prepared this assessment and received a letter from the EPA in March 2017 indicating the EPA’s agreement with the Company’s conclusions. The stockpiled material was removed in 2015 and the Company will not be required to close or retrofit any of the wastewater treatment lagoons as RCRA hazardous waste management units and may continue to use them in their current manner. The Company has applied to the EPA for closure of this consent decree. As of December 31, 2017 and 2016, there is no liability recorded related to this issue. Calgon Carbon Japan (CCJ) On February 21, 2017, the Japan Fair Trade Commission (the JFTC) informed the Company’s subsidiary, CCJ that it is investigating CCJ along with several other manufacturers and distributors that participate in the activated carbon market in Japan over concerns of anti-competitive conduct. The JFTC is investigating whether manufacturers and sellers of activated carbon used in water purification plants, garbage incineration plants and other similar facilities in Japan have acted in concert with each other in violation of the Japan Anti-Monopoly Act. JFTC agents searched the offices of CCJ, reviewing and collecting contracts and other business records and interviewed certain CCJ employees. It remains difficult to predict the outcome of this matter or what remedies, if any, may be imposed by the JFTC. CCJ is cooperating with the JFTC as it conducts its investigation. Pending Merger Following the September 21, 2017 announcement of the Pending Merger with a subsidiary of Kuraray, putative class action lawsuits were filed. On November 2, 2017, a purported stockholder of the Company filed a putative class action against the Company and its Board of Directors, in the United States District Court for the District of Delaware, entitled Mitchell v. Calgon Carbon Corporation, et al., Case 1:17-cv-01572-MEM (Mitchell Lawsuit). Also on November 2, 2017, another purported stockholder of the Company filed a second putative class action against the Company, its Board of Directors, Kuraray, and certain of its subsidiaries, in the United States District Court for the Western District of Pennsylvania, entitled Assad v. Calgon Carbon Corporation, et al., Case 2:17-cv-01433-AJS (Assad Lawsuit). On November 8, 2017, a third purported stockholder filed a putative class action against the Company and its Board of Directors, in the United States District Court for the Western District of Pennsylvania, entitled Biederman v. Calgon Carbon Corporation, et al., Case 2:17-cv-01459-AJS (Biederman Lawsuit). The Mitchell Lawsuit, the Assad Lawsuit, and the Biederman Lawsuit (Merger Lawsuits) alleged violations of Sections 14(a) and 20(a) of the Exchange Act in connection with the proposed transaction. The complaints in the Merger Lawsuits alleged that the preliminary proxy statement on Schedule 14A filed by the Company with the Securities and Exchange Commission on October 27, 2017 omitted material information regarding the Company’s financial projections and the financial analysis conducted by Morgan Stanley in connection with its fairness opinion. The Merger Lawsuits sought class action certification and a variety of relief, including, among other things, to enjoin the merger, or, in the event the merger is consummated, rescission of the merger or an award of rescissory damages, plus attorneys’ fees and costs. The Company believes that the Merger Lawsuits are without merit and deny that any disclosures issued in connection with the proposed transaction omit material information or are materially false and misleading. In connection with the Merger Lawsuits and in order to moot plaintiffs’ unmeritorious claims and provide additional information to investors, the Company voluntarily supplemented certain information provided in the preliminary proxy statement with various disclosures contained in its definitive proxy statement, filed on November 28, 2017. On December 11, 2017, a plaintiff in the Mitchell Lawsuit dismissed the action with prejudice as to himself and without prejudice as to the putative class. The Assad Lawsuit and the Biederman Lawsuit were consolidated and recaptioned by the federal district court for the Western District of Pennsylvania as In re Calgon Carbon Corporation Shareholder Litigation, No. 2:17-cv-01433-AJS. On December 22, 2017, plaintiffs in this consolidated lawsuit dismissed the action with prejudice as to themselves and without prejudice as to the putative class. On December 14, 2017, the Company received a letter from a law firm representing purported stockholder Inter-Local Pension Fund GCC/IBT (Inter-Local Fund), demanding an inspection of the Company’s books and records pursuant to Section 220 of the Delaware General Corporation Law (Section 220). The demand letter stated that Inter-Local Fund seeks to investigate the events leading to the Pending Merger in order to determine whether to pursue litigation for breaches of fiduciary duty against all or some of the members of the Board of Directors and/or management or others. The Company rejected the demand. On December 22, 2017, Inter-Local Fund filed a lawsuit in the Delaware Court of Chancery, captioned as Inter-Local Pension Fund GCC/IBT v. Calgon Carbon Corp., C.A. No 2017-0910 (Section 220 Action), which seeks to compel an inspection of books and records pursuant to Section 220 purportedly so that the plaintiff may “determine whether wrongdoing or mismanagement has taken place such that it would be appropriate to file claims for breach of fiduciary duty, and to investigate the independence or disinterestedness of the Company’s directors … .” On January 16, 2018, the Company filed an answer to the Section 220 Action. The Company believes that the Section 220 Action is without merit and deny that plaintiff has a proper purpose for the inspection sought by the Section 220 demand letter. Other In addition to the matters described above, the Company is involved in various other legal proceedings, lawsuits and claims, including employment, product warranty and environmental matters of a nature considered normal to its business. It is the Company’s policy to accrue for amounts related to these legal matters when it is probable that a liability has been incurred and the loss amount is reasonably estimable. Management is currently unable to estimate the amount or range of reasonably possible losses, if any, resulting from such lawsuits and claims.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Information
Supplemental Cash Flow Information	17. Supplemental Cash Flow Information Cash paid for interest for the years ended December 31, 2017, 2016, and 2015 was $8.0 million, $2.6 million, and $1.1 million, respectively. Capitalized interest for the years ended December 31, 2017, 2016, and 2015 was $0.8 million, $0.3 million, and $0.4 million, respectively. Income taxes paid, net of refunds for the years ended December 31, 2017, 2016, and 2015 were $16.8 million, $9.5 million, and $13.9 million, respectively. The Company has reflected $3.9 million, $1.9 million, and $(0.1) million of its capital expenditures as a non-cash increase (decrease) in accounts payable and accrued liabilities for changes in unpaid capital expenditures for the years ended December 31, 2017, 2016, and 2015, respectively.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Information
Segment Information	18. Segment Information In conjunction with the acquisition of the New Business, management undertook a planning process which included reviewing how the Company compiles and reports financial information for review by the Company’s chief operating decision maker (CODM) to assess performance and allocate resources. Beginning January 1, 2017, the Company realigned its internal management reporting structure to incorporate the New Business into the existing business, and reorganized its current reportable segments. The realigned internal management reporting structure resulted in three new reportable segments for review by the CODM. Beginning January 1, 2017, the Company’s CODM, its chief executive officer, receives and reviews financial information in this format. The Company is reporting its results using the new reportable segment structure and has restated prior periods to conform to the change in reportable segments. Those segments are Activated Carbon, Alternative Materials, and Advanced Water Purification. The manufacturing and marketing of granular and powdered wood-based activated carbon and coal-based activated carbon reactivation portions of the New Business were combined with the existing Activated Carbon segment and renamed the Activated Carbon segment. In addition, sales of carbon adsorption equipment and associated costs previously reported in the Equipment segment were combined into the new Activated Carbon segment, as this activity is now aligned with the associated leasing of this same equipment. Diatomaceous earth and perlite filtration media sales and associated costs of the New Business are being reported in the newly created Alternative Materials segment, which also includes the carbon cloth sales and associated costs that were previously reported in the Consumer segment. The previously reported Equipment segment has been renamed the Advanced Water Purification segment, and now excludes any carbon related equipment sales. In addition, some product sales and services related to the ultraviolet light and advanced ion exchange separation technologies that were previously included in the Activated Carbon and Service segment are all now reported in the Advanced Water Purification segment. The Activated Carbon segment manufactures and markets granular and powdered activated carbon for use in applications to remove organic compounds from liquids, gases, water, and air. This segment also consists of activities related to activated carbon including reactivation of spent carbon and the sale or leasing of related equipment, and maintenance at customer sites. The Alternative Materials segment supplies diatomaceous earth and perlite filtration media for use in applications for decolorization, purification, decontamination, and filtration of liquids in various applications including food and beverage, industrial, and pharmaceuticals, as well as carbon cloth for use in military, industrial, and medical applications. The Advanced Water Purification segment provides solutions to customers’ water process problems through the design, fabrication, and operation of systems, as well as the sale of materials and services that utilize the Company’s enabling technologies: ultraviolet light and advanced ion exchange separation. Intersegment net sales are not material. The following segment information represents the results of operations: Year Ended December 31 2017 2016 2015 Net sales Activated Carbon $ 547,000 $ 476,771 $ 496,949 Alternative Materials 56,393 14,404 9,163 Advanced Water Purification 16,418 23,071 28,892 Consolidated net sales $ 619,811 $ 514,246 $ 535,004 Segment operating income (loss) Activated Carbon $ 47,052 $ 32,968 $ 65,398 Alternative Materials 403 (3,201) 1,421 Advanced Water Purification (4,788) (5,245) (2,025) 42,667 24,522 64,794 Reconciling items: Merger related expenses (4,641) — — Other operating income 4,148 — — Interest income 49 99 58 Interest expense (7,842) (2,385) (773) Other income (expense) — net (818) (2,163) (693) Income before income tax provision $ 33,563 $ 20,073 $ 63,386 Year Ended December 31 2017 2016 2015 Depreciation and amortization Activated Carbon $ 40,286 $ 35,507 $ 33,216 Alternative Materials 5,343 1,213 610 Advanced Water Purification 1,038 1,350 1,627 Depreciation and amortization $ 46,667 $ 38,070 $ 35,453 Expenditures for long-lived assets Activated Carbon $ 56,886 $ 32,046 $ 59,408 Alternative Materials 2,603 492 403 Advanced Water Purification 1,759 1,256 2,417 Total expenditures (1) $ 61,248 $ 33,794 $ 62,228 (1) Includes $7.9 million, $4.0 million and $2.1 million which are included in accounts payable and accrued liabilities at December 31, 2017, 2016 and 2015, respectively. Segment assets, which are reviewed by management, consist of the total of the net property, plant, and equipment, intangibles, and goodwill balances on the Company’s consolidated balance sheets as follows: December 31 2017 2016 Total assets Activated Carbon $ 432,154 $ 392,918 Alternative Materials 75,345 67,394 Advanced Water Purification 13,850 12,989 Segment assets 521,349 473,301 Unallocated assets 333,235 301,917 Total assets $ 854,584 $ 775,218 Year Ended December 31 2017 2016 2015 Net sales by product Carbon products $ 487,833 $ 432,718 $ 460,251 Filtration media products 49,016 5,709 — Capital equipment 41,133 34,349 35,114 Equipment leasing 14,426 14,041 15,235 Carbon cloth products 7,377 8,695 9,163 Spare parts 4,649 4,515 4,179 Other services 15,377 14,219 11,062 Total net sales $ 619,811 $ 514,246 $ 535,004 Geographic Information Year Ended December 31 2017 2016 2015 Net sales United States $ 291,058 $ 271,076 $ 288,645 France 42,698 23,646 20,875 United Kingdom 37,858 36,552 43,217 Germany 32,439 21,416 17,804 Japan 32,047 35,243 35,753 Italy 29,057 5,206 2,432 China 26,169 18,559 17,943 Canada 17,292 13,858 17,065 Belgium 10,359 9,373 10,383 Spain 9,336 3,812 3,302 Netherlands 8,557 5,696 5,184 South Korea 7,022 10,231 12,218 India 5,056 3,417 713 Switzerland 4,973 3,117 3,340 Sweden 3,975 3,027 3,077 Other 61,915 50,017 53,053 Total net sales (1) $ 619,811 $ 514,246 $ 535,004 (1) Net sales are attributable to countries based on location of customer. December 31 2017 2016 2015 Property, plant and equipment, net United States $ 239,354 $ 225,105 $ 228,057 France 65,473 52,650 — Belgium 52,185 46,648 47,921 China 12,536 12,482 13,779 United Kingdom 12,452 12,586 15,849 Italy 12,389 11,624 — Japan 5,011 5,207 5,255 Singapore 57 74 65 Denmark 33 41 53 Brazil 11 14 14 Canada 9 11 24 Germany — — 2 Total property, plant and equipment, net $ 399,510 $ 366,442 $ 311,019

Government Grants

Government Grants	12 Months Ended
	Dec. 31, 2017
Government Grants
Government Grants	19. Government Grants In 2014, the Company received an incentive of 3.86 million Renminbi (RMB) or approximately $0.6 million from the Suzhou Wuzhong Economic Development Zone (WEDZ), where the Company’s Suzhou, China facility is located. This incentive was provided based on the Company’s commitment to the construction of carbon reactivation lines in two phases. In 2016, the Company received an incentive of 3.86 million RMB or approximately $0.6 million from the JiangSu Provincial Bureau based on the same Company commitment. For the years ended December 31, 2017, 2016 and 2015, the Company did not recognize income for these incentives as all required documentation had not yet been completed. As of December 31, 2017 and 2016, the Company had a $0.9 million and $0.8 million liability recorded as a component of accrued pension and other liabilities within its consolidated balance sheets for the unearned portion of the incentives. In September 2016, the Company entered into an agreement with a U.S. government agency to manufacture activated carbon products used in military personal protection equipment and collective protection equipment at another of the Company’s manufacturing plants to assure uninterrupted supply of the critical military materials. As part of this agreement, the Company will be reimbursed for approved capital improvements made in conjunction with the federal award up to $15.4 million. As of December 31, 2017, the Company has received funds of $0.3 million, which was recorded as a component of accrued pension and other liabilities within the consolidated balance sheets.

Acquisition of the New Business

Acquisition of the New Business	12 Months Ended
	Dec. 31, 2017
Acquisition of the New Business
Acquisition of the New Business	20. Acquisition of the New Business In April 2016, the Company entered into an agreement where it made an irrevocable offer to purchase the New Business, which primarily serves food and beverage, industrial and pharmaceutical customers in Europe and Asia, and has approximately 300 employees. The Company completed this acquisition for $157.4 million on November 2, 2016 (acquisition date) and financed the transaction through borrowings under the Revolver. During the year ended December 31, 2017, the Company paid an addition $1.2 million as a result of the working capital adjustment associated with the purchase price of the New Business. The Company’s financial statements for the year ended December 31, 2017 include the New Business’ results of operations, consisting of net sales of $104.0 million and income from operations of $4.2 million. The Company’s financial statements for the year ended December 31, 2016 include the New Business’ results of operations from the acquisition date through December 31, 2016. Net sales and loss from operations during this period were $12.1 million and $(8.8) million, respectively. The transaction was accounted for under the acquisition method of accounting in accordance with ASC 805 “Business Combinations.” Under the acquisition method of accounting, the tangible and identifiable intangible assets acquired and liabilities assumed are recorded based on their fair value at the acquisition date, with excess consideration paid over the net assets acquired recorded as goodwill. The Company completed the detailed valuation analyses necessary to assess the fair values of the tangible and intangible assets acquired and liabilities assumed and the amount of goodwill to be recognized as of the acquisition date. The final determination of the fair values was completed within the measurement period of up to one year from the acquisition date as permitted, and adjustments to provisional amounts that were identified during the measurement period were recorded in the reporting period in which the adjustment was determined. Fair values are based on a series of judgments about future events and uncertainties and rely heavily on estimates and assumptions. The judgments used to determine the fair values assigned to each class of assets acquired and liabilities assumed can materially impact the results of operations. Post closing adjustments made within the measurement period were not material and are reflected in the following table. The following table summarizes the allocation of the purchase price as of the November 2, 2016 acquisition date: Measurement Initial Period As of Valuation Adjustments December 31, 2017 Assets Cash and cash equivalents $ 3,826 $ — $ 3,826 Receivables 10,077 — 10,077 Inventories 20,895 (2,772) 18,123 Other current assets 1,171 (303) 868 Property, plant, and equipment 67,697 (721) 66,976 Intangibles 37,248 549 37,797 Goodwill 42,844 4,873 47,717 Other assets 179 209 388 Total assets $ 183,937 $ 1,835 $ 185,772 Liabilities Accounts payable and accrued liabilities $ 6,151 $ (612) $ 5,539 Payroll and benefits payable 4,360 (1,045) 3,315 Accrued income taxes 581 — 581 Deferred income taxes - long term 7,406 (934) 6,472 Accrued pension and other liabilities 8,014 3,192 11,206 Total liabilities $ 26,512 $ 601 $ 27,113 Net assets $ 157,425 $ 1,234 $ 158,659 Cash paid for acquisition 157,425 1,234 158,659 Cash acquired (3,826) — (3,826) Net cash paid for acquisition $ 153,599 $ 1,234 $ 154,833 The Company determined the fair value of the majority of the current assets and current liabilities approximated their carrying value given the highly liquid and short-term nature of these assets and liabilities. The fair value of finished goods inventory was determined based on the estimated selling price of the inventory less the costs of disposal and a reasonable profit allowance for the selling effort. The final step-up in fair value of inventory was $1.3 million. The fair value of property, plant and equipment was determined by using certain estimates and assumptions that are not observable in the market and thus represent a Level 3 fair value measurement. As part of the purchase price allocation, the Company determined that the separately identifiable intangible assets consisted of trade names and trademarks, unpatented technology and know-how, and customer relationships, in the amounts of $7.3 million, $14.2 million, and $16.3 million, respectively. Unpatented technology and know-how, as well as customer relationships are being amortized over a weighted-average estimated useful life of 20 years. Trade names and trademarks are considered to have an indefinite life and will be tested for impairment annually or when events or changes in the business environment indicate that the carrying value of the intangible assets may exceed their fair value. The Company used the income approach valuation technique to measure the fair value of the intangible assets, based on the present value of their future economic benefits reflecting current market expectations. Specifically, the relief from royalty method was used to value the trade names and trademarks as well as the unpatented technology and know-how. The customer relationships were valued using a multi-period excess earnings method. The assumptions used in these fair value measurements are not observable in active markets and thus represent Level 3 fair value measurements. Refer to Note 4 for further information related to intangibles. Goodwill is calculated as the excess of the consideration transferred over the net assets recognized and represents growth opportunities and expected cost synergies of the combined company. The combined company is expected to be an industry leader in the activated carbon and filtration media markets, with enhanced diversification, a strong presence in Europe, and an expanded reach into emerging markets. Goodwill recognized as a result of the acquisition is not deductible for tax purposes. Refer to Note 4 for further information related to goodwill. With the incorporation of the New Business into the existing business and the resulting change in reportable segments, $29.2 million of goodwill has been reported in the Activated Carbon segment and $18.5 million in the Alternative Materials segment. Contingent liabilities assumed include AROs for legal obligations associated with the normal operation of the acquired silica mining facilities up to the end of the quarries’ exploration. The Company evaluated the ARO to determine the cost associated with mine reclamation and landfill closures and applied an appropriate discount rate to determine the fair value. The assumptions used in these fair value measurements are not observable in active markets and thus represent Level 3 fair value measurements. Refer to Note 3 for further information related to AROs. During the years ended December 31, 2017 and 2016, the Company incurred approximately $2.8 million and $14.2 million of acquisition-related integration and transaction costs, respectively. These costs include advisory, legal, accounting transition services and information technology integration efforts, and are included in the selling, general and administrative expenses line item in the consolidated statements of comprehensive income. Pro Forma Information (Unaudited) The Company’s consolidated financial statements for 2016 include the New Business’ results of operations from the acquisition date. The following unaudited pro forma results of operations assume the New Business had been acquired on January 1, 2016. These unaudited pro forma results reflect adjustments that are directly attributable to the business combination, which are not expected to have a continuing impact, and are factually supportable. The unaudited pro forma results do not include any synergies or other effects of the planned integration that would have occurred had the New Business been acquired on January 1, 2016. The unaudited pro forma results are not necessarily indicative of the actual results of operations that would have been realized nor are they necessarily indicative of future results of the combined operations. Year Ended December 31, 2016 Net sales $ 601,153 Net income 29,326 Net income per common share Basic $ Diluted $ These unaudited pro forma amounts have been calculated after adjusting for the incremental depreciation and amortization expenses of $3.2 million associated with the step-up fair value adjustments to property, plant and equipment and intangible assets in the year ended December 31, 2016. The Company financed the acquisition of the New Business by borrowing $160 million under the Revolver. The unaudited pro forma amounts have been calculated after adjusting for the incremental interest expense of $3.3 million for the year ended December 31, 2016. The 2016 unaudited pro forma results were adjusted to eliminate the $1.5 million of incremental cost of products sold to reflect the step up of inventory recognized. The unaudited pro forma results for the year ended December 31, 2016 were adjusted to exclude the $14.0 million of transaction costs that were incurred by the Company in 2016.

Pending Merger

Pending Merger	12 Months Ended
	Dec. 31, 2017
Pending Merger
Pending Merger	21. Pending Merger On September 21, 2017, the Company entered into a definitive merger agreement under which a subsidiary of the Japanese chemical manufacturer Kuraray agreed to acquire the Company, by way of a reverse triangular merger. Following the consummation of the Pending Merger, the Company would become a wholly owned subsidiary of Kuraray. At the time of the merger, each issued and outstanding share of the Company’s common stock, excluding common stock held in treasury, will be automatically converted into the right to receive $21.50 in cash. Upon consummation of the merger, the Company’s common stock will no longer be publicly traded and will be delisted from the New York Stock Exchange. The parties have made customary representations and warranties and agreed to customary covenants in the definitive merger agreement. The covenants include that the Company shall, and shall cause each of its subsidiaries to, conduct business only in the ordinary course of business consistent with past practice, and shall not engage in certain types of transactions without the consent of Kuraray, including declaring or paying a dividend, other than dividends or distributions payable in the ordinary course of business as are authorized by the Company’s Board of Directors. In addition, if the definitive merger agreement is terminated under certain circumstances, the Company would be obligated to pay Kuraray a termination fee of $33.2 million. The Company incurred $4.6 million of investment banking, legal, accounting, and other professional fees and expenses in 2017 related to the Pending Merger. In connection with the Pending Merger, the Company has agreed to pay an investment banking firm a fee of approximately $19.0 million for its services, of which $2.0 million was due and payable upon the announcement of the execution of the merger agreement and included in the amount incurred in 2017. Approximately $17.0 million of the fee is contingent upon the closing of the Pending Merger. On October 16, 2017 the U.S. Federal Trade Commission granted early termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 and on October 25, 2017, the parties received clearance from the German Federal Cartel Office. The applicable prior notice period under the International Traffic in Arms Regulations relating to the merger and other transactions contemplated by the merger agreement expired on November 28, 2017. On December 28, 2017, the Company’s stockholders voted to approve the merger. On November 22, 2017, the Company and Kuraray filed a joint voluntary notice with the Committee on Foreign Investment in the United States (“CFIUS”). On January 19, 2018, at the conclusion of the initial review period, CFIUS notified the parties that CFIUS will initiate an additional 45 calendar day investigation period. The parties are now targeting the first quarter of 2018 for the closing of the merger, which remains subject to CFIUS clearance and other customary closing conditions.

QUARTERLY FINANCIAL DATA - UNAU

QUARTERLY FINANCIAL DATA - UNAUDITED	12 Months Ended
	Dec. 31, 2017
QUARTERLY FINANCIAL DATA - UNAUDITED
QUARTERLY FINANCIAL DATA - UNAUDITED	QUARTERLY FINANCIAL DATA — UNAUDITED 2017 2016 (Dollars in thousands, except per share data) 1st Quarter (1) 2nd Quarter 3rd Quarter 4th Quarter (2) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (3) Net sales $ 142,703 $ 152,998 $ 162,561 $ 161,549 $ 120,199 $ 132,597 $ 123,970 $ 137,480 Net sales less cost of products sold (excluding depreciation and amortization) $ 43,888 $ 46,712 $ 48,543 $ 49,772 $ 41,740 $ 44,934 $ 38,540 $ 42,634 Net income (loss) $ 775 $ 5,853 $ 5,111 $ 9,362 $ 5,458 $ 7,896 $ 6,385 $ (5,942) Common Stock Data: Basic: Net income (loss) per common share $ 0.02 $ 0.12 $ 0.10 $ 0.19 $ 0.11 $ 0.16 $ 0.13 $ (0.12) Diluted: Net income (loss) per common share $ 0.02 $ 0.12 $ 0.10 $ 0.19 $ 0.11 $ 0.15 $ 0.13 $ (0.12) Average common shares outstanding Basic 50,411 50,470 50,489 50,508 50,308 50,225 50,246 50,255 Diluted 50,486 50,511 50,624 50,561 51,041 50,987 50,984 51,081 (1) Includes $2.4 million of discrete income tax charges related to the incorporation of the Company’s former U.S. Belgium branch to a Belgium controlled foreign corporation, which was part of an overall single integrated plan of reorganization that included the Company’s acquisition of the New Business in November 2016. Results were also negatively impacted by $2.1 million of transaction expenses related to the acquisition of the New Business. (2) Includes a gain of $4.1 million on the sale of an idled plant in the UK. (3) Results were negatively impacted by $12.2 million of costs related to the acquisition of the New Business, consisting primarily of $10.5 million of transaction costs. Refer to Note 20 to the consolidated financial statements in Item 8 of this Annual Report for further information.

Schedule II Valuation and Quali

Schedule II Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Schedule II Valuation and Qualifying Accounts
Schedule II Valuation and Qualifying Accounts	Schedule II Valuation and Qualifying Accounts (Dollars in thousands) Additions Charged to Deductions Balance at Costs and Returns and Balance at Description Beginning of Year Expenses Write-Offs End of Year Year Ended December 31, 2017 Allowance for doubtful accounts $ 1,416 $ 610 $ (206) $ 1,820 Year Ended December 31, 2016 Allowance for doubtful accounts 1,675 2,926 (3,185) 1,416 Year Ended December 31, 2015 Allowance for doubtful accounts 1,526 1,402 (1,253) 1,675 Additions Charged to Charged to Deductions Balance at Costs and Other Returns and Balance at Description Beginning of Year Expenses Accounts Write-Offs End of Year Year Ended December 31, 2017 Income tax valuation allowance $ 2,510 $ 387 $ 114 $ (948) $ 2,063 Year Ended December 31, 2016 Income tax valuation allowance 2,682 153 (325) — 2,510 Year Ended December 31, 2015 Income tax valuation allowance 2,576 183 — (77) 2,682

Summary of Accounting Policies

Summary of Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Summary of Accounting Policies
Operations	Operations Calgon Carbon Corporation (the Company) is a global leader in innovative solutions, high quality products and reliable services designed to protect human health and the environment from harmful contaminants in water and air. As a leading manufacturer of activated carbon, with broad capabilities in ultraviolet light disinfection, the Company provides purification solutions for drinking water, wastewater, pollution abatement, and a variety of industrial and commercial manufacturing processes. The Company’s operations are principally conducted in three business segments: Activated Carbon, Alternative Materials, and Advanced Water Purification. Each of these segments includes the production, design and marketing of products and services specifically developed for the purification, separation and concentration of liquids and gases and other media. The Activated Carbon segment relies on activated carbon as a base material, while the Advanced Water Purification segment relies on a variety of methods and materials which involve other products. The Alternative Materials segment supplies diatomaceous earth and perlite filtration media for use in applications for decolorization, purification, decontamination, and filtration of liquids in various applications including food and beverage, industrial and pharmaceuticals; as well as activated carbon cloth for use in military, industrial, and medical applications. The Company’s largest markets are in the United States (U.S.), Europe, and Japan. The Company also has markets in Africa, Canada, China, India, Latin America, and in other parts of Asia. On November 2, 2016, the Company completed the acquisition of the wood-based activated carbon, reactivation, and mineral-based filtration media business of CECA, a subsidiary of Arkema Group (New Business). With the complementary New Business located in Europe, the Company became an even more global and diverse industry leader in activated carbon and reactivation, as well as filtration media in the form of diatomaceous earth and perlites. Refer to Notes 18 and 20 for additional information regarding the acquisition.
Acquisition	On September 21, 2017, the Company entered into a definitive merger agreement under which a subsidiary of the Japanese chemical manufacturer Kuraray Co., Ltd. (Kuraray) agreed to acquire the Company, by way of a reverse triangular merger (Pending Merger). Following the consummation of the Pending Merger, the Company would become a wholly owned subsidiary of Kuraray. Refer to Note 21 for additional information regarding the Pending Merger.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of majority-owned and controlled subsidiaries. Investments in business entities in which the Company does not have control, but has the ability to exercise significant influence over the operating and financial policies, are accounted for under the equity method. All intercompany transactions and accounts have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with accounting principles generally accepted in the U.S. requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Foreign Currency	Foreign Currency Substantially all assets and liabilities of the Company’s international operations are translated at year-end exchange rates; income and expenses are translated at average exchange rates prevailing during the year. Translation adjustments represent other comprehensive income or loss and are accumulated in a separate component of stockholders’ equity. Transaction gains and losses are included in other income (expense) — net.
Revenue Recognition	Revenue Recognition Revenue and related costs are recognized when goods are shipped or services are rendered to customers provided that ownership and risk of loss have passed to the customer, the price to the customer is fixed or determinable, persuasive evidence of an arrangement exists and collection is reasonably assured. Revenue for major equipment projects is recognized under the percentage of completion method. The Company’s major equipment projects generally have a long project life cycle from bid solicitation to project completion. The nature of the contracts are generally fixed price with milestone billings. The Company recognizes revenue for these projects based on the fixed sales prices multiplied by the percentage of completion. In applying the percentage of completion method, a project’s percent complete as of any balance sheet date is computed as the ratio of total costs incurred to date divided by the total estimated costs at completion. As changes in the estimates of total costs at completion and/or estimated total losses on projects are identified, appropriate earnings adjustments are recorded during the period that the change is identified. The Company has a history of making reasonably dependable estimates of costs at completion on contracts that follow the percentage of completion method; however, due to uncertainties inherent in the estimation process, it is possible that actual project costs at completion could vary from estimates. The principal components of costs include material, direct labor, subcontracts, and allocated indirect costs. Indirect costs primarily consist of administrative labor and associated operating expenses, which are allocated to the respective projects on actual hours charged to the project utilizing a standard hourly rate.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid, short-term investments made with an original maturity of three months or less to be cash equivalents. From time to time, the Company could have cash deposited with financial institutions in excess of federally insured limits. As of December 31, 2017 and 2016, the Company had $3.8 million and $4.8 million, respectively, of cash deposits with U.S. financial institutions in excess of federally insured limits. The Company’s foreign subsidiaries held cash and cash equivalents of $33.1 million and $27.4 million as of December 31, 2017 and 2016, respectively. Generally, cash and cash equivalents held by foreign subsidiaries are not readily available for use in the U.S. without adverse tax consequences.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially expose the Company to concentrations of credit risk consist primarily of cash and cash equivalents and customer receivables. The Company places its cash with financial institutions and invests in low-risk, highly liquid instruments. With respect to customer receivables, the Company believes that it has no significant concentration of credit risk as no single customer accounted for more than 10 percent of gross annual revenues as of December 31, 2017. The Company closely monitors the credit risk associated with its customers and to date has not experienced material losses.
Allowance for Doubtful Accounts	Allowance for Doubtful Accounts The Company maintains allowances for doubtful accounts for estimated losses resulting from the inability of its customers to make required payments. The amount of allowance recorded is primarily based upon a periodic review of specific customer transactions that remain outstanding at least three months beyond their respective due dates.
Inventories	Inventories Inventories are carried at the lower of cost or net realizable value. Inventory costs are primarily determined using the first-in, first-out (FIFO) method.
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment is recorded at cost. Repair and maintenance costs are expensed as incurred. Depreciation for financial reporting purposes is computed on the straight-line method over the estimated service lives of the assets, which are from 15 to 30 years for land improvements and buildings, 5 to 15 years for furniture, machinery and equipment, 5 to 10 years for customer capital, 5 years for vehicles, and 5 to 10 years for computer hardware and software. Depletion is computed for mineral rights for the diatomite ore deposits using the units-of-production method and is included in the Company’s depreciation expense. Expenditures for new facilities and improvements that substantially extend the capacity or useful life of an asset are capitalized.
Asset Retirement Obligations	Asset Retirement Obligations The Company has asset retirement obligations (AROs) related to reclamation obligations associated with the normal operation of the diatomite mining facilities. These AROs consist primarily of costs associated with mine reclamation and landfill closures. The fair values of these AROs are recorded on a discounted basis at the time the obligation is incurred, and accreted over time for the change in present value. Additionally, the Company capitalizes asset retirement costs by increasing the carrying amount of the related long-lived assets and depreciating these assets over the remaining life of the active mining facilities.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess of the cost of an acquired business over the fair value of the identifiable tangible and intangible assets acquired and liabilities assumed in a business combination. Identifiable intangible assets acquired in business combinations are recorded based on their fair values at the date of acquisition. In accordance with guidance within Financial Accounting Standards Board (FASB) Accounting Standards Codification (ASC) 350 “Intangibles - Goodwill and Other,” goodwill and identifiable intangible assets with indefinite lives are not subject to amortization but must be evaluated for impairment. The Company evaluates goodwill and indefinite-lived intangible assets for impairment annually, or when events occur or circumstances change that may reduce the fair value of the asset below its carrying amount. The Company has elected to perform the annual impairment test of its goodwill and indefinite-lived intangible assets, as required, on December 31 of each year by initially comparing the fair value of each of the Company’s reporting units or indefinite-lived assets to its related carrying value. If the carrying amount of the intangible asset exceeds its fair value, the Company recognizes an impairment loss in the amount of the excess. If the fair value of the reporting unit is less than its carrying value, the Company performs an additional step to determine the implied fair value of the goodwill. The implied fair value of goodwill is determined by first allocating the fair value of the reporting unit to all of the assets and liabilities of the unit and then computing the excess of the unit’s fair value over the amounts assigned to the assets and liabilities. If the carrying value of goodwill exceeds the implied fair value of goodwill, such excess represents the amount of goodwill impairment, and the Company recognizes such impairment accordingly. Fair values are estimated using discounted cash flows and other valuation methodologies that are based on projections of the amounts and timing of future revenues and cash flows, assumed discount rates and other assumptions as deemed appropriate. The Company also considers such factors as historical performance, anticipated market conditions, operating expense trends and capital expenditure requirements. The Company’s identifiable intangible assets other than goodwill and trade names and trademarks have finite lives. Certain of these intangible assets are amortized using an accelerated methodology, while the majority are amortized on a straight-line basis over their estimated useful lives. In addition, intangible assets with finite lives are evaluated for impairment whenever events or circumstances indicate that their carrying amount may not be recoverable, as prescribed by guidance within ASC 360 “Property, Plant, and Equipment.”
Long-Lived Assets	Long-Lived Assets The Company evaluates long-lived assets under the provisions of ASC 360 “Property, Plant, and Equipment” which addresses financial accounting and reporting for the impairment of long-lived assets and for long-lived assets to be disposed of. For assets to be held and used, the Company groups a long-lived asset or assets with other assets and liabilities at the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. An impairment loss for an asset group reduces only the carrying amounts of a long-lived asset or assets of the group being evaluated. The loss is allocated to the long-lived assets of the group on a pro-rata basis using the relative carrying amounts of those assets, except that the loss allocated to an individual long-lived asset of the group does not reduce the carrying amount of that asset below its fair value whenever that fair value is determinable without undue cost and effort. Estimates of future cash flows to test the recoverability of a long-lived asset group include only the future cash flows that are directly associated with and that are expected to arise as a direct result of the use and eventual disposition of the asset group. The future cash flow estimates used by the Company exclude interest charges.
Fair Value	Fair Value Fair value is defined as 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. 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 developed based on the best information available in the circumstances (unobservable inputs). The fair value hierarchy consists of three broad levels, which gives 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 — Quoted prices (unadjusted) in active markets for identical assets or liabilities; · Level 2 — Inputs, other than the quoted prices in active markets, that are observable either directly or indirectly; and · Level 3 — Unobservable inputs that reflect the reporting entity’s own assumptions. The Company’s financial instruments, excluding derivative instruments, consist primarily of cash and cash equivalents, short and long-term debt as well as accounts receivable and accounts payable. The fair value of accounts receivable and accounts payable approximates their carrying value because of the short-term maturity of the instruments.
Derivative Instruments	Derivative Instruments The Company applies ASC 815 “Derivatives and Hedging” which establishes accounting and reporting standards for derivative instruments, including certain derivative instruments embedded in other contracts and for hedging activities. Derivative financial instruments are utilized by the Company to manage risk exposure to movements in foreign exchange rates, interest rates or the prices of natural gas. The Company enters into derivative financial instruments with high credit quality counterparties and diversifies its positions among such counterparties. In addition, various master netting arrangements are in place with counterparties to facilitate settlement of gains and losses on these contracts. The Company does not net its derivative positions by counterparty for purposes of balance sheet presentation and disclosure. Changes in the value of the derivative financial instruments are measured at the balance sheet date and recognized in current earnings or other comprehensive income depending on whether the derivative is designated as part of a hedge transaction and meets certain other criteria. The Company does not hold derivative financial instruments for trading purposes.
Pensions	Pensions The Company accounts for its pensions in accordance with ASC 715 “Compensation – Retirement Benefits.” Accounting for pensions involves estimating the cost of benefits to be provided well into the future and attributing that cost over the time period each employee works. To accomplish this, extensive use is made of assumptions about inflation, investment returns, mortality, turnover and discount rates. These assumptions are reviewed annually. In determining the expected return on plan assets, the Company evaluates long-term actual return information, the mix of investments that comprise plan assets and future estimates of long-term investment returns. The Company uses country specific mortality tables and updates them periodically as better information becomes available. In determining the discount rates for pension obligations, the Company evaluates long-term corporate bonds that receive one of the two highest ratings given by a recognized rating agency. Amortization of the actuarial net gain or loss as a result of experience differing from that assumed and from changes in assumptions is included as a component of net periodic pension cost for the year. The Company uses a 10% corridor such that if, as of the beginning of the year, the net gain or loss exceeds 10% of the greater of the projected benefit obligation or the market-related value of plan assets, the amortization is that excess divided by the average future working lifetime of participating employees expected to receive benefits under the plan or the average remaining life expectancy of the plan’s participants if the percentage of actives is less than 10% of the total population. As only the excess actuarial gain or loss is amortized, this approach will not fully amortize the net actuarial gain or loss.
Stock-Based Compensation	Stock-Based Compensation The Company applies ASC 718 “Compensation — Stock Compensation” and accordingly records compensation expense for stock options over the vesting period using the fair value on the date of grant, as calculated by the Company using the Black-Scholes model. For time vested restricted stock awards, the nonvested restricted stock grant date fair value, which is the market price of the underlying common stock, is expensed over the vesting period. For certain performance based stock awards that vest subject to a market condition, the initial grant date fair value is determined using a Monte Carlo simulation model and is expensed on a straight-line basis over the performance period. For certain performance based stock awards that vest subject to a performance condition, the initial grant date fair value is the market price of the underlying common stock. This fair value is expensed on a straight-line basis over the performance period when it is probable that the performance condition will be achieved. The Company’s stock-based compensation plans are more fully described in Note 10.
Net Income per Common Share	Net Income per Common Share Basic net income per common share is computed by dividing net income by the weighted average number of common shares outstanding during the period. Diluted net income per common share is computed by dividing net income by the weighted average number of common shares outstanding plus all potentially dilutive common shares outstanding during the period. Potentially dilutive common shares are determined using the treasury stock method. Under the treasury stock method, the Company’s stock-based compensation awards are treated as if they had been exercised, with any proceeds used to repurchase common stock at the average market price during the period. Any incremental difference between the assumed number of shares issued and purchased is included in the diluted share computation. For the Company’s performance based stock awards, their contingent features result in an assessment for any potentially dilutive common stock by using the end of the reporting period as if it were the end of the contingency period for all awards granted.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences of temporary differences between the book and tax basis of assets and liabilities based upon enacted tax rates. If it is more likely than not that some portion or all of a deferred tax asset will not be realized, a valuation allowance is recognized. The Company assesses its ability to realize deferred tax assets based on normalized historical performance and on projections of future taxable income in the relevant tax jurisdictions. Normalized historical performance for purposes of this assessment includes adjustments for those income and expense items that are unusual and non-recurring in nature and are not expected to affect results in future periods. Such unusual and non-recurring items include the effects of legal fees or settlements associated with specific litigation matters, acquisition and restructuring costs. The Company’s projections of future taxable income consider known events, such as the passage of legislation or expected occurrences, and do not reflect a general growth assumption. The Company’s estimates of future taxable income are reviewed annually or whenever events or changes in circumstances indicate that such projections should be modified. The Company utilizes guidance within ASC 740 “Income Taxes” regarding the accounting for uncertainty in income taxes. This guidance prescribes recognition and measurement standards for a tax position taken or expected to be taken in a tax return. According to this guidance, the evaluation of a tax position is a two step process. The first step is the determination of whether a tax position should be recognized in the financial statements. The benefit of a tax position taken or expected to be taken in a tax return is to be recognized only if the Company determines that it is more likely than not that the tax position will be sustained upon examination by the tax authorities based upon the technical merits of the position. In step two, for those tax positions which should be recognized, the measurement of a tax position is determined as being the largest amount of benefit that is greater than 50% likely of being realized upon ultimate settlement. Except for the estimated U.S. transition tax, no provision is made for U.S. income taxes on the undistributed earnings of non-U.S. subsidiaries because these earnings are intended to be indefinitely reinvested outside the U.S. These earnings would become subject to additional income tax if they were remitted as dividends, were loaned to the Company or a U.S. affiliate, or if the Company were to sell its ownership interest in the subsidiaries. Refer to Note 14 for additional information on the estimated U.S. transition tax.
Leases	Leases The Company leases certain facilities, equipment and vehicles. Certain of the Company’s leases contain renewal options, rent escalation clauses and landlord incentives. Renewal terms generally reflect market rates at the time of renewal. Rent expense for noncancelable operating leases with scheduled rent increases or landlord incentives is recognized on a straight-line basis over the lease term, including any applicable rent holidays, beginning with the lease commencement date. The excess of straight-line rent expense over scheduled payment amounts and landlord incentives is recorded as a deferred liability.
Contingencies	Contingencies The Company from time to time is subject to various legal proceedings, lawsuits and claims, including employment, product warranty and environmental matters of the nature considered normal to its business. It is the Company’s policy to accrue for amounts related to legal matters when it is probable that a liability has been incurred and the loss amount is reasonably estimable. Estimates are developed through consultation with legal counsel involved in the defense and are based upon an analysis of probable results, assuming a combination of litigation and settlement strategies. Legal fees associated with defending these various lawsuits and claims are expensed when incurred.
Government Grants	Government Grants The Company’s policy for accounting for government grants, including non-monetary grants at fair value, is to recognize them only when there is reasonable assurance that (a) the Company will comply with the conditions attached to the grants and (b) the grants will be received. A grant will be recognized over the period necessary to match it to the related costs, for which it is intended to compensate, on a systematic basis. A grant related to assets is presented by deducting it from the asset’s depreciation expense and is reported within cash flows from investing activities. A grant related to income will be deducted from the related expense and reported within cash flows from operating activities.
Labor Agreements	Labor Agreements Collective bargaining agreements cover approximately 48% of the Company’s full-time labor force as of December 31, 2017 and expire at various dates through 2021. Approximately 3% of the Company’s labor force is operating under a contract that expired on December 31, 2017, which is in the process of being renegotiated. The Company has certain contracts with national labor organizations in the U.S. and Europe that expire in July and December 2018, respectively, affecting 4% and 25% of the Company’s labor force, respectively.
New Accounting Pronouncements	New Accounting Pronouncements In May 2014, the FASB issued Accounting Standards Update (ASU) 2014-09, “Revenue (Topic 606): Revenue from Contracts with Customers”, as amended, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes most current revenue recognition guidance, including industry-specific guidance. The core principle of ASU 2014-09 is that an entity should recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services by applying five steps listed in the guidance. ASU 2014-09 also requires disclosure of both quantitative and qualitative information that enables users of the financial statements to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from customers. The new revenue standard is effective for fiscal years, and interim periods within those years, beginning after December 15, 2017. The Company will adopt the new revenue standard effective January 1, 2018 using the modified retrospective method. The Company will recognize the cumulative effect of initially applying the new revenue standard as an adjustment to the opening balance of retained earnings, for those contracts not completed as of the adoption date, however this effect is not expected to be material. While certain assets and liabilities will also change upon adoption of this standard, the changes are again not expected to be material. There will be no restatement of comparative prior year information, as those periods will continue to be reported under the accounting standards in effect for those periods. Prospectively, the Company does not expect that the adoption of the new revenue standard will have a material impact to the Company’s net income on an ongoing basis. For the majority of the Company’s revenue which consists of product sales, the Company does not anticipate a material change to result from the adoption of the new standard, as the revenue recognition will continue to be at a point in time. Approximately 6% of the Company’s consolidated net sales for the year ended December 31, 2017 were recognized on a percentage of completion basis. For some of these contracts, the new guidance will instead require revenue to be recognized at a point in time due to the nature of the product, which in some cases has an alternative use to the Company. In 2017, these sales are reported in both the Activated Carbon and Advanced Water Purification reportable segments. In July 2015, the FASB issued Accounting Standards Update 2015-11, “Simplifying the Measurement of Inventory” which requires entities to measure most inventory at the lower of cost and net realizable value. This simplifies the current guidance under which an entity measures inventory at the lower of cost or market. Market in this context is defined as one of three different measures, one of which is net realizable value. Net realizable value is the estimated selling prices in the ordinary course of business, less reasonably predictable costs of completion, disposal, and transportation. The Company adopted this ASU on a prospective basis as of January 1, 2017 and it did not have a material impact on the Company’s consolidated financial statements. In February 2016, the FASB issued ASU 2016-02, “Leases (Topic 842)” which introduces a lessee model that brings most leases on the balance sheet, requiring lessees to recognize the right to use assets and lease obligations that arise from lease arrangements exceeding a twelve month term. Lessees will also need to disclose qualitative and quantitative information about lease transactions, such as information about variable lease payments and options to renew and terminate leases. For income statement purposes, the FASB retained a dual model, requiring leases to be classified as either operating or finance. Classification will be based on criteria that are largely similar to those applied in current lease accounting, but without explicit bright lines. Lessor accounting is similar to the current model, but updated to align with certain changes to the lessee model and the new revenue recognition standard. The new guidance is effective for fiscal years, and interim periods within those years, beginning after December 15, 2018. Entities are required to use a modified retrospective transition for existing leases. The Company is evaluating the provisions of this ASU and assessing the impact it may have on the Company’s consolidated financial statements and related disclosures. At a minimum, total assets and total liabilities will increase in the period the ASU is adopted. As of December 31, 2017, the Company’s undiscounted future minimum payments outstanding for lease obligations were approximately $41 million. In March 2016, the FASB issued ASU 2016-09, “Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting” which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification in the statement of cash flows. The Company adopted the provisions of this ASU effective January 1, 2017 and it did not have a material impact on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, “Financial Instruments – Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” which adds a Current Expected Credit Loss (CECL) model that is based on expected losses rather than incurred losses, which is applicable to trade receivables. The new guidance is effective for annual reporting periods beginning after December 15, 2019, including interim periods within those annual reporting periods. Entities are required to use the modified retrospective approach. The Company is evaluating the provisions of this ASU and assessing the impact it may have on the Company’s consolidated financial statements and related disclosures. In August and November 2016, the FASB issued ASU 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments” and ASU 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash” to add or clarify guidance on the classification of certain cash receipts and payments and restricted cash in the statement of cash flows. Entities must apply the guidance retrospectively to all periods presented, but may apply it prospectively from the earliest date practicable if retrospective application would be impracticable. The Company is planning to adopt the provisions of this ASU, effective January 1, 2018. The adoption of this ASU is not expected to have a material impact on the Company’s consolidated financial statements. In March 2017, the FASB issued ASU 2017-07, “Compensation – Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” which requires that employers disclose components of their pension service cost in the same line item as other compensation costs related to relevant employees. The ASU also requires that other components of net benefit costs be presented separately from the service cost component within the income statement, and outside of income from operations. The provisions of this ASU are effective for annual reporting periods beginning after December 15, 2017, and interim periods within those annual reporting periods. The Company will retrospectively adopt this ASU as of January 1, 2018 as required, which will result in a reclassification of $2.6 million and $3.0 million for the years ended December 31, 2017 and 2016, respectively, for the components of net periodic pension cost other than service cost outside of income from operations on the Company’s consolidated financial statements.

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2017
Inventories
Schedule of inventories	December 31 2017 2016 Raw materials $ 29,940 $ 24,831 Finished goods 91,707 100,284 Total $ 121,647 $ 125,115

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment
Schedule of property, plant and equipment	December 31 2017 2016 Land and improvements $ 39,679 $ 37,479 Mineral rights 11,424 11,240 Buildings 96,694 90,385 Machinery, equipment and customer capital 524,162 494,722 Computer hardware and software 45,499 43,631 Furniture and vehicles 12,189 10,893 Construction-in-progress 61,459 30,525 791,106 718,875 Less accumulated depreciation (391,596) (352,433) Property, plant and equipment, net $ 399,510 $ 366,442

Goodwill and Other Identifiab33

Goodwill and Other Identifiable Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Other Identifiable Intangible Assets
Schedule of changes in carrying amount of goodwill by segment	Activated Alternative Advanced Carbon Materials Water Purification Segment Segment Segment Total Balance as of January 1, 2016 $ 19,604 $ 60 $ 6,113 $ 25,777 Goodwill acquired (Note 20) 26,415 16,429 — 42,844 Foreign currency translation (1,673) (679) 47 (2,305) Balance as of December 31, 2016 44,346 15,810 6,160 66,316 Measurement period adjustments 2,788 2,085 — 4,873 Foreign currency translation 4,054 2,427 103 6,584 Balance as of December 31, 2017 $ 51,188 $ 20,322 $ 6,263 $ 77,773
Summary of identifiable intangible assets	December 31, 2017 Weighted Average Gross Net Amortization Carrying Foreign Accumulated Carrying Period Amount Exchange Amortization Amount Amortized intangible assets : Customer relationships 18.9 Years $ 25,584 $ 1,250 $ (9,859) $ 16,975 Product certification 8.4 Years 8,453 (89) (4,427) 3,937 Unpatented technology 20.0 Years 14,174 1,273 (839) 14,608 Licenses 20.0 Years 964 (81) (394) 489 17.9 Years 49,175 2,353 (15,519) 36,009 Indefinite-lived intangible assets : Trade names and trademarks 7,362 695 — 8,057 Total $ 56,537 $ 3,048 $ (15,519) $ 44,066 December 31, 2016 Weighted Average Gross Net Amortization Carrying Foreign Accumulated Carrying Period Amount Exchange Amortization Amount Amortized intangible assets: Customer relationships 18.9 Years $ 25,035 $ (873) $ (8,900) $ 15,262 Product certification 7.4 Years 8,649 (90) (4,320) 4,239 Unpatented technology 20.0 Years 14,174 (586) (114) 13,474 Licenses 20.0 Years 964 (99) (354) 511 17.3 Years 48,822 (1,648) (13,688) 33,486 Indefinite-lived intangible assets: Trade names and trademarks 7,362 (305) — 7,057 Total $ 56,184 $ (1,953) $ (13,688) $ 40,543
Schedule of estimated amortization expense to be recognized during next five years	For the year ending December 31: 2018 $ 2,230 2019 2,477 2020 2,389 2021 2,344 2022 2,333

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Measurements
Schedule of carrying amount, fair value, and classification within fair value hierarchy of financial instrument assets (liabilities)	Fair Value December 31, 2017 December 31, 2016 Hierarchy Carrying Fair Carrying Fair Level Amount Value Amount Value Derivative assets 2 $ 560 $ 560 $ 1,168 $ 1,168 Derivative liabilities 2 (1,095) (1,095) (1,452) (1,452) Acquisition earn-out liability 2 — — (125) (125) Long-term debt, including current portion 2 (233,500) (233,500) (225,000) (225,000)

Derivative Instruments (Tables)

Derivative Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments
Schedule of fair value of outstanding derivative contracts	December 31 Asset Derivatives Balance Sheet Locations 2017 2016 Derivatives designated as hedging instruments: Foreign exchange contracts Other current assets $ 129 $ 670 Natural gas contracts Other current assets — 255 Foreign exchange contracts Other assets — 179 Natural gas contracts Other assets 1 43 Interest rate swap contract Other assets 121 — Derivatives not designated as hedging instruments: Foreign exchange contracts Other current assets 309 21 Total asset derivatives $ 560 $ 1,168 December 31 Liability Derivatives Balance Sheet Locations 2017 2016 Derivatives designated as hedging instruments: Foreign exchange contracts Accounts payable and accrued liabilities $ 639 $ 30 Natural gas contracts Accounts payable and accrued liabilities 143 — Foreign exchange contracts Accrued pension and other liabilities 52 1 Natural gas contracts Accrued pension and other liabilities 50 — Derivatives not designated as hedging instruments: Foreign exchange contracts Accounts payable and accrued liabilities 211 1,421 Total liability derivatives $ 1,095 $ 1,452
Schedule of outstanding derivative contracts	December 31 (in thousands except for millions of British Thermal Units (mmbtu)) 2017 2016 2015 Natural gas contracts (mmbtu) 1,105,000 540,000 955,000 Foreign exchange contracts $ 75,006 $ 199,420 $ 37,016 Interest rate swap contract $ 50,000 $ — $ —
Schedule of gross and net amounts of derivative assets and liabilities	December 31, 2017 December 31, 2016 Fair Value Fair Value Fair Value Fair Value of Assets of Liabilities of Assets of Liabilities Gross derivative amounts recognized in the balance sheet $ 560 $ 1,095 $ 1,168 $ 1,452 Gross derivative amounts not offset in the balance sheet (341) (341) (52) (52) Net amount $ 219 $ 754 $ 1,116 $ 1,400
Schedule of amount of gain or (loss) on derivatives recognized in OCI and recognized from accumulated OCI into earnings (effective portion)	Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion) Year Ended December 31 2017 2016 2015 Foreign exchange contracts $ (1,421) $ 399 $ 647 Natural gas contracts (467) 835 (984) Interest rate swap contract (190) — — Total $ (2,078) $ 1,234 $ (337) Amount of Gain or (Loss) Recognized from Accumulated OCI into Earnings (Effective Portion) (1) Year Ended December 31 2017 2016 2015 Foreign exchange contracts $ 102 $ 206 $ 2,077 Natural gas contracts 66 (339) (941) Interest rate swap contract (311) — — Total $ (143) $ (133) $ 1,136 (1) Assuming market rates remain constant with the rates as of December 31, 2017, a loss of $0.7 million is expected to be recognized in earnings over the next 12 months.
Schedule of fair value gains and losses on derivative contracts not qualified for hedge accounting treatment	Amount of Gain or (Loss) Recognized in Earnings on Derivatives Year Ended December 31 2017 2016 2015 Foreign exchange contracts $ (9,096) $ 4,425 $ (1,042) Total $ (9,096) $ 4,425 $ (1,042)

Product Warranties (Tables)

Product Warranties (Tables)	12 Months Ended
	Dec. 31, 2017
Product Warranties
Schedule of change in warranty reserve	December 31 2017 2016 Balance as of January 1 $ 1,402 $ 1,252 Payments and replacement product (390) (1,495) Additions to warranty reserve for warranties issued during the period 618 1,647 Change in the warranty reserve for pre-existing warranties 6 (2) Balance as of December 31 $ 1,636 $ 1,402

Borrowing Arrangements (Tables)

Borrowing Arrangements (Tables)	12 Months Ended
	Dec. 31, 2017
Borrowing Arrangements
Schedule of long-term debt	December 31 2017 2016 Total long-term debt $ 233,500 $ 225,000 Less current portion of long-term debt (5,000) (5,000) Net long-term debt $ 228,500 $ 220,000

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Pensions
Schedule of reconciliation of changes in plans' benefit obligations and fair value of assets, funded status and amounts recognized in accumulated other comprehensive income	U.S. Plans European Plans 2017 2016 2017 2016 Change in projected benefit obligations Projected benefit obligations as of January 1 $ 110,732 $ 108,938 $ 43,495 $ 39,201 Service cost 959 957 524 395 Interest cost 4,413 4,589 972 1,142 Employee contributions — — 72 73 Actuarial loss 7,796 4,293 593 7,018 Benefits paid (4,327) (4,094) (1,055) (1,527) Acquisition — — — 3,899 Plan amendments — — — (91) Settlement (2,021) (3,951) (2,173) (1,224) Foreign currency exchange rate changes — — 4,836 (5,391) Projected benefit obligations as of December 31 $ 117,552 $ 110,732 $ 47,264 $ 43,495 Change in plan assets Fair value of plan assets as of January 1 $ 88,240 $ 89,382 $ 27,936 $ 29,351 Actual return on plan assets 12,547 6,221 2,012 4,212 Employer contributions 838 682 2,087 1,744 Employee contributions — — 72 73 Benefits paid (4,327) (4,094) (1,055) (1,527) Settlement (2,021) (3,951) (2,173) (1,224) Foreign currency exchange rate changes — — 2,775 (4,693) Fair value of plan assets as of December 31 $ 95,277 $ 88,240 $ 31,654 $ 27,936 Funded status as of December 31 $ (22,275) $ (22,492) $ (15,610) $ (15,559) Amounts recognized in the balance sheets consist of: Noncurrent asset — Other assets $ — $ — $ 710 $ 141 Current liability — Payroll and benefits payable (82) (82) (630) (493) Noncurrent liability — Accrued pension and other liabilities (22,193) (22,410) (15,690) (15,207) Net amount recognized $ (22,275) $ (22,492) $ (15,610) $ (15,559) Amounts recognized in accumulated other comprehensive income consist of: Accumulated prior service cost $ — $ — $ (91) $ (91) Accumulated net actuarial loss 36,273 38,694 10,720 10,549 Net amount recognized, before tax effect $ 36,273 $ 38,694 $ 10,629 $ 10,458
Schedule of assumptions used to determine benefit obligations	U.S. Plans European Plans Weighted average actuarial assumptions as of December 31: 2017 2016 2017 2016 Discount rate 3.63 % 4.09 % 2.02 % 2.11 % Rate of increase in compensation levels 3.00 % 3.00 % 2.95 % 2.87 %
Schedule of projected benefit obligations, accumulated benefit obligations and fair value of plan assets	U.S. Plans European Plans December 31 December 31 2017 2016 2017 2016 The projected benefit obligation and accumulated benefit obligation for all defined benefit plans was as follows: Projected benefit obligation $ 117,552 $ 110,732 $ 47,264 $ 43,495 Accumulated benefit obligation 114,322 107,037 43,940 40,886 Fair value of plan assets 95,277 88,240 31,654 27,936 The aggregate projected benefit obligation and fair value of plan assets for plans with projected benefit obligations in excess of plan assets was as follows: Projected benefit obligation $ 117,552 $ 110,732 $ 33,896 $ 31,570 Fair value of plan assets 95,277 88,240 17,575 15,872 The aggregate accumulated benefit obligation and fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets was as follows: Accumulated benefit obligation $ 114,322 $ 107,037 $ 30,572 $ 28,962 Fair value of plan assets 95,277 88,240 17,575 15,872
Schedule of information about expected cash flows for pension plans	U.S. Plans European Plans Employer contributions 2018 $ 2,126 $ 1,950 Benefit payments 2018 $ 6,188 $ 1,429 2019 6,551 1,291 2020 6,791 1,433 2021 6,756 1,377 2022 7,933 1,645 2023 - 2027 36,611 10,311
Schedule of components of net periodic pension costs	U.S. Plans European Plans Year Ended December 31 Year Ended December 31 Net periodic pension cost 2017 2016 2015 2017 2016 2015 Service cost $ 959 $ 957 $ 1,136 $ 524 $ 395 $ 288 Interest cost 4,413 4,589 4,499 972 1,142 1,250 Expected return on assets (5,855) (6,040) (7,070) (1,322) (1,416) (1,705) Amortization of prior service cost (credit) — — 15 (9) — — Net actuarial loss amortization 2,987 3,010 2,606 452 229 219 Settlement 537 1,149 607 426 361 199 Net periodic pension cost $ 3,041 $ 3,665 $ 1,793 $ 1,043 $ 711 $ 251
Schedule of changes in plan assets and benefit obligations recognized in other comprehensive income (loss)	U.S. Plans European Plans Year Ended December 31 Year Ended December 31 Amounts recognized in 2017 2016 2015 2017 2016 2015 Current year actuarial gain (loss) $ (1,103) $ (4,112) $ (3,348) $ 98 $ (4,222) $ (984) Amortization of actuarial loss 2,987 3,010 2,606 452 229 219 Current year prior service credit — — — — 91 — Amortization of prior service cost (credit) — — 15 (9) — — Settlement 537 1,149 607 426 361 199 Foreign currency exchange — — — (1,138) 1,122 603 Total recognized in other comprehensive income (loss) $ 2,421 $ 47 $ (120) $ (171) $ (2,419) $ 37 Total recognized in net periodic pension cost and other comprehensive income (loss) $ (620) $ (3,618) $ (1,913) $ (1,214) $ (3,130) $ (214)
Schedule of estimated amounts that will be amortized from accumulated other comprehensive income into net periodic pension cost	U.S. Plans European Plans Amounts expected to be recognized in net periodic pension cost 2018 2018 Prior service credit $ — $ (10) Net actuarial loss 2,825 367 Total as of December 31 $ 2,825 $ 357
Schedule of assumptions used in measurement of net periodic pension cost	U.S. Plans European Plans December 31 December 31 Weighted average actuarial assumptions 2017 2016 2015 2017 2016 2015 Discount rate 4.09 % 4.38 % 4.01 % 2.11 % 2.97 % 3.00 % Expected annual return on plan assets 6.87 % 7.00 % 7.50 % 4.46 % 5.28 % 5.54 % Rate of increase in compensation levels 3.00 % 3.00 % 3.00 % 2.87 % 3.07 % 3.38 %
United States
Pensions
Schedule of fair values of pension plans assets	U.S. Plans Fair Value Measurements Fair Value Measurements as of December 31, 2017 as of December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and cash equivalents $ 2,984 $ — $ — $ 2,984 $ 4,414 $ — $ — $ 4,414 Equity securities Large cap 17,260 — — 17,260 16,528 — — 16,528 Small/mid cap 11,485 — — 11,485 9,584 — — 9,584 International equity (a) 7,927 — — 7,927 6,377 — — 6,377 Emerging markets (b) 6,190 — — 6,190 5,333 — — 5,333 Fixed income securities Corporate bonds (c) — 25,906 — 25,906 — 23,034 — 23,034 Government bonds (d) 690 14,370 — 15,060 561 13,785 — 14,346 International bonds (e) — 5,001 — 5,001 — 3,966 — 3,966 Commodities (f) 1,737 — — 1,737 2,051 — — 2,051 Real estate (g) 1,727 — — 1,727 2,607 — — 2,607 Total $ 50,000 $ 45,277 $ — $ 95,277 $ 47,455 $ 40,785 $ — $ 88,240 (a) This category consists of international equity securities from Europe, Australia and Southeast Asia. (b) This category invests in global emerging markets outside the U.S. The strategy targets broad diversification across various economic sectors in emerging economies. (c) This category invests primarily in investment grade corporate securities. (d) This category includes securities and mutual funds which invest in a diversified portfolio of longer duration bonds. The funds typically invest primarily in U.S. investment grade securities. (e) This includes securities and mutual funds which invest in a diversified portfolio of longer duration foreign bonds. (f) This fund invests in assets of commodity linked derivative instruments and fixed income securities. (g) This fund primarily invests in equity related securities of real estate companies and other real estate securities. A significant portion of the total assets are typically in foreign securities.
Europe
Pensions
Schedule of fair values of pension plans assets	European Plans Fair Value Measurements Fair Value Measurements as of December 31, 2017 as of December 31, 2016 Asset Category Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Cash and cash equivalents $ 2,833 $ — $ — $ 2,833 $ 2,005 $ — $ — $ 2,005 Equity securities M&G PP UK equity passive fund (a) 1,092 — — 1,092 950 — — 950 M&G PP overseas equity passive fund (b) 5,062 — — 5,062 4,291 — — 4,291 LGIM dynamic diversified fund (c) 2,672 — — 2,672 3,758 — — 3,758 W. Blair dynamic diversified allocation fund (d) 2,418 — — 2,418 1,160 — — 1,160 Fixed income securities Delta Lloyd fixed income (e) — — 738 738 — — 1,158 1,158 Corporate bonds (f) 548 — — 548 428 — — 428 Government bonds (g) 12,823 — — 12,823 10,582 — — 10,582 Real estate (h) 2,581 — — 2,581 2,796 — — 2,796 Insurance reserves (i) — — 887 887 — — 808 808 Total $ 30,029 $ — $ 1,625 $ 31,654 $ 25,970 $ — $ 1,966 $ 27,936 (a) This fund invests in the shares of UK companies. (b) This fund invests in overseas companies with fixed proportions representing each region’s economic importance. (c) This fund invests in a range of different asset classes, including equities, bonds, properties, commodities, listed infrastructure, private equity, and global real estate companies. (d) This fund utilizes a combination of traditional assets (equities, bonds, currencies, etc.), and investment strategies based on advanced derivative techniques. (e) This category invests in fixed income investments with Delta Lloyd. (f) This category invests primarily in investment grade corporate bonds, and other debt instruments, including higher yielding corporate bonds, government debt, convertible and preferred stocks, money market instruments and equities. (g) This category invests mainly in long-term gilts. (h) This category invests in commercial properties in the UK and is well diversified in the retail, office, and industrial sectors. (i) This category invests in individual insurance policies in the name of the individual plan members.
Schedule of changes in fair value measurements using significant unobservable inputs	Delta Lloyd Insurance Fixed Income Reserves Balance as of January 1, 2016 $ 1,864 $ 1,259 Purchases — 101 Sales/Maturities (668) (525) Foreign currency translation (38) (27) Balance as of December 31, 2016 $ 1,158 $ 808 Purchases — 95 Sales/Maturities (554) (129) Foreign currency translation 134 113 Balance as of December 31, 2017 $ 738 $ 887

Stock Compensation Plans (Table

Stock Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Stock Compensation Plans
Summary of status and activity of employee and non-employee directors' nonvested stock awards	Weighted- Weighted- Weighted- Average ROC Average TSR Average Restricted Grant Date Performance Grant Date Performance Grant Date Stock Fair Value Stock Fair Value Stock Fair Value Awards (per share) Awards (a) (per share) Awards (a) (per share) Nonvested as of January 1, 2017 250,540 $ 17.02 79,948 $ 17.56 93,044 $ 15.09 Granted 170,226 14.25 33,158 14.37 42,469 11.22 Vested (113,285) 18.01 — — — — Forfeited (5,784) 15.16 (24,890) 20.54 (23,900) 21.39 Nonvested as of December 31, 2017 301,697 $ 15.12 88,216 $ 15.52 111,613 $ 12.27 (a) The number of shares shown for the performance stock awards is based on the target number of share awards.
Employee stock options
Stock Compensation Plans
Summary of status and activity of stock options	Weighted- Weighted- Average Average Remaining Exercise Price Contractual Term Aggregate Employee stock options: Shares (per share) (in years) Intrinsic Value Outstanding as of January 1, 2017 1,666,802 $ 17.67 4.69 $ 1,993 Granted 540,466 14.37 Exercised (18,199) 14.28 Forfeited (5,174) 14.27 Expired (137,355) 19.19 Outstanding as of December 31, 2017 2,046,540 $ 16.74 4.37 $ 9,421 Vested and expected to vest as of December 31, 2017 2,046,540 $ 16.74 4.37 $ 9,421 Exercisable as of December 31, 2017 1,279,612 $ 18.21 3.49 $ 4,001
Schedule of assumptions used to calculate fair values of employee stock option grants	Year Ended December 31 2017 2016 2015 Weighted-average grant date fair value per stock option $ $ $ Expected dividend yield % % % Expected volatility % % % Risk-free interest rates % % % Expected lives of options years years years
Performance stock awards | Total Stockholder Return
Stock Compensation Plans
Schedule of significant assumptions used for performance stock awards	Year Ended December 31 2017 2016 2015 Dividend yield % % % Expected volatility 30.4 % 26.8 % 25.9 % Risk-free interest rates 1.31 % 0.83 % 0.93 % Performance period 3 years 3 years 3 years
Directors | Non employee stock options
Stock Compensation Plans
Summary of status and activity of stock options	Weighted- Weighted- Average Average Remaining Exercise Price Contractual Term Aggregate Non-employee director stock options: Shares (per share) (in years) Intrinsic Value Outstanding as of January 1, 2017 17,565 $ 8.37 0.42 $ 154 Exercised (17,565) 8.37 Outstanding, vested and exercisable — $ — — $ —

Accumulated Other Comprehensi40

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Accumulated Other Comprehensive Income (Loss)
Schedule of changes in components of accumulated other comprehensive income (loss), net of tax	Total Foreign Defined Accumulated Currency Benefit Other Translation Pension Plan Comprehensive Adjustments Adjustments Derivatives Income (Loss) Balance as of December 31, 2014, net of tax $ 1,943 $ (30,358) $ 905 $ (27,510) Other comprehensive loss before reclassifications (13,013) (2,446) (199) (15,658) Amounts reclassified from other comprehensive income (loss) — 2,330 (792) 1,538 Net current period other comprehensive loss (13,013) (116) (991) (14,120) Balance as of December 31, 2015, net of tax (11,070) (30,474) (86) (41,630) Other comprehensive income (loss) before reclassifications (10,956) (4,879) 809 (15,026) Amounts reclassified from other comprehensive income (loss) — 2,980 77 3,057 Net current period other comprehensive income (loss) (10,956) (1,899) 886 (11,969) Balance as of December 31, 2016, net of tax (22,026) (32,373) 800 (53,599) Other comprehensive income (loss) before reclassifications 27,989 (1,537) (1,409) 25,043 Amounts reclassified from other comprehensive income (loss) — 2,829 86 2,915 Net current period other comprehensive income (loss) 27,989 1,292 (1,323) 27,958 Balance as of December 31, 2017, net of tax $ 5,963 $ (31,081) $ (523) $ (25,641)
Schedule of details about components and amount reclassified from accumulated other comprehensive income (loss)	Amount Reclassified from Accumulated Other Details about Accumulated Comprehensive Income (Loss) (1) Affected Line Item in the Other Comprehensive Year Ended December 31 Statement where Income (Loss) Components 2017 2016 2015 Net Income is Presented Defined Benefit Pension Plan Adjustments: Prior service credit $ 9 $ — $ (15) (2) Actuarial losses (4,402) (4,749) (3,631) (2) (4,393) (4,749) (3,646) Total before tax 1,564 1,769 1,316 Tax benefit (2,829) (2,980) (2,330) Net of tax Derivatives: Foreign exchange contracts 102 206 2,077 Cost of products sold (excluding depreciation and amortization) Natural gas contracts 66 (339) (941) Cost of products sold (excluding depreciation and amortization) Interest rate swap contract (311) — — Interest expense (143) (133) 1,136 Total before tax 57 56 (344) Tax benefit (expense) (86) (77) 792 Net of tax Total reclassifications for the period $ (2,915) $ (3,057) $ (1,538) Net of tax (1) Amounts in parentheses indicate expenses. (2) These accumulated other comprehensive (loss) components are included in the computation of net periodic pension cost.
Schedule of components of income tax expense (benefit) included in other comprehensive income (loss)	Year Ended December 31 2017 2016 2015 Defined benefit pension plan $ 1,239 $ (647) $ 183 Derivatives (615) 519 (521)

Basic and Diluted Net Income 41

Basic and Diluted Net Income per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Basic and Diluted Net Income Per Common Share
Schedule of computation of basic and diluted net income per common share	Year Ended December 31 (In thousands, except per share amounts) 2017 2016 2015 Net income available to common stockholders $ 21,101 $ 13,797 $ 43,463 Weighted average shares outstanding Basic 50,470 50,259 51,902 Effect of dilutive securities 76 764 807 Diluted 50,546 51,023 52,709 Basic net income per common share $ 0.42 $ 0.27 $ 0.84 Diluted net income per common share $ 0.42 $ 0.27 $ 0.82

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Taxes
Schedule of components of provision for income taxes	Year Ended December 31 2017 2016 2015 Current Federal $ 15,799 $ 6,481 $ 5,967 State and local 1,505 523 577 Foreign 4,497 4,664 6,597 21,801 11,668 13,141 Deferred Federal (9,860) (1,795) 5,471 State and local 52 435 563 Foreign 469 (4,032) 748 (9,339) (5,392) 6,782 Provision for income taxes $ 12,462 $ 6,276 $ 19,923
Schedule of differences between U.S. federal statutory tax rate and effective income tax rate	Year Ended December 31 2017 2016 2015 U.S. federal statutory rate 35.0 % 35.0 % 35.0 % State income taxes, net of federal income tax benefit 1.9 2.9 1.8 Tax rate differential on foreign income (9.8) (6.5) (3.1) Permanent tax differences (1.3) 3.2 (1.6) Valuation allowance (1.2) 0.8 0.3 Tax statute expiration (0.3) (0.3) (0.6) Change in uncertain tax positions 0.1 0.4 0.1 Deferred tax benefit for Section 987 — (2.7) — Corporate restructuring 9.4 — — U.S. tax reform 1.8 — — Other — net 1.5 (1.5) (0.5) Effective income tax rate 37.1 % 31.3 % 31.4 %
Schedule of gross operating loss carryforwards and tax credit carryforwards	Type Amount Expiration Date Foreign tax credits $ 13 State tax credits (1) 2,231 2023 - 2027; unlimited Operating loss carryforwards — federal 421 Operating loss carryforwards — state (2) 6,619 2018 - 2037 Operating loss carryforwards — foreign (3) 15,692 2022 - unlimited (1) Of the total state tax credit carryforwards, approximately 44% begin to expire in 2023. (2) Of the total state operating loss-carryforwards, approximately 98% expire in 2025 or later. (3) Of the total foreign tax operating loss carryforwards, approximately 80% have no expiration.
Schedule of components of deferred taxes	December 31 2017 2016 Deferred tax assets Net operating loss and credit carryforwards (1) (2) $ 6,191 $ 7,763 Accruals and other timing items 10,653 15,824 Inventories 8,730 11,181 Pensions 9,156 12,186 Valuation allowance (2,063) (2,510) Total deferred tax assets 32,667 44,444 Deferred tax liabilities Property, plant and equipment 25,850 45,300 Goodwill and other intangible assets 14,374 15,716 U.S. liability on foreign deferred taxes 512 1,095 Total deferred tax liabilities 40,736 62,111 Net deferred tax liability $ (8,069) $ (17,667) (1) Uncertain tax liabilities of approximately $0.1 million and $0.2 million partially offset the net operating losses and credit carryforwards in 2017 and 2016, respectively. (2) Net indirect benefits on uncertain tax liabilities of approximately $12 thousand and $72 thousand are included in the U.S. net operating loss and credit carryforwards in 2017 and 2016, respectively.
Schedule of reconciliation of unrecognized income tax benefits	Year Ended December 31 2017 2016 2015 Balance as of January 1 $ 785 $ 778 $ 1,187 Gross increases for tax positions of current year 112 108 78 Lapse of statute of limitations (135) (101) (417) Settlement of uncertain tax positions — — (70) Balance as of December 31 $ 762 $ 785 $ 778
Summary of tax years that remain subject to examination for major jurisdictions	Jurisdiction Years United States 2012 - 2017 Kentucky 2013 - 2017 Pennsylvania 2014 - 2017 Belgium 2014 - 2017 China 2014 - 2017 Germany 2014 - 2017 United Kingdom 2014 - 2017 Japan 2012, 2016, 2017 Singapore 2014 - 2017 France 2016 - 2017 Italy 2013 - 2017

Commitments (Tables)

Commitments (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments
Schedule of future minimum purchase requirements under terms of long-term supply contracts	Due 2018 2019 2020 2021 2022 Thereafter Raw and other materials $ 821 $ 821 $ 821 $ 821 $ — $ — Information systems and services 2,245 705 15 — — — Total contractual cash obligations $ 3,066 $ 1,526 $ 836 $ 821 $ — $ —
Schedule of total payments made for purchases under long-term supply contracts	December 31 2017 (1) 2016 2015 Raw and other materials $ 815 $ 21,178 $ 27,832 Information systems and services 2,291 1,384 1,871 Total payments $ 3,106 $ 22,562 $ 29,703

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Information
Schedule of results of operations, expenditures for long-lived assets and total assets by segment	Year Ended December 31 2017 2016 2015 Net sales Activated Carbon $ 547,000 $ 476,771 $ 496,949 Alternative Materials 56,393 14,404 9,163 Advanced Water Purification 16,418 23,071 28,892 Consolidated net sales $ 619,811 $ 514,246 $ 535,004 Segment operating income (loss) Activated Carbon $ 47,052 $ 32,968 $ 65,398 Alternative Materials 403 (3,201) 1,421 Advanced Water Purification (4,788) (5,245) (2,025) 42,667 24,522 64,794 Reconciling items: Merger related expenses (4,641) — — Other operating income 4,148 — — Interest income 49 99 58 Interest expense (7,842) (2,385) (773) Other income (expense) — net (818) (2,163) (693) Income before income tax provision $ 33,563 $ 20,073 $ 63,386 Year Ended December 31 2017 2016 2015 Depreciation and amortization Activated Carbon $ 40,286 $ 35,507 $ 33,216 Alternative Materials 5,343 1,213 610 Advanced Water Purification 1,038 1,350 1,627 Depreciation and amortization $ 46,667 $ 38,070 $ 35,453 Expenditures for long-lived assets Activated Carbon $ 56,886 $ 32,046 $ 59,408 Alternative Materials 2,603 492 403 Advanced Water Purification 1,759 1,256 2,417 Total expenditures (1) $ 61,248 $ 33,794 $ 62,228 (1) Includes $7.9 million, $4.0 million and $2.1 million which are included in accounts payable and accrued liabilities at December 31, 2017, 2016 and 2015, respectively. Segment assets, which are reviewed by management, consist of the total of the net property, plant, and equipment, intangibles, and goodwill balances on the Company’s consolidated balance sheets as follows: December 31 2017 2016 Total assets Activated Carbon $ 432,154 $ 392,918 Alternative Materials 75,345 67,394 Advanced Water Purification 13,850 12,989 Segment assets 521,349 473,301 Unallocated assets 333,235 301,917 Total assets $ 854,584 $ 775,218
Schedule of net sales by product	Year Ended December 31 2017 2016 2015 Net sales by product Carbon products $ 487,833 $ 432,718 $ 460,251 Filtration media products 49,016 5,709 — Capital equipment 41,133 34,349 35,114 Equipment leasing 14,426 14,041 15,235 Carbon cloth products 7,377 8,695 9,163 Spare parts 4,649 4,515 4,179 Other services 15,377 14,219 11,062 Total net sales $ 619,811 $ 514,246 $ 535,004
Schedule of geographic information for net sales	Year Ended December 31 2017 2016 2015 Net sales United States $ 291,058 $ 271,076 $ 288,645 France 42,698 23,646 20,875 United Kingdom 37,858 36,552 43,217 Germany 32,439 21,416 17,804 Japan 32,047 35,243 35,753 Italy 29,057 5,206 2,432 China 26,169 18,559 17,943 Canada 17,292 13,858 17,065 Belgium 10,359 9,373 10,383 Spain 9,336 3,812 3,302 Netherlands 8,557 5,696 5,184 South Korea 7,022 10,231 12,218 India 5,056 3,417 713 Switzerland 4,973 3,117 3,340 Sweden 3,975 3,027 3,077 Other 61,915 50,017 53,053 Total net sales (1) $ 619,811 $ 514,246 $ 535,004 (1) Net sales are attributable to countries based on location of customer.
Schedule of geographic information for property, plant and equipment, net	December 31 2017 2016 2015 Property, plant and equipment, net United States $ 239,354 $ 225,105 $ 228,057 France 65,473 52,650 — Belgium 52,185 46,648 47,921 China 12,536 12,482 13,779 United Kingdom 12,452 12,586 15,849 Italy 12,389 11,624 — Japan 5,011 5,207 5,255 Singapore 57 74 65 Denmark 33 41 53 Brazil 11 14 14 Canada 9 11 24 Germany — — 2 Total property, plant and equipment, net $ 399,510 $ 366,442 $ 311,019

Acquisition of the New Busine45

Acquisition of the New Business (Tables)	12 Months Ended
	Dec. 31, 2017
Acquisition of the New Business
Schedule of preliminary purchase price allocation	Measurement Initial Period As of Valuation Adjustments December 31, 2017 Assets Cash and cash equivalents $ 3,826 $ — $ 3,826 Receivables 10,077 — 10,077 Inventories 20,895 (2,772) 18,123 Other current assets 1,171 (303) 868 Property, plant, and equipment 67,697 (721) 66,976 Intangibles 37,248 549 37,797 Goodwill 42,844 4,873 47,717 Other assets 179 209 388 Total assets $ 183,937 $ 1,835 $ 185,772 Liabilities Accounts payable and accrued liabilities $ 6,151 $ (612) $ 5,539 Payroll and benefits payable 4,360 (1,045) 3,315 Accrued income taxes 581 — 581 Deferred income taxes - long term 7,406 (934) 6,472 Accrued pension and other liabilities 8,014 3,192 11,206 Total liabilities $ 26,512 $ 601 $ 27,113 Net assets $ 157,425 $ 1,234 $ 158,659 Cash paid for acquisition 157,425 1,234 158,659 Cash acquired (3,826) — (3,826) Net cash paid for acquisition $ 153,599 $ 1,234 $ 154,833
Schedule of unaudited pro forma results of operations including acquisition	Year Ended December 31, 2016 Net sales $ 601,153 Net income 29,326 Net income per common share Basic $ Diluted $

QUARTERLY FINANCIAL DATA - UN46

QUARTERLY FINANCIAL DATA - UNAUDITED (Tables)	12 Months Ended
	Dec. 31, 2017
QUARTERLY FINANCIAL DATA - UNAUDITED
Schedule of quarterly financial data - unaudited	2017 2016 (Dollars in thousands, except per share data) 1st Quarter (1) 2nd Quarter 3rd Quarter 4th Quarter (2) 1st Quarter 2nd Quarter 3rd Quarter 4th Quarter (3) Net sales $ 142,703 $ 152,998 $ 162,561 $ 161,549 $ 120,199 $ 132,597 $ 123,970 $ 137,480 Net sales less cost of products sold (excluding depreciation and amortization) $ 43,888 $ 46,712 $ 48,543 $ 49,772 $ 41,740 $ 44,934 $ 38,540 $ 42,634 Net income (loss) $ 775 $ 5,853 $ 5,111 $ 9,362 $ 5,458 $ 7,896 $ 6,385 $ (5,942) Common Stock Data: Basic: Net income (loss) per common share $ 0.02 $ 0.12 $ 0.10 $ 0.19 $ 0.11 $ 0.16 $ 0.13 $ (0.12) Diluted: Net income (loss) per common share $ 0.02 $ 0.12 $ 0.10 $ 0.19 $ 0.11 $ 0.15 $ 0.13 $ (0.12) Average common shares outstanding Basic 50,411 50,470 50,489 50,508 50,308 50,225 50,246 50,255 Diluted 50,486 50,511 50,624 50,561 51,041 50,987 50,984 51,081 (1) Includes $2.4 million of discrete income tax charges related to the incorporation of the Company’s former U.S. Belgium branch to a Belgium controlled foreign corporation, which was part of an overall single integrated plan of reorganization that included the Company’s acquisition of the New Business in November 2016. Results were also negatively impacted by $2.1 million of transaction expenses related to the acquisition of the New Business. (2) Includes a gain of $4.1 million on the sale of an idled plant in the UK. (3) Results were negatively impacted by $12.2 million of costs related to the acquisition of the New Business, consisting primarily of $10.5 million of transaction costs. Refer to Note 20 to the consolidated financial statements in Item 8 of this Annual Report for further information.

Summary of Accounting Policie47

Summary of Accounting Policies -Business Segments (Details) - segment	Jan. 01, 2017	Dec. 31, 2017
Summary of Accounting Policies
Number of reportable segments	3	3

Summary of Accounting Policie48

Summary of Accounting Policies - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash deposits
Cash deposits with U.S. financial institutions in excess of federally insured limits	$ 3,800	$ 4,800
Cash and cash equivalents	42,328	37,984	$ 53,629	$ 53,133
Foreign subsidiaries
Cash deposits
Cash and cash equivalents	$ 33,100	$ 27,400

Summary of Accounting Policie49

Summary of Accounting Policies - Property, Plant and Equipment Estimated Service Lives (Details)	12 Months Ended
	Dec. 31, 2017
Land improvements and buildings | Minimum
Summary of Accounting Policies
Useful life	15 years
Land improvements and buildings | Maximum
Summary of Accounting Policies
Useful life	30 years
Furniture, machinery and equipment | Minimum
Summary of Accounting Policies
Useful life	5 years
Furniture, machinery and equipment | Maximum
Summary of Accounting Policies
Useful life	15 years
Customer capital | Minimum
Summary of Accounting Policies
Useful life	5 years
Customer capital | Maximum
Summary of Accounting Policies
Useful life	10 years
Vehicles
Summary of Accounting Policies
Useful life	5 years
Computer hardware and software | Minimum
Summary of Accounting Policies
Useful life	5 years
Computer hardware and software | Maximum
Summary of Accounting Policies
Useful life	10 years

Summary of Accounting Policie50

Summary of Accounting Policies - Pensions (Details) - Long-term corporate bonds - United States	Dec. 31, 2017item
Minimum
Pensions
Number of highest ratings on long-term corporate bonds evaluated in determining the discount rates for pension obligations	1
Maximum
Pensions
Number of highest ratings on long-term corporate bonds evaluated in determining the discount rates for pension obligations	2

Summary of Accounting Policie51

Summary of Accounting Policies - Labor Agreements (Details) - Labor force concentration risk	Dec. 31, 2017
Collective bargaining agreements
Concentration of risk
Percentage of labor force covered	48.00%
Collective bargaining agreements that expired on December 31, 2017
Concentration of risk
Percentage of labor force covered	3.00%
Collective bargaining agreements expiring in July or December 2018 | United States
Concentration of risk
Percentage of labor force covered	4.00%
Collective bargaining agreements expiring in July or December 2018 | Europe
Concentration of risk
Percentage of labor force covered	25.00%

Summary of Accounting Policie52

Summary of Accounting Policies - New Accounting Pronouncements - ASU 2014-09, Revenue (Details)	12 Months Ended
	Dec. 31, 2017
Consolidated net sales | Revenue recognition basis | Contracts accounted for on percentage of completion method
Concentration Risk [Line Items]
Percentage of total	6.00%

Summary of Accounting Policie53

Summary of Accounting Policies - New Accounting Pronouncements - ASU 2016-02, Leases (Details) $ in Millions	Dec. 31, 2017USD ($)
Leases
Undiscounted future minimum payments outstanding for lease obligations	$ 41

Summary of Accounting Policie54

Summary of Accounting Policies - New Accounting Pronouncements - ASU 2017-07, Compensation - Retirement Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Adoption of new accounting pronouncement
Income from operations	$ 42,174	$ 24,522	$ 64,794
Other income (expense) - net	818	2,163	$ 693
Proforma adjustment | ASU 2017-07, “Compensation – Retirement Benefits
Adoption of new accounting pronouncement
Income from operations	2,600	3,000
Other income (expense) - net	$ 2,600	$ 3,000

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventories
Raw materials	$ 29,940	$ 24,831
Finished goods	91,707	100,284
Total	121,647	125,115
Reserves for obsolete and slow-moving items	$ 2,800	$ 2,600

Property, Plant and Equipment56

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment
Property, plant and equipment, gross	$ 791,106	$ 791,106	$ 718,875
Less accumulated depreciation	(391,596)	(391,596)	(352,433)
Property, plant and equipment, net	399,510	399,510	366,442	$ 311,019
Depreciation expense		44,400	36,300	$ 33,700
Gain on the sale of an idled plant	4,100	4,148
Proceeds from sale of idle plant assets		4,700
Accrued pension and other liabilities
Property, Plant and Equipment
Asset retirement obligations	2,800	2,800	1,800
Other operating income
Property, Plant and Equipment
Gain on the sale of an idled plant		4,100
Land and improvements
Property, Plant and Equipment
Property, plant and equipment, gross	39,679	39,679	37,479
Mineral rights
Property, Plant and Equipment
Property, plant and equipment, gross	11,424	11,424	11,240
Buildings
Property, Plant and Equipment
Property, plant and equipment, gross	96,694	96,694	90,385
Machinery, equipment and customer capital
Property, Plant and Equipment
Property, plant and equipment, gross	524,162	524,162	494,722
Computer hardware and software
Property, Plant and Equipment
Property, plant and equipment, gross	45,499	45,499	43,631
Furniture and vehicles
Property, Plant and Equipment
Property, plant and equipment, gross	12,189	12,189	10,893
Construction-in-progress
Property, Plant and Equipment
Property, plant and equipment, gross	$ 61,459	$ 61,459	$ 30,525

Goodwill and Other Identifiab57

Goodwill and Other Identifiable Intangible Assets - Changes in Carrying Amount of Goodwill by Segment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)
Goodwill
Number of reporting units | segment	5
Changes in the carrying amount of goodwill
Balance as of beginning of year	$ 66,316	$ 25,777
Acquisition	4,873	42,844
Foreign currency translation	6,584	(2,305)
Balance as of end of period	77,773	66,316
Activated Carbon
Changes in the carrying amount of goodwill
Balance as of beginning of year	44,346	19,604
Acquisition	2,788	26,415
Foreign currency translation	4,054	(1,673)
Balance as of end of period	51,188	44,346
Alternative Materials
Changes in the carrying amount of goodwill
Balance as of beginning of year	15,810	60
Acquisition	2,085	16,429
Foreign currency translation	2,427	(679)
Balance as of end of period	20,322	15,810
Advanced Water Purification
Changes in the carrying amount of goodwill
Balance as of beginning of year	6,160	6,113
Foreign currency translation	103	47
Balance as of end of period	$ 6,263	$ 6,160

Goodwill and Other Identifiab58

Goodwill and Other Identifiable Intangible Assets - Summary of Identifiable Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amortized intangible assets:
Weighted Average Amortization Period	17 years 10 months 24 days	17 years 3 months 18 days
Gross Carrying Amount	$ 49,175	$ 48,822
Foreign Exchange	2,353	(1,648)
Accumulated Amortization	(15,519)	(13,688)
Net Carrying Amount	36,009	33,486
Amortization expense	2,300	1,800	$ 1,700
Identifiable intangible assets
Gross Carrying Amount	56,537	56,184
Foreign Exchange	3,048	(1,953)
Net Carrying Amount	44,066	40,543
Estimated amortization expense to be recognized during the next five years
2,018	2,230
2,019	2,477
2,020	2,389
2,021	2,344
2,022	2,333
Trade names and trademarks
Indefinite lived intangible assets:
Gross Carrying Amount	7,362	7,362
Foreign Exchange	695	(305)
Indefinite-Lived Intangible Assets (Excluding Goodwill), Total	$ 8,057	$ 7,057
Customer relationships
Amortized intangible assets:
Weighted Average Amortization Period	18 years 10 months 24 days	18 years 10 months 24 days
Gross Carrying Amount	$ 25,584	$ 25,035
Foreign Exchange	1,250	(873)
Accumulated Amortization	(9,859)	(8,900)
Net Carrying Amount	$ 16,975	$ 15,262
Product certification
Amortized intangible assets:
Weighted Average Amortization Period	8 years 4 months 24 days	7 years 4 months 24 days
Gross Carrying Amount	$ 8,453	$ 8,649
Foreign Exchange	(89)	(90)
Accumulated Amortization	(4,427)	(4,320)
Net Carrying Amount	$ 3,937	$ 4,239
Unpatented technology and know-how
Amortized intangible assets:
Weighted Average Amortization Period	20 years	20 years
Gross Carrying Amount	$ 14,174	$ 14,174
Foreign Exchange	1,273	(586)
Accumulated Amortization	(839)	(114)
Net Carrying Amount	$ 14,608	$ 13,474
Licenses
Amortized intangible assets:
Weighted Average Amortization Period	20 years	20 years
Gross Carrying Amount	$ 964	$ 964
Foreign Exchange	(81)	(99)
Accumulated Amortization	(394)	(354)
Net Carrying Amount	$ 489	$ 511

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Measurements
Derivative assets	$ 560	$ 1,168
Derivative liabilities	(1,095)	(1,452)
Carrying Amount
Fair Value Measurements
Derivative assets	560	1,168
Derivative liabilities	(1,095)	(1,452)
Acquisition earn-out liability		(125)
Long-term debt, including current portion	(233,500)	(225,000)
Fair Value | Level 2
Fair Value Measurements
Long-term debt, including current portion	(233,500)	(225,000)
Recurring | Fair Value | Level 2
Fair Value Measurements
Derivative assets	560	1,168
Derivative liabilities	$ (1,095)	(1,452)
Acquisition earn-out liability		$ (125)

Derivative Instruments - Genera

Derivative Instruments - General Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	May 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Maximum
Managing risk exposure
Value of forecasted exposure hedged by derivatives as per management policy (as a percent)	75.00%
Foreign exchange contracts
Managing risk exposure
Notional amount of contract	$ 75,006		$ 199,420	$ 37,016
Foreign exchange contracts | Maximum
Managing risk exposure
Maturity period of derivatives	18 months
Natural gas contracts | Maximum
Managing risk exposure
Maturity period of derivatives	24 months
Interest rate swap contract
Managing risk exposure
Notional amount of contract	$ 50,000	$ 50,000

Derivative Instruments - Fair V

Derivative Instruments - Fair Value of Outstanding Derivative Contracts (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Derivative Instruments
Asset Derivatives	$ 560	$ 1,168
Liability Derivatives	1,095	1,452
Derivatives designated as hedging instruments | Foreign exchange contracts | Other current assets
Derivative Instruments
Asset Derivatives	129	670
Derivatives designated as hedging instruments | Foreign exchange contracts | Other assets
Derivative Instruments
Asset Derivatives		179
Derivatives designated as hedging instruments | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivative Instruments
Liability Derivatives	639	30
Derivatives designated as hedging instruments | Foreign exchange contracts | Accrued pension and other liabilities
Derivative Instruments
Liability Derivatives	52	1
Derivatives designated as hedging instruments | Natural gas contracts | Other current assets
Derivative Instruments
Asset Derivatives		255
Derivatives designated as hedging instruments | Natural gas contracts | Other assets
Derivative Instruments
Asset Derivatives	1	43
Derivatives designated as hedging instruments | Natural gas contracts | Accounts payable and accrued liabilities
Derivative Instruments
Liability Derivatives	143
Derivatives designated as hedging instruments | Natural gas contracts | Accrued pension and other liabilities
Derivative Instruments
Liability Derivatives	50
Derivatives designated as hedging instruments | Interest rate swap contract | Other assets
Derivative Instruments
Asset Derivatives	121
Derivatives not designated as hedging instruments | Foreign exchange contracts | Other current assets
Derivative Instruments
Asset Derivatives	309	21
Derivatives not designated as hedging instruments | Foreign exchange contracts | Accounts payable and accrued liabilities
Derivative Instruments
Liability Derivatives	$ 211	$ 1,421

Derivative Instruments - Notion

Derivative Instruments - Notional Amounts of Outstanding Derivative Contracts (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017USD ($)MMBTU	Dec. 31, 2016USD ($)MMBTU	Dec. 31, 2015USD ($)MMBTU	May 31, 2017USD ($)
Natural gas contracts
Derivative Instruments
Outstanding derivative contracts that were entered into to hedge forecasted transactions (in mmbtu) | MMBTU	1,105,000	540,000	955,000
Foreign exchange contracts
Derivative Instruments
Outstanding derivative contracts that were entered into to hedge forecasted transactions	$ 75,006	$ 199,420	$ 37,016
Interest rate swap contract
Derivative Instruments
Outstanding derivative contracts that were entered into to hedge forecasted transactions	$ 50,000			$ 50,000

Derivative Instruments - Gross

Derivative Instruments - Gross and Net Amounts of Derivative Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value of Assets
Gross derivative amounts recognized in the balance sheet	$ 560	$ 1,168
Gross derivative amounts not offset in the balance sheet that are eligible for offsetting	(341)	(52)
Net amount	219	1,116
Fair Value of Liabilities
Gross derivative amounts recognized in the balance sheet	1,095	1,452
Gross derivative amounts not offset in the balance sheet that are eligible for offsetting	(341)	(52)
Net amount	$ 754	$ 1,400

Derivative Instruments - Deriva

Derivative Instruments - Derivatives in Cash Flow Hedging Relationships (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments
Loss relating to accumulated OCI expected to be recognized in earnings over the next 12 months	$ 700
Cash flow hedges
Derivative Instruments
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	(2,078)	$ 1,234	$ (337)
Amount of gain or (loss) recognized in earnings on derivatives related to ineffective portion and amount excluded from effectiveness testing	0	0	0
Cash flow hedges | Cost of products sold (excluding depreciation and amortization)
Derivative Instruments
Amount of Gain or (Loss) Recognized from Accumulated OCI into Earnings (Effective Portion)	(143)	(133)	1,136
Cash flow hedges | Foreign exchange contracts
Derivative Instruments
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	(1,421)	399	647
Cash flow hedges | Foreign exchange contracts | Cost of products sold (excluding depreciation and amortization)
Derivative Instruments
Amount of Gain or (Loss) Recognized from Accumulated OCI into Earnings (Effective Portion)	102	206	2,077
Cash flow hedges | Natural gas contracts
Derivative Instruments
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	(467)	835	(984)
Cash flow hedges | Natural gas contracts | Cost of products sold (excluding depreciation and amortization)
Derivative Instruments
Amount of Gain or (Loss) Recognized from Accumulated OCI into Earnings (Effective Portion)	66	$ (339)	$ (941)
Cash flow hedges | Interest rate swap contract
Derivative Instruments
Amount of Gain or (Loss) Recognized in OCI on Derivatives (Effective Portion)	(190)
Cash flow hedges | Interest rate swap contract | Interest expense
Derivative Instruments
Amount of Gain or (Loss) Recognized from Accumulated OCI into Earnings (Effective Portion)	$ (311)

Derivative Instruments - Deri65

Derivative Instruments - Derivatives Not Designated as Hedging Instruments (Details) - Other expense - net - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Derivative Instruments
Amount of Gain or (Loss) Recognized in Earnings on Derivatives Not Designated as Hedging Instruments	$ (9,096)	$ 4,425	$ (1,042)
Foreign exchange contracts
Derivative Instruments
Amount of Gain or (Loss) Recognized in Earnings on Derivatives Not Designated as Hedging Instruments	$ (9,096)	$ 4,425	$ (1,042)

Derivative Instruments - Non De

Derivative Instruments - Non Designated Contracts on Intercompany Loan (Details) - Intercompany loan - Other expense - net - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Foreign exchange contracts
Net losses on non-designated foreign exchange contracts	$ 9.6	$ (4.4)
Foreign exchange transaction gains	$ 10.3	$ (5)

Product Warranties (Details)

Product Warranties (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Product Warranties
Warranty period from the shipment date	18 months
Warranty period from the project startup date	12 months
Change in warranty reserve
Beginning Balance	$ 1,402	$ 1,252
Payments and replacement product	(390)	(1,495)
Additions to warranty reserve for warranties issued during the period	618	1,647
Change in the warranty reserve for pre-existing warranties	6	(2)
Ending Balance	$ 1,636	$ 1,402

Borrowing Arrangements - Long-T

Borrowing Arrangements - Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Borrowing Arrangements
Total long-term debt	$ 233,500	$ 225,000
Less current portion of long-term debt	(5,000)	(5,000)
Long-term debt	$ 228,500	$ 220,000

Borrowing Arrangements - Debt A

Borrowing Arrangements - Debt Agreements (Details)	Nov. 02, 2016USD ($)	Oct. 04, 2016USD ($)	Dec. 31, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2017JPY (¥)	Dec. 31, 2017USD ($)	Dec. 31, 2016JPY (¥)	Dec. 31, 2016USD ($)	Mar. 24, 2016JPY (¥)
Borrowing arrangements
Amount borrowed					$ 151,411,000	$ 328,249,000	$ 111,400,000
Amount shown as current portion of long-term debt									$ 5,000,000		$ 5,000,000
Repayment of outstanding balance						$ 4,002,000
First Amended and Restated Credit Agreement
Borrowing arrangements
Maximum borrowing capacity		$ 400,000,000
Issuance costs incurred		800,000
Debt issuance costs expensed		100,000
Permitted annual dividends					$ 14,000,000
First Amended and Restated Credit Agreement | Minimum
Borrowing arrangements
Rate of interest at balance sheet date (as a percent)								3.37%	3.37%
First Amended and Restated Credit Agreement | Maximum
Borrowing arrangements
Rate of interest at balance sheet date (as a percent)								3.62%	3.62%
First Amended and Restated Credit Agreement | Permitted dividends | Minimum
Borrowing arrangements
Sum of availability under Credit Agreement and amount of U.S. cash on hand									$ 50,000,000
Japanese Credit Agreement | CCJ
Borrowing arrangements
Maximum borrowing capacity | ¥												¥ 2,000,000,000
Quarterly nonrefundable commitment fee payable (as a percent)					0.25%
Amount outstanding | ¥								¥ 0		¥ 0
Availability under the credit facility								¥ 2,000,000,000	$ 17,800,000
Japanese Credit Agreement | TIBOR | CCJ
Borrowing arrangements
Average interest rate (as a percent)								2.06%	2.06%	1.31%	1.31%
Japanese Term Loan due May 2017 | CCJ
Borrowing arrangements
Repayment of outstanding balance				$ 4,000,000
Other Credit Facilities
Borrowing arrangements
Maximum borrowing capacity									$ 7,000,000		$ 6,000,000
Amount outstanding									0		0
Other Credit Facilities | Bank guarantees
Borrowing arrangements
Amount outstanding									5,100,000		3,500,000
Other Credit Facilities | Surety bonds
Borrowing arrangements
Amount outstanding									1,100,000		1,100,000
Revolving credit facility | First Amended and Restated Credit Agreement
Borrowing arrangements
Maximum borrowing capacity		300,000,000
Increase in borrowing capacity that may be requested		100,000,000
Quarterly nonrefundable commitment fee payable (as a percent)					0.25%
Amount borrowed	$ 160,000,000		$ 160,000,000
Amount outstanding									138,500,000		125,000,000
Availability under the credit facility									159,200,000		172,500,000
Letters of credit | First Amended and Restated Credit Agreement
Borrowing arrangements
Maximum borrowing capacity		75,000,000
Amount outstanding									2,300,000		2,500,000
Swing loans | First Amended and Restated Credit Agreement
Borrowing arrangements
Maximum borrowing capacity		15,000,000
Term loan facility | First Amended and Restated Credit Agreement
Borrowing arrangements
Maximum borrowing capacity		100,000,000
Amount borrowed		$ 100,000,000
Amount shown as current portion of long-term debt									5,000,000		5,000,000
Amount outstanding									95,000,000		$ 100,000,000
Availability under the credit facility									$ 0
Term loan facility | First Amended and Restated Credit Agreement | January 1, 2017 until January 1, 2019
Borrowing arrangements
Required quarterly repayments as a percentage of outstanding principal balance					1.25%
Term loan facility | First Amended and Restated Credit Agreement | January 1, 2019 until October 4, 2023 maturity date
Borrowing arrangements
Required quarterly repayments as a percentage of outstanding principal balance					2.00%

Borrowing Arrangements - Maturi

Borrowing Arrangements - Maturities of Debt and Interest Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Borrowing Arrangements
Principal payments on debt outstanding in 2018	$ 5
Principal payments on debt outstanding in 2019	8
Principal payments on debt outstanding in 2020	8
Principal payments on debt outstanding in 2021	146.5
Principal payments on debt outstanding in 2022	8
Interest Expense
Interest expense	7.8	$ 2.4	$ 0.8
Interest costs capitalized	$ 0.8	$ 0.3	$ 0.4

Employee Benefit Plans - Settle

Employee Benefit Plans - Settlements and Other Changes (Details) - Qualified plans - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Lump sum settlement payments of benefits	$ 4.2	$ 5.2	$ 3.8
Settlement charges	$ 1	$ 1.5	$ 0.8

Employee Benefit Plans - Change

Employee Benefit Plans - Changes in Benefit Obligations and Fair Value of Assets, Funded Status and Actuarial Assumptions for Pension Plans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States
Change in Projected Benefit Obligations
Projected benefit obligation as of beginning of year	$ 110,732	$ 108,938
Service cost	959	957	$ 1,136
Interest cost	4,413	4,589	4,499
Actuarial loss (gain)	7,796	4,293
Benefits paid	(4,327)	(4,094)
Settlement	(2,021)	(3,951)
Projected benefit obligation as of end of year	117,552	110,732	108,938
Change in Plan Assets
Fair value of plan assets as of beginning of year	88,240	89,382
Actual return on plan assets	12,547	6,221
Employer contributions	838	682
Benefits paid	(4,327)	(4,094)
Settlement	(2,021)	(3,951)
Fair value of plan assets as of end of year	95,277	88,240	89,382
Funded status as of end of year	(22,275)	(22,492)
Amounts recognized in the Balance Sheets:
Net amount recognized	(22,275)	(22,492)
Amounts recognized in Accumulated Other Comprehensive Income consist of:
Accumulated net actuarial loss	36,273	38,694
Net amount recognized, before tax effect	$ 36,273	$ 38,694
Weighted-average assumptions used to determine benefit obligations at period end:
Discount rate (as a percent)	3.63%	4.09%
Rate of increase in compensation levels (as a percent)	3.00%	3.00%
United States | Payroll and benefits payable
Amounts recognized in the Balance Sheets:
Current liability	$ (82)	$ (82)
United States | Accrued pension and other liabilities
Amounts recognized in the Balance Sheets:
Noncurrent liability	(22,193)	(22,410)
Europe
Change in Projected Benefit Obligations
Projected benefit obligation as of beginning of year	43,495	39,201
Service cost	524	395	288
Interest cost	972	1,142	1,250
Employee contributions	72	73
Actuarial loss (gain)	593	7,018
Benefits paid	(1,055)	(1,527)
Acquisition		3,899
Plan Amendments		(91)
Settlement	(2,173)	(1,224)
Foreign currency exchange rate changes	4,836	(5,391)
Projected benefit obligation as of end of year	47,264	43,495	39,201
Change in Plan Assets
Fair value of plan assets as of beginning of year	27,936	29,351
Actual return on plan assets	2,012	4,212
Employer contributions	2,087	1,744
Employee contributions	72	73
Benefits paid	(1,055)	(1,527)
Settlement	(2,173)	(1,224)
Foreign currency exchange rate changes	2,775	(4,693)
Fair value of plan assets as of end of year	31,654	27,936	$ 29,351
Funded status as of end of year	(15,610)	(15,559)
Amounts recognized in the Balance Sheets:
Net amount recognized	(15,610)	(15,559)
Amounts recognized in Accumulated Other Comprehensive Income consist of:
Accumulated prior service cost	(91)	(91)
Accumulated net actuarial loss	10,720	10,549
Net amount recognized, before tax effect	$ 10,629	$ 10,458
Weighted-average assumptions used to determine benefit obligations at period end:
Discount rate (as a percent)	2.02%	2.11%
Rate of increase in compensation levels (as a percent)	2.95%	2.87%
Europe | Other assets
Amounts recognized in the Balance Sheets:
Noncurrent asset	$ 710	$ 141
Europe | Payroll and benefits payable
Amounts recognized in the Balance Sheets:
Current liability	(630)	(493)
Europe | Accrued pension and other liabilities
Amounts recognized in the Balance Sheets:
Noncurrent liability	$ (15,690)	$ (15,207)

Employee Benefit Plans - Fair V

Employee Benefit Plans - Fair Values of Pension Plan Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States
Pensions
Fair value of plan assets	$ 95,277	$ 88,240	$ 89,382
United States | Level 1
Pensions
Fair value of plan assets	50,000	47,455
United States | Level 2
Pensions
Fair value of plan assets	45,277	40,785
United States | Cash and cash equivalents
Pensions
Fair value of plan assets	2,984	4,414
United States | Cash and cash equivalents | Level 1
Pensions
Fair value of plan assets	2,984	4,414
United States | Large cap equities
Pensions
Fair value of plan assets	17,260	16,528
United States | Large cap equities | Level 1
Pensions
Fair value of plan assets	17,260	16,528
United States | Small/mid cap equity securities
Pensions
Fair value of plan assets	11,485	9,584
United States | Small/mid cap equity securities | Level 1
Pensions
Fair value of plan assets	11,485	9,584
United States | International equity
Pensions
Fair value of plan assets	7,927	6,377
United States | International equity | Level 1
Pensions
Fair value of plan assets	7,927	6,377
United States | Emerging markets
Pensions
Fair value of plan assets	6,190	5,333
United States | Emerging markets | Level 1
Pensions
Fair value of plan assets	6,190	5,333
United States | Corporate bonds
Pensions
Fair value of plan assets	25,906	23,034
United States | Corporate bonds | Level 2
Pensions
Fair value of plan assets	25,906	23,034
United States | Government bonds
Pensions
Fair value of plan assets	15,060	14,346
United States | Government bonds | Level 1
Pensions
Fair value of plan assets	690	561
United States | Government bonds | Level 2
Pensions
Fair value of plan assets	14,370	13,785
United States | International bonds
Pensions
Fair value of plan assets	5,001	3,966
United States | International bonds | Level 2
Pensions
Fair value of plan assets	5,001	3,966
United States | Commodities
Pensions
Fair value of plan assets	1,737	2,051
United States | Commodities | Level 1
Pensions
Fair value of plan assets	1,737	2,051
United States | Real estate
Pensions
Fair value of plan assets	1,727	2,607
United States | Real estate | Level 1
Pensions
Fair value of plan assets	1,727	2,607
Europe
Pensions
Fair value of plan assets	31,654	27,936	$ 29,351
Europe | Level 1
Pensions
Fair value of plan assets	30,029	25,970
Europe | Level 3
Pensions
Fair value of plan assets	1,625	1,966
Europe | Cash and cash equivalents
Pensions
Fair value of plan assets	2,833	2,005
Europe | Cash and cash equivalents | Level 1
Pensions
Fair value of plan assets	2,833	2,005
Europe | M&G PP UK equity passive fund
Pensions
Fair value of plan assets	1,092	950
Europe | M&G PP UK equity passive fund | Level 1
Pensions
Fair value of plan assets	1,092	950
Europe | M&G PP overseas equity passive fund
Pensions
Fair value of plan assets	5,062	4,291
Europe | M&G PP overseas equity passive fund | Level 1
Pensions
Fair value of plan assets	5,062	4,291
Europe | LGIM dynamic diversified fund
Pensions
Fair value of plan assets	2,672	3,758
Europe | LGIM dynamic diversified fund | Level 1
Pensions
Fair value of plan assets	2,672	3,758
Europe | W. Blair dynamic diversified allocation fund
Pensions
Fair value of plan assets	2,418	1,160
Europe | W. Blair dynamic diversified allocation fund | Level 1
Pensions
Fair value of plan assets	2,418	1,160
Europe | Delta Lloyd fixed income
Pensions
Fair value of plan assets	738	1,158
Europe | Delta Lloyd fixed income | Level 3
Pensions
Fair value of plan assets	738	1,158
Europe | Corporate bonds
Pensions
Fair value of plan assets	548	428
Europe | Corporate bonds | Level 1
Pensions
Fair value of plan assets	548	428
Europe | Government Bonds
Pensions
Fair value of plan assets	12,823	10,582
Europe | Government Bonds | Level 1
Pensions
Fair value of plan assets	12,823	10,582
Europe | Real estate
Pensions
Fair value of plan assets	2,581	2,796
Europe | Real estate | Level 1
Pensions
Fair value of plan assets	2,581	2,796
Europe | Insurance reserves
Pensions
Fair value of plan assets	887	808
Europe | Insurance reserves | Level 3
Pensions
Fair value of plan assets	$ 887	$ 808

Employee Benefit Plans - Chan74

Employee Benefit Plans - Changes in Fair Value Measurements of Pension Plan Assets Using Significant Unobservable Inputs (Details) - Europe - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Delta Lloyd fixed income
Changes in fair value measurements using significant unobservable inputs
Fair value of plan assets at beginning of year	$ 1,158	$ 1,864
Sales/Maturities	(554)	(668)
Foreign currency translation	134	(38)
Fair value of plan assets at end of year	738	1,158
Insurance reserves
Changes in fair value measurements using significant unobservable inputs
Fair value of plan assets at beginning of year	808	1,259
Purchases	95	101
Sales/Maturities	(129)	(525)
Foreign currency translation	113	(27)
Fair value of plan assets at end of year	$ 887	$ 808

Employee Benefit Plans - Projec

Employee Benefit Plans - Projected and Accumulated Benefit Obligations, Employer Contributions and Benefit Payments for Pension Plans (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States
Projected benefit obligation and accumulated benefit obligation for all defined benefit pension plans
Projected benefit obligation	$ 117,552	$ 110,732	$ 108,938
Accumulated benefit obligation	114,322	107,037
Fair value of plan assets	95,277	88,240	89,382
Aggregate projected benefit obligation and fair value of plan assets for pension pans with projected benefit obligations in excess of plan assets
Projected benefit obligation	117,552	110,732
Fair value of plan assets	95,277	88,240
Aggregate accumulated benefit obligation and fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets
Accumulated benefit obligation	114,322	107,037
Fair value of plan assets	95,277	88,240
Employer contributions
2,018	2,126
Benefit Payments
2,018	6,188
2,019	6,551
2,020	6,791
2,021	6,756
2,022	7,933
2023- 2027	36,611
Europe
Projected benefit obligation and accumulated benefit obligation for all defined benefit pension plans
Projected benefit obligation	47,264	43,495	39,201
Accumulated benefit obligation	43,940	40,886
Fair value of plan assets	31,654	27,936	$ 29,351
Aggregate projected benefit obligation and fair value of plan assets for pension pans with projected benefit obligations in excess of plan assets
Projected benefit obligation	33,896	31,570
Fair value of plan assets	17,575	15,872
Aggregate accumulated benefit obligation and fair value of plan assets for plans with accumulated benefit obligations in excess of plan assets
Accumulated benefit obligation	30,572	28,962
Fair value of plan assets	17,575	$ 15,872
Employer contributions
2,018	1,950
Benefit Payments
2,018	1,429
2,019	1,291
2,020	1,433
2,021	1,377
2,022	1,645
2023- 2027	$ 10,311

Employee Benefit Plans - Compon

Employee Benefit Plans - Components of Net Periodic Pension Costs and Future Amounts to be Recognized (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States
Components of net periodic pension costs of the plans
Service cost	$ 959	$ 957	$ 1,136
Interest cost	4,413	4,589	4,499
Expected return on plan assets	(5,855)	(6,040)	(7,070)
Amortization of prior service credit			15
Net actuarial loss amortization	2,987	3,010	2,606
Settlement	537	1,149	607
Net periodic pension cost	3,041	3,665	1,793
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Current year actuarial gain (loss)	(1,103)	(4,112)	(3,348)
Amortization of actuarial loss	2,987	3,010	2,606
Amortization of prior service cost			15
Settlement	537	1,149	607
Total recognized in other comprehensive income (loss)	2,421	47	(120)
Total recognized in net periodic pension cost and other comprehensive income (loss)	(620)	(3,618)	(1,913)
Estimated amounts that will be amortized from accumulated other comprehensive income (loss) into net periodic pension cost
Net actuarial loss	2,825
Total	2,825
Europe
Components of net periodic pension costs of the plans
Service cost	524	395	288
Interest cost	972	1,142	1,250
Expected return on plan assets	(1,322)	(1,416)	(1,705)
Amortization of prior service credit	(9)
Net actuarial loss amortization	452	229	219
Settlement	426	361	199
Net periodic pension cost	1,043	711	251
Other Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive Income (Loss)
Current year actuarial gain (loss)	98	(4,222)	(984)
Amortization of actuarial loss	452	229	219
Current year prior service credit		91
Amortization of prior service cost	(9)
Settlement	426	361	199
Foreign currency exchange	(1,138)	1,122	603
Total recognized in other comprehensive income (loss)	(171)	(2,419)	37
Total recognized in net periodic pension cost and other comprehensive income (loss)	(1,214)	$ (3,130)	$ (214)
Estimated amounts that will be amortized from accumulated other comprehensive income (loss) into net periodic pension cost
Prior service credit	(10)
Net actuarial loss	367
Total	$ 357

Employee Benefit Plans - Assump

Employee Benefit Plans - Assumptions for Net Periodic Pension Cost and Asset Allocation (Details) - item	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States
Assumptions used in the measurement of the net periodic pension cost
Discount rate (as a percent)	4.09%	4.38%	4.01%
Expected annual return on plan assets (as a percent)	6.87%	7.00%	7.50%
Rate of increase in compensation levels (as a percent)	3.00%	3.00%	3.00%
United States | Long-term corporate bonds | Minimum
Assumptions used in the measurement of the net periodic pension cost
Number of highest ratings on long-term corporate bonds evaluated in determining the discount rates for pension obligations	1
United States | Long-term corporate bonds | Maximum
Assumptions used in the measurement of the net periodic pension cost
Number of highest ratings on long-term corporate bonds evaluated in determining the discount rates for pension obligations	2
United States | Equity Securities | Minimum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	40.00%
United States | Equity Securities | Maximum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	50.00%
United States | Fixed Income Securities | Minimum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	45.00%
United States | Fixed Income Securities | Maximum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	55.00%
United States | Other Investments
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	5.00%
Europe
Assumptions used in the measurement of the net periodic pension cost
Discount rate (as a percent)	2.11%	2.97%	3.00%
Expected annual return on plan assets (as a percent)	4.46%	5.28%	5.54%
Rate of increase in compensation levels (as a percent)	2.87%	3.07%	3.38%
Europe | Equity Securities | Minimum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	25.00%
Europe | Equity Securities | Maximum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	35.00%
Europe | Fixed Income Securities | Minimum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	40.00%
Europe | Fixed Income Securities | Maximum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	50.00%
Europe | Other Investments | Minimum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	20.00%
Europe | Other Investments | Maximum
Assumptions used in the measurement of the net periodic pension cost
Asset allocation assumptions / targeted portfolio mix (as a percent)	30.00%

Employee Benefit Plans - Multi-

Employee Benefit Plans - Multi-Employer Pension Plan (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Multi-employer pension plan | Payroll and benefits payable
Multi-employer pension plan
Accrued plan liability	$ 1.1	$ 0.9

Employee Benefit Plans - Define

Employee Benefit Plans - Defined Contribution Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Benefit Plans
Total expenses related to the defined contribution plans	$ 3.6	$ 3.8	$ 3.1

Stock Compensation Plans - Gene

Stock Compensation Plans - General (Details) - shares	12 Months Ended		84 Months Ended
	Dec. 31, 2017	Dec. 31, 2010	Dec. 31, 2017
Employee stock options
Stock Awards Vesting
Expiration period		10 years	7 years
2008 Equity Incentive Plan
Stock Awards Vesting
Maximum number of shares available for grants	7,600,000		7,600,000
2008 Equity Incentive Plan | Incentive Stock Options
Stock Awards Vesting
Maximum number of shares available for grants	1,500,000		1,500,000
2008 Equity Incentive Plan | Incentive Stock Options | Ten percent employee | Minimum
Stock Awards Vesting
Exercise price expressed as a percentage of fair market value	110.00%
2008 Equity Incentive Plan | Employee and nonemployee stock options | Minimum
Stock Awards Vesting
Expiration period	7 years
2008 Equity Incentive Plan | Employee and nonemployee stock options | Maximum
Stock Awards Vesting
Expiration period	10 years
2008 Equity Incentive Plan | Stock appreciation rights | Minimum
Stock Awards Vesting
Expiration period	7 years
2008 Equity Incentive Plan | Stock appreciation rights | Maximum
Stock Awards Vesting
Expiration period	10 years
Prior Plans | Employee and nonemployee stock options
Stock Awards Vesting
Expiration period	10 years
Prior Plans | Employee and nonemployee stock options | Minimum
Stock Awards Vesting
Vesting period	6 months

Stock Compensation Plans - Stat

Stock Compensation Plans - Status and Activity of Employee Stock Options (Details) - Employee stock options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Options
Outstanding as of beginning of year (in shares)	1,666,802
Granted (in shares)	540,466
Exercised (in shares)	(18,199)
Forfeited (in shares)	(5,174)
Expired (in shares)	(137,355)
Outstanding as of end of year (in shares)	2,046,540	1,666,802
Vested and expected to vest (in shares)	2,046,540
Exercisable (in shares)	1,279,612
Weighted-Average Exercise Price
Outstanding as of beginning of year (in dollars per share)	$ 17.67
Granted (in dollars per share)	14.37
Exercised (in dollars per share)	14.28
Forfeited (in dollars per share)	14.27
Expired (in dollars per share)	19.19
Outstanding as of end of year (in dollars per share)	16.74	$ 17.67
Vested and expected to vest (in dollars per share)	16.74
Exercisable (in dollars per share)	$ 18.21
Weighted-Average Remaining Contractual Term
Outstanding	4 years 4 months 13 days	4 years 8 months 9 days
Vested and expected to vest	4 years 4 months 13 days
Exercisable	3 years 5 months 27 days
Aggregate Intrinsic Value
Outstanding	$ 9,421	$ 1,993
Vested and expected to vest	9,421
Exercisable	$ 4,001

Stock Compensation Plans - St82

Stock Compensation Plans - Status and Activity of Non-Employee Director Stock Options (Details) - Non employee stock options - Directors - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Options
Outstanding as of beginning of year (in shares)	17,565
Exercised (in shares)	(17,565)
Outstanding as of end of year (in shares)		17,565
Weighted-Average Exercise Price
Outstanding as of beginning of year (in dollars per share)	$ 8.37
Exercised (in dollars per share)	$ 8.37
Outstanding as of end of year (in dollars per share)		$ 8.37
Weighted-Average Remaining Contractual Term
Outstanding		5 months 1 day
Aggregate Intrinsic Value
Outstanding		$ 154

Stock Compensation Plans - Fair

Stock Compensation Plans - Fair Value Assumptions for Employee Stock Options and Additional Stock Option Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended				84 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2010	Dec. 31, 2017
Assumptions used to calculate fair values
Expected volatility (as a percent)		29.00%	19.00%
Risk-free interest rates (as a percent)	1.89%	1.04%	1.48%
Stock options
Cash received from the exercise of options	$ 407	$ 286	$ 1,095
Employee stock options
Assumptions used to calculate fair values
Weighted-average grant date fair value per stock option (in dollars per share)	$ 3.23	$ 3.11	$ 3.30
Expected dividend yield (as a percent)	1.31%	1.10%	0.96%
Expected volatility (as a percent)	28.00%
Expected lives of options	4 years	4 years	4 years
Option term				10 years	7 years
Employee and nonemployee stock options
Stock options
Weighted-average grant date fair value options vested (in dollars per share)	$ 3.19	$ 3.75	$ 4.49
Total grant date fair value of options vested	$ 1,500	$ 1,500	$ 1,500
Total intrinsic value of stock options exercised	300	200	400
Cash received from the exercise of options	$ 400	$ 300	$ 1,100

Stock Compensation Plans - Rest

Stock Compensation Plans - Restricted and Performance Based Stock Awards (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Restricted Stock Awards
Summary of non-vested stock awards
Nonvested as of beginning of year (in shares)	250,540
Granted (in shares)	170,226
Vested (in shares)	(113,285)
Forfeited (in shares)	(5,784)
Nonvested as of end of year (in shares)	301,697	250,540
Nonvested stock awards, Weighted-Average Grant Date Fair Value
Nonvested as of beginning of year (in dollars per share)	$ 17.02
Granted (in dollars per share)	14.25	$ 14.65	$ 21.06
Vested (in dollars per share)	18.01
Forfeited (in dollars per share)	15.16
Nonvested as of end of year (in dollars per share)	$ 15.12	$ 17.02
Stock Awards
Total grant date fair value amount of awards granted	$ 2.4	$ 2.3	$ 2.4
Total fair value amount of awards vested	$ 2	$ 2	$ 2
Restricted Stock Awards | Time vested
Stock Compensation Plans
Vesting period	3 years
Performance stock awards | Total Stockholder Return
Stock Compensation Plans
Vesting period	3 years	3 years	3 years
Summary of non-vested stock awards
Vested (in shares)	0
Nonvested stock awards, Weighted-Average Grant Date Fair Value
Nonvested as of beginning of year (in dollars per share)	$ 15.09
Granted (in dollars per share)	11.22	$ 9.66	$ 21.96
Vested (in dollars per share)	0
Forfeited (in dollars per share)	21.39
Nonvested as of end of year (in dollars per share)	$ 12.27	$ 15.09
Stock Awards
Total grant date fair value amount of awards granted	$ 0.5	$ 0.5	$ 0.5
Total fair value amount of awards vested		$ 0.5	0.2
Performance stock awards | Total Stockholder Return | Minimum
Stock Compensation Plans
Vesting percentage	0.00%
Performance stock awards | Total Stockholder Return | Maximum
Stock Compensation Plans
Vesting percentage	200.00%
Performance stock awards | Total Stockholder Return | Target
Summary of non-vested stock awards
Nonvested as of beginning of year (in shares)	93,044
Granted (in shares)	42,469
Forfeited (in shares)	(23,900)
Nonvested as of end of year (in shares)	111,613	93,044
Performance stock awards | Return on Capital
Stock Compensation Plans
Vesting period	3 years
Expense recognized	$ 0	$ 0	$ 0
Summary of non-vested stock awards
Vested (in shares)	0	0	0
Nonvested stock awards, Weighted-Average Grant Date Fair Value
Nonvested as of beginning of year (in dollars per share)	$ 17.56
Granted (in dollars per share)	14.37	$ 13.76	$ 20.74
Forfeited (in dollars per share)	20.54
Nonvested as of end of year (in dollars per share)	$ 15.52	$ 17.56
Stock Awards
Total grant date fair value amount of awards granted	$ 0.5	$ 0.5	$ 0.5
Performance stock awards | Return on Capital | Minimum
Stock Compensation Plans
Vesting percentage	0.00%
Performance stock awards | Return on Capital | Maximum
Stock Compensation Plans
Vesting percentage	200.00%
Performance stock awards | Return on Capital | Target
Summary of non-vested stock awards
Nonvested as of beginning of year (in shares)	79,948
Granted (in shares)	33,158
Forfeited (in shares)	(24,890)
Nonvested as of end of year (in shares)	88,216	79,948

Stock Compensation Plans - Sign

Stock Compensation Plans - Significant Assumptions and Historical Vesting for TSR Performance Stock Awards (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Significant assumptions used
Expected volatility (as a percent)		29.00%	19.00%
Risk-free interest rates (as a percent)	1.89%	1.04%	1.48%
Performance stock awards | Total Stockholder Return
Significant assumptions used
Expected dividend yield (as a percent)	1.31%	1.10%	0.96%
Expected volatility (as a percent)	30.40%	26.80%	25.90%
Risk-free interest rates (as a percent)	1.31%	0.83%	0.93%
Performance (vesting) period	3 years	3 years	3 years
Historical vesting of stock awards
Shares Issued	0

Stock Compensation Plans - Stoc

Stock Compensation Plans - Stock-Based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Total Stock-Based Compensation
Income tax benefit related to stock-based compensation	$ 1.6	$ 1.3	$ 1.2
Future compensation cost related to nonvested share-based compensation arrangements	$ 4.3
Weighted-average period over which future compensation cost is expected to be recognized	1 year 7 months 6 days
Selling, general and administrative expense
Total Stock-Based Compensation
Compensation expense related to all stock-based compensation	$ 4.3	$ 4.1	$ 3.8

Stockholders' Equity - Share Re

Stockholders' Equity - Share Repurchase Program (Details) - Share repurchase program December 2013 - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2013
Shareholders' Equity
Total purchases authorized under share repurchase program				$ 150
Shares repurchased	518,576	2,002,444
Average purchase price (in dollars per share)	$ 15.81	$ 17.45
Amount of remaining authorization to repurchase common stock			$ 64.1

Accumulated Other Comprehensi88

Accumulated Other Comprehensive Income (Loss) - Changes in Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss)
Balance (Note 11)	$ 381,143	$ 393,991	$ 405,473
Total other comprehensive income (loss)	27,958	(11,969)	(14,120)
Balance (Note 11)	424,421	381,143	393,991
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss)
Balance (Note 11)	(53,599)	(41,630)	(27,510)
Other comprehensive income (loss) before reclassifications	25,043	(15,026)	(15,658)
Amounts reclassified from other comprehensive income (loss)	2,915	3,057	1,538
Total other comprehensive income (loss)	27,958	(11,969)	(14,120)
Balance (Note 11)	(25,641)	(53,599)	(41,630)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss)
Balance (Note 11)	(22,026)	(11,070)	1,943
Other comprehensive income (loss) before reclassifications	27,989	(10,956)	(13,013)
Total other comprehensive income (loss)	27,989	(10,956)	(13,013)
Balance (Note 11)	5,963	(22,026)	(11,070)
Defined Benefit Pension Plan Adjustments
Accumulated Other Comprehensive Income (Loss)
Balance (Note 11)	(32,373)	(30,474)	(30,358)
Other comprehensive income (loss) before reclassifications	(1,537)	(4,879)	(2,446)
Amounts reclassified from other comprehensive income (loss)	2,829	2,980	2,330
Total other comprehensive income (loss)	1,292	(1,899)	(116)
Balance (Note 11)	(31,081)	(32,373)	(30,474)
Derivatives
Accumulated Other Comprehensive Income (Loss)
Balance (Note 11)	800	(86)	905
Other comprehensive income (loss) before reclassifications	(1,409)	809	(199)
Amounts reclassified from other comprehensive income (loss)	86	77	(792)
Total other comprehensive income (loss)	(1,323)	886	(991)
Balance (Note 11)	$ (523)	$ 800	$ (86)

Accumulated Other Comprehensi89

Accumulated Other Comprehensive Income (Loss) - Amount Reclassified by Component (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)									$ (430,896)	$ (346,398)	$ (343,522)
Interest expense									(7,842)	(2,385)	(773)
Income before income tax provision									33,563	20,073	63,386
Tax benefit (expense)									(12,462)	(6,276)	(19,923)
Net income	$ 9,362	$ 5,111	$ 5,853	$ 775	$ (5,942)	$ 6,385	$ 7,896	$ 5,458	21,101	13,797	43,463
Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Net income									(2,915)	(3,057)	(1,538)
Defined Benefit Pension Plan Adjustments
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax									(4,393)	(4,749)	(3,646)
Amounts reclassified, tax benefit									1,564	1,769	1,316
Amounts reclassified net of tax									(2,829)	(2,980)	(2,330)
Prior service credit
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax									9		(15)
Actuarial losses
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified before tax									(4,402)	(4,749)	(3,631)
Derivatives
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Amounts reclassified net of tax									(86)	(77)	792
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Income before income tax provision									(143)	(133)	1,136
Tax benefit (expense)									57	56	(344)
Net income									(86)	(77)	792
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss) | Foreign exchange contracts
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)									102	206	2,077
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss) | Natural gas contracts
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Cost of products sold (excluding depreciation and amortization)									66	$ (339)	$ (941)
Derivatives | Reclassified from Accumulated Other Comprehensive Income (Loss) | Interest rate swap contract
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)
Interest expense									$ (311)

Accumulated Other Comprehensi90

Accumulated Other Comprehensive Income (Loss) - Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Pension Plan Adjustments
Accumulated Other Comprehensive Income (Loss)
Income tax benefit included in accumulated other comprehensive loss	$ 16,700	$ 17,700	$ 17,100
Components of income tax expense (benefit) included in other comprehensive income (loss)
Income tax expense (benefit) included in other comprehensive income (loss)	1,239	(647)	183
Derivatives
Accumulated Other Comprehensive Income (Loss)
Income tax benefit included in accumulated other comprehensive loss	200		100
Income tax expense in accumulated other comprehensive income		400
Components of income tax expense (benefit) included in other comprehensive income (loss)
Income tax expense (benefit) included in other comprehensive income (loss)	$ (615)	$ 519	$ (521)

Basic and Diluted Net Income 91

Basic and Diluted Net Income per Common Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic and Diluted Net Income Per Common Share
Net income available to common stockholders									$ 21,101	$ 13,797	$ 43,463
Weighted Average Shares Outstanding
Basic (in shares)	50,508	50,489	50,470	50,411	50,255	50,246	50,225	50,308	50,470	50,259	51,902
Effect of dilutive securities (in shares)									76	764	807
Diluted (in shares)	50,561	50,624	50,511	50,486	51,081	50,984	50,987	51,041	50,546	51,023	52,709
Basic net income per common share (in dollars per share)	$ 0.19	$ 0.10	$ 0.12	$ 0.02	$ (0.12)	$ 0.13	$ 0.16	$ 0.11	$ 0.42	$ 0.27	$ 0.84
Diluted net income per common share (in dollars per share)	$ 0.19	$ 0.10	$ 0.12	$ 0.02	$ (0.12)	$ 0.13	$ 0.15	$ 0.11	$ 0.42	$ 0.27	$ 0.82
Stock based compensation awards excluded from the dilutive calculations as the effect would have been antidilutive (in shares)									1,000	1,200	800

Income Taxes - Components of Pr

Income Taxes - Components of Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal	$ 15,799	$ 6,481	$ 5,967
State and local	1,505	523	577
Foreign	4,497	4,664	6,597
Provision for income taxes, current	21,801	11,668	13,141
Deferred
Federal	(9,860)	(1,795)	5,471
State and local	52	435	563
Foreign	469	(4,032)	748
Provision for income taxes, deferred	(9,339)	(5,392)	6,782
Provision for income taxes	$ 12,462	$ 6,276	$ 19,923

Income Taxes - Tax Cuts and Job

Income Taxes - Tax Cuts and Jobs Act of 2017 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reasonable estimate of the effect of the Tax Cuts and Jobs Act of 2017
U.S. federal corporate tax rate (as a percent)		35.00%	35.00%	35.00%
Reasonably estimated amount of net income tax expense associated with the Act		$ 0.6
Reasonably estimated one-time net transition tax associated with the Act		$ 6.8
Elected period for payment of one-time net transition tax		8 years
Annual payments of long-term transition tax payable in years 2018 through 2022		$ 0.5
Payment of long-term transition tax payable in 2023		1
Payment of long-term transition tax payable in 2024		1.4
Payment of long-term transition tax payable in 2025		$ 1.7
Expected
Reasonable estimate of the effect of the Tax Cuts and Jobs Act of 2017
U.S. federal corporate tax rate (as a percent)	21.00%

Income Taxes - Income from Oper

Income Taxes - Income from Operations Outside United States and Undistributed Earnings of Foreign Subsidiaries (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax [Line Items]
Income generated by operations outside the United States	$ 12	$ 9.6	$ 28.1
Deferred income taxes on undistributed foreign earnings	0
Undistributed foreign earnings subjected to transition tax	79.9
Prior to effects of Tax Cuts and Jobs Act of 2017
Income Tax [Line Items]
Deferred income taxes on undistributed foreign earnings	0
Undistributed earnings of non-U.S. subsidiaries	$ 100.1

Income Taxes - Other Taxes and

Income Taxes - Other Taxes and Research and Development Tax Credit (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income taxes
Tax expense recognized from incorporation of Belgium branch	$ 2.4	$ 2.4
Tax expense (benefit) recognized			$ 0.5
Research and Development Tax Credit
Income taxes
Tax expense (benefit) recognized				$ (1.4)

Income Taxes - U.S. Federal Sta

Income Taxes - U.S. Federal Statutory to Effective Income Tax Rate Differences (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Differences between the U.S. federal statutory tax rate and the effective income tax rate
U.S. federal statutory rate (as a percent)	35.00%	35.00%	35.00%
State income taxes, net of federal income tax benefit (as a percent)	1.90%	2.90%	1.80%
Tax rate differential on foreign income (as a percent)	(9.80%)	(6.50%)	(3.10%)
Permanent tax differences (as a percent)	(1.30%)		(1.60%)
Permanent tax differences (as a percent)		3.20%
Valuation allowance (as a percent)	(1.20%)	0.80%	0.30%
Tax statute expiration (as a percent)	(0.30%)	(0.30%)	(0.60%)
Change in uncertain tax positions (as a percent)	0.10%	0.40%	0.10%
Deferred tax benefit for Section 987		(2.70%)
Corporate restructuring (as a percent)	9.40%
U.S. tax reform (as a percent)	1.80%
Other - net (as a percent)	1.50%	(1.50%)	(0.50%)
Effective income tax rate (as a percent)	37.10%	31.30%	31.40%

Income Taxes - Tax Credit Carry

Income Taxes - Tax Credit Carryforwards (Details) $ in Thousands	Dec. 31, 2017USD ($)
Foreign
Tax credit carryforwards
Tax credits	$ 13
State
Tax credit carryforwards
Tax credits	$ 2,231
State | Tax year 2023 or later
Tax credit carryforwards
Percentage of tax credit carryforwards	44.00%

Income Taxes - Operating Loss C

Income Taxes - Operating Loss Carryforwards (Details) $ in Thousands	Dec. 31, 2017USD ($)
Federal
Gross operating loss carryforwards
Operating loss carryforwards	$ 421
State
Gross operating loss carryforwards
Operating loss carryforwards	$ 6,619
State | Tax year 2025 or later
Gross operating loss carryforwards
Percentage of operating loss carryforwards	98.00%
Foreign
Gross operating loss carryforwards
Operating loss carryforwards	$ 15,692
Foreign | No expiration
Gross operating loss carryforwards
Percentage of operating loss carryforwards	80.00%

Income Taxes - Components of De

Income Taxes - Components of Deferred Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Deferred tax assets
Net operating loss and credit carryforwards	$ 6,191	$ 7,763
Accruals and other timing items	10,653	15,824
Inventories	8,730	11,181
Pensions	9,156	12,186
Valuation allowance	(2,063)	(2,510)
Total deferred tax assets	32,667	44,444
Deferred tax liabilities
Property, plant and equipment	25,850	45,300
Goodwill and other intangible assets	14,374	15,716
U.S. liability on foreign deferred taxes	512	1,095
Total deferred tax liabilities	40,736	62,111
Net deferred tax liability	(8,069)	(17,667)
Uncertain tax liabilities that partially offset net operating losses and credit carryforwards	100	200
Net indirect benefits on uncertain tax liabilities	$ 12	$ 72

Income Taxes - Uncertain Tax Po

Income Taxes - Uncertain Tax Positions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of the unrecognized income tax benefits
Balance at beginning of year	$ 785	$ 778	$ 1,187
Gross increases for tax positions of current year	112	108	78
Lapse of statute of limitations	(135)	(101)	(417)
Settlement of uncertain tax positions			(70)
Balance at end of year	762	785	$ 778
Interest and penalties accrued on prior year uncertain positions	41	23
Interest and penalties reversed due to the expiration of the statute of limitations	65	3
Amount accrued for payment of interest and penalties related to unrecognized tax benefits	300	300
Unrecognized tax benefits that would impact effective tax rate	700	600
Unrecognized tax benefits that will be recognized within the next twelve months which will impact effective tax rate	300
Accrued pension and other liabilities
Reconciliation of the unrecognized income tax benefits
Uncertain tax positions	$ 900	$ 900

Commitments - Operating Leases

Commitments - Operating Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Future minimum rental payments required under operating leases
2,018	$ 8.6
2,019	6
2,020	4.1
2,021	3.2
2,022	3
Thereafter	16.5
Total rental expense on operating leases	$ 9.7	$ 8	$ 8.9

Commitments - Long-term Supply

Commitments - Long-term Supply Contracts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Future minimum purchase requirements
2,018	$ 3,066
2,019	1,526
2,020	836
2,021	821
Total payments	3,106	$ 22,562	$ 29,703
Raw and other materials
Future minimum purchase requirements
2,018	821
2,019	821
2,020	821
2,021	821
Total payments	815	21,178	27,832
Information systems and services
Future minimum purchase requirements
2,018	2,245
2,019	705
2,020	15
Total payments	$ 2,291	$ 1,384	$ 1,871

Contingencies - Environmental a

Contingencies - Environmental and Anti-Dumping (Details) $ in Millions	1 Months Ended					3 Months Ended	12 Months Ended
	Nov. 30, 2017company$ / lb	Sep. 30, 2016$ / lb	Oct. 31, 2015$ / lb	Feb. 28, 2013	Oct. 31, 2011USD ($)$ / lb	Dec. 31, 2017USD ($)item	Dec. 31, 2017USD ($)item	Dec. 31, 2016USD ($)
Minimum
Commitments and contingencies
Period for which reviews are possible				5 years
Waterlink's Columbus, Ohio property | Accrued pension and other liabilities
Commitments and contingencies
Recorded liability for environmental loss contingencies | $						$ 0.3	$ 0.3	$ 0.3
Big Sandy Plant
Commitments and contingencies
Number of ground water monitoring wells installed | item						2	2
Recorded liability for environmental loss contingencies | $						$ 0	$ 0	$ 0
Period of Review III
Commitments and contingencies
Ongoing duty deposit rate (as a percent)					0
Receivable recorded for anticipated refunds of anti-dumping duties | $					$ 1.1
Duty deposits received | $						$ 0.8
Period of Review VII
Commitments and contingencies
Anti-dumping margins for separate rate respondents (in dollars per pound)			0.476
Period of Review VII | Calgon Carbon Tianjin
Commitments and contingencies
Anti-dumping margins for separate rate respondents (in dollars per pound)			0.476
Period of Review VII | Minimum
Commitments and contingencies
Anti-dumping margins for mandatory respondents (in dollars per pound)			0
Period of Review VII | Maximum
Commitments and contingencies
Anti-dumping margins for mandatory respondents (in dollars per pound)			0.476
Period of Review VIII
Commitments and contingencies
Anti-dumping margins for separate rate respondents (in dollars per pound)		0.616
Period of Review VIII | Calgon Carbon Tianjin
Commitments and contingencies
Anti-dumping margins for separate rate respondents (in dollars per pound)		0.616
Period of Review VIII | Minimum
Commitments and contingencies
Anti-dumping margins for mandatory respondents (in dollars per pound)		0.009
Period of Review VIII | Maximum
Commitments and contingencies
Anti-dumping margins for mandatory respondents (in dollars per pound)		0.797
Period Of Review IX | Minimum
Commitments and contingencies
Import (anti-dumping) duty (in dollars per pound)	0
Period Of Review IX | Maximum
Commitments and contingencies
Import (anti-dumping) duty (in dollars per pound)	0.10
Period Of Review X
Commitments and contingencies
Number of mandatory respondents | company	2
Carbon Imports - Anti-dumping duties
Commitments and contingencies
Import (anti-dumping) duty (in dollars per pound)		0.616
Prior period over which Commerce Department reviews anti-dumping tariffs							12 months

Supplemental Cash Flow Infor104

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental Cash Flow Information
Cash paid for interest	$ 8	$ 2.6	$ 1.1
Capitalized interest	0.8	0.3	0.4
Income taxes paid, net of refunds	16.8	9.5	13.9
Non-cash increase (decrease) in accounts payable and accrued liabilities for changes in unpaid capital expenditures	$ 3.9	$ 1.9	$ (0.1)

Segment Information - Results o

Segment Information - Results of Operations (Details) $ in Thousands	Jan. 01, 2017segment	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Segment Information
Number of reportable segments | segment	3									3
Net Sales		$ 161,549	$ 162,561	$ 152,998	$ 142,703	$ 137,480	$ 123,970	$ 132,597	$ 120,199	$ 619,811	$ 514,246	$ 535,004
Other operating income										4,148
Income (loss) from operations										42,174	24,522	64,794
Interest income										49	99	58
Interest expense										(7,842)	(2,385)	(773)
Other expense — net										(818)	(2,163)	(693)
Income before income tax provision										33,563	20,073	63,386
Depreciation and amortization										46,667	38,070	35,453
Activated Carbon
Segment Information
Net Sales										547,000	476,771	496,949
Depreciation and amortization										40,286	35,507	33,216
Alternative Materials
Segment Information
Net Sales										56,393	14,404	9,163
Depreciation and amortization										5,343	1,213	610
Advanced Water Purification
Segment Information
Net Sales										16,418	23,071	28,892
Depreciation and amortization										1,038	1,350	1,627
Business operating segments
Segment Information
Income (loss) from operations										42,667	24,522	64,794
Business operating segments | Activated Carbon
Segment Information
Income (loss) from operations										47,052	32,968	65,398
Business operating segments | Alternative Materials
Segment Information
Income (loss) from operations										403	(3,201)	1,421
Business operating segments | Advanced Water Purification
Segment Information
Income (loss) from operations										(4,788)	$ (5,245)	$ (2,025)
Reconciling items: Unallocated
Segment Information
Merger related expenses										$ (4,641)

Segment Information - Expenditu

Segment Information - Expenditures for Long-Lived Assets and Total Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Information
Expenditures for long-lived assets	$ 61,248	$ 33,794	$ 62,228
Assets	854,584	775,218
Accounts payable and accrued liabilities
Segment Information
Property, plant and equipment expenditures	7,900	4,000	2,100
Activated Carbon
Segment Information
Expenditures for long-lived assets	56,886	32,046	59,408
Assets	432,154	392,918
Alternative Materials
Segment Information
Expenditures for long-lived assets	2,603	492	403
Assets	75,345	67,394
Advanced Water Purification
Segment Information
Expenditures for long-lived assets	1,759	1,256	$ 2,417
Assets	13,850	12,989
Business operating segments
Segment Information
Assets	521,349	473,301
Reconciling items: Unallocated
Segment Information
Assets	$ 333,235	$ 301,917

Segment Information - Net Sales

Segment Information - Net Sales by Product (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net Sales by Product
Net Sales	$ 161,549	$ 162,561	$ 152,998	$ 142,703	$ 137,480	$ 123,970	$ 132,597	$ 120,199	$ 619,811	$ 514,246	$ 535,004
Carbon products
Net Sales by Product
Net Sales									487,833	432,718	460,251
Filtration media products
Net Sales by Product
Net Sales									49,016	5,709
Capital equipment
Net Sales by Product
Net Sales									41,133	34,349	35,114
Equipment leasing
Net Sales by Product
Net Sales									14,426	14,041	15,235
Carbon cloth products
Net Sales by Product
Net Sales									7,377	8,695	9,163
Spare parts
Net Sales by Product
Net Sales									4,649	4,515	4,179
Other services
Net Sales by Product
Net Sales									$ 15,377	$ 14,219	$ 11,062

Segment Information - Geographi

Segment Information - Geographic Information - Net Sales (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Information
Net sales	$ 161,549	$ 162,561	$ 152,998	$ 142,703	$ 137,480	$ 123,970	$ 132,597	$ 120,199	$ 619,811	$ 514,246	$ 535,004
United States
Segment Information
Net sales									291,058	271,076	288,645
France
Segment Information
Net sales									42,698	23,646	20,875
United Kingdom
Segment Information
Net sales									37,858	36,552	43,217
Germany
Segment Information
Net sales									32,439	21,416	17,804
Japan
Segment Information
Net sales									32,047	35,243	35,753
Italy
Segment Information
Net sales									29,057	5,206	2,432
China
Segment Information
Net sales									26,169	18,559	17,943
Canada
Segment Information
Net sales									17,292	13,858	17,065
Belgium
Segment Information
Net sales									10,359	9,373	10,383
Spain
Segment Information
Net sales									9,336	3,812	3,302
Netherlands
Segment Information
Net sales									8,557	5,696	5,184
South Korea
Segment Information
Net sales									7,022	10,231	12,218
India
Segment Information
Net sales									5,056	3,417	713
Switzerland
Segment Information
Net sales									4,973	3,117	3,340
Sweden
Segment Information
Net sales									3,975	3,027	3,077
Other
Segment Information
Net sales									$ 61,915	$ 50,017	$ 53,053

Segment Information - Geogra109

Segment Information - Geographic Information - Property, Plant and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Information
Property, plant and equipment, net	$ 399,510	$ 366,442	$ 311,019
United States
Segment Information
Property, plant and equipment, net	239,354	225,105	228,057
France
Segment Information
Property, plant and equipment, net	65,473	52,650
Belgium
Segment Information
Property, plant and equipment, net	52,185	46,648	47,921
China
Segment Information
Property, plant and equipment, net	12,536	12,482	13,779
United Kingdom
Segment Information
Property, plant and equipment, net	12,452	12,586	15,849
Italy
Segment Information
Property, plant and equipment, net	12,389	11,624
Japan
Segment Information
Property, plant and equipment, net	5,011	5,207	5,255
Singapore
Segment Information
Property, plant and equipment, net	57	74	65
Denmark
Segment Information
Property, plant and equipment, net	33	41	53
Brazil
Segment Information
Property, plant and equipment, net	11	14	14
Canada
Segment Information
Property, plant and equipment, net	$ 9	$ 11	24
Germany
Segment Information
Property, plant and equipment, net			$ 2

Government Grants (Details)

Government Grants (Details) ¥ in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)	Dec. 31, 2016CNY (¥)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014CNY (¥)item	Dec. 31, 2014USD ($)item	Sep. 30, 2016USD ($)
China carbon reactivation lines construction commitment incentive
Government Grants
Incentive received		¥ 3,860	$ 0.6		¥ 3,860	$ 0.6
Number of phases within which the construction of carbon reactivation lines has been committed to be completed | item					2	2
Incentive recognized	$ 0		0	$ 0
China carbon reactivation lines construction commitment incentive | Accrued pension and other liabilities
Government Grants
Unearned portion of incentives	0.9		$ 0.8
U.S. government Agency manufacturing agreement | Maximum
Government Grants
Total award amount							$ 15.4
U.S. government Agency manufacturing agreement | Accrued pension and other liabilities
Government Grants
Unearned portion of incentives	$ 0.3

Acquisition of the New Busin111

Acquisition of the New Business - Description (Details) $ in Thousands	Nov. 02, 2016USD ($)employee	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Purchase of assets and business
Additional payment for acquisition										$ 1,234
Operating results
Net sales		$ 161,549	$ 162,561	$ 152,998	$ 142,703	$ 137,480	$ 123,970	$ 132,597	$ 120,199	619,811	$ 514,246	$ 535,004
Income from operations										42,174	24,522	$ 64,794
Activated Carbon and Filter Aid Business (New Business)
Purchase of assets and business
Cash paid for acquisition	$ 157,425									158,659
Additional payment for acquisition										1,200
Operating results since acquisition date
Net sales											12,100
Loss from operations											$ (8,800)
Activated Carbon and Filter Aid Business (New Business)
Purchase of assets and business
Number of employees | employee	300
Operating results
Net sales										104,000
Income from operations										$ 4,200

Acquisition of the New Busin112

Acquisition of the New Business - Purchase Price Allocations (Details) - USD ($) $ in Thousands	Nov. 02, 2016	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2015
Assets
Goodwill			$ 66,316	$ 77,773	$ 66,316	$ 77,773	$ 25,777
Payments to acquire business
Net cash paid for acquisition					$ 153,599
Separately identifiable intangible assets
Weighted-average estimated useful life				17 years 10 months 24 days	17 years 3 months 18 days
Activated Carbon
Assets
Goodwill			44,346	$ 51,188	$ 44,346	51,188	19,604
Alternative Materials
Assets
Goodwill			15,810	$ 20,322	$ 15,810	20,322	$ 60
Unpatented technology and know-how
Separately identifiable intangible assets
Weighted-average estimated useful life				20 years	20 years
Customer relationships
Separately identifiable intangible assets
Weighted-average estimated useful life				18 years 10 months 24 days	18 years 10 months 24 days
Activated Carbon and Filter Aid Business (New Business)
Assets
Cash and cash equivalents	$ 3,826			$ 3,826		3,826
Receivables	10,077			10,077		10,077
Inventories	20,895			18,123		18,123
Other current assets	1,171			868		868
Property, plant and equipment	67,697			66,976		66,976
Intangibles	37,248			37,797		37,797
Goodwill	42,844			47,717		47,717
Other assets	179			388		388
Total assets	183,937			185,772		185,772
Liabilities
Accounts payable and accrued liabilities	6,151			5,539		5,539
Payroll and benefits payable	4,360			3,315		3,315
Accrued income taxes	581			581		581
Deferred income taxes - long term	7,406			6,472		6,472
Accrued pension and other liabilities	8,014			11,206		11,206
Total liabilities	26,512			27,113		27,113
Net assets	157,425			158,659		158,659
Payments to acquire business
Cash paid for acquisition	157,425			158,659
Cash acquired	(3,826)			(3,826)
Net cash paid for acquisition	153,599			154,833
Cash paid for acquisition - Measurement Period Adjustments						1,234
Measurement Period Adjustments
Inventories						(2,772)
Other current assets						(303)
Property, plant, and equipment						(721)
Intangibles						549
Goodwill						4,873
Other assets						209
Total Assets						1,835
Accounts payable and accrued liabilities						(612)
Payroll and benefits payable						(1,045)
Deferred income taxes - long term						(934)
Accrued pension and other liabilities						3,192
Total liabilities						601
Net assets						1,234
Step-up of inventory				1,300		1,300
Deductible goodwill for tax purposes				0		$ 0
Acquisition costs
Merger related fees and expenses incurred		$ 2,100	$ 10,500
Activated Carbon and Filter Aid Business (New Business) | Selling, general and administrative expense
Acquisition costs
Acquisition-related integration and transaction costs incurred				2,800	$ 14,200
Activated Carbon and Filter Aid Business (New Business) | Activated Carbon
Measurement Period Adjustments
Goodwill				29,200
Activated Carbon and Filter Aid Business (New Business) | Alternative Materials
Measurement Period Adjustments
Goodwill				$ 18,500
Activated Carbon and Filter Aid Business (New Business) | Unpatented technology and know-how
Separately identifiable intangible assets
Finite-lived intangibles	$ 14,200
Weighted-average estimated useful life	20 years
Activated Carbon and Filter Aid Business (New Business) | Customer relationships
Separately identifiable intangible assets
Finite-lived intangibles	$ 16,300
Weighted-average estimated useful life	20 years
Activated Carbon and Filter Aid Business (New Business) | Trade names and trademarks
Separately identifiable intangible assets
Indefinite-lived intangible assets	$ 7,300

Acquisition of the New Busin113

Acquisition of the New Business - Pro Forma Information (Details) - Activated Carbon and Filter Aid Business (New Business) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016USD ($)$ / shares
Pro forma results of operations
Net sales | $	$ 601,153
Net income | $	$ 29,326
Net income per common share
Basic (in dollars per share) | $ / shares	$ 0.58
Diluted (in dollars per share) | $ / shares	$ 0.57

Acquisition of the New Busin114

Acquisition of the New Business - Pro Forma Adjustments (Details) - USD ($) $ in Thousands	Nov. 02, 2016	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pro forma results of operations
Amount borrowed			$ 151,411	$ 328,249	$ 111,400
First Amended and Restated Credit Agreement | Revolving credit facility
Pro forma results of operations
Amount borrowed	$ 160,000	$ 160,000
Activated Carbon and Filter Aid Business (New Business)
Pro forma results of operations
Net income				29,326
Activated Carbon and Filter Aid Business (New Business) | Incremental deprecation and amortization associated with fair value adjustments to property, plant and equipment and intangible assets, before tax
Pro forma results of operations
Net income				(3,200)
Activated Carbon and Filter Aid Business (New Business) | Incremental interest expense, before tax
Pro forma results of operations
Net income				(3,300)
Activated Carbon and Filter Aid Business (New Business) | Step-up of inventory, before tax
Pro forma results of operations
Net income				1,500
Activated Carbon and Filter Aid Business (New Business) | Transaction costs, before tax
Pro forma results of operations
Net income				$ 14,000

Pending Merger (Details)

Pending Merger (Details) - USD ($) $ / shares in Units, $ in Millions	Jan. 19, 2018	Dec. 31, 2017	Mar. 31, 2018	Sep. 21, 2017
Definitive merger agreement with Kuraray
Merger
Termination fee if merger agreement is terminated		$ 33.2
Merger related fees and expenses incurred		$ 4.6
Definitive merger agreement with Kuraray | Investment banking agreement
Merger
Contractual obligation				$ 19
Announcement of the execution of the merger agreement | Definitive merger agreement with Kuraray | Investment banking agreement
Merger
Contractual obligation				2
Closing of Pending Merger | Definitive merger agreement with Kuraray | Investment banking agreement
Merger
Contractual obligation				$ 17
Calgon Carbon Corporation | Kuraray Co., Ltd. (Kuraray) | Expected
Merger
Cash for outstanding common stock (in dollars per share)			$ 21.50
Calgon Carbon Corporation | Kuraray Co., Ltd. (Kuraray) | Pending satisfaction of closing conditions
Merger
Additional investigation period initiated by the Committee on Foreign Investment in the United States	45 days

QUARTERLY FINANCIAL DATA - U116

QUARTERLY FINANCIAL DATA - UNAUDITED (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
QUARTERLY FINANCIAL DATA
Net sales	$ 161,549	$ 162,561	$ 152,998	$ 142,703	$ 137,480	$ 123,970	$ 132,597	$ 120,199	$ 619,811	$ 514,246	$ 535,004
Net sales less cost of products sold (excluding depreciation and amortization)	49,772	48,543	46,712	43,888	42,634	38,540	44,934	41,740
Net income	$ 9,362	$ 5,111	$ 5,853	$ 775	$ (5,942)	$ 6,385	$ 7,896	$ 5,458	$ 21,101	$ 13,797	$ 43,463
Basic:
Basic net income per common share (in dollars per share)	$ 0.19	$ 0.10	$ 0.12	$ 0.02	$ (0.12)	$ 0.13	$ 0.16	$ 0.11	$ 0.42	$ 0.27	$ 0.84
Diluted:
Diluted net income per common share (in dollars per share)	$ 0.19	$ 0.10	$ 0.12	$ 0.02	$ (0.12)	$ 0.13	$ 0.15	$ 0.11	$ 0.42	$ 0.27	$ 0.82
Average common shares outstanding
Basic (in shares)	50,508	50,489	50,470	50,411	50,255	50,246	50,225	50,308	50,470	50,259	51,902
Diluted (in shares)	50,561	50,624	50,511	50,486	51,081	50,984	50,987	51,041	50,546	51,023	52,709
Significant quarterly financial information
Tax expense recognized from incorporation of Belgium branch				$ 2,400					$ 2,400
Gain on the sale of an idled plant	$ 4,100								$ 4,148
Activated Carbon and Filter Aid Business (New Business)
Significant quarterly financial information
Costs related to the acquisition					$ 12,200
Transaction costs				$ 2,100	$ 10,500

Schedule II Valuation and Qu117

Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts
Valuation and Qualifying Accounts
Balance at Beginning of Year	$ 1,416	$ 1,675	$ 1,526
Additions Charged to Costs and Expenses	610	2,926	1,402
Deductions Returns and Write-Offs	(206)	(3,185)	(1,253)
Balance at End of Year	1,820	1,416	1,675
Income tax valuation allowance
Valuation and Qualifying Accounts
Balance at Beginning of Year	2,510	2,682	2,576
Additions Charged to Costs and Expenses	387	153	183
Charged to Other Accounts	114	(325)
Deductions Returns and Write-Offs	(948)		(77)
Balance at End of Year	$ 2,063	$ 2,510	$ 2,682