Arq (ARQ) 10-Q 6 Nov 18 2018 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2018	Nov. 01, 2018
Document and Entity Information [Abstract]
Entity Registrant Name	Advanced Emissions Solutions, Inc.
Entity Central Index Key	1,515,156
Document Type	10-Q
Document Period End Date	Sep. 30, 2018
Amendment Flag	false
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
Entity Common Stock, Shares Outstanding		19,915,631

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 31,914	$ 30,693
Receivables, net	817	1,113
Receivables, related parties, net	4,104	3,247
Prepaid expenses and other assets	2,631	1,835
Total current assets	39,466	36,888
Property and equipment, net of accumulated depreciation of $1,126 and $1,486, respectively	229	410
Equity method investments	5,383	4,351
Deferred tax assets	36,008	38,661
Other long-term assets	2,070	2,308
Total Assets	83,156	82,618
Current liabilities:
Accounts payable	660	1,000
Accrued payroll and related liabilities	1,970	1,384
Billings in excess of costs on uncompleted contracts	0	1,830
Other current liabilities	627	2,664
Total current liabilities	3,257	6,878
Other long-term liabilities	295	2,285
Total Liabilities	3,552	9,163
Commitments and contingencies (Note 5)
Stockholders’ equity:
Preferred stock: par value of $.001 per share, 50,000,000 shares authorized, none outstanding	0	0
Common stock: par value of $.001 per share, 100,000,000 shares authorized, 22,646,524 and 22,465,821 shares issued, and 19,921,128 and 20,752,055 shares outstanding at September 30, 2018 and December 31, 2017, respectively	23	22
Treasury stock, at cost: 2,725,396 and 1,713,766 shares as of September 30, 2018 and December 31, 2017, respectively	(27,566)	(16,397)
Additional paid-in capital	96,251	105,308
Retained earnings (deficit)	10,896	(15,478)
Total stockholders’ equity	79,604	73,455
Total Liabilities and Stockholders’ Equity	$ 83,156	$ 82,618

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accumulated depreciation and amortization	$ 1,126	$ 1,486
Preferred stock par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Preferred stock, shares outstanding (in shares)	0	0
Common stock par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	22,646,524	22,465,821
Common stock, shares outstanding (in shares)	19,921,128	20,752,055
Treasury stock (in shares)	2,725,396	1,713,766

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 5,147	$ 5,098	$ 13,319	$ 41,573
Operating expenses:
Payroll and benefits	2,555	1,679	7,528	5,894
Rent and occupancy	250	255	766	555
Legal and professional fees	698	1,062	3,459	3,316
General and administrative	584	1,114	2,332	2,964
Depreciation and amortization	74	87	262	687
Total operating expenses	5,115	6,238	16,568	44,653
Operating income (loss)	32	(1,140)	(3,249)	(3,080)
Other income (expense):
Earnings from equity method investments	9,715	12,120	37,857	36,089
Interest expense	(399)	(678)	(1,147)	(1,999)
Other	86	(924)	146	2,492
Total other income	9,402	10,518	36,856	36,582
Income before income tax expense	9,434	9,378	33,607	33,502
Income tax expense	3,931	3,586	5,151	12,614
Net income	$ 5,503	$ 5,792	$ 28,456	$ 20,888
Earnings per common share (Note 1):
Basic (in dollars per share)	$ 0.28	$ 0.28	$ 1.41	$ 0.96
Diluted (in dollars per share)	$ 0.28	$ 0.28	$ 1.40	$ 0.96
Weighted-average number of common shares outstanding:
Basic (in shares)	19,726	20,808	20,090	21,569
Diluted (in shares)	19,876	20,854	20,228	21,598
Cash dividends declared per common share outstanding (in dollars per share)	$ 0.25	$ 0.25	$ 0.75	$ 0.5
Chemicals
Revenues:
Total revenues	$ 1,043	$ 717	$ 2,390	$ 3,844
Operating expenses:
Cost of revenue	954	574	2,567	2,977
License royalties, related party
Revenues:
Total revenues	4,104	2,804	10,857	6,425
Equipment sales
Revenues:
Total revenues	0	1,577	72	31,304
Operating expenses:
Cost of revenue	$ 0	$ 1,467	$ (346)	$ 28,260

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Cash flows from operating activities
Net income	$ 5,503	$ 5,792	$ 28,456	$ 20,888
Adjustments to reconcile net income to net cash used in operating activities:
Deferred tax expense from change in valuation allowance			2,731	0
Depreciation and amortization			262	687
Debt prepayment penalty and amortization of debt issuance costs			0	109
Impairment of cost method investment			0	464
Provision for bad debt expense			153	0
Stock-based compensation expense			1,929	1,648
Earnings from equity method investments	(9,715)	(12,120)	(37,857)	(36,089)
Other non-cash items, net			37	436
Changes in operating assets and liabilities:
Receivables			482	7,027
Related party receivables			(857)	(869)
Prepaid expenses and other assets			(797)	(513)
Costs incurred on uncompleted contracts			15,945	27,081
Deferred tax assets, net			(966)	11,086
Other long-term assets			0	(766)
Accounts payable			(340)	(603)
Accrued payroll and related liabilities			587	(825)
Other current liabilities			(1,974)	(917)
Billings on uncompleted contracts			(15,945)	(30,140)
Other long-term liabilities			(157)	147
Legal settlements and accruals			0	(11,606)
Distributions from equity method investees, return on investment			4,000	3,675
Net cash used in operating activities			(4,311)	(9,080)
Cash flows from investing activities
Distributions from equity method investees in excess of cumulative earnings			33,575	33,363
Acquisition of property, equipment and intangibles, net			(191)	(343)
Purchases of and contributions to equity method investees			(750)	(61)
Net cash provided by investing activities			32,634	32,959
Cash flows from financing activities
Dividends paid			(15,226)	(10,458)
Repurchase of common shares			(11,169)	(13,024)
Repurchase of common shares to satisfy tax withholdings			(707)	(518)
Borrowings on Line of Credit			0	808
Repayments on Line of Credit			0	(808)
Net cash used in financing activities			(27,102)	(24,000)
Increase (decrease) in Cash and Cash Equivalents and Restricted Cash			1,221	(121)
Cash and Cash Equivalents and Restricted Cash, beginning of period			30,693	26,944	$ 26,944
Cash and Cash Equivalents and Restricted Cash, end of period	31,914	26,823	31,914	26,823	$ 30,693
Supplemental disclosure of cash flow information:
Cash paid for interest			1,020	2,391
Cash paid for income taxes			4,756	1,160
Supplemental disclosure of non-cash investing and financing activities:
Dividends declared, not paid	$ 85	$ 93	$ 85	$ 93

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Nature of Operations Advanced Emissions Solutions, Inc. ("ADES" or the "Company") is a Delaware corporation with its principal office located in Highlands Ranch, Colorado. The Company is principally engaged in emissions control ("EC") technologies and associated consumables, equipment and services. The Company's proprietary environmental technologies enable customers to reduce emissions of mercury and other pollutants, maximize utilization levels and improve operating efficiencies to meet the challenges of existing and pending EC regulations. The Company generates substantial earnings and tax credits under Section 45 ("Section 45 tax credits") of the Internal Revenue Code ("IRC") from its equity investments in certain entities and royalty payments related to technologies that are licensed to Tinuum Group, LLC, a Colorado limited liability company ("Tinuum Group"). Such technologies allow Tinuum Group to provide its customers with various solutions to enhance combustion and reduce emissions of nitrogen oxide ("NO x ") and mercury from coal burned to generate electrical power. The Company’s sales occur principally throughout the United States. See Note 10 for additional information regarding the Company's operating segments. Basis of Presentation The accompanying Condensed Consolidated Financial Statements of ADES are unaudited and have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP") and with Article 10 of Regulation S-X of the Securities and Exchange Commission. In compliance with those instructions, certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The unaudited Condensed Consolidated Financial Statements of ADES in this quarterly report ("Quarterly Report") are presented on a consolidated basis and include ADES and its wholly-owned subsidiaries (collectively, the "Company"). Also included within the unaudited Condensed Consolidated Financial Statements are the Company's unconsolidated equity investments, Tinuum Group, Tinuum Services, LLC ("Tinuum Services"), and GWN Manager, LLC ("GWN Manager"), which are accounted for under the equity method of accounting, and Highview Enterprises Limited (the "Highview Investment"), which is accounted for in accordance with U.S. GAAP applicable to equity investments that do not qualify for the equity method of accounting. Results of operations and cash flows for the interim periods are not necessarily indicative of the results that may be expected for the entire year. All significant intercompany transactions and accounts were eliminated for all periods presented in this Quarterly Report. In the opinion of management, these Condensed Consolidated Financial Statements include all normal and recurring adjustments considered necessary for a fair presentation of the results of operations, financial position and cash flows for the interim periods presented. These Condensed Consolidated Financial Statements of ADES should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (the "2017 Form 10-K"). Except for accounting for revenue from contracts with customers, which is discussed in Note 2 , significant accounting policies disclosed therein have not changed. Earnings Per Share Basic earnings per share is computed using the two-class method, which is an earnings allocation formula that determines earnings per share for common stock and any participating securities according to dividend and participating rights in undistributed earnings. The Company's restricted stock awards ("RSA's") granted prior to December 31, 2016 contain non-forfeitable rights to dividends or dividend equivalents and are deemed to be participating securities. RSA's granted subsequent to December 31, 2016 do not contain non-forfeitable rights to dividends and are not deemed to be participating securities. Under the two-class method, net income for the period is allocated between common stockholders and the holders of the participating securities based on the weighted-average number of common shares outstanding during the period, excluding participating, unvested RSA's ("common shares"), and the weighted-average number of participating unvested RSA's outstanding during the period, respectively. The allocated, undistributed income for the period is then divided by the weighted-average number of common shares and participating, unvested RSA's outstanding during the period to arrive at basic earnings per common share and participating security for the period, respectively. Pursuant to U.S. GAAP, the Company has elected not to separately present basic or diluted earnings per share attributable to participating securities in the Condensed Consolidated Statements of Operations. Diluted earnings per share is computed in a manner consistent with that of basic earnings per share, while considering other potentially dilutive securities. Potentially dilutive securities consist of both unvested, participating and non-participating RSA's, as well as outstanding options to purchase common stock ("Stock Options") and contingent performance stock units ("PSU's") (collectively, "Potential dilutive shares"). The dilutive effect, if any, for non-participating RSA's, Stock Options and PSU's is determined using the greater of dilution as calculated under the treasury stock method or the two-class method. Potential dilutive shares are excluded from diluted earnings per share when their effect is anti-dilutive. When there is a net loss for a period, all Potential dilutive shares are anti-dilutive and are excluded from the calculation of diluted loss per share for that period. Each PSU represents a contingent right to receive shares of the Company’s common stock, and the number of shares may range from zero to two times the number of PSU's granted on the award date depending upon the price performance of the Company's common stock as measured against a general index and a specific peer group index over requisite performance periods. The number of Potential dilutive shares related to PSU's is based on the number of shares of the Company's common stock, if any, that would be issuable at the end of the respective reporting period, assuming that the end of the reporting period is the end of the contingency period applicable to such PSU's. See Note 7 for additional information related to PSU's. The following table sets forth the calculations of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2018 2017 2018 2017 Net income $ 5,503 $ 5,792 $ 28,456 $ 20,888 Less: Dividends and undistributed income allocated to participating securities 18 32 94 141 Income attributable to common stockholders $ 5,485 $ 5,760 $ 28,362 $ 20,747 Basic weighted-average common shares outstanding 19,726 20,808 20,090 21,569 Add: dilutive effect of equity instruments 150 46 138 29 Diluted weighted-average shares outstanding 19,876 20,854 20,228 21,598 Earnings per share - basic $ 0.28 $ 0.28 $ 1.41 $ 0.96 Earnings per share - diluted $ 0.28 $ 0.28 $ 1.40 $ 0.96 For the three and nine months ended September 30, 2018 and 2017 , RSA's and Stock Options convertible to 0.3 million and 0.2 million shares, respectively, and 0.3 million and 0.2 million shares, respectively, of common stock for each of the periods presented were outstanding but were not included in the computation of diluted net income per share because the effect would have been anti-dilutive. For the nine months ended September 30, 2018 , Stock Options to purchase 0.1 million shares were outstanding, which vest based on the Company achieving specified performance targets, but were not included in the computation of diluted net income per share for a portion of the period because they were determined not to be contingently issuable. For the three and nine months ended September 30, 2017 , Stock Options to purchase 0.4 million and 0.4 million shares, respectively, of common stock, which vest based on the Company achieving specified performance targets, were outstanding, but were not included in the computation of diluted net income per share because they were determined not to be contingently issuable. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to makes estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. There have been no changes in the Company’s critical accounting estimates from those that were disclosed in the 2017 Form 10-K, except for the adoption of ASC 606 - Revenue from Contracts with Customers ("ASC 606"), effective January 1, 2018, which affected revenue recognition and warranty estimates accruals related to the Company's extended equipment contracts, and an estimated liability related to a royalty settlement agreement, both of which are no longer considered significant estimates. Actual results could differ from these estimates. Risks and Uncertainties The Company’s earnings are significantly affected by equity earnings it receives from Tinuum Group. As of September 30, 2018 , Tinuum Group has 18 invested RC facilities of which 11 are leased to a single customer. A majority of these leases are periodically renewed and the loss of this customer by Tinuum Group would have a significant adverse impact on its financial position, results of operations and cash flows, which in turn would have material adverse impact on the Company’s financial position, results of operations and cash flows. Reclassifications Certain balances have been reclassified from the prior year to conform to the current year presentation. No reclassifications have any impact to income before income taxes or net income. New Accounting Guidance In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) ("ASU 2016-02"), which requires lessees to recognize a right of use asset and related lease liability for those leases classified as operating leases at the commencement date and have lease terms of more than 12 months. This topic retains the distinction between finance leases and operating leases. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, and interim periods within those years, and must be applied under a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842): Targeted Improvements ("ASU 2018-11"). The amendments in ASU 2018-11 provide entities with an additional (and optional) transition method to adopt the new lease requirements by allowing entities to initially apply the requirements by recognizing a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, an entity’s reporting for the comparative periods presented in the financial statements in which the entity adopts the new lease requirements would continue to be in accordance with current GAAP (Topic 840). An entity electing this additional (and optional) transition method must provide the required Topic 840 disclosures for all periods that continue to be in accordance with Topic 840. The amendments do not change the existing disclosure requirements in Topic 840. The Company intends to adopt ASC 2016-02 effective January 1, 2019 using the additional (and optional) transition method provided under ASU 2018-11. As of the date of this filing, the Company has materially completed its assessment of ASU 2016-02 and related amendments for the impact to the financial statements as of the adoption date, completed a detailed review of existing lease agreements, continued its review of controls and procedures that may need to be revised or added from the adoption of ASU 2016-02 and completed the documentation of the standard's financial statement impact at adoption and financial statement disclosure changes. Based on the Company's current assessment of ASU 2016-02, it has determined that at adoption it will record approximately $0.2 million of "right of use" assets and incremental lease liabilities, respectively, with no impact to the opening balance of retained earnings. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in ASU 2016-13 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those years, and must be adopted under a modified retrospective method approach. Entities may adopt ASU 2016-13 earlier as of the fiscal years beginning after December 15, 2018, including interim periods within those years. The Company is currently evaluating the provisions of this guidance and assessing its impact on the Company's financial statements and disclosures. The Company does not believe this standard will have a material impact on the Company's financial statements and disclosures. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"). The amendments in ASU 2018-13 improve the effectiveness of fair value measurement disclosures and modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement ("Topic 820"), based on the concepts in FASB Concepts Statement, Conceptual Framework for Financial Reporting - Chapter 8: Notes to Financial Statements, including the consideration of costs and benefits. ASU 2018-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted upon issuance of this Update. An entity is permitted to early adopt any removed or modified disclosures upon issuance of this Update and delay adoption of the additional disclosures until their effective date. The Company is currently evaluating the provisions of this Update and assessing its impact on the Company's financial statement disclosures. The Company does not believe this standard will have a material impact on the Company's financial statement disclosures.

Revenues

Revenues	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Revenues	Revenues Adoption of ASC 606 On January 1, 2018, the Company adopted ASC 606 using the modified retrospective method applied to those contracts that were not completed as of January 1, 2018. The Company recognized the cumulative effect of initially applying ASC 606 to the opening balance of the Accumulated deficit. The comparative information has not been restated and continues to be reported under the accounting standards in effect for those periods. The financial statement impact from the adoption of ASC 606 as of January 1, 2018 was primarily due to the following: • The recognition of revenues and related cost of revenue from Equipment Sales for three uncompleted dry sorbent injection (“DSI”) equipment systems (the “DSI Systems”) as of December 31, 2017, which were accounted for under the guidance in ASC 605-35, Revenue Recognition - Construction-Type and Production-Type Contracts (“ASC 605-35”). Under ASC 605-35, the Company accounted for revenues and associated cost of revenue for equipment systems from inception of the contract under the completed contract method and recognized revenue and cost of revenue when the equipment systems were deemed substantially complete. As of December 31, 2017, none of the DSI Systems had met the revenue recognition criteria under the completed contract method. As of January 1, 2018, the Company has determined that the performance obligation associated with each DSI System has been satisfied under ASC 606 guidance. • The recognition of revenues and related cost of revenue for a licensing arrangement (the “Licensing Arrangement”) in which the Company satisfied its performance obligation under ASC 606 as of January 1, 2018. As a result, the Company’s deferred revenue and related deferred project costs on the three DSI Systems and the Licensing Arrangement, and the resultant income tax effects, were recognized through a cumulative effect adjustment to the Accumulated deficit as of January 1, 2018. In addition, the Company recorded a contract asset in the amount of $0.3 million related to one DSI System contract for which the Company has completed its performance obligations but is not contractually able to bill the customer until the end of the warranty period. The cumulative effect of the change from the adoption of ASC 606 to the Consolidated Balance Sheet as of January 1, 2018 is shown in the table that follows: Balance as of Impact of Balance as of (in thousands) December 31, 2017 Adoption January 1, 2018 Balance Sheet Receivables, net $ 1,113 $ 339 $ 1,452 Deferred tax assets $ 38,661 $ (889 ) $ 37,772 Other long-term assets $ 2,308 $ (322 ) $ 1,986 Billings in excess of costs on uncompleted contracts $ 1,830 $ (1,830 ) $ — Other current liabilities $ 2,664 $ 9 $ 2,673 Other long-term liabilities $ 2,285 $ (2,000 ) $ 285 Accumulated deficit $ (15,478 ) $ 2,950 $ (12,528 ) The following tables show the impact of the adoption of ASC 606 on the Condensed Consolidated Balance Sheet and Condensed Consolidated Statement of Operations as of and for the three and nine months ended September 30, 2018 , respectively: Balance as Reported Impact of Balance as Adjusted (in thousands) September 30, 2018 Adoption September 30, 2018 Balance Sheet Receivables, net $ 817 $ — $ 817 Deferred tax assets $ 36,008 $ 425 $ 36,433 Other long-term assets $ 2,070 $ 322 $ 2,392 Billings in excess of costs on uncompleted contracts $ — $ — $ — Other current liabilities $ 627 $ — $ 627 Other long-term liabilities $ 295 $ 2,000 $ 2,295 Retained earnings (deficit) $ 10,896 $ (1,253 ) $ 9,643 For the three months ended As Reported Impact of As Adjusted (in thousands) September 30, 2018 Adoption September 30, 2018 Statement of Operations Revenues: Equipment sales $ — $ 10,042 $ 10,042 License royalties, related party $ 4,104 $ (4,104 ) $ — Total revenues $ 5,147 $ 5,938 $ 11,085 Operating expenses: Equipment sales cost of revenue $ — $ 7,874 $ 7,874 Total operating expenses $ 5,115 $ 7,874 $ 12,989 Operating loss $ 32 $ (1,936 ) $ (1,904 ) Other income (expense) Royalties, related party $ — $ 4,104 $ 4,104 Total other income (expense) $ 9,402 $ 4,104 $ 13,506 Income before income tax expense $ 9,434 $ 2,168 $ 11,602 Income tax expense $ 3,931 $ 464 $ 4,395 Net income $ 5,503 $ 1,704 $ 7,207 For the nine months ended As Reported Impact of As Adjusted (in thousands) September 30, 2018 Adoption September 30, 2018 Statement of Operations Revenues: Equipment sales $ 72 $ 17,574 $ 17,646 License royalties, related party $ 10,857 $ (10,857 ) $ — Total revenues $ 13,319 $ 6,717 $ 20,036 Operating expenses: Equipment sales cost of revenue $ (346 ) $ 15,399 $ 15,053 Total operating expenses $ 16,568 $ 15,399 $ 31,967 Operating loss $ (3,249 ) $ (8,682 ) $ (11,931 ) Other income (expense) Royalties, related party $ — $ 10,857 $ 10,857 Total other income (expense) $ 36,856 $ 10,857 $ 47,713 Income before income tax expense $ 33,607 $ 2,175 $ 35,782 Income tax expense $ 5,151 $ 464 $ 5,615 Net income $ 28,456 $ 1,711 $ 30,167 As of and for the three and nine months ended September 30, 2018 , the significant difference between the financial statement balances reported compared to the financial statement balances without the adoption of ASC 606 were as follows: • Equipment sales -As of adoption, the Company derecognized contract assets of $16.5 million and contract liabilities of $18.3 million and recorded a contract asset of $0.3 million related to the three DSI Systems contracts that met the revenue recognition requirements under ASC 606. After tax, the net adjustment for the three DSI Systems was $1.7 million . Under revenue recognition guidance in effect prior to the adoption of ASC 606, one DSI Systems contract would have met revenue recognition criteria as of June 30, 2018, and a second DSI System contract would have met revenue recognition criteria as of September 30, 2018 . For the first DSI System contract, the Company would have recorded $7.5 million of Equipment sales and $7.5 million Equipment sales cost of revenue, respectively, for the three months ended June 30, 2018. For the second DSI System contract, the Company would have recognized Equipment sales of $10.0 million and Equipment sales cost of revenue of $7.9 million , respectively, for the three months ended September 30, 2018 . For the nine months ended September 30, 2018 , the Company would have recognized $17.6 million of Equipment sales and $15.4 million of Equipment sales cost of revenue, respectively, for the two DSI System contracts. • Licensing Arrangement - As of adoption, the Company derecognized a contract liability of $2.0 million and a contract asset of $0.3 million related to the Licensing Arrangement, which met the revenue recognition requirements under ASC 606. After tax, the net adjustment for this contract was $1.3 million . Under revenue recognition guidance in effect prior to the adoption of ASC 606, this contract would not have met revenue recognition criteria as of September 30, 2018 . • Royalties, related party - As of adoption, and based on guidance provided in ASC 606 related to licensing arrangements where royalties are earned on a usage-based royalty arrangement, for the three and nine months ended September 30, 2018 , as well as the corresponding periods from the prior year, the Company has reported license royalties earned from Tinuum Group as revenues rather than as non-operating income under financial statement presentation guidance in effect prior to the adoption of ASC 606. This reclassification had no impact to the Company’s income before income tax expense or net income for all periods presented. Revenue Recognition The Company recognizes revenue from a contract with a customer when a performance obligation under the terms of a contract with a customer is satisfied, which is when the customer controls the promised goods or services that are transferred in satisfaction of the performance obligation. Revenue is measured as the amount of consideration that is expected to be received in exchange for transferring goods or providing services, and the transaction price is generally fixed and generally does not contain variable or noncash consideration. In addition, the Company’s contracts with customers generally do not contain customer refund or return provisions or other similar obligations. Transfer of control and satisfaction of performance obligations are further discussed in each of the revenue components listed below. The Company uses estimates and judgments in determining the nature and timing of satisfaction of performance obligations, the standalone selling price (“SSP”) of performance obligations and the allocation of the transaction price to multiple performance obligations. The Company’s principal revenue components are Chemical sales and License royalties. Chemicals The Company recognizes revenue for direct sales of proprietary chemicals and other ancillary items when the customer obtains control, which is generally at the point in time that delivery to and acceptance by the customer has occurred. Customer contracts for sales of chemicals are short duration and performance obligations generally do not extend beyond one year. Certain chemical customer contracts are comprised of evaluation tests of the Company’s chemicals’ effectiveness and efficiency in reducing emissions. These contracts entail the delivery of chemicals to the customer and the Company's evaluation of results of emissions reduction over the term of the contract. Under these types of arrangements, which are generally for durations that are short term, the Company has determined that the customer is simultaneously receiving benefits of emissions reduction from the consumption of the chemicals over the testing period and this represents a single performance obligation that is satisfied over time. This determination may require significant judgment. The Company recognizes revenue over time using an input model that is generally based on the cost of chemicals consumed by the customer during the testing period. The use of an input model and the use of total costs as the measure of progress in the satisfaction of the performance obligations may require significant judgment. In addition, under these types of contracts, the Company has determined that the services performed and related costs incurred by the Company during the testing period represent costs to fulfill a contract. License Royalties The Company generates revenues from royalties (“M-45 Royalties”) earned under a licensing arrangement (“M-45 License”) of its M-45 TM and M-45-PC TM emissions control technologies (“M-45 Technology”) between the Company and Tinuum Group. The Company recognizes M-45 Royalties at a point in time based on the use of the M-45 Technology at certain RC facilities or through Tinuum Group’s use of licensed technology for rates in excess of amounts allowed for RC application. The amount of M-45 Royalties recognized is generally based on a percentage of pre-tax margins (as defined in the M-45 License) of the RC facilities using the M-45 Technology. Arrangements with Multiple Performance Obligations Contracts with customers may include multiple performance obligations, which are comprised of the sale of chemicals, equipment and services performed as part of an emissions reduction arrangement. For such arrangements, the Company allocates revenue to each performance obligation based on its relative SSP. When a directly observable SSP for a performance obligation is not available, the Company primarily estimates SSPs based on the expected cost plus a margin method. These estimates as well as the timing of the satisfaction of performance obligations associated with the services component represent significant judgments made by the Company. These arrangements are generally short duration and performance obligations generally do not extend beyond one year. Contract Assets and Liabilities Contract assets are comprised of unbilled receivables and are included in Receivables, net in the Condensed Consolidated Balance Sheet. Unbilled receivables represent a conditional right to consideration in exchange for goods or services transferred to a customer. Trade receivables represent an unconditional right to consideration in exchange for goods or services transferred to a customer. The Company invoices its customers in accordance with the terms of the contract. Credit terms are generally net 30 from the date of invoice. The timing between the satisfaction of performance obligations and when payment is due from the customer is generally not significant. The Company records allowances for doubtful trade receivables when it is probable that the balances will not be collected. Contract liabilities are comprised of deferred revenue, which represents an obligation to transfer goods or services to a customer for which the Company has received consideration from the customer and, if deliverable within one year or less, is included in Other current liabilities in the Condensed Consolidated Balance Sheet and, if deliverable outside of one year, is included in Other long-term liabilities in the Condensed Consolidated Balance Sheet. Disaggregation of Revenue During the three and nine months ended September 30, 2018 , all performance obligations related to revenues recognized were satisfied at a point in time. The Company disaggregates its revenues by its major components as well as between its two operating segments, which are further discussed in Note 10 to the condensed consolidated financial statements. The following tables disaggregate revenues by major source for the three and nine months ended September 30, 2018 (in thousands): Three Months Ended September 30, 2018 Segment EC RC Total Revenue component Chemical sales $ 1,043 $ — $ 1,043 License royalties, related party — 4,104 4,104 Equipment sales — — — Revenues from customers 1,043 4,104 5,147 Earnings from equity method investments — 9,715 9,715 Segment revenues $ 1,043 $ 13,819 $ 14,862 Nine Months Ended September 30, 2018 Segment EC RC Total Revenue component Chemical sales $ 2,390 $ — $ 2,390 License royalties, related party — 10,857 10,857 Equipment sales 72 — 72 Revenues from customers 2,462 10,857 13,319 Earnings from equity method investments — 37,857 37,857 Segment revenues $ 2,462 $ 48,714 $ 51,176 Practical Expedients and Exemptions The Company does not disclose the value of unsatisfied performance obligations for contracts with an original expected length of one year or less. Sales and other taxes that are collected concurrently with revenue-producing activities are excluded from revenue. The Company has also elected to account for freight costs as activities to fulfill the promise to transfer the goods, and therefore these activities are also not assessed as a separate service to customers. The Company accounts for all shipping and handling activities that occur after control of the related good transfers as fulfillment activities. These activities are included in Cost of Revenue line items of the Condensed Consolidated Statement of Operations. The Company generally expenses sales commissions when incurred because the amortization period of the asset that the Company would have recognized is one year or less. These costs are recorded within sales and marketing expenses within the General and administrative line item of the Condensed Consolidated Statement of Operations.

Equity Method Investments

Equity Method Investments	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments Tinuum Group, LLC The Company's ownership interest in Tinuum Group was 42.5% as of September 30, 2018 and December 31, 2017 . Tinuum Group supplies technology equipment and technical services at select coal-fired generators, but its primary purpose is to put into operation facilities that produce and sell RC that lower emissions and therefore qualify for Section 45 tax credits. Tinuum Group has been determined to be a variable interest entity ("VIE"); however, the Company does not have the power to direct the activities that most significantly impact Tinuum Group's economic performance and has therefore accounted for the investment under the equity method of accounting. The Company determined that the voting partners of Tinuum Group have identical voting rights, equity control interests and board control interests, and therefore, concluded that the power to direct the activities that most significantly impact Tinuum Group's economic performance was shared. The following table summarizes the results of operations of Tinuum Group: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Gross profit $ 26,530 $ 23,812 $ 81,626 $ 70,895 Operating, selling, general and administrative expenses 5,908 5,174 17,406 14,975 Income from operations 20,622 18,638 64,220 55,920 Other expenses (577 ) (3,331 ) (2,801 ) (4,278 ) Class B preferred return — (384 ) (12 ) (1,526 ) Loss attributable to noncontrolling interest 17,126 11,953 38,145 29,240 Net income available to members $ 37,171 $ 26,876 $ 99,552 $ 79,356 ADES equity earnings from Tinuum Group $ 8,075 $ 11,050 $ 33,575 $ 33,363 As of September 30, 2018 and December 31, 2017 , the amount of Tinuum Group's temporary Class B preferred equity was zero and $0.8 million , respectively. The difference between the Company's proportionate share of Tinuum Group's net income available to members (at its equity interest of 42.5% ) as presented in the table below and the Company's earnings from its Tinuum Group equity method investment as reported in the Condensed Consolidated Statements of Operations relates to the Company receiving distributions in excess of the carrying value of the equity investment, and therefore recognizing such excess distributions as equity method earnings in the period the distributions occur, as discussed below. As shown in the tables below, the Company’s carrying value in Tinuum Group was reduced to zero for the three and nine months ended September 30, 2018 , as cumulative cash distributions received from Tinuum Group exceeded the Company's pro-rata share of cumulative earnings in Tinuum Group. The carrying value of the Company's investment in Tinuum Group shall remain zero as long as the cumulative amount of distributions received from Tinuum Group continues to exceed the Company's cumulative pro-rata share of Tinuum Group's net income available to its members. For periods during which the ending balance of the Company's investment in Tinuum Group is zero, the Company only recognizes equity earnings from Tinuum Group to the extent that cash distributions are received from Tinuum Group during the period. For periods during which the ending balance of the Company's investment is greater than zero (e.g., when the cumulative earnings in Tinuum Group exceeds cumulative cash distributions received), the Company recognizes its pro-rata share of Tinuum Group's net income available to its members for the period, less any amount necessary to recover the cumulative earnings short-fall balance as of the end of the immediately preceding period. During the three and nine months ended September 30, 2018 , the Company's cumulative amount of distributions received from Tinuum Group exceeded the Company's cumulative pro-rata share of Tinuum Group's net income available to its members. As such, the Company recognized equity earnings from Tinuum Group for the three and nine months ended September 30, 2018 of $8.1 million and $33.6 million , respectively. During the three and nine months ended September 30, 2017 , the Company recognized equity earnings from Tinuum Group in the amount of $11.1 million and $33.4 million , respectively. As of September 30, 2018 and 2017 , the Company's carrying value in Tinuum Group was zero and zero , respectively. Thus, the amount of equity earnings or loss reported on the Company's Condensed Consolidated Statement of Operations may differ from a mathematical calculation of net income or loss attributable to the equity interest based upon the factor of the equity interest and the net income or loss attributable to members as shown on Tinuum Group’s statement of operations. Additionally, for periods during which the carrying value of the Company's investment in Tinuum Group is greater than zero, distributions from Tinuum Group are reported on the Condensed Consolidated Statements of Cash Flows as "Distributions from equity method investees, return on investment" within Operating cash flows. For periods during which the carrying value of the Company's investment in Tinuum Group is zero, such cash distributions are reported on the Condensed Consolidated Statements of Cash Flows as "Distributions from equity method investees in excess of investment basis" within Investing cash flows. The following tables present the Company's investment balance, equity earnings and cash distributions in excess of the investment balance for the three and nine months ended September 30, 2018 and 2017 ( in thousands ): Description Date(s) Investment balance ADES equity earnings (loss) Cash distributions Memorandum Account: Cash distributions and equity earnings in (excess) of investment balance Beginning balance 12/31/2017 $ — $ — $ — $ (12,218 ) ADES proportionate share of income from Tinuum Group (1) First Quarter 12,458 12,458 — — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) First Quarter (12,218 ) (12,218 ) — 12,218 Cash distributions from Tinuum Group First Quarter (11,050 ) — 11,050 — Adjustment for current year cash distributions in excess of investment balance First Quarter 10,810 10,810 — (10,810 ) Total investment balance, equity earnings (loss) and cash distributions 3/31/2018 $ — $ 11,050 $ 11,050 $ (10,810 ) ADES proportionate share of income from Tinuum Group (1) Second Quarter $ 14,059 $ 14,059 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Second Quarter (10,810 ) (10,810 ) — 10,810 Cash distributions from Tinuum Group Second Quarter (14,450 ) — 14,450 — Adjustment for current year cash distributions in excess of investment balance Second Quarter 11,201 11,201 (11,201 ) Total investment balance, equity earnings (loss) and cash distributions 6/30/2018 $ — $ 14,450 $ 14,450 $ (11,201 ) ADES proportionate share of income from Tinuum Group (1) Third Quarter $ 15,798 $ 15,798 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Third Quarter (11,201 ) (11,201 ) — 11,201 Cash distributions from Tinuum Group Third Quarter (8,075 ) — 8,075 — Adjustment for current year cash distributions in excess of investment balance Third Quarter 3,478 3,478 — (3,478 ) Total investment balance, equity earnings (loss) and cash distributions 9/30/2018 $ — $ 8,075 $ 8,075 $ (3,478 ) Description Date(s) Investment balance ADES equity earnings (loss) Cash distributions Memorandum Account: Cash distributions and equity earnings in (excess) of investment balance Beginning balance 12/31/2016 $ — $ — $ — $ (9,894 ) ADES proportionate share of income from Tinuum Group (1) First Quarter 10,457 10,457 — — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) First Quarter (9,894 ) (9,894 ) — 9,894 Cash distributions from Tinuum Group First Quarter (13,175 ) — 13,175 — Adjustment for current year cash distributions in excess of investment balance First Quarter 12,612 12,612 — (12,612 ) Total investment balance, equity earnings (loss) and cash distributions 3/31/2017 $ — $ 13,175 $ 13,175 $ (12,612 ) ADES proportionate share of income from Tinuum Group (1) Second Quarter $ 11,761 $ 11,761 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Second Quarter (11,761 ) (11,761 ) — 11,761 Cash distributions from Tinuum Group Second Quarter (9,138 ) — 9,138 — Adjustment for current year cash distributions in excess of investment balance Second Quarter 9,138 9,138 — (9,138 ) Total investment balance, equity earnings (loss) and cash distributions 6/30/2017 $ — $ 9,138 $ 9,138 $ (9,989 ) ADES proportionate share of income from Tinuum Group (1) Third Quarter $ 11,393 $ 11,393 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Third Quarter (9,989 ) (9,989 ) — 9,989 Cash distributions from Tinuum Group Third Quarter (11,050 ) — 11,050 — Adjustment for current year cash distributions in excess of investment balance Third Quarter 9,646 9,646 — (9,646 ) Total investment balance, equity earnings (loss) and cash distributions 9/30/2017 $ — $ 11,050 $ 11,050 $ (9,646 ) (1) For the three and nine months ended September 30, 2018 and 2017 , the amounts of the Company's 42.5% proportionate share of net income available to members as shown in the table above may differ from mathematical calculations of the Company’s 42.5% equity interest in Tinuum Group multiplied by the amounts of net income available to members as shown in the table above of Tinuum Group results of operations due to adjustments related to the Class B preferred return. Tinuum Services, LLC The Company has a 50% voting and economic interest in Tinuum Services, which is equivalent to the voting and economic interest of NexGen Refined Coal, LLC ("NexGen"). The Company has determined that Tinuum Services is not a VIE and has evaluated its consolidation analysis under the voting interest model. Because the Company does not own greater than 50% of the outstanding voting shares, either directly or indirectly, it has accounted for its investment in Tinuum Services under the equity method of accounting. The Company’s investment in Tinuum Services as of September 30, 2018 and December 31, 2017 was $5.3 million and $4.3 million , respectively. During the nine months ended September 30, 2018 , the Company funded a capital call of $0.8 million , which increased its investment balance in Tinuum Services. The following table summarizes the results of operations of Tinuum Services: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Gross loss $ (21,362 ) $ (17,344 ) $ (64,069 ) $ (47,472 ) Operating, selling, general and administrative expenses 43,947 34,872 127,783 106,825 Loss from operations (65,309 ) (52,216 ) (191,852 ) (154,297 ) Other income 78 34 443 103 Loss attributable to noncontrolling interest 68,509 54,305 199,971 159,627 Net income $ 3,278 $ 2,123 $ 8,562 $ 5,433 ADES equity earnings from Tinuum Services $ 1,639 $ 1,061 $ 4,281 $ 2,717 Included within the Consolidated Statements of Operations of Tinuum Services for the three and nine months ended September 30, 2018 and 2017 , respectively, were losses related to VIE's of Tinuum Services. These losses do not impact the Company's equity earnings from Tinuum Services as 100% of those losses are attributable to a noncontrolling interest and eliminated in the calculations of Tinuum Services' net income attributable to the Company's interest. The following table details the components of the Company's respective equity method investments included within the Earnings from equity method investments line item on the Condensed Consolidated Statements of Operations : Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Earnings from Tinuum Group $ 8,075 $ 11,050 $ 33,575 $ 33,363 Earnings from Tinuum Services 1,639 1,061 4,281 2,717 Earnings from other 1 9 1 9 Earnings from equity method investments $ 9,715 $ 12,120 $ 37,857 $ 36,089 The following table details the components of the cash distributions from the Company's respective equity method investments included in the Condensed Consolidated Statements of Cash Flows . Distributions from equity method investees are reported on the Condensed Consolidated Statements of Cash Flows as " Distributions from equity method investees, return on investment " within Operating cash flows until such time as the carrying value in an equity method investee company is reduced to zero; thereafter, such distributions are reported as " Distributions from equity method investees in excess of cumulative earnings " within Investing cash flows. Nine Months Ended September 30, (in thousands) 2018 2017 Distributions from equity method investees, return on investment Tinuum Services $ 4,000 $ 3,675 $ 4,000 $ 3,675 Distributions from equity method investees in excess of investment basis Tinuum Group $ 33,575 $ 33,363 $ 33,575 $ 33,363

Borrowings

Borrowings	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Borrowings	Borrowings Line of Credit On September 30, 2018, ADA-ES., Inc., a wholly-owned subsidiary of the Company ("ADA"), as borrower, the Company, as guarantor, and a bank (the "Lender") entered into an amendment (the "Twelfth Amendment") to the 2013 Loan and Security Agreement (the "Line of Credit"). The Twelfth Amendment decreased the Line of Credit to $5.0 million due to decreased collateral requirements, extended the maturity date of the Line of Credit to September 30, 2020 and permitted the Line of Credit to be used as collateral (in place of restricted cash) for letters of credit ("LC's") up to $5.0 million related to equipment projects and certain other agreements. Under the Line of Credit, there is no minimum balance requirement based on the Company meeting certain conditions and maintaining minimum trailing twelve-month EBITDA (earnings before interest, taxes, depreciation and amortization), as previously defined in the "Eleventh Amendment" to the Line of Credit, of $24.0 million . As of September 30, 2018 , there were no outstanding borrowings under the Line of Credit. Other In March 2017, a customer drew on an LC related to an equipment system in the amount of $0.8 million , which was funded by borrowing availability under the Line of Credit. The Company subsequently repaid this amount to the Lender as of March 31, 2017. The Company is contesting the LC draw on this LC and is pursuing legal actions to recover the entire amount from the customer. The Company recorded an asset for the LC Draw net of an estimated allowance of $0.4 million . This amount is included in Other long-term assets on the Condensed Consolidated Balance Sheets . The following table presents the LC's outstanding and collateral, by asset type, reported on the Condensed Consolidated Balance Sheets . There were no LC's outstanding or collateral as of September 30, 2018 . As of December 31, 2017 (in thousands) LC Outstanding Utilization of LOC Availability Royalty Award $ 3,500 $ 3,500 Total LC outstanding $ 3,500 $ 3,500

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings The Company is from time to time subject to, and is presently involved in, various pending or threatened legal actions and proceedings, including those that arise in the ordinary course of its business. Such matters are subject to many uncertainties and to outcomes, the financial impacts of which are not predictable with assurance and that may not be known for extended periods of time. The Company records a liability in its consolidated financial statements for costs related to claims, settlements, and judgments where management has assessed that a loss is probable and an amount can be reasonably estimated. Settlement and royalty indemnity In 2011, the Company and Norit International B.V. ("Norit") entered into a settlement agreement (the "Norit Settlement Agreement") whereby the Company paid amounts related to a non-solicitation breach of contract claim ("Norit Litigation"), and was also required to pay additional damages (the "Royalty Award") related to certain future revenues generated from an activated carbon manufacturing plant (the "Red River Plant") that the Company owned through a joint venture with ADA Carbon Solutions, LLC ("Carbon Solutions"). Payments due under the Royalty Award were due quarterly in arrears through June 2018. Additionally, in 2011, the Company entered into the Settlement Agreement Regarding ADA-ES’ Indemnity Obligations (the "Indemnity Settlement Agreement") whereby the Company agreed to settle certain indemnity obligations asserted against the Company related to the Norit Litigation and relinquished all of its equity interest in Carbon Solutions. Under the Norit Settlement Agreement, the Company was required to pledge LC's as collateral for a portion of Royalty Award future payments due. In March 2017, the Company was required to increase its LC's under the Royalty Award based on a provision that required additional amounts be pledged because the Company had achieved annual earnings in excess of $20.0 million for the fiscal year ended December 31, 2016. Under this provision, the Company was required to provide an additional LC of $5.0 million , which was secured under the Line of Credit in March 2017. Under a separate provision of the Norit Settlement Agreement effective during 2017, the Company was required to increase the LC's, subject to the aggregate amount of estimated future payments due related to the Royalty Award, for any dividends issued by the Company prior to January 1, 2018 in amount equal to 50% of the aggregate fair market value of such dividends (the "Dividends Provision"). Based on the estimated remaining future payments due under the Royalty Award, the Dividends Provision did not impact the amount of LC's pledged during 2017. During the nine months ended September 30, 2017, the Company revised its estimate for future Royalty Award payments based in part on an updated forecast provided to the Company from Carbon Solutions. This forecast included a material reduction in estimated future revenues generated at the Red River Plant. Based primarily on the updated forecast, the Company recorded a $3.4 million reduction to the Royalty Award accrual. In December 2017, the Company, Carbon Solutions and the parent company of Carbon Solutions agreed to terminate certain provisions of the Indemnity Settlement Agreement (the "Indemnity Termination Agreement"). Pursuant to an agreement executed concurrently with the Indemnity Termination Agreement, the Company, Norit and an affiliate of Norit (collectively referred to as "Norit") agreed to a final payment in the amount of $3.3 million (the "Settlement Payment") to settle all outstanding royalty obligations owed under the terms of the Norit Settlement Agreement. This amount was paid by the Company on December 29, 2017. Under the Indemnity Termination Agreement, and upon payment of the Settlement Payment, the Company was relieved of certain financial and indemnity obligations required by the terms of the Norit Settlement Agreement, including the obligation to maintain LC's securing future royalty payment obligations. As of December 31, 2017, $3.5 million in LC's related to the Royalty Award were outstanding, but were canceled by all parties in January 2018, pursuant to the Indemnity Termination Agreement. Advanced Emission Solutions, Inc. Profit Sharing Retirement Plan The Advanced Emissions Solutions, Inc. Profit Sharing Retirement Plan (the “401(k) Plan”) is subject to the jurisdiction of the Internal Revenue Service ("IRS") and the Department of Labor ("DOL"). In 2016, the DOL opened an investigation into the 401(k) Plan, and the Company (in its role as Plan Sponsor) cooperated with that investigation. In February 2018, as part of ongoing discussions, the Company and the DOL came to an agreement whereby the Company would make a restorative payment to the 401(k) Plan in the amount of $1.0 million as an estimate of lost earnings for 401(k) Plan participants as of January 1, 2015. Thereafter, the DOL would close the investigation with no further action against the 401(k) Plan or its fiduciaries, including any further investigation. The Company determined this contingency to be both probable and reasonably estimable and accrued $1.0 million as of December 31, 2017. The liability was recorded in the Other current liabilities line item on the Consolidated Balance Sheet. The expense recognized related to this accrual was included in the Other line item in the Consolidated Statements of Operations for the year ended December 31, 2017. The Company made a payment of $1.0 million to the 401(k) Plan on June 1, 2018 and no liability existed as of September 30, 2018. On September 7, 2018, the Company received notification that the DOL had closed its investigation and no further action is required by the Company. Other Commitments and Contingencies Tinuum Group The Company also has certain limited obligations contingent upon future events in connection with the activities of Tinuum Group. The Company, NexGen and two entities affiliated with NexGen have provided an affiliate of the Goldman Sachs Group, Inc. with limited guaranties (the "Tinuum Group Party Guaranties") related to certain losses it may suffer as a result of inaccuracies or breach of representations and covenants. The Company also is a party to a contribution agreement with NexGen under which any party called upon to pay on a Tinuum Group Party Guaranty is entitled to receive contributions from the other party equal to 50% of the amount paid. No liability or expense provision has been recorded by the Company related to this contingent obligation as the Company believes that it is not probable that a loss will occur with respect to Tinuum Group Party Guaranties.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Stock Repurchase Program Under a stock repurchase program authorized by the Board in December 2017 (the "Stock Repurchase Program"), during the three and nine months ended September 30, 2018 , the Company purchased zero and 825,418 shares, respectively, of its common stock for cash of zero and $9.1 million , respectively, inclusive of commissions and fees. Of these amounts, $2.2 million was purchased in a single block through a privately negotiated transaction. Under the terms of the Stock Repurchase Program, the Company was authorized to purchase up to $20.0 million of its outstanding common stock, and it remained in effect until July 31, 2018. On September 12, 2018 , the Company repurchased 186,212 shares of its common stock for $2.1 million in a single block through a privately negotiated transaction. On May 5, 2017, the Board authorized the commencement of a modified Dutch Auction tender offer ("Tender Offer") to purchase for cash up to 925,000 shares of the Company's common stock at a price per share of not less than $9.40 nor greater than $10.80 , for a maximum aggregate purchase price of $10.0 million , with an option to purchase an additional 2% of the outstanding shares of common stock if the Tender Offer was oversubscribed. The Tender Offer expired on June 6, 2017 and a total of 2,858,425 shares were validly tendered and not properly withdrawn at or below the final purchase price of $9.40 per share. Because the Tender Offer was oversubscribed, the Company purchased a prorated portion of the shares properly tendered by each tendering stockholder (other than "odd lot" holders whose shares were purchased on a priority basis) at the final per share purchase price. Accordingly, the Company acquired 1,370,891 shares of its common stock ("Tendered Shares") at a price of $9.40 per share, for a total cost of approximately $12.9 million , excluding fees and other expenses related to the Tender Offer. The Tendered Shares represented approximately 6.2% of the Company's outstanding shares prior to the Tender Offer. The Tendered Shares include the 925,000 shares the Company initially offered to purchase and 445,891 additional shares that the Company elected to purchase pursuant to its right to purchase up to an additional 2% of its outstanding shares of common stock. The Company recorded the Tendered Shares at cost, which included fees and expenses related to the Tender Offer, and reported the Tendered Shares as Treasury Stock in the Condensed Consolidated Balance Sheet. The Company’s Board and executive officers did not participate in the Tender Offer, except for one director of the Board, who is a manager of a financial institution and holds dispositive powers over the shares of the Company's common stock held by the financial institution, which tendered 70,178 of its shares of the Company's common stock. Quarterly Cash Dividend Dividends declared by the Board, and paid quarterly per share on all outstanding shares of comment stock during the three and nine months ended September 30, 2018 and 2017 were as follows: 2018 2017 Per share Date paid Per share Date paid Dividends declared during quarter ended: March 31 $ 0.25 March 8, 2018 $ — — June 30 0.25 June 8, 2018 0.25 July 17, 2017 September 30 0.25 September 6, 2018 0.25 September 7, 2017 $ 0.75 $ 0.50 A portion of the dividends declared remain accrued subsequent to the payment dates and represent dividends accumulated on nonvested shares of common stock held by employees and directors of the Company that contain forfeitable dividend rights that are not payable until the underlying shares of common stock vest. These amounts are included in both Other current liabilities and Other long-term liabilities on the Condensed Consolidated Balance Sheet as of September 30, 2018 . Tax Asset Protection Plan United States federal income tax rules, and Section 382 of the Internal Revenue Code in particular, could substantially limit the use of net operating losses and other tax assets if ADES experiences an "ownership change" (as defined in the Internal Revenue Code). In general, an ownership change occurs if there is a cumulative change in the ownership of ADES by "5 percent stockholders" that exceeds 50 percentage points over a rolling three-year period. On May 5, 2017, the Board approved the declaration of a dividend of rights to purchase Series B Junior Participating Preferred Stock for each outstanding share of common stock as part of a tax asset protection plan (the "Tax Asset Protection Plan") designed to protect the Company’s ability to utilize its net operating losses and tax credits. The Tax Asset Protection Plan is intended to act as a deterrent to any person acquiring beneficial ownership of 4.99% or more of the Company’s outstanding common stock. On April 6, 2018, the Board approved the First Amendment to the Tax Asset Protection Plan (the "Amendment") that amends the Tax Asset Protection Plan dated May 5, 2017 (the "TAPP"). The Amendment amends the definition of "Final Expiration Date" under the TAPP to extend the duration of the TAPP and makes associated changes in connection therewith. At the Company's 2018 annual meeting, the Company's stockholders approved the Amendment, thus the Final Expiration Date will be the close of business on December 31, 2019.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company grants equity-based awards to employees and non-employee directors that may include RSA's, stock options, PSU's and stock appreciation rights ("SAR's"). Stock-based compensation expense related to employees is included within the Payroll and benefits line item in the Condensed Consolidated Statements of Operations . Stock-based compensation expense related to non-employee directors is included within the General and administrative line item in the Condensed Consolidated Statements of Operations . Total stock-based compensation expense for the three and nine months ended September 30, 2018 and 2017 was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 RSA expense $ 919 $ 298 $ 1,871 $ 1,103 Stock option expense — 143 58 443 PSU expense — 34 — 102 Total stock-based compensation expense $ 919 $ 475 $ 1,929 $ 1,648 The amount of unrecognized compensation cost as of September 30, 2018 , and the expected weighted-average period over which the cost will be recognized is as follows: As of September 30, 2018 ( in thousands ) Unrecognized Compensation Cost Expected Weighted- RSA expense $ 2,118 2.19 Total unrecognized stock-based compensation expense $ 2,118 2.19 Restricted Stock Awards Restricted stock is typically granted with vesting terms of three years. The fair value of RSA's is determined based on the closing price of the Company’s common stock on the authorization date of the grant multiplied by the number of shares subject to the stock award. Compensation expense for RSA's is generally recognized on a straight-line basis over the entire vesting period. A summary of RSA activity under the Company's various stock compensation plans for the nine months ended September 30, 2018 is presented below: Shares Weighted-Average Non-vested at January 1, 2018 276,607 $ 9.03 Granted 205,998 $ 11.00 Vested (180,740 ) $ 9.85 Forfeited (1,135 ) $ 10.44 Non-vested at September 30, 2018 300,730 $ 9.88 Stock Options Stock options generally vest over three years or upon satisfaction of performance-based conditions and have a contractual limit of five years from the date of grant to exercise. The fair value of stock options granted is determined on the date of grant using the Black-Scholes option pricing model and the related expense is recognized on a straight-line basis over the entire vesting period. A summary of stock option activity for the nine months ended September 30, 2018 is presented below: Number of Options Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average Options outstanding, January 1, 2018 622,446 $ 11.64 Options granted — — Options exercised (92,666 ) 8.25 Options expired / forfeited — — Options outstanding, September 30, 2018 529,780 $ 12.23 $ 592 1.71 Options exercisable, September 30, 2018 529,780 $ 12.23 $ 592 1.71 The Company did not receive cash from the exercise of stock options during the three months ended September 30, 2018 as 67,715 shares were withheld as payment of the exercise price. The total intrinsic value of options exercised during the three months ended September 30, 2018 was $0.3 million . Performance Share Units Compensation expense is recognized for PSU awards on a straight-line basis over the applicable service period, which is generally three years, based on the estimated fair value at the date of grant using a Monte Carlo simulation model. There were no PSU's granted during the nine months ended September 30, 2018 . A summary of PSU activity for the nine months ended September 30, 2018 is presented below: Units Weighted-Average Non-vested at January 1, 2018 19,406 $ 19.95 Granted — — Vested / Settled (1) (19,406 ) $ 19.95 Forfeited / Canceled — — Non-vested at September 30, 2018 — $ — (1) The number of units shown in the table above were based on target performance. The final number of shares of common stock issued was based on the achievement of market conditions established within the awards. The following table shows the PSU's that were settled by issuing shares of the Company's common stock relative to a broad stock index and a peer group performance index. Year of Grant Net Number of Issued Shares upon Vesting Shares Withheld to Settle Tax Withholding Obligations TSR Multiple Range Russell 3000 Multiple Low High Low High Nine Months Ended September 30, 2018 2015 12,311 4,061 112.50 112.50 — — Nine Months Ended September 30, 2017 2014 6,476 3,573 0.75 1.00 — — 2015 3,869 2,310 0.60 0.60 — —

Supplemental Financial Informat

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Supplemental Financial Information	Supplemental Financial Information Supplemental Balance Sheet Information The following table summarizes the components of Prepaid expenses and other assets and Other long-term assets as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) September 30, December 31, Prepaid expenses and other assets: Prepaid expenses $ 435 $ 776 Inventory 13 74 Prepaid income taxes 2,153 902 Other 30 83 $ 2,631 $ 1,835 Other long-term assets: Deposits $ 222 $ 223 Intangibles, net 889 805 Highview Investment 552 552 Other 407 728 $ 2,070 $ 2,308 Included within Other long-term assets is the Company's investment ("Highview Investment") in Highview Enterprises Limited's equity securities ("Highview"), a London, England based developmental stage company specializing in power storage. In 2014, the Company acquired an 8% ownership interest in the common stock of Highview for $2.8 million in cash. As of September 30, 2018 , the Company's ownership interest is approximately 4% . The Highview Investment is evaluated for impairment upon an indicator of impairment such as an event or change in circumstances that may have a significant adverse effect on the fair value of the investment. During the year ended December 31, 2017 , the Company recorded an impairment charge of $0.5 million which is included in the Other line item in the Condensed Consolidated Statement of Operations based on an estimated fair value of £1.00 per share compared to the carrying value prior to the impairment charge of £2.00 per share. The estimated fair value as of December 31, 2017 was based on an equity financing that Highview commenced during the third quarter of 2017 at a price of £1.00 per share. The following table details the components of Other current liabilities and Other long-term liabilities as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) September 30, December 31, Other current liabilities: Income taxes payable $ 25 $ 207 Estimated restorative payment to the 401(k) Plan (1) — 1,000 Dividends payable 57 45 Warranty liabilities 26 316 Other 519 1,096 $ 627 $ 2,664 Other long-term liabilities: Deferred rent $ 128 $ 192 Dividends payable 167 93 Deferred revenue, related party — 2,000 $ 295 $ 2,285 (1) See Note 5 for further discussion on the 401(k) Plan. The tables below detail additional components of Other current liabilities as presented above: The changes in the carrying amount of the Company’s warranty obligations from December 31, 2017 through September 30, 2018 were as follows: As of (in thousands) September 30, Balance, beginning of period $ 316 Warranties accrued, net 9 Consumption of warranty obligations accrued (337 ) Change in estimate related to previous warranties accrued 38 Balance, end of period $ 26 Supplemental Condensed Consolidated Statements of Operations Information The following table details the components of Interest expense in the Condensed Consolidated Statements of Operations: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 453A interest $ 388 $ 614 $ 1,128 $ 1,646 Credit agreement interest — 64 — 137 Other 11 — 19 216 $ 399 $ 678 $ 1,147 $ 1,999 The following table details the components of the Other line item of the Condensed Consolidated Statements of Operations : Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Impairment of Highview investment $ — $ (464 ) $ — $ (464 ) Revision in estimated royalty indemnity liability — — — 3,400 Other 86 (460 ) 146 (444 ) $ 86 $ (924 ) $ 146 $ 2,492

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three and nine months ended September 30, 2018 and 2017 , the Company's income tax expense and effective tax rates based on forecasted pretax income were: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except for rate) 2018 2017 2018 2017 Income tax expense $ 3,931 $ 3,586 $ 5,151 $ 12,614 Effective tax rate 42 % 38 % 15 % 38 % The effective tax rates for the three and nine months ended September 30, 2018 and 2017 were different from the federal statutory rates in effect during the respective periods due to state income tax expense, net of federal benefit, and from changes in the valuation allowance against deferred tax assets. During the three and nine months ended September 30, 2018 , we recorded an increase and decrease, respectively, of the valuation allowance based on changes in forecasts of future taxable income. The income tax expense recorded for the three and nine months ended September 30, 2018 was comprised of estimated federal income tax expense of $2.9 million and $3.4 million , respectively, and estimated state income tax expense of $1.0 million and $1.8 million , respectively. The income tax expense recorded for the three and nine months ended September 30, 2017 was comprised of estimated federal income tax expense of $3.2 million and $11.9 million , respectively, and estimated state income tax expense of $0.4 million and $0.7 million , respectively. On December 22, 2017 (the "Enactment Date"), the U.S. government enacted comprehensive tax legislation commonly referred to as the Tax Cuts and Jobs Act (the "Tax Act"). The Tax Act makes broad and complex changes to the U.S. tax code and the key provision applicable to the Company for the three and nine months ended September 30, 2018 was the reduction of the U.S. federal corporate tax rate from 35 percent to 21 percent. Concurrent with the enactment of the Tax Act, in December 2017, the SEC staff issued Staff Accounting Bulletin 118 ("SAB 118"), which provides guidance on accounting for the tax effects of the Tax Act. SAB 118 provides a measurement period that should not extend beyond one year from the Enactment Date for companies to complete the accounting under Accounting Standards Codification 740 - Income Taxes ("ASC 740"). In March 2018, the FASB codified SAB 118 into ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Tax Act for which the accounting under ASC 740 is complete. To the extent that an entity's accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. The Company's accounting for the income tax effects of the Tax Act affecting its consolidated financial statements was generally complete as of December 31, 2017 and there were no effects from the Tax Act on the condensed consolidated financial statements as of and for the three and nine months ended September 30, 2018 . The Company does not anticipate any other accounting impacts of the Tax Act during the period within one year from the Enactment Date; however, it will continue to assess any potential impact from the Tax Act through this period. The Company assesses the valuation allowance recorded against deferred tax assets at each reporting date. The determination of whether a valuation allowance for deferred tax assets is appropriate requires the evaluation of positive and negative evidence that can be objectively verified. Consideration must be given to all sources of taxable income available to realize the deferred tax asset, including, as applicable, the future reversal of existing temporary differences, future taxable income forecasts exclusive of the reversal of temporary differences and carryforwards, taxable income in carryback years and tax planning strategies. In estimating income taxes, the Company assesses the relative merits and risks of the appropriate income tax treatment of transactions taking into account statutory, judicial, and regulatory guidance. As of September 30, 2018 , the Company increased the valuation allowance as a result of updating its forecasts of future taxable income, which was primarily driven by updated forecasts of capital expenditures on RC facilities that are in the engineering and installation phase.

Business Segment Information

Business Segment Information	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Business Segment Information	Business Segment Information Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by a company's chief operating decision maker ("CODM"), or a decision-making group, in deciding how to allocate resources and in assessing financial performance. As of September 30, 2018 , the Company's CODM was the Company's CEO. The Company's operating and reportable segments are organized by products and services provided. As of September 30, 2018 , the Company has two reportable segments: (1) Refined Coal ("RC"); and (2) Emissions Control ("EC"). The business segment measurements provided to and evaluated by the CODM are computed in accordance with the principles listed below: • The accounting policies of the operating segments are the same as those described in the summary of significant accounting policies in the 2017 Form 10-K, except as described below. • RC segment revenues includes the Company's equity method earnings and losses from the Company's equity method investments and royalties earned from Tinuum Group. • Segment operating income (loss) includes segment revenues and allocation of certain "Corporate general and administrative expenses," which include Payroll and benefits , Rent and occupancy , Legal and professional fees , General and administrative and Depreciation and amortization . • RC segment operating income includes interest expense directly attributable to the RC segment. As of September 30, 2018 and December 31, 2017 , substantially all of the Company's material assets are located in the U.S. and all significant customers are U.S. companies. The following table presents the Company's operating segment results for the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Revenues: Refined Coal: Earnings in equity method investments $ 9,715 $ 12,120 $ 37,857 $ 36,089 Royalties, related party 4,104 2,804 10,857 6,425 13,819 14,924 48,714 42,514 Emissions Control: Chemicals 1,043 717 2,390 3,844 Equipment Sales — 1,577 72 31,304 1,043 2,294 2,462 35,148 Total segment reporting revenues 14,862 17,218 51,176 77,662 Adjustments to reconcile to reported revenues: Refined Coal: Earnings in equity method investments (9,715 ) (12,120 ) (37,857 ) (36,089 ) Total reported revenues $ 5,147 $ 5,098 $ 13,319 $ 41,573 Segment operating income (loss): Refined Coal (1) $ 12,798 $ 13,991 $ 45,775 $ 40,149 Emissions Control (1,168 ) (895 ) (3,493 ) 1,265 Total segment operating income $ 11,630 $ 13,096 $ 42,282 $ 41,414 (1) Included within the RC segment operating income for the three and nine months ended September 30, 2018 and 2017 is 453A interest expense of $0.4 million and $1.1 million and $0.6 million and $1.6 million , respectively. A reconciliation of reportable segment operating income to the Company's consolidated net income is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Segment operating income $ 11,630 $ 13,096 $ 42,282 $ 41,414 Adjustments to reconcile to net income attributable to the Company Corporate payroll and benefits (957 ) (1,222 ) (3,054 ) (4,375 ) Corporate rent and occupancy (135 ) (91 ) (414 ) (208 ) Corporate legal and professional fees (634 ) (964 ) (3,222 ) (3,091 ) Corporate general and administrative (523 ) (857 ) (2,069 ) (2,513 ) Corporate depreciation and amortization (23 ) (38 ) (97 ) (296 ) Corporate interest (expense) income, net (10 ) (46 ) (18 ) (329 ) Other income (expense), net 86 (500 ) 199 2,900 Income tax expense (3,931 ) (3,586 ) (5,151 ) (12,614 ) Net income $ 5,503 $ 5,792 $ 28,456 $ 20,888 Corporate general and administrative expenses include certain costs that benefit the business as a whole but are not directly related to one of the Company's segments. Such costs include, but are not limited to, accounting and human resources staff, information systems costs, legal fees, facility costs, audit fees and corporate governance expenses. A reconciliation of reportable segment assets to the Company's consolidated assets is as follows: As of (in thousands) September 30, December 31, Assets: Refined Coal (1) $ 10,033 $ 8,092 Emissions Control 2,593 3,755 Total segment assets 12,626 11,847 All Other and Corporate (2) 70,530 70,771 Consolidated $ 83,156 $ 82,618 (1) Includes $5.4 million and $4.4 million of investments in equity method investees, respectively. (2) Included within All Other and Corporate are the Company's deferred tax assets.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value of financial instruments The carrying amounts of financial instruments, including cash and cash equivalents, accounts receivable, accounts payable and accrued expenses, approximate fair value due to the short maturity of these instruments. Accordingly, these instruments are not presented in the table below. The following table provides the estimated fair values of the remaining financial instruments: As of September 30, 2018 As of December 31, 2017 (in thousands) Carrying Value Fair Value Carrying Value Fair Value Financial Instruments: Highview Investment (1) $ 552 $ 552 $ 552 $ 552 Highview technology license payable $ 219 $ 219 $ 210 $ 210 (1) Fair value is based on the investee's equity financing at £1.00 per share that commenced during the three months ended September 30, 2017. The fair value measurement represents a Level 3 measurement as it is based on significant inputs not observable in the market. Concentration of credit risk The Company's financial instruments that are exposed to concentrations of credit risk consist primarily of cash and cash equivalents. The Company holds cash and cash equivalents at one financial institution as of September 30, 2018 . If that institution was unable to perform its obligations, the Company would be at risk regarding the amount of cash and investments in excess of the Federal Deposit Insurance Corporation limits (currently $250 thousand ) that would be returned to the Company. Assets and Liabilities Measured at Fair Value on a Recurring Basis As of September 30, 2018 and December 31, 2017 , the Company had no financial instruments carried and measured at fair value on a recurring basis.

Restructuring

Restructuring	9 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Restructuring	Restructuring The Company recorded restructuring charges during the three and nine months ended September 30, 2018 in connection with a reduction in force, the departure of certain executive officers and management's further alignment of the business with strategic objectives. These charges related to severance arrangements with departing employees and executives, as well as non-cash charges related to the acceleration of vesting of certain stock awards. The Company recorded restructuring charges during the second and third quarters of 2018, dependent upon termination dates of individuals impacted. There were no material restructuring charges during the three and nine months ended September 30, 2017 . A summary of the pretax restructuring charges, incurred by segment, excluding facility charges shown below, is as follows: Pretax Charge (in thousands, except employee data) Approximate Number of Employees Refined Coal (1) Emissions Control (1) All Other and Corporate (1) Total Three Months Ended September 30, 2018 Restructuring charges 7 $ 168 $ 500 $ 434 $ 1,102 Changes in estimates — — — — Total pretax charge, net of reversals $ 168 $ 500 $ 434 $ 1,102 Nine Months Ended September 30, 2018 Restructuring charges 13 $ 448 $ 996 $ 557 $ 2,001 Changes in estimates — — — — Total pretax charge, net of reversals $ 448 $ 996 $ 557 $ 2,001 (1) Restructuring charges were allocated consistent with the allocations made in Note 10 - Business Segment Information. The following table summarizes the Company's change in restructuring accruals for the nine months ended September 30, 2018 : (in thousands) Employee Severance Remaining accrual as of December 31, 2017 $ — Expense provision (1) 2,001 Cash payments and other (1) (1,192 ) Change in estimates — Remaining accrual as of September 30, 2018 $ 809 (1) Included within the Expense provision and Cash payments and other line items in the above table is equity based compensation of $0.8 million for the nine months ended September 30, 2018, resulting from the accelerated vesting of modified equity-based compensation awards for certain terminated employees. As of September 30, 2018 , all restructuring charges have been accrued. Restructuring accruals are included within the Accrued payroll and related liabilities line item in the Condensed Consolidated Balance Sheets . Restructuring expenses are included within the Payroll and benefits line item in the Condensed Consolidated Statements of Operations .

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2018
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Unless disclosed elsewhere within the notes to the Condensed Consolidated Financial Statements, the following are the significant matters that occurred subsequent to September 30, 2018 . Invested RC Facility On October 24, 2018 , the Company announced that Tinuum Group completed a transaction for an additional RC facility. The RC facility is located at a coal plant that has historically burned in excess of 3.0 million tons of coal per year and is royalty bearing to ADES. With this addition, Tinuum Group has 19 invested facilities in full-time operation. Dividends On November 6, 2018 , the Company's Board declared a quarterly dividend of $0.25 per share of common stock, which is payable on December 6, 2018 to stockholders of record at the close of business on November 20, 2018 . Related Party Transaction Gilbert Li, a director of the Company, is the Co-Founder and Managing Partner of Alta Fundamental Advisers, a private investment company (“Alta”). Alta currently beneficially owns approximately 6.7% of the Company’s outstanding common stock, as it was granted an exemption in December 2017 under the TAPP to purchase up to 7% of the outstanding common stock. Alta has requested an additional exemption under the TAPP for the acquisition or ownership of up to 10% of the outstanding common stock of the Company (the “Alta Exemption Request”) in order that it may purchase additional shares of common stock without triggering the shareholder rights described in the TAPP. On November 6, 2018, the Board, with Mr. Li abstaining, and the Audit Committee of the Board, approved the Alta Exemption Request and the related party transaction.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Basis of Presentation	The accompanying Condensed Consolidated Financial Statements of ADES are unaudited and have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP") and with Article 10 of Regulation S-X of the Securities and Exchange Commission. In compliance with those instructions, certain information and footnote disclosures normally included in annual consolidated financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The unaudited Condensed Consolidated Financial Statements of ADES in this quarterly report ("Quarterly Report") are presented on a consolidated basis and include ADES and its wholly-owned subsidiaries (collectively, the "Company"). Also included within the unaudited Condensed Consolidated Financial Statements are the Company's unconsolidated equity investments, Tinuum Group, Tinuum Services, LLC ("Tinuum Services"), and GWN Manager, LLC ("GWN Manager"), which are accounted for under the equity method of accounting, and Highview Enterprises Limited (the "Highview Investment"), which is accounted for in accordance with U.S. GAAP applicable to equity investments that do not qualify for the equity method of accounting. Results of operations and cash flows for the interim periods are not necessarily indicative of the results that may be expected for the entire year. All significant intercompany transactions and accounts were eliminated for all periods presented in this Quarterly Report. In the opinion of management, these Condensed Consolidated Financial Statements include all normal and recurring adjustments considered necessary for a fair presentation of the results of operations, financial position and cash flows for the interim periods presented. These Condensed Consolidated Financial Statements of ADES should be read in conjunction with the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (the "2017 Form 10-K"). Except for accounting for revenue from contracts with customers, which is discussed in Note 2 , significant accounting policies disclosed therein have not changed.
Earnings Per Share	Basic earnings per share is computed using the two-class method, which is an earnings allocation formula that determines earnings per share for common stock and any participating securities according to dividend and participating rights in undistributed earnings. The Company's restricted stock awards ("RSA's") granted prior to December 31, 2016 contain non-forfeitable rights to dividends or dividend equivalents and are deemed to be participating securities. RSA's granted subsequent to December 31, 2016 do not contain non-forfeitable rights to dividends and are not deemed to be participating securities. Under the two-class method, net income for the period is allocated between common stockholders and the holders of the participating securities based on the weighted-average number of common shares outstanding during the period, excluding participating, unvested RSA's ("common shares"), and the weighted-average number of participating unvested RSA's outstanding during the period, respectively. The allocated, undistributed income for the period is then divided by the weighted-average number of common shares and participating, unvested RSA's outstanding during the period to arrive at basic earnings per common share and participating security for the period, respectively. Pursuant to U.S. GAAP, the Company has elected not to separately present basic or diluted earnings per share attributable to participating securities in the Condensed Consolidated Statements of Operations. Diluted earnings per share is computed in a manner consistent with that of basic earnings per share, while considering other potentially dilutive securities. Potentially dilutive securities consist of both unvested, participating and non-participating RSA's, as well as outstanding options to purchase common stock ("Stock Options") and contingent performance stock units ("PSU's") (collectively, "Potential dilutive shares"). The dilutive effect, if any, for non-participating RSA's, Stock Options and PSU's is determined using the greater of dilution as calculated under the treasury stock method or the two-class method. Potential dilutive shares are excluded from diluted earnings per share when their effect is anti-dilutive. When there is a net loss for a period, all Potential dilutive shares are anti-dilutive and are excluded from the calculation of diluted loss per share for that period. Each PSU represents a contingent right to receive shares of the Company’s common stock, and the number of shares may range from zero to two times the number of PSU's granted on the award date depending upon the price performance of the Company's common stock as measured against a general index and a specific peer group index over requisite performance periods. The number of Potential dilutive shares related to PSU's is based on the number of shares of the Company's common stock, if any, that would be issuable at the end of the respective reporting period, assuming that the end of the reporting period is the end of the contingency period applicable to such PSU's. See Note 7 for additional information related to PSU's.
Use of Estimates	The preparation of financial statements in conformity with U.S. GAAP requires management to makes estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. There have been no changes in the Company’s critical accounting estimates from those that were disclosed in the 2017 Form 10-K, except for the adoption of ASC 606 - Revenue from Contracts with Customers ("ASC 606"), effective January 1, 2018, which affected revenue recognition and warranty estimates accruals related to the Company's extended equipment contracts, and an estimated liability related to a royalty settlement agreement, both of which are no longer considered significant estimates. Actual results could differ from these estimates.
Risks and Uncertainties	The Company’s earnings are significantly affected by equity earnings it receives from Tinuum Group. As of September 30, 2018 , Tinuum Group has 18 invested RC facilities of which 11 are leased to a single customer. A majority of these leases are periodically renewed and the loss of this customer by Tinuum Group would have a significant adverse impact on its financial position, results of operations and cash flows, which in turn would have material adverse impact on the Company’s financial position, results of operations and cash flows. The Company's financial instruments that are exposed to concentrations of credit risk consist primarily of cash and cash equivalents. The Company holds cash and cash equivalents at one financial institution as of September 30, 2018 . If that institution was unable to perform its obligations, the Company would be at risk regarding the amount of cash and investments in excess of the Federal Deposit Insurance Corporation limits (currently $250 thousand ) that would be returned to the Company.
Reclassifications	Certain balances have been reclassified from the prior year to conform to the current year presentation. No reclassifications have any impact to income before income taxes or net income.
New Accounting Guidance	In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) ("ASU 2016-02"), which requires lessees to recognize a right of use asset and related lease liability for those leases classified as operating leases at the commencement date and have lease terms of more than 12 months. This topic retains the distinction between finance leases and operating leases. ASU 2016-02 is effective for fiscal years beginning after December 15, 2018, and interim periods within those years, and must be applied under a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. In July 2018, the FASB issued ASU 2018-11, Leases (Topic 842): Targeted Improvements ("ASU 2018-11"). The amendments in ASU 2018-11 provide entities with an additional (and optional) transition method to adopt the new lease requirements by allowing entities to initially apply the requirements by recognizing a cumulative effect adjustment to the opening balance of retained earnings in the period of adoption. Consequently, an entity’s reporting for the comparative periods presented in the financial statements in which the entity adopts the new lease requirements would continue to be in accordance with current GAAP (Topic 840). An entity electing this additional (and optional) transition method must provide the required Topic 840 disclosures for all periods that continue to be in accordance with Topic 840. The amendments do not change the existing disclosure requirements in Topic 840. The Company intends to adopt ASC 2016-02 effective January 1, 2019 using the additional (and optional) transition method provided under ASU 2018-11. As of the date of this filing, the Company has materially completed its assessment of ASU 2016-02 and related amendments for the impact to the financial statements as of the adoption date, completed a detailed review of existing lease agreements, continued its review of controls and procedures that may need to be revised or added from the adoption of ASU 2016-02 and completed the documentation of the standard's financial statement impact at adoption and financial statement disclosure changes. Based on the Company's current assessment of ASU 2016-02, it has determined that at adoption it will record approximately $0.2 million of "right of use" assets and incremental lease liabilities, respectively, with no impact to the opening balance of retained earnings. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326) Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). The main objective of ASU 2016-13 is to provide financial statement users with more decision-useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. To achieve this objective, the amendments in ASU 2016-13 replace the incurred loss impairment methodology in current U.S. GAAP with a methodology that reflects expected credit losses and requires consideration of a broader range of reasonable and supportable information to inform credit loss estimates. ASU 2016-13 is effective for fiscal years beginning after December 15, 2019, including interim periods within those years, and must be adopted under a modified retrospective method approach. Entities may adopt ASU 2016-13 earlier as of the fiscal years beginning after December 15, 2018, including interim periods within those years. The Company is currently evaluating the provisions of this guidance and assessing its impact on the Company's financial statements and disclosures. The Company does not believe this standard will have a material impact on the Company's financial statements and disclosures. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement ("ASU 2018-13"). The amendments in ASU 2018-13 improve the effectiveness of fair value measurement disclosures and modify the disclosure requirements on fair value measurements in Topic 820, Fair Value Measurement ("Topic 820"), based on the concepts in FASB Concepts Statement, Conceptual Framework for Financial Reporting - Chapter 8: Notes to Financial Statements, including the consideration of costs and benefits. ASU 2018-13 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2019. The amendments on changes in unrealized gains and losses, the range and weighted average of significant unobservable inputs used to develop Level 3 fair value measurements, and the narrative description of measurement uncertainty should be applied prospectively for only the most recent interim or annual period presented in the initial fiscal year of adoption. All other amendments should be applied retrospectively to all periods presented upon their effective date. Early adoption is permitted upon issuance of this Update. An entity is permitted to early adopt any removed or modified disclosures upon issuance of this Update and delay adoption of the additional disclosures until their effective date. The Company is currently evaluating the provisions of this Update and assessing its impact on the Company's financial statement disclosures. The Company does not believe this standard will have a material impact on the Company's financial statement disclosures.
Revenue from Contract with Customer	The Company recognizes revenue from a contract with a customer when a performance obligation under the terms of a contract with a customer is satisfied, which is when the customer controls the promised goods or services that are transferred in satisfaction of the performance obligation. Revenue is measured as the amount of consideration that is expected to be received in exchange for transferring goods or providing services, and the transaction price is generally fixed and generally does not contain variable or noncash consideration. In addition, the Company’s contracts with customers generally do not contain customer refund or return provisions or other similar obligations. Transfer of control and satisfaction of performance obligations are further discussed in each of the revenue components listed below. The Company uses estimates and judgments in determining the nature and timing of satisfaction of performance obligations, the standalone selling price (“SSP”) of performance obligations and the allocation of the transaction price to multiple performance obligations. The Company’s principal revenue components are Chemical sales and License royalties. Chemicals The Company recognizes revenue for direct sales of proprietary chemicals and other ancillary items when the customer obtains control, which is generally at the point in time that delivery to and acceptance by the customer has occurred. Customer contracts for sales of chemicals are short duration and performance obligations generally do not extend beyond one year. Certain chemical customer contracts are comprised of evaluation tests of the Company’s chemicals’ effectiveness and efficiency in reducing emissions. These contracts entail the delivery of chemicals to the customer and the Company's evaluation of results of emissions reduction over the term of the contract. Under these types of arrangements, which are generally for durations that are short term, the Company has determined that the customer is simultaneously receiving benefits of emissions reduction from the consumption of the chemicals over the testing period and this represents a single performance obligation that is satisfied over time. This determination may require significant judgment. The Company recognizes revenue over time using an input model that is generally based on the cost of chemicals consumed by the customer during the testing period. The use of an input model and the use of total costs as the measure of progress in the satisfaction of the performance obligations may require significant judgment. In addition, under these types of contracts, the Company has determined that the services performed and related costs incurred by the Company during the testing period represent costs to fulfill a contract. License Royalties The Company generates revenues from royalties (“M-45 Royalties”) earned under a licensing arrangement (“M-45 License”) of its M-45 TM and M-45-PC TM emissions control technologies (“M-45 Technology”) between the Company and Tinuum Group. The Company recognizes M-45 Royalties at a point in time based on the use of the M-45 Technology at certain RC facilities or through Tinuum Group’s use of licensed technology for rates in excess of amounts allowed for RC application. The amount of M-45 Royalties recognized is generally based on a percentage of pre-tax margins (as defined in the M-45 License) of the RC facilities using the M-45 Technology. Arrangements with Multiple Performance Obligations Contracts with customers may include multiple performance obligations, which are comprised of the sale of chemicals, equipment and services performed as part of an emissions reduction arrangement. For such arrangements, the Company allocates revenue to each performance obligation based on its relative SSP. When a directly observable SSP for a performance obligation is not available, the Company primarily estimates SSPs based on the expected cost plus a margin method. These estimates as well as the timing of the satisfaction of performance obligations associated with the services component represent significant judgments made by the Company. These arrangements are generally short duration and performance obligations generally do not extend beyond one year.
Fair Value of Financial Instruments	The carrying amounts of financial instruments, including cash and cash equivalents, accounts receivable, accounts payable and accrued expenses, approximate fair value due to the short maturity of these instruments.
Segment Reporting	Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by a company's chief operating decision maker ("CODM"), or a decision-making group, in deciding how to allocate resources and in assessing financial performance. As of September 30, 2018 , the Company's CODM was the Company's CEO. The Company's operating and reportable segments are organized by products and services provided. As of September 30, 2018 , the Company has two reportable segments: (1) Refined Coal ("RC"); and (2) Emissions Control ("EC"). The business segment measurements provided to and evaluated by the CODM are computed in accordance with the principles listed below: • The accounting policies of the operating segments are the same as those described in the summary of significant accounting policies in the 2017 Form 10-K, except as described below. • RC segment revenues includes the Company's equity method earnings and losses from the Company's equity method investments and royalties earned from Tinuum Group. • Segment operating income (loss) includes segment revenues and allocation of certain "Corporate general and administrative expenses," which include Payroll and benefits , Rent and occupancy , Legal and professional fees , General and administrative and Depreciation and amortization . • RC segment operating income includes interest expense directly attributable to the RC segment.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2018
Accounting Policies [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the calculations of basic and diluted earnings per share: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2018 2017 2018 2017 Net income $ 5,503 $ 5,792 $ 28,456 $ 20,888 Less: Dividends and undistributed income allocated to participating securities 18 32 94 141 Income attributable to common stockholders $ 5,485 $ 5,760 $ 28,362 $ 20,747 Basic weighted-average common shares outstanding 19,726 20,808 20,090 21,569 Add: dilutive effect of equity instruments 150 46 138 29 Diluted weighted-average shares outstanding 19,876 20,854 20,228 21,598 Earnings per share - basic $ 0.28 $ 0.28 $ 1.41 $ 0.96 Earnings per share - diluted $ 0.28 $ 0.28 $ 1.40 $ 0.96

Revenues (Tables)

Revenues (Tables)	9 Months Ended
	Sep. 30, 2018
Revenue from Contract with Customer [Abstract]
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The cumulative effect of the change from the adoption of ASC 606 to the Consolidated Balance Sheet as of January 1, 2018 is shown in the table that follows: Balance as of Impact of Balance as of (in thousands) December 31, 2017 Adoption January 1, 2018 Balance Sheet Receivables, net $ 1,113 $ 339 $ 1,452 Deferred tax assets $ 38,661 $ (889 ) $ 37,772 Other long-term assets $ 2,308 $ (322 ) $ 1,986 Billings in excess of costs on uncompleted contracts $ 1,830 $ (1,830 ) $ — Other current liabilities $ 2,664 $ 9 $ 2,673 Other long-term liabilities $ 2,285 $ (2,000 ) $ 285 Accumulated deficit $ (15,478 ) $ 2,950 $ (12,528 ) The following tables show the impact of the adoption of ASC 606 on the Condensed Consolidated Balance Sheet and Condensed Consolidated Statement of Operations as of and for the three and nine months ended September 30, 2018 , respectively: Balance as Reported Impact of Balance as Adjusted (in thousands) September 30, 2018 Adoption September 30, 2018 Balance Sheet Receivables, net $ 817 $ — $ 817 Deferred tax assets $ 36,008 $ 425 $ 36,433 Other long-term assets $ 2,070 $ 322 $ 2,392 Billings in excess of costs on uncompleted contracts $ — $ — $ — Other current liabilities $ 627 $ — $ 627 Other long-term liabilities $ 295 $ 2,000 $ 2,295 Retained earnings (deficit) $ 10,896 $ (1,253 ) $ 9,643 For the three months ended As Reported Impact of As Adjusted (in thousands) September 30, 2018 Adoption September 30, 2018 Statement of Operations Revenues: Equipment sales $ — $ 10,042 $ 10,042 License royalties, related party $ 4,104 $ (4,104 ) $ — Total revenues $ 5,147 $ 5,938 $ 11,085 Operating expenses: Equipment sales cost of revenue $ — $ 7,874 $ 7,874 Total operating expenses $ 5,115 $ 7,874 $ 12,989 Operating loss $ 32 $ (1,936 ) $ (1,904 ) Other income (expense) Royalties, related party $ — $ 4,104 $ 4,104 Total other income (expense) $ 9,402 $ 4,104 $ 13,506 Income before income tax expense $ 9,434 $ 2,168 $ 11,602 Income tax expense $ 3,931 $ 464 $ 4,395 Net income $ 5,503 $ 1,704 $ 7,207 For the nine months ended As Reported Impact of As Adjusted (in thousands) September 30, 2018 Adoption September 30, 2018 Statement of Operations Revenues: Equipment sales $ 72 $ 17,574 $ 17,646 License royalties, related party $ 10,857 $ (10,857 ) $ — Total revenues $ 13,319 $ 6,717 $ 20,036 Operating expenses: Equipment sales cost of revenue $ (346 ) $ 15,399 $ 15,053 Total operating expenses $ 16,568 $ 15,399 $ 31,967 Operating loss $ (3,249 ) $ (8,682 ) $ (11,931 ) Other income (expense) Royalties, related party $ — $ 10,857 $ 10,857 Total other income (expense) $ 36,856 $ 10,857 $ 47,713 Income before income tax expense $ 33,607 $ 2,175 $ 35,782 Income tax expense $ 5,151 $ 464 $ 5,615 Net income $ 28,456 $ 1,711 $ 30,167
Schedule of Disaggregation of Revenue	The following tables disaggregate revenues by major source for the three and nine months ended September 30, 2018 (in thousands): Three Months Ended September 30, 2018 Segment EC RC Total Revenue component Chemical sales $ 1,043 $ — $ 1,043 License royalties, related party — 4,104 4,104 Equipment sales — — — Revenues from customers 1,043 4,104 5,147 Earnings from equity method investments — 9,715 9,715 Segment revenues $ 1,043 $ 13,819 $ 14,862 Nine Months Ended September 30, 2018 Segment EC RC Total Revenue component Chemical sales $ 2,390 $ — $ 2,390 License royalties, related party — 10,857 10,857 Equipment sales 72 — 72 Revenues from customers 2,462 10,857 13,319 Earnings from equity method investments — 37,857 37,857 Segment revenues $ 2,462 $ 48,714 $ 51,176

Equity Method Investments (Tabl

Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 2018
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	The following table summarizes the results of operations of Tinuum Services: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Gross loss $ (21,362 ) $ (17,344 ) $ (64,069 ) $ (47,472 ) Operating, selling, general and administrative expenses 43,947 34,872 127,783 106,825 Loss from operations (65,309 ) (52,216 ) (191,852 ) (154,297 ) Other income 78 34 443 103 Loss attributable to noncontrolling interest 68,509 54,305 199,971 159,627 Net income $ 3,278 $ 2,123 $ 8,562 $ 5,433 ADES equity earnings from Tinuum Services $ 1,639 $ 1,061 $ 4,281 $ 2,717 The following tables present the Company's investment balance, equity earnings and cash distributions in excess of the investment balance for the three and nine months ended September 30, 2018 and 2017 ( in thousands ): Description Date(s) Investment balance ADES equity earnings (loss) Cash distributions Memorandum Account: Cash distributions and equity earnings in (excess) of investment balance Beginning balance 12/31/2017 $ — $ — $ — $ (12,218 ) ADES proportionate share of income from Tinuum Group (1) First Quarter 12,458 12,458 — — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) First Quarter (12,218 ) (12,218 ) — 12,218 Cash distributions from Tinuum Group First Quarter (11,050 ) — 11,050 — Adjustment for current year cash distributions in excess of investment balance First Quarter 10,810 10,810 — (10,810 ) Total investment balance, equity earnings (loss) and cash distributions 3/31/2018 $ — $ 11,050 $ 11,050 $ (10,810 ) ADES proportionate share of income from Tinuum Group (1) Second Quarter $ 14,059 $ 14,059 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Second Quarter (10,810 ) (10,810 ) — 10,810 Cash distributions from Tinuum Group Second Quarter (14,450 ) — 14,450 — Adjustment for current year cash distributions in excess of investment balance Second Quarter 11,201 11,201 (11,201 ) Total investment balance, equity earnings (loss) and cash distributions 6/30/2018 $ — $ 14,450 $ 14,450 $ (11,201 ) ADES proportionate share of income from Tinuum Group (1) Third Quarter $ 15,798 $ 15,798 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Third Quarter (11,201 ) (11,201 ) — 11,201 Cash distributions from Tinuum Group Third Quarter (8,075 ) — 8,075 — Adjustment for current year cash distributions in excess of investment balance Third Quarter 3,478 3,478 — (3,478 ) Total investment balance, equity earnings (loss) and cash distributions 9/30/2018 $ — $ 8,075 $ 8,075 $ (3,478 ) Description Date(s) Investment balance ADES equity earnings (loss) Cash distributions Memorandum Account: Cash distributions and equity earnings in (excess) of investment balance Beginning balance 12/31/2016 $ — $ — $ — $ (9,894 ) ADES proportionate share of income from Tinuum Group (1) First Quarter 10,457 10,457 — — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) First Quarter (9,894 ) (9,894 ) — 9,894 Cash distributions from Tinuum Group First Quarter (13,175 ) — 13,175 — Adjustment for current year cash distributions in excess of investment balance First Quarter 12,612 12,612 — (12,612 ) Total investment balance, equity earnings (loss) and cash distributions 3/31/2017 $ — $ 13,175 $ 13,175 $ (12,612 ) ADES proportionate share of income from Tinuum Group (1) Second Quarter $ 11,761 $ 11,761 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Second Quarter (11,761 ) (11,761 ) — 11,761 Cash distributions from Tinuum Group Second Quarter (9,138 ) — 9,138 — Adjustment for current year cash distributions in excess of investment balance Second Quarter 9,138 9,138 — (9,138 ) Total investment balance, equity earnings (loss) and cash distributions 6/30/2017 $ — $ 9,138 $ 9,138 $ (9,989 ) ADES proportionate share of income from Tinuum Group (1) Third Quarter $ 11,393 $ 11,393 $ — $ — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) Third Quarter (9,989 ) (9,989 ) — 9,989 Cash distributions from Tinuum Group Third Quarter (11,050 ) — 11,050 — Adjustment for current year cash distributions in excess of investment balance Third Quarter 9,646 9,646 — (9,646 ) Total investment balance, equity earnings (loss) and cash distributions 9/30/2017 $ — $ 11,050 $ 11,050 $ (9,646 ) (1) For the three and nine months ended September 30, 2018 and 2017 , the amounts of the Company's 42.5% proportionate share of net income available to members as shown in the table above may differ from mathematical calculations of the Company’s 42.5% equity interest in Tinuum Group multiplied by the amounts of net income available to members as shown in the table above of Tinuum Group results of operations due to adjustments related to the Class B preferred return. The following table details the components of the Company's respective equity method investments included within the Earnings from equity method investments line item on the Condensed Consolidated Statements of Operations : Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Earnings from Tinuum Group $ 8,075 $ 11,050 $ 33,575 $ 33,363 Earnings from Tinuum Services 1,639 1,061 4,281 2,717 Earnings from other 1 9 1 9 Earnings from equity method investments $ 9,715 $ 12,120 $ 37,857 $ 36,089 The following table details the components of the cash distributions from the Company's respective equity method investments included in the Condensed Consolidated Statements of Cash Flows . Distributions from equity method investees are reported on the Condensed Consolidated Statements of Cash Flows as " Distributions from equity method investees, return on investment " within Operating cash flows until such time as the carrying value in an equity method investee company is reduced to zero; thereafter, such distributions are reported as " Distributions from equity method investees in excess of cumulative earnings " within Investing cash flows. Nine Months Ended September 30, (in thousands) 2018 2017 Distributions from equity method investees, return on investment Tinuum Services $ 4,000 $ 3,675 $ 4,000 $ 3,675 Distributions from equity method investees in excess of investment basis Tinuum Group $ 33,575 $ 33,363 $ 33,575 $ 33,363 The following table summarizes the results of operations of Tinuum Group: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Gross profit $ 26,530 $ 23,812 $ 81,626 $ 70,895 Operating, selling, general and administrative expenses 5,908 5,174 17,406 14,975 Income from operations 20,622 18,638 64,220 55,920 Other expenses (577 ) (3,331 ) (2,801 ) (4,278 ) Class B preferred return — (384 ) (12 ) (1,526 ) Loss attributable to noncontrolling interest 17,126 11,953 38,145 29,240 Net income available to members $ 37,171 $ 26,876 $ 99,552 $ 79,356 ADES equity earnings from Tinuum Group $ 8,075 $ 11,050 $ 33,575 $ 33,363

Borrowings (Tables)

Borrowings (Tables)	9 Months Ended
	Sep. 30, 2018
Debt Disclosure [Abstract]
Schedule of Borrowings	The following table presents the LC's outstanding and collateral, by asset type, reported on the Condensed Consolidated Balance Sheets . There were no LC's outstanding or collateral as of September 30, 2018 . As of December 31, 2017 (in thousands) LC Outstanding Utilization of LOC Availability Royalty Award $ 3,500 $ 3,500 Total LC outstanding $ 3,500 $ 3,500

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2018
Equity [Abstract]
Schedule of Dividends Declared	Dividends declared by the Board, and paid quarterly per share on all outstanding shares of comment stock during the three and nine months ended September 30, 2018 and 2017 were as follows: 2018 2017 Per share Date paid Per share Date paid Dividends declared during quarter ended: March 31 $ 0.25 March 8, 2018 $ — — June 30 0.25 June 8, 2018 0.25 July 17, 2017 September 30 0.25 September 6, 2018 0.25 September 7, 2017 $ 0.75 $ 0.50

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Allocation of Compensation Expense	Total stock-based compensation expense for the three and nine months ended September 30, 2018 and 2017 was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 RSA expense $ 919 $ 298 $ 1,871 $ 1,103 Stock option expense — 143 58 443 PSU expense — 34 — 102 Total stock-based compensation expense $ 919 $ 475 $ 1,929 $ 1,648
Schedule of Unrecognized Compensation Cost	The amount of unrecognized compensation cost as of September 30, 2018 , and the expected weighted-average period over which the cost will be recognized is as follows: As of September 30, 2018 ( in thousands ) Unrecognized Compensation Cost Expected Weighted- RSA expense $ 2,118 2.19 Total unrecognized stock-based compensation expense $ 2,118 2.19
Summary of Restricted Stock Activity	A summary of RSA activity under the Company's various stock compensation plans for the nine months ended September 30, 2018 is presented below: Shares Weighted-Average Non-vested at January 1, 2018 276,607 $ 9.03 Granted 205,998 $ 11.00 Vested (180,740 ) $ 9.85 Forfeited (1,135 ) $ 10.44 Non-vested at September 30, 2018 300,730 $ 9.88
Summary of Option Activity	A summary of stock option activity for the nine months ended September 30, 2018 is presented below: Number of Options Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average Options outstanding, January 1, 2018 622,446 $ 11.64 Options granted — — Options exercised (92,666 ) 8.25 Options expired / forfeited — — Options outstanding, September 30, 2018 529,780 $ 12.23 $ 592 1.71 Options exercisable, September 30, 2018 529,780 $ 12.23 $ 592 1.71
Schedule of Award Activity	A summary of PSU activity for the nine months ended September 30, 2018 is presented below: Units Weighted-Average Non-vested at January 1, 2018 19,406 $ 19.95 Granted — — Vested / Settled (1) (19,406 ) $ 19.95 Forfeited / Canceled — — Non-vested at September 30, 2018 — $ — (1) The number of units shown in the table above were based on target performance. The final number of shares of common stock issued was based on the achievement of market conditions established within the awards.
Schedule of Performance-Based Units, Settled	The following table shows the PSU's that were settled by issuing shares of the Company's common stock relative to a broad stock index and a peer group performance index. Year of Grant Net Number of Issued Shares upon Vesting Shares Withheld to Settle Tax Withholding Obligations TSR Multiple Range Russell 3000 Multiple Low High Low High Nine Months Ended September 30, 2018 2015 12,311 4,061 112.50 112.50 — — Nine Months Ended September 30, 2017 2014 6,476 3,573 0.75 1.00 — — 2015 3,869 2,310 0.60 0.60 — —

Supplemental Financial Inform_2

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2018
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Prepaid Expenses and Other Assets and Other assets	The following table summarizes the components of Prepaid expenses and other assets and Other long-term assets as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) September 30, December 31, Prepaid expenses and other assets: Prepaid expenses $ 435 $ 776 Inventory 13 74 Prepaid income taxes 2,153 902 Other 30 83 $ 2,631 $ 1,835 Other long-term assets: Deposits $ 222 $ 223 Intangibles, net 889 805 Highview Investment 552 552 Other 407 728 $ 2,070 $ 2,308
Schedule of Other Liabilities	The following table details the components of Other current liabilities and Other long-term liabilities as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) September 30, December 31, Other current liabilities: Income taxes payable $ 25 $ 207 Estimated restorative payment to the 401(k) Plan (1) — 1,000 Dividends payable 57 45 Warranty liabilities 26 316 Other 519 1,096 $ 627 $ 2,664 Other long-term liabilities: Deferred rent $ 128 $ 192 Dividends payable 167 93 Deferred revenue, related party — 2,000 $ 295 $ 2,285 (1) See Note 5 for further discussion on the 401(k) Plan.
Schedule of Product Warranty Liability	The changes in the carrying amount of the Company’s warranty obligations from December 31, 2017 through September 30, 2018 were as follows: As of (in thousands) September 30, Balance, beginning of period $ 316 Warranties accrued, net 9 Consumption of warranty obligations accrued (337 ) Change in estimate related to previous warranties accrued 38 Balance, end of period $ 26
Schedule of Statement of Operations, Supplemental Disclosures	The following table details the components of Interest expense in the Condensed Consolidated Statements of Operations: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 453A interest $ 388 $ 614 $ 1,128 $ 1,646 Credit agreement interest — 64 — 137 Other 11 — 19 216 $ 399 $ 678 $ 1,147 $ 1,999 The following table details the components of the Other line item of the Condensed Consolidated Statements of Operations : Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Impairment of Highview investment $ — $ (464 ) $ — $ (464 ) Revision in estimated royalty indemnity liability — — — 3,400 Other 86 (460 ) 146 (444 ) $ 86 $ (924 ) $ 146 $ 2,492

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense and Effective Tax Rates	For the three and nine months ended September 30, 2018 and 2017 , the Company's income tax expense and effective tax rates based on forecasted pretax income were: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except for rate) 2018 2017 2018 2017 Income tax expense $ 3,931 $ 3,586 $ 5,151 $ 12,614 Effective tax rate 42 % 38 % 15 % 38 %

Business Segment Information (T

Business Segment Information (Tables)	9 Months Ended
	Sep. 30, 2018
Segment Reporting [Abstract]
Segment Operating Results	The following table presents the Company's operating segment results for the three and nine months ended September 30, 2018 and 2017 : Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Revenues: Refined Coal: Earnings in equity method investments $ 9,715 $ 12,120 $ 37,857 $ 36,089 Royalties, related party 4,104 2,804 10,857 6,425 13,819 14,924 48,714 42,514 Emissions Control: Chemicals 1,043 717 2,390 3,844 Equipment Sales — 1,577 72 31,304 1,043 2,294 2,462 35,148 Total segment reporting revenues 14,862 17,218 51,176 77,662 Adjustments to reconcile to reported revenues: Refined Coal: Earnings in equity method investments (9,715 ) (12,120 ) (37,857 ) (36,089 ) Total reported revenues $ 5,147 $ 5,098 $ 13,319 $ 41,573 Segment operating income (loss): Refined Coal (1) $ 12,798 $ 13,991 $ 45,775 $ 40,149 Emissions Control (1,168 ) (895 ) (3,493 ) 1,265 Total segment operating income $ 11,630 $ 13,096 $ 42,282 $ 41,414 (1) Included within the RC segment operating income for the three and nine months ended September 30, 2018 and 2017 is 453A interest expense of $0.4 million and $1.1 million and $0.6 million and $1.6 million , respectively.
Reconciliation of Reportable Segment Amounts to Consolidated Balances	A reconciliation of reportable segment operating income to the Company's consolidated net income is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2018 2017 2018 2017 Segment operating income $ 11,630 $ 13,096 $ 42,282 $ 41,414 Adjustments to reconcile to net income attributable to the Company Corporate payroll and benefits (957 ) (1,222 ) (3,054 ) (4,375 ) Corporate rent and occupancy (135 ) (91 ) (414 ) (208 ) Corporate legal and professional fees (634 ) (964 ) (3,222 ) (3,091 ) Corporate general and administrative (523 ) (857 ) (2,069 ) (2,513 ) Corporate depreciation and amortization (23 ) (38 ) (97 ) (296 ) Corporate interest (expense) income, net (10 ) (46 ) (18 ) (329 ) Other income (expense), net 86 (500 ) 199 2,900 Income tax expense (3,931 ) (3,586 ) (5,151 ) (12,614 ) Net income $ 5,503 $ 5,792 $ 28,456 $ 20,888
Reconciliation of Assets from Segment to Consolidated	A reconciliation of reportable segment assets to the Company's consolidated assets is as follows: As of (in thousands) September 30, December 31, Assets: Refined Coal (1) $ 10,033 $ 8,092 Emissions Control 2,593 3,755 Total segment assets 12,626 11,847 All Other and Corporate (2) 70,530 70,771 Consolidated $ 83,156 $ 82,618 (1) Includes $5.4 million and $4.4 million of investments in equity method investees, respectively. (2) Included within All Other and Corporate are the Company's deferred tax assets.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2018
Fair Value Disclosures [Abstract]
Schedule of Estimated Fair Values of Remaining Financial Instruments	The following table provides the estimated fair values of the remaining financial instruments: As of September 30, 2018 As of December 31, 2017 (in thousands) Carrying Value Fair Value Carrying Value Fair Value Financial Instruments: Highview Investment (1) $ 552 $ 552 $ 552 $ 552 Highview technology license payable $ 219 $ 219 $ 210 $ 210 (1) Fair value is based on the investee's equity financing at £1.00 per share that commenced during the three months ended September 30, 2017. The fair value measurement represents a Level 3 measurement as it is based on significant inputs not observable in the market.

Restructuring (Tables)

Restructuring (Tables)	9 Months Ended
	Sep. 30, 2018
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	A summary of the pretax restructuring charges, incurred by segment, excluding facility charges shown below, is as follows: Pretax Charge (in thousands, except employee data) Approximate Number of Employees Refined Coal (1) Emissions Control (1) All Other and Corporate (1) Total Three Months Ended September 30, 2018 Restructuring charges 7 $ 168 $ 500 $ 434 $ 1,102 Changes in estimates — — — — Total pretax charge, net of reversals $ 168 $ 500 $ 434 $ 1,102 Nine Months Ended September 30, 2018 Restructuring charges 13 $ 448 $ 996 $ 557 $ 2,001 Changes in estimates — — — — Total pretax charge, net of reversals $ 448 $ 996 $ 557 $ 2,001 (1) Restructuring charges were allocated consistent with the allocations made in Note 10 - Business Segment Information.
Schedule of Restructuring Reserve by Type of Cost	The following table summarizes the Company's change in restructuring accruals for the nine months ended September 30, 2018 : (in thousands) Employee Severance Remaining accrual as of December 31, 2017 $ — Expense provision (1) 2,001 Cash payments and other (1) (1,192 ) Change in estimates — Remaining accrual as of September 30, 2018 $ 809 (1) Included within the Expense provision and Cash payments and other line items in the above table is equity based compensation of $0.8 million for the nine months ended September 30, 2018, resulting from the accelerated vesting of modified equity-based compensation awards for certain terminated employees.

Basis of Presentation - Calcula

Basis of Presentation - Calculations of Basic and Diluted Earnings per Share (Details) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares	Sep. 30, 2017USD ($)$ / sharesshares	Sep. 30, 2018USD ($)$ / sharesshares	Sep. 30, 2017USD ($)$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net income | $	$ 5,503	$ 5,792	$ 28,456	$ 20,888
Less: Dividends and undistributed income allocated to participating securities | $	18	32	94	141
Income attributable to common stockholders | $	$ 5,485	$ 5,760	$ 28,362	$ 20,747
Basic weighted-average common shares outstanding (in shares)	19,726	20,808	20,090	21,569
Add: dilutive effect of equity instruments (in shares)	150	46	138	29
Diluted weighted-average shares outstanding (in shares)	19,876	20,854	20,228	21,598
Earnings per share - basic (in dollars per share) | $ / shares	$ 0.28	$ 0.28	$ 1.41	$ 0.96
Earnings per share - diluted (in dollars per share) | $ / shares	$ 0.28	$ 0.28	$ 1.40	$ 0.96
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares excluded from diluted shares outstanding		400	100	400
Performance share units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of contingent right to receive a common stock			0
Performance share units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of contingent right to receive a common stock			2
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares excluded from diluted shares outstanding	300	200	300	200

Basis of Presentation - Risks a

Basis of Presentation - Risks and New Accounting Guidance (Details) $ in Millions	Jan. 01, 2019USD ($)	Sep. 30, 2018debt_instrument
Forecast
Concentration Risk [Line Items]
Right-of-use assets | $	$ 0.2
Tinuum Group, LLC
Concentration Risk [Line Items]
Number of instruments held		18
Customer Concentration Risk | Tinuum Group, LLC
Concentration Risk [Line Items]
Number of instruments held		11

Revenues - Narrative (Details)

Revenues - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	$ 5,147		$ 5,098	$ 13,319	$ 41,573
Collection terms				Credit terms are generally net 30 from the date of invoice.
Equipment sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	0		1,577	$ 72	31,304
Equipment sales cost of revenue	0		$ 1,467	(346)	$ 28,260
Difference between Revenue Guidance in Effect before and after Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	11,085			20,036
Difference between Revenue Guidance in Effect before and after Topic 606 | Equipment sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	10,042			17,646
Equipment sales cost of revenue	7,874			15,053
ASU No. 2014-09 | DSI Systems | Restatement Adjustment
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract asset						$ (16,500)
Contract liability						(18,300)
ASU No. 2014-09 | Licensing Arrangement | Restatement Adjustment
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract asset						(300)
Contract liability						(2,000)
ASU No. 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606 | DSI Systems
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Contract asset						$ 300
Total revenues				1,700
ASU No. 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606 | Licensing Arrangement
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues				1,300
ASU No. 2014-09 | Calculated under Revenue Guidance in Effect before Topic 606
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	5,938			6,717
ASU No. 2014-09 | Calculated under Revenue Guidance in Effect before Topic 606 | Equipment sales
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Total revenues	10,042	$ 7,500		17,574
Equipment sales cost of revenue	$ 7,874	$ 7,500		$ 15,399

Revenues - Adoption of ASC 606

Revenues - Adoption of ASC 606 (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jan. 01, 2018	Dec. 31, 2017
Balance Sheet
Receivables, net	$ 817			$ 817		$ 1,452	$ 1,113
Deferred tax assets	36,008			36,008		37,772	38,661
Other long-term assets	2,070			2,070		1,986	2,308
Billings in excess of costs on uncompleted contracts	0			0		0
Other current liabilities	627			627		2,673	2,664
Other long-term liabilities	295			295		285	2,285
Retained earnings (deficit)	10,896			10,896		(12,528)	(15,478)
Statement of Operations
Total revenues	5,147		$ 5,098	13,319	$ 41,573
Operating expenses:
Total operating expenses	5,115		6,238	16,568	44,653
Operating loss	32		(1,140)	(3,249)	(3,080)
Other income (expense):
Royalties, related party	0			0
Total other income (expense)	9,402		10,518	36,856	36,582
Income before income tax expense	9,434		9,378	33,607	33,502
Income tax expense	3,931		3,586	5,151	12,614
Net income	5,503		5,792	28,456	20,888
Equipment sales
Statement of Operations
Total revenues	0		1,577	72	31,304
Operating expenses:
Equipment sales cost of revenue	0		1,467	(346)	28,260
License royalties, related party
Statement of Operations
Total revenues	4,104		$ 2,804	10,857	$ 6,425
Calculated under Revenue Guidance in Effect before Topic 606
Balance Sheet
Receivables, net							1,113
Deferred tax assets							38,661
Other long-term assets							2,308
Billings in excess of costs on uncompleted contracts							1,830
Other current liabilities							2,664
Other long-term liabilities							2,285
Retained earnings (deficit)							$ (15,478)
Calculated under Revenue Guidance in Effect before Topic 606 | ASU No. 2014-09
Balance Sheet
Receivables, net	0			0
Deferred tax assets	425			425
Other long-term assets	322			322
Billings in excess of costs on uncompleted contracts	0			0
Other current liabilities	0			0
Other long-term liabilities	2,000			2,000
Retained earnings (deficit)	(1,253)			(1,253)
Statement of Operations
Total revenues	5,938			6,717
Operating expenses:
Total operating expenses	7,874			15,399
Operating loss	(1,936)			(8,682)
Other income (expense):
Royalties, related party	4,104			10,857
Total other income (expense)	4,104			10,857
Income before income tax expense	2,168			2,175
Income tax expense	464			464
Net income	1,704			1,711
Calculated under Revenue Guidance in Effect before Topic 606 | ASU No. 2014-09 | Equipment sales
Statement of Operations
Total revenues	10,042	$ 7,500		17,574
Operating expenses:
Equipment sales cost of revenue	7,874	$ 7,500		15,399
Calculated under Revenue Guidance in Effect before Topic 606 | ASU No. 2014-09 | License royalties, related party
Statement of Operations
Total revenues	(4,104)			(10,857)
Difference between Revenue Guidance in Effect before and after Topic 606
Balance Sheet
Receivables, net	817			817
Deferred tax assets	36,433			36,433
Other long-term assets	2,392			2,392
Billings in excess of costs on uncompleted contracts	0			0
Other current liabilities	627			627
Other long-term liabilities	2,295			2,295
Retained earnings (deficit)	9,643			9,643
Statement of Operations
Total revenues	11,085			20,036
Operating expenses:
Total operating expenses	12,989			31,967
Operating loss	(1,904)			(11,931)
Other income (expense):
Royalties, related party	4,104			10,857
Total other income (expense)	13,506			47,713
Income before income tax expense	11,602			35,782
Income tax expense	4,395			5,615
Net income	7,207			30,167
Difference between Revenue Guidance in Effect before and after Topic 606 | Equipment sales
Statement of Operations
Total revenues	10,042			17,646
Operating expenses:
Equipment sales cost of revenue	7,874			15,053
Difference between Revenue Guidance in Effect before and after Topic 606 | License royalties, related party
Statement of Operations
Total revenues	$ 0			$ 0
Difference between Revenue Guidance in Effect before and after Topic 606 | ASU No. 2014-09
Balance Sheet
Receivables, net						339
Deferred tax assets						(889)
Other long-term assets						(322)
Billings in excess of costs on uncompleted contracts						(1,830)
Other current liabilities						9
Other long-term liabilities						(2,000)
Retained earnings (deficit)						$ 2,950

Revenues - Disaggregation of Re

Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue component	$ 5,147	$ 5,098	$ 13,319	$ 41,573
Earnings from equity method investments	9,715	12,120	37,857	36,089
Operating Segments
Disaggregation of Revenue [Line Items]
Total reported revenues	14,862	17,218	51,176	77,662
Chemical sales
Disaggregation of Revenue [Line Items]
Revenue component	1,043	717	2,390	3,844
License royalties, related party
Disaggregation of Revenue [Line Items]
Revenue component	4,104	2,804	10,857	6,425
Equipment sales
Disaggregation of Revenue [Line Items]
Revenue component	0	1,577	72	31,304
Emissions Control
Disaggregation of Revenue [Line Items]
Revenue component	1,043		2,462
Earnings from equity method investments	0		0
Emissions Control | Operating Segments
Disaggregation of Revenue [Line Items]
Total reported revenues	1,043	2,294	2,462	35,148
Emissions Control | Chemical sales
Disaggregation of Revenue [Line Items]
Revenue component	1,043		2,390
Emissions Control | Chemical sales | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue component	1,043	717	2,390	3,844
Emissions Control | License royalties, related party
Disaggregation of Revenue [Line Items]
Revenue component	0		0
Emissions Control | Equipment sales
Disaggregation of Revenue [Line Items]
Revenue component	0		72
Emissions Control | Equipment sales | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue component	0	1,577	72	31,304
Refined Coal
Disaggregation of Revenue [Line Items]
Revenue component	4,104		10,857
Earnings from equity method investments	9,715		37,857
Refined Coal | Operating Segments
Disaggregation of Revenue [Line Items]
Earnings from equity method investments	9,715	12,120	37,857	36,089
Total reported revenues	13,819	$ 14,924	48,714	$ 42,514
Refined Coal | Chemical sales
Disaggregation of Revenue [Line Items]
Revenue component	0		0
Refined Coal | License royalties, related party
Disaggregation of Revenue [Line Items]
Revenue component	4,104		10,857
Refined Coal | Equipment sales
Disaggregation of Revenue [Line Items]
Revenue component	$ 0		$ 0

Equity Method Investments - Nar

Equity Method Investments - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Jan. 20, 2010
Schedule of Equity Method Investments [Line Items]
Equity method investments	$ 5,383,000		$ 5,383,000				$ 4,351,000
Earnings from equity method investments	$ 9,715,000	$ 12,120,000	37,857,000	$ 36,089,000
Payments to acquire membership interest			$ 750,000	61,000
Tinuum Group, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest, percent	42.50%		42.50%				42.50%
Temporary equity	$ 0		$ 0				$ 800,000
Equity method investments	0	0	0	0	$ 0	$ 0	0	$ 0	$ 0	$ 0
Earnings from equity method investments	8,075,000	11,050,000	33,575,000	33,363,000
Tinuum Services, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest, percent											50.00%
Equity method investments	5,300,000		5,300,000				$ 4,300,000
Earnings from equity method investments	1,639,000	$ 1,061,000	$ 4,281,000	$ 2,717,000
Payments to acquire membership interest	$ 800,000
Percent of losses removed from net income, attributable to noncontrolling interest	100.00%		100.00%

Equity Method Investments - Res

Equity Method Investments - Results of Operations and Summary of Distributions (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
ADES equity earnings	$ 9,715			$ 12,120			$ 37,857	$ 36,089
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Distributions from equity method investees, return on investment							4,000	3,675
Included in investing cash flows							33,575	33,363
Tinuum Group, LLC
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Gross profit (loss)	26,530			23,812			81,626	70,895
Operating, selling, general and administrative expenses	5,908			5,174			17,406	14,975
Income (loss) from operations	20,622			18,638			64,220	55,920
Other income	(577)			(3,331)			(2,801)	(4,278)
Class B preferred return	0			(384)			(12)	(1,526)
Loss attributable to noncontrolling interest	17,126			11,953			38,145	29,240
Net income available to members	37,171			26,876			99,552	79,356
ADES equity earnings	8,075			11,050			33,575	33,363
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Distributions from equity method investees in excess of investment basis							33,575	33,363
Included in investing cash flows	8,075	$ 14,450	$ 11,050	11,050	$ 9,138	$ 13,175
Tinuum Services, LLC
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
Gross profit (loss)	(21,362)			(17,344)			(64,069)	(47,472)
Operating, selling, general and administrative expenses	43,947			34,872			127,783	106,825
Income (loss) from operations	(65,309)			(52,216)			(191,852)	(154,297)
Other income	78			34			443	103
Loss attributable to noncontrolling interest	68,509			54,305			199,971	159,627
Net income available to members	3,278			2,123			8,562	5,433
ADES equity earnings	1,639			1,061			4,281	2,717
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Distributions from equity method investees, return on investment							4,000	3,675
Earnings from other
Equity Method Investment, Summarized Financial Information, Income Statement [Abstract]
ADES equity earnings	$ 1			$ 9			$ 1	$ 9

Equity Method Investments - Rol

Equity Method Investments - Rollforward of CCS Investment (Details) - USD ($)	3 Months Ended						9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Equity Method Investments [Roll Forward]
Beginning balance			$ 4,351,000				$ 4,351,000
Cash distributions from Tinuum Group							33,575,000	$ 33,363,000
Total investment balance, equity earnings (loss) and cash distributions	$ 5,383,000						5,383,000
Tinuum Group, LLC
Equity Method Investments [Roll Forward]
Beginning balance	0	$ 0	0	$ 0	$ 0	$ 0	0	0
ADES proportionate share of income from Tinuum Group	15,798,000	14,059,000	12,458,000	11,393,000	11,761,000	10,457,000
Recovery of prior cash distributions in excess of investment balance (prior to cash distributions)	11,201,000	10,810,000	12,218,000	9,989,000	11,761,000	9,894,000
Cash distributions from Tinuum Group	8,075,000	14,450,000	11,050,000	11,050,000	9,138,000	13,175,000
Adjustment for current year cash distributions in excess of investment balance	3,478,000	11,201,000	10,810,000	9,646,000	9,138,000	12,612,000
Total investment balance, equity earnings (loss) and cash distributions	$ 0	0	0	0	0	0	$ 0	0
Ownership interest, percent	42.50%						42.50%		42.50%
Ownership interest multiplied by net income available to members, percent	42.50%						42.50%
Tinuum Group, LLC | ADES equity earnings (loss)
Equity Method Investments [Roll Forward]
Beginning balance	$ 14,450,000	11,050,000	0	9,138,000	13,175,000	0	$ 0	0
ADES proportionate share of income from Tinuum Group	15,798,000	14,059,000	12,458,000	11,393,000	11,761,000	10,457,000
Recovery of prior cash distributions in excess of investment balance (prior to cash distributions)	11,201,000	10,810,000	12,218,000	9,989,000	11,761,000	9,894,000
Adjustment for current year cash distributions in excess of investment balance	3,478,000	11,201,000	10,810,000	9,646,000	9,138,000	12,612,000
Total investment balance, equity earnings (loss) and cash distributions	8,075,000	14,450,000	11,050,000	11,050,000	9,138,000	13,175,000	8,075,000	11,050,000
Tinuum Group, LLC | Cash distributions
Equity Method Investments [Roll Forward]
Beginning balance	14,450,000	11,050,000	0	9,138,000	13,175,000	0	0	0
Cash distributions from Tinuum Group	8,075,000	14,450,000	11,050,000	11,050,000	9,138,000	13,175,000
Total investment balance, equity earnings (loss) and cash distributions	8,075,000	14,450,000	11,050,000	11,050,000	9,138,000	13,175,000	8,075,000	11,050,000
Tinuum Group, LLC | Memorandum Account: Cash distributions and equity loss in (excess) of investment balance
Equity Method Investments [Roll Forward]
Beginning balance	(11,201,000)	(10,810,000)	(12,218,000)	(9,989,000)	(12,612,000)	(9,894,000)	(12,218,000)	(9,894,000)
Recovery of prior cash distributions in excess of investment balance (prior to cash distributions)	11,201,000	10,810,000	12,218,000	9,989,000	11,761,000	9,894,000
Adjustment for current year cash distributions in excess of investment balance	3,478,000	11,201,000	10,810,000	9,646,000	9,138,000	12,612,000
Total investment balance, equity earnings (loss) and cash distributions	$ (3,478,000)	$ (11,201,000)	$ (10,810,000)	$ (9,646,000)	$ (9,989,000)	$ (12,612,000)	$ (3,478,000)	$ (9,646,000)

Borrowings - Line of Credit (De

Borrowings - Line of Credit (Details)	Sep. 30, 2018USD ($)
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 5,000,000
Outstanding amount	0
Maximum
Debt Instrument [Line Items]
Line of credit facility, used as collateral	5,000,000
Minimum
Debt Instrument [Line Items]
Requirements for EBITDA	$ 24,000,000

Borrowings - Other (Details)

Borrowings - Other (Details) - USD ($)	Sep. 30, 2018	Dec. 31, 2017	Sep. 30, 2017	Mar. 31, 2017
Debt Instrument [Line Items]
LC Outstanding		$ 3,500,000
Utilization of LOC Availability	$ 0
Letter of Credit
Debt Instrument [Line Items]
Allowance for doubtful accounts receivable			$ 400,000
Utilization of LOC Availability		3,500,000
Equipment Systems, ACI
Debt Instrument [Line Items]
LC Outstanding				$ 800,000
Royalty Award
Debt Instrument [Line Items]
LC Outstanding		3,500,000
Royalty Award | Letter of Credit
Debt Instrument [Line Items]
Utilization of LOC Availability		$ 3,500,000

Commitments and Contingencies -

Commitments and Contingencies - Settlement and Royalty Indemnity (Details) - USD ($)	Dec. 29, 2017	Mar. 31, 2017	Sep. 30, 2017	Dec. 31, 2016	Dec. 31, 2017
Loss Contingencies [Line Items]
Reduction to royalty award accrual			$ 3,400,000
Letters of credit					$ 3,500,000
Royalty Award
Loss Contingencies [Line Items]
Letters of credit					$ 3,500,000
Norit Litigation
Loss Contingencies [Line Items]
Benchmark for earnings for increase in letters of credit				$ 20,000,000
Increase in letters of credit as collateral		$ 5,000,000
Ability to pay dividends, percent of market fair value					50.00%
Payments for Legal Settlements	$ 3,300,000

Commitments and Contingencies_2

Commitments and Contingencies - Profit Sharing Retirement Plan (Details) - USD ($)	1 Months Ended
	Feb. 28, 2018	Sep. 30, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Restorative payment to the 401(k) Plan to be made	$ 1,000,000
Other Current Liabilities
Other Commitments [Line Items]
Liability, defined benefit plan		$ 0	$ 1,000,000

Commitments and Contingencies_3

Commitments and Contingencies - Tinuum Group (Details)	Sep. 30, 2018
Tinuum Group, LLC
Related Party Transaction [Line Items]
Limited guarantees. percent	50.00%

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 12, 2018	Jun. 06, 2017	Sep. 30, 2018	Sep. 30, 2018	May 05, 2017	May 04, 2017
Class of Stock [Line Items]
Number of shares tendered and not properly withdrawn (in shares)		2,858,425
Tendered shares as percent of shares outstanding						6.20%
Maximum
Class of Stock [Line Items]
Number of shares authorized to be repurchased (in shares)					925,000
Share price (amount per shares)					$ 10.80
Authorized amount					$ 10
Additional authorized amount (percent)					2.00%
Requirement to own shares outstanding as percent					4.99%
Minimum
Class of Stock [Line Items]
Share price (amount per shares)					$ 9.40
Common Stock
Class of Stock [Line Items]
Shares acquired (in shares)		1,370,891	0	825,418
Treasury stock acquired		$ 12.9	$ 0	$ 9.1
Stock repurchased (in shares)	186,212
Stock repurchased	$ 2.1
Additional tendered shares acquires (in shares)		445,891
Common Stock | Manager of a Financial Institution
Class of Stock [Line Items]
Shares acquired (in shares)		70,178
Common Stock | Maximum
Class of Stock [Line Items]
Number of shares authorized to be repurchased (in shares)			20,000,000	20,000,000
Common Stock | Single Block through a Privately Negotiated Transaction
Class of Stock [Line Items]
Treasury stock acquired			$ 2.2	$ 2.2

Stockholders' Equity - Dividend

Stockholders' Equity - Dividends (Details) - $ / shares	3 Months Ended						9 Months Ended
	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2018	Sep. 30, 2017
Equity [Abstract]
Dividends declared (in dollars per share)	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0	$ 0.75	$ 0.5

Stock-Based Compensation - Allo

Stock-Based Compensation - Allocation of Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 919	$ 475	$ 1,929	$ 1,648
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	919	298	1,871	1,103
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	0	143	58	443
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 0	$ 34	$ 0	$ 102

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Unrecognized Compensation Cost (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 2,118
Expected Weighted- Average Period of Recognition (in years)	2 years 2 months 9 days
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 2,118
Expected Weighted- Average Period of Recognition (in years)	2 years 2 months 9 days

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from stock options exercised	$ 0
Intrinsic value of options exercised	$ 300,000
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Expected term (in years)		5 years
Shares withheld as payment of exercise price	67,715
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Service period		3 years

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Non-vested Restricted Stock Activity (Details) - Restricted stock awards	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Number of SAR's Outstanding and Exercisable
Non-vested shares, Beginning balance (in shares) | shares	276,607
Granted (in shares) | shares	205,998
Vested (in shares) | shares	(180,740)
Forfeited (in shares) | shares	(1,135)
Non-vested shares, Ending balance (in shares) | shares	300,730
Weighted-Average Grant Date Fair Value
Non-vested shares, Weighted-Average Grant Date Fair Value, Beginning Balance (in usd per share) | $ / shares	$ 9.03
Granted, Weighted-Average Grant Date Fair Value (in usd per share) | $ / shares	11
Vested in period, Weighted-Average Grant Date Fair Value (in usd per share) | $ / shares	9.85
Forfeited, Weighted-Average Grant Date Fair Value (in usd per share) | $ / shares	10.44
Non-vested shares, Weighted-Average Grant Date Fair Value, Ending Balance (in usd per share) | $ / shares	$ 9.88

Stock-Based Compensation - Su_3

Stock-Based Compensation - Summary of Option Activity (Details) - Stock options $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)$ / sharesshares
Employee and Director Options
Options outstanding, start of year (in shares) | shares	622,446
Options granted (in shares) | shares	0
Options exercised (in shares) | shares	(92,666)
Options expired / forfeited (in shares) | shares	0
Options outstanding, end of year (in shares) | shares	529,780
Options vested and exercisable (in shares) | shares	529,780
Weighted Average Exercise Price
Options outstanding, start of year (in usd per share) | $ / shares	$ 11.64
Options granted (in usd per share) | $ / shares	0
Options exercised (in usd per share) | $ / shares	8.25
Options expired / forfeited (in usd per share) | $ / shares	0
Options outstanding, end of year (in usd per share) | $ / shares	12.23
Options vested and exercisable, weighted average exercise price (in usd per share) | $ / shares	$ 12.23
Options outstanding, intrinsic value | $	$ 592
Options exercisable, intrinsic value | $	$ 592
Options outstanding, weighted average remaining contractual term	1 year 8 months 16 days
Options exercisable, weighted average remaining contractual term	1 year 8 months 16 days

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Non-vested PSUs (Details) - Performance share units	9 Months Ended
	Sep. 30, 2018$ / sharesshares
Number of SAR's Outstanding and Exercisable
Non-vested shares, Beginning balance (in shares) | shares	19,406
Granted (in shares) | shares	0
Vested / Settled (in shares) | shares	(19,406)
Forfeited/Canceled (in shares) | shares	0
Non-vested shares, Ending balance (in shares) | shares	0
Weighted-Average Grant Date Fair Value
Non-vested shares, Weighted-Average Grant Date Fair Value, Beginning Balance (in usd per share) | $ / shares	$ 19.95
Granted, Weighted-Average Grant Date Fair Value (in usd per share) | $ / shares	0
Vested / Settled in period, Weighted-Average Grant Date Fair Value (in usd per share) | $ / shares	19.95
Forfeited, Weighted-Average Grant Date Fair Value (in usd per share) | $ / shares	0
Non-vested shares, Weighted-Average Grant Date Fair Value, Ending Balance (in usd per share) | $ / shares	$ 0

Stock-Based Compensation - Perf

Stock-Based Compensation - Performance Share Units Settled (Details) - Performance share units	9 Months Ended
	Sep. 30, 2018shares	Sep. 30, 2017shares
2,015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Number of Issued Shares upon Vesting	12,311	3,869
Shares Withheld to Settle Tax Withholding Obligations	4,061	2,310
2015 | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Multiple Range	112.50	0.60
Russell 3000 Multiple	0	0
2015 | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Multiple Range	112.50	0.60
Russell 3000 Multiple	0	0
2,014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net Number of Issued Shares upon Vesting		6,476
Shares Withheld to Settle Tax Withholding Obligations		3,573
2014 | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Multiple Range		0.75
Russell 3000 Multiple		0
2014 | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
TSR Multiple Range		1
Russell 3000 Multiple		0

Supplemental Financial Inform_3

Supplemental Financial Information - Prepaid expenses and other assets and Other assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Prepaid expenses and other assets:
Prepaid expenses	$ 435		$ 776
Inventory	13		74
Prepaid income taxes	2,153		902
Other	30		83
Other current assets	2,631		1,835
Other long-term assets:
Deposits	222		223
Intangibles, net	889		805
Highview Investment	552		552
Other	407		728
Total	$ 2,070	$ 1,986	$ 2,308

Supplemental Financial Inform_4

Supplemental Financial Information - Narrative (Details) $ in Thousands	9 Months Ended		12 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2017£ / shares	Sep. 30, 2017£ / shares
Investment [Line Items]
Impairment charges | $	$ 0	$ 464
Highview Enterprises Limited
Investment [Line Items]
Ownership interest, percent	4.00%			8.00%
Payments to acquire investments | $				$ 2,800
Share price, estimated fair value (per shares) | £ / shares						£ 1
Highview Enterprises Limited | Cost method investment
Investment [Line Items]
Impairment charges | $			$ 500
Share price, estimated fair value (per shares) | £ / shares					£ 1
Share price (amount per shares) | £ / shares					£ 2

Supplemental Financial Inform_5

Supplemental Financial Information - Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Other current liabilities:
Income taxes payable	$ 25		$ 207
Estimated restorative payment to the 401(k) Plan	0		1,000
Dividends payable	57		45
Warranty liabilities	26		316
Other	519		1,096
Other current liabilities	627	$ 2,673	2,664
Other long-term liabilities:
Deferred rent	128		192
Dividends payable	167		93
Deferred revenue, related party	0		2,000
Other long-term liabilities	$ 295	$ 285	$ 2,285

Supplemental Financial Inform_6

Supplemental Financial Information - Warranty Obligations (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance, beginning of period	$ 316
Warranties accrued, net	9
Consumption of warranty obligations accrued	(337)
Change in estimate related to previous warranties accrued	38
Balance, end of period	$ 26

Supplemental Financial Inform_7

Supplemental Financial Information - Supplemental Income Statement, Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
453A interest	$ 388	$ 614	$ 1,128	$ 1,646
Credit agreement interest	0	64	0	137
Other	11	0	19	216
Interest expense	$ 399	$ 678	$ 1,147	$ 1,999

Supplemental Financial Inform_8

Supplemental Financial Information - Supplemental Income Statement, Other (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Impairment of Highview investment	$ 0	$ (464)	$ 0	$ (464)
Revision in estimated royalty indemnity liability	0	0	0	3,400
Other	86	(460)	146	(444)
Other nonoperating income (expense)	$ 86	$ (924)	$ 146	$ 2,492

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Income tax expense	$ 3,931	$ 3,586	$ 5,151	$ 12,614
Effective tax rate	42.00%	38.00%	15.00%	38.00%
Estimated federal income tax expense	$ 2,900	$ 3,200	$ 3,400	$ 11,900
Estimated state income tax expense	$ 1,000	$ 400	$ 1,800	$ 700

Business Segment Information -

Business Segment Information - Segment Operating Results (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 30, 2018USD ($)segment	Sep. 30, 2017USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			2
Revenues:
Earnings in equity method investments	$ 9,715	$ 12,120	$ 37,857	$ 36,089
Royalties, related party	0		0
Total revenues	5,147	5,098	13,319	41,573
Segment operating income (loss):
Total segment operating income	32	(1,140)	(3,249)	(3,080)
453A interest	388	614	1,128	1,646
Refined Coal
Revenues:
Earnings in equity method investments	9,715		37,857
Total revenues	4,104		10,857
Refined Coal | RMC6, LLC (RCM6)
Segment operating income (loss):
453A interest	400	600	1,100	1,600
Emissions Control
Revenues:
Earnings in equity method investments	0		0
Total revenues	1,043		2,462
Operating Segments
Revenues:
Total reported revenues	14,862	17,218	51,176	77,662
Segment operating income (loss):
Total segment operating income	11,630	13,096	42,282	41,414
Operating Segments | Refined Coal
Revenues:
Earnings in equity method investments	9,715	12,120	37,857	36,089
Royalties, related party	4,104	2,804	10,857	6,425
Total reported revenues	13,819	14,924	48,714	42,514
Segment operating income (loss):
Total segment operating income	12,798	13,991	45,775	40,149
Operating Segments | Emissions Control
Revenues:
Total reported revenues	1,043	2,294	2,462	35,148
Segment operating income (loss):
Total segment operating income	(1,168)	(895)	(3,493)	1,265
Intersegment Eliminations | Refined Coal
Revenues:
Earnings in equity method investments	(9,715)	(12,120)	(37,857)	(36,089)
Chemicals
Revenues:
Total revenues	1,043	717	2,390	3,844
Chemicals | Refined Coal
Revenues:
Total revenues	0		0
Chemicals | Emissions Control
Revenues:
Total revenues	1,043		2,390
Chemicals | Operating Segments | Emissions Control
Revenues:
Total revenues	1,043	717	2,390	3,844
Equipment sales
Revenues:
Total revenues	0	1,577	72	31,304
Equipment sales | Refined Coal
Revenues:
Total revenues	0		0
Equipment sales | Emissions Control
Revenues:
Total revenues	0		72
Equipment sales | Operating Segments | Emissions Control
Revenues:
Total revenues	$ 0	$ 1,577	$ 72	$ 31,304

Business Segment Information _2

Business Segment Information - Reconciliation of Reportable Segment Amounts (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Segment operating income	$ 32	$ (1,140)	$ (3,249)	$ (3,080)
Corporate payroll and benefits	(2,555)	(1,679)	(7,528)	(5,894)
Corporate rent and occupancy	(250)	(255)	(766)	(555)
Corporate legal and professional fees	(698)	(1,062)	(3,459)	(3,316)
Corporate general and administrative	(584)	(1,114)	(2,332)	(2,964)
Corporate depreciation and amortization	(74)	(87)	(262)	(687)
Other income (expense), net	86	(924)	146	2,492
Income tax expense	(3,931)	(3,586)	(5,151)	(12,614)
Net income	5,503	5,792	28,456	20,888
Operating Segments
Segment Reporting Information [Line Items]
Segment operating income	11,630	13,096	42,282	41,414
Segment Reconciling Items
Segment Reporting Information [Line Items]
Corporate payroll and benefits	(957)	(1,222)	(3,054)	(4,375)
Corporate rent and occupancy	(135)	(91)	(414)	(208)
Corporate legal and professional fees	(634)	(964)	(3,222)	(3,091)
Corporate general and administrative	(523)	(857)	(2,069)	(2,513)
Corporate depreciation and amortization	(23)	(38)	(97)	(296)
Corporate interest (expense) income, net	(10)	(46)	(18)	(329)
Other income (expense), net	86	(500)	199	2,900
Income tax expense	$ (3,931)	$ (3,586)	$ (5,151)	$ (12,614)

Business Segment Information _3

Business Segment Information - Segment Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Segment Reporting [Abstract]
Equity method investments	$ 5,383	$ 4,351
Segment Reporting Information [Line Items]
Assets	83,156	82,618
Operating Segments
Segment Reporting Information [Line Items]
Assets	12,626	11,847
Operating Segments | Refined Coal
Segment Reporting Information [Line Items]
Assets	10,033	8,092
Operating Segments | Emissions Control
Segment Reporting Information [Line Items]
Assets	2,593	3,755
All Other and Corporate
Segment Reporting Information [Line Items]
Assets	$ 70,530	$ 70,771

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Value of Financial Instruments (Details) $ in Thousands	Sep. 30, 2018USD ($)	Dec. 31, 2017USD ($)	Sep. 30, 2017£ / shares
Highview Enterprises Limited
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Share price, estimated fair value (per shares) | £ / shares			£ 1
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cost method investment	$ 552	$ 552
Highview technology license payable	219	210
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cost method investment	552	552
Highview technology license payable	$ 219	$ 210

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ in Thousands	Sep. 30, 2018USD ($)Financial_Institution
Fair Value Disclosures [Abstract]
Number of financial institutions with certificates of deposit investments | Financial_Institution	1
Time deposits, $250,000 or more | $	$ 250

Restructuring - Net Pretax Bene

Restructuring - Net Pretax Benefits (Charges), Incurred by Segment (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018USD ($)employee	Sep. 30, 2018USD ($)employee
Restructuring Cost and Reserve [Line Items]
Approximate Number of Employees | employee	7	13
Restructuring charges	$ 1,102	$ 2,001
Changes in estimates	0	0
Total pretax charge, net of reversals	1,102	2,001
Operating Segments | Refined Coal
Restructuring Cost and Reserve [Line Items]
Restructuring charges	168	448
Changes in estimates	0	0
Total pretax charge, net of reversals	168	448
Operating Segments | Emissions Control
Restructuring Cost and Reserve [Line Items]
Restructuring charges	500	996
Changes in estimates	0	0
Total pretax charge, net of reversals	500	996
All Other and Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring charges	434	557
Changes in estimates	0	0
Total pretax charge, net of reversals	$ 434	$ 557

Restructuring - Utilization of

Restructuring - Utilization of Restructuring Accruals (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Restructuring Reserve [Roll Forward]
Stock-based compensation expense related to accelerated vesting of modified-equity based compensation awards	$ 919	$ 475	$ 1,929	$ 1,648
Employee Severance
Restructuring Reserve [Roll Forward]
Remaining accrual as of December 31, 2017			0
Expense provision			2,001
Cash payments and other			(1,192)
Change in estimates			0
Remaining accrual as of September 30, 2018	$ 809		809
Stock-based compensation expense related to accelerated vesting of modified-equity based compensation awards			$ 800

Subsequent Events (Details)

Subsequent Events (Details) T in Millions	Nov. 06, 2018$ / shares	Oct. 24, 2018Tfacilities	Sep. 30, 2018$ / shares	Jun. 30, 2018$ / shares	Mar. 31, 2018$ / shares	Sep. 30, 2017$ / shares	Jun. 30, 2017$ / shares	Mar. 31, 2017$ / shares	Sep. 30, 2018$ / shares	Sep. 30, 2017$ / shares
Subsequent Event [Line Items]
Dividends declared (in dollars per share)			$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0	$ 0.75	$ 0.5
Subsequent Event | Advanced Emissions Solutions, Inc. | Advanced Emissions Solutions, Inc.
Subsequent Event [Line Items]
Dividends declared (in dollars per share)	$ 0.25
Subsequent Event | Alta Fundamental Advisers | Advanced Emissions Solutions, Inc.
Related Party Transaction
Beneficial ownership, percent of shares outstanding owned	6.70%
Subsequent Event | Maximum | Alta Fundamental Advisers | Advanced Emissions Solutions, Inc.
Related Party Transaction
Beneficial ownership, percent of shares outstanding that can be owned	7.00%
Beneficial ownership deterrent percentage of acquiring outstanding common stock	10.00%
Subsequent Event | RC Facility | Advanced Emissions Solutions, Inc. | Advanced Emissions Solutions, Inc.
Subsequent Event [Line Items]
Number of facilities in full-time operations | facilities		19
Subsequent Event | RC Facility | Minimum | Advanced Emissions Solutions, Inc. | Advanced Emissions Solutions, Inc.
Subsequent Event [Line Items]
Number of tons of coal burned per year | T		3