Arq (ARQ) 10-Q 9 Nov 20 2020 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2020	Oct. 30, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2020
Document Transition Report	false
Entity File Number	001-37822
Entity Registrant Name	Advanced Emissions Solutions, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-5472457
Entity Address, Address Line One	8051 E. Maplewood Ave
Entity Address, Address Line Two	Suite 210
Entity Address, City or Town	Greenwood Village
Entity Address, State or Province	CO
Entity Address, Postal Zip Code	80111
City Area Code	720
Local Phone Number	598-3500
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Title of 12(b) Security	Common stock, par value $0.001 per share
Trading Symbol	ADES
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		18,547,887
Entity Central Index Key	0001515156
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Amendment Flag	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 15,029	$ 12,080
Receivables, net	10,273	7,430
Receivables, related parties	3,626	4,246
Inventories, net	10,419	15,460
Prepaid expenses and other assets	16,888	7,832
Total current assets	56,235	47,048
Restricted cash, long-term	10,000	5,000
Property, plant and equipment, net of accumulated depreciation of $2,322 and $7,444, respectively	29,823	44,001
Intangible assets, net	2,134	4,169
Equity method investments	22,885	39,155
Deferred tax assets, net	3,371	14,095
Other long-term assets, net	31,206	20,331
Total Assets	155,654	173,799
Current liabilities:
Accounts payable	7,530	8,046
Accrued payroll and related liabilities	4,114	3,024
Current portion of long-term debt	24,360	23,932
Other current liabilities	4,102	4,311
Total current liabilities	40,106	39,313
Long-term debt, net of current portion	5,486	20,434
Other long-term liabilities	25,712	5,760
Total Liabilities	71,304	65,507
Commitments and contingencies (Note 13)
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, 23,166,033 and 22,960,157 shares issued, and 18,547,887 and 18,362,624 shares outstanding at September 30, 2020 and December 31, 2019, respectively	23	23
Treasury stock, at cost: 4,618,146 and 4,597,533 shares as of September 30, 2020 and December 31, 2019, respectively	(47,692)	(47,533)
Additional paid-in capital	100,005	98,466
Retained earnings	32,014	57,336
Total stockholders’ equity	84,350	108,292
Total Liabilities and Stockholders’ Equity	$ 155,654	$ 173,799

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Accumulated depreciation and amortization	$ 2,322	$ 7,444
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)	23,166,033	22,960,157
Common stock, shares outstanding (in shares)	18,547,887	18,362,624
Treasury stock (in shares)	4,618,146	4,597,533

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues:
Total revenues	$ 19,471	$ 19,133	$ 43,217	$ 54,039
Operating expenses:
Payroll and benefits	2,285	2,651	8,839	8,005
Legal and professional fees	1,321	2,907	4,386	7,105
General and administrative	1,900	1,984	6,693	5,894
Depreciation, amortization, depletion and accretion	1,777	2,043	5,807	4,902
Impairment of long-lived assets	0	0	26,103	0
Total operating expenses	22,296	21,524	85,748	64,245
Operating loss	(2,825)	(2,391)	(42,531)	(10,206)
Other income (expense):
Earnings from equity method investments	9,518	14,426	25,959	57,051
Interest expense	(881)	(1,729)	(3,053)	(5,820)
Other	17	212	208	342
Total other income	8,654	12,909	23,114	51,573
Income (loss) before income tax expense	5,829	10,518	(19,417)	41,367
Income tax expense	854	6,595	1,315	14,928
Net income (loss)	$ 4,975	$ 3,923	$ (20,732)	$ 26,439
Earnings (loss) per common share (Note 1):
Basic (in dollars per share)	$ 0.27	$ 0.22	$ (1.15)	$ 1.45
Diluted (in dollars per share)	$ 0.27	$ 0.21	$ (1.15)	$ 1.44
Weighted-average number of common shares outstanding:
Basic (in shares)	18,093	18,112	18,014	18,184
Diluted (in shares)	18,103	18,339	18,014	18,394
Consumables
Revenues:
Total revenues	$ 15,844	$ 14,748	$ 33,231	$ 41,243
Operating expenses:
Consumables cost of revenue, exclusive of depreciation and amortization	15,013	11,939	33,920	38,339
License royalties, related party
Revenues:
Total revenues	$ 3,627	$ 4,385	$ 9,986	$ 12,796

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative effect of change in accounting principle	Common Stock	Treasury Stock	Additional Paid-in Capital	Retained Earnings	Retained EarningsCumulative effect of change in accounting principle
Beginning Balance (in shares) at Dec. 31, 2018			22,640,677	(4,064,188)
Beginning Balance at Dec. 31, 2018	$ 67,947	$ 28,817	$ 23	$ (41,740)	$ 96,750	$ 12,914	$ 28,817
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			218,465
Stock-based compensation	317				317
Repurchase of common shares to satisfy minimum tax withholdings (in shares)			(22,707)
Repurchase of common shares to satisfy minimum tax withholdings	(245)				(245)
Cash dividends declared on common stock	(4,629)					(4,629)
Repurchase of common shares (in shares)				(63,876)
Repurchase of common shares	(693)			$ (693)
Net income (loss)	14,402					14,402
Ending Balance (in shares) at Mar. 31, 2019			22,836,435	(4,128,064)
Ending Balance at Mar. 31, 2019	105,916		$ 23	$ (42,433)	96,822	51,504
Beginning Balance (in shares) at Dec. 31, 2018			22,640,677	(4,064,188)
Beginning Balance at Dec. 31, 2018	67,947	$ 28,817	$ 23	$ (41,740)	96,750	12,914	$ 28,817
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	26,439
Ending Balance (in shares) at Sep. 30, 2019			22,915,429	(4,320,931)
Ending Balance at Sep. 30, 2019	107,300		$ 23	$ (44,666)	97,706	54,237
Beginning Balance (in shares) at Mar. 31, 2019			22,836,435	(4,128,064)
Beginning Balance at Mar. 31, 2019	105,916		$ 23	$ (42,433)	96,822	51,504
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			31,715
Stock-based compensation	541				541
Repurchase of common shares to satisfy minimum tax withholdings (in shares)			(745)
Repurchase of common shares to satisfy minimum tax withholdings	(9)				(9)
Cash dividends declared on common stock	(4,663)					(4,663)
Repurchase of common shares (in shares)				(184,715)
Repurchase of common shares	(2,138)			$ (2,138)
Net income (loss)	8,114					8,114
Ending Balance (in shares) at Jun. 30, 2019			22,867,405	(4,312,779)
Ending Balance at Jun. 30, 2019	107,761		$ 23	$ (44,571)	97,354	54,955
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			22,305
Stock-based compensation	468				468
Stock issued from exercise of stock options (in shares)			25,820
Repurchase of common shares to satisfy minimum tax withholdings (in shares)			(101)
Repurchase of common shares to satisfy minimum tax withholdings	(116)				(116)
Cash dividends declared on common stock	(4,641)					(4,641)
Repurchase of common shares (in shares)				(8,152)
Repurchase of common shares	(95)			$ (95)
Net income (loss)	3,923					3,923
Ending Balance (in shares) at Sep. 30, 2019			22,915,429	(4,320,931)
Ending Balance at Sep. 30, 2019	107,300		$ 23	$ (44,666)	97,706	54,237
Beginning Balance (in shares) at Dec. 31, 2019			22,960,157	(4,597,533)
Beginning Balance at Dec. 31, 2019	108,292		$ 23	$ (47,533)	98,466	57,336
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			218,259
Stock-based compensation	506				506
Repurchase of common shares to satisfy minimum tax withholdings (in shares)			(64,198)
Repurchase of common shares to satisfy minimum tax withholdings	(376)				(376)
Cash dividends declared on common stock	(4,590)					(4,590)
Repurchase of common shares (in shares)				(20,613)
Repurchase of common shares	(159)			$ (159)
Net income (loss)	(1,893)					(1,893)
Ending Balance (in shares) at Mar. 31, 2020			23,114,218	(4,618,146)
Ending Balance at Mar. 31, 2020	101,780		$ 23	$ (47,692)	98,596	50,853
Beginning Balance (in shares) at Dec. 31, 2019			22,960,157	(4,597,533)
Beginning Balance at Dec. 31, 2019	108,292		$ 23	$ (47,533)	98,466	57,336
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(20,732)
Ending Balance (in shares) at Sep. 30, 2020			23,166,033	(4,618,146)
Ending Balance at Sep. 30, 2020	84,350		$ 23	$ (47,692)	100,005	32,014
Beginning Balance (in shares) at Mar. 31, 2020			23,114,218	(4,618,146)
Beginning Balance at Mar. 31, 2020	101,780		$ 23	$ (47,692)	98,596	50,853
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			3,549
Stock-based compensation	1,138				1,138
Repurchase of common shares to satisfy minimum tax withholdings (in shares)			(384)
Repurchase of common shares to satisfy minimum tax withholdings	(2)				(2)
Net income (loss)	(23,814)					(23,814)
Ending Balance (in shares) at Jun. 30, 2020			23,110,285	(4,618,146)
Ending Balance at Jun. 30, 2020	79,102		$ 23	$ (47,692)	99,732	27,039
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation (in shares)			87,701
Stock-based compensation	426				426
Repurchase of common shares to satisfy minimum tax withholdings (in shares)			(31,953)
Repurchase of common shares to satisfy minimum tax withholdings	(153)				(153)
Net income (loss)	4,975					4,975
Ending Balance (in shares) at Sep. 30, 2020			23,166,033	(4,618,146)
Ending Balance at Sep. 30, 2020	$ 84,350		$ 23	$ (47,692)	$ 100,005	$ 32,014

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities
Net (loss) income	$ (20,732)	$ 26,439
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Deferred income tax expense	10,724	10,634
Depreciation, amortization, depletion and accretion	5,807	4,902
Impairment of long-lived assets	26,103	0
Operating lease expense	3,130	2,371
Amortization of debt discount and debt issuance costs	1,064	1,324
Stock-based compensation expense	2,070	1,326
Earnings from equity method investments	(25,959)	(57,051)
Other non-cash items, net	45	697
Changes in operating assets and liabilities:
Receivables and related party receivables	(1,331)	2,685
Prepaid expenses and other assets	(9,056)	(440)
Inventories, net	4,688	4,566
Other long-term assets, net	(1,908)	(43)
Accounts payable	(1,123)	1,010
Accrued payroll and related liabilities	1,089	(4,386)
Other current liabilities	(220)	(278)
Operating lease liabilities	(1,678)	(2,435)
Other long-term liabilities	(23)	(529)
Distributions from equity method investees, return on investment	42,228	56,806
Net cash provided by operating activities	34,918	47,598
Cash flows from investing activities
Acquisition of business	0	(661)
Acquisition of property, plant, equipment, and intangible assets, net	(4,879)	(6,430)
Mine development costs	(723)	(2,083)
Net cash used in investing activities	(5,602)	(9,174)
Cash flows from financing activities
Principal payments on term loan	(18,000)	(24,000)
Principal payments on finance lease obligations	(1,026)	(1,016)
Dividends paid	(4,956)	(13,729)
Repurchase of common shares	(159)	(2,926)
Repurchase of common shares to satisfy tax withholdings	(531)	(370)
Borrowings from Paycheck Protection Program Loan	3,305	0
Net cash used in financing activities	(21,367)	(42,041)
Increase (decrease) in Cash and Cash Equivalents and Restricted Cash	7,949	(3,617)
Cash and Cash Equivalents and Restricted Cash, beginning of period	17,080	23,772
Cash and Cash Equivalents and Restricted Cash, end of period	25,029	20,155
Supplemental disclosure of non-cash investing and financing activities:
Acquisition of property, plant and equipment through accounts payable	446	0
Acquisition of property, plant and equipment through finance lease	158	0
Dividends payable	$ 47	$ 204

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2020
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 Greenwood Village, Colorado and operations located in Louisiana. The Company is principally engaged in the sale of consumable air and water treatment options including activated carbon ("AC") and chemical technologies. The Company's proprietary environmental technologies in the power generation and industrial ("PGI") market 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 emission control regulations. Through its wholly-owned subsidiary, ADA Carbon Solutions, LLC ("Carbon Solutions"), which the Company acquired on December 7, 2018 (the "Acquisition Date"), the Company manufactures and sells AC used to capture and remove contaminants for coal-fired power plants and industrial and water treatment markets. Carbon Solutions also owns an associated lignite mine that supplies the primary raw material for manufacturing AC. Through its equity ownership in Tinuum Group, LLC ("Tinuum Group") and Tinuum Services, LLC ("Tinuum Services"), both of which are unconsolidated entities, the Company generates substantial earnings. Tinuum Group provides reduction of mercury and nitrogen oxide ("NOx") emissions at select coal-fired power generators through the production and sale of refined coal ("RC") that qualifies for tax credits under the Internal Revenue Code ("IRC") Section 45 - Production Tax Credit ("Section 45 tax credits"). The Company also earns royalties for technologies that are licensed to Tinuum Group and used at certain RC facilities to enhance combustion and reduced emissions of NOx and mercury from coal burned to generate electrical power. Tinuum Services operates and maintains the RC facilities under operating and maintenance agreements with Tinuum Group and owners or lessees of the RC facilities. The Company’s sales occur principally in the United States. See Note 18 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 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 in consolidation 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, stockholders' equity 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, 2019 (the "2019 Form 10-K"). Significant accounting policies disclosed therein have not changed, except as described later in Note 1. Earnings (Loss) Per Share Basic earnings (loss) per share is computed using the two-class method, which is an earnings allocation formula that determines earnings (loss) per share for common stock and any participating securities according to dividend and participating rights in undistributed earnings (losses). 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 (loss) 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. The following table sets forth the calculations of basic and diluted earnings (loss) per share: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2020 2019 2020 2019 Net income (loss) $ 4,975 $ 3,923 $ (20,732) $ 26,439 Less: Dividends and undistributed income (loss) allocated to participating securities — 5 (10) 37 Income (loss) attributable to common stockholders $ 4,975 $ 3,918 $ (20,722) $ 26,402 Basic weighted-average common shares outstanding 18,093 18,112 18,014 18,184 Add: dilutive effect of equity instruments 10 227 — 210 Diluted weighted-average shares outstanding 18,103 18,339 18,014 18,394 Earnings (loss) per share - basic $ 0.27 $ 0.22 $ (1.15) $ 1.45 Earnings (loss) per share - diluted $ 0.27 $ 0.21 $ (1.15) $ 1.44 For the three and nine months ended September 30, 2020 and 2019, RSA's and Stock Options convertible to 0.5 million and 0.9 million, and 0.3 million and 0.3 million shares of common stock, respectively, were outstanding but were not included in the computation of diluted net income (loss) per share because the effect would have been anti-dilutive. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make 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 2019 Form 10-K except for assumptions regarding impairment of long-lived assets and the valuation of assets acquired and liabilities assumed in an asset acquisition. Actual results could differ from these estimates. Due to the coronavirus ("COVID-19") pandemic, there has been uncertainty and disruption in the global economy and financial markets. Additionally, due to COVID-19, overall power generation and coal-fired power demand may change, which could also have a material adverse effect on the Company. The Company is not aware of any specific event or circumstance due to COVID-19 that would require an update to its estimates or judgments or a revision of the carrying values of its assets or liabilities through the date of this Quarterly Report. These estimates may change as new events occur and additional information is obtained. Actual results could differ materially from these estimates under different assumptions or conditions. Risks and Uncertainties The Company’s earnings are significantly affected by equity earnings it receives from Tinuum Group. As of September 30, 2020, Tinuum Group has 21 invested RC facilities of which 9 are leased to a single customer. A majority of these leases are periodically renewed. Further, the ability to generate Section 45 tax credits related to Tinuum's RC facilities e xpires in 2021. The loss of a single customer by Tinuum Group or the expiration of Section 45 tax credits would have a significant adverse impact on Tinuum Group's financial position, results of operations and cash flows, which in turn would have a material adverse impact on the Company’s financial position, results of operations and cash flows. The Company's revenues, sales volumes, earnings and cash flows are significantly affected by prices of competing power generation sources such as natural gas and renewable energy. Low natural gas prices make it a competitive alternative to coal-fired power generation and therefore, coal consumption may be reduced, which reduces the demand for our products. In addition, coal consumption and demand for our products is also affected by the demand for electricity, which is higher in the warmer and colder months of the year. Abnormal temperatures during the summer and winter months may significantly reduce coal consumption and thus the demand for the Company's products. Reclassifications Certain balances have been reclassified from the prior year to conform to the current year presentation. Such reclassifications had no effect on the Company’s results of operations or financial position in any of the periods presented. New Accounting Standards Not Yet Adopted 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 "smaller reporting companies" (as defined by the Securities and Exchange Commission) for fiscal years beginning after December 15, 2022, 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 and does not believe this standard will have a material impact on the Company's financial statements and disclosures. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) Simplifying the Accounting for Income Taxes ("ASU 2019-12"). The amendments in ASU 2019-12 simplify various aspects related to accounting for income taxes by removing certain exceptions contained in Topic 740 and also clarify and amends existing guidance in Topic 740 to improve consistent application. ASU 2019-12 is effective for public business entities beginning after December 15, 2020, including interim periods within those years, and early adoption is permitted. The Company is currently evaluating the provisions of this guidance and assessing its impact on the Company's financial statements and disclosures and does not believe this standard will have a material impact on the Company's financial statements and disclosures.

Customer Supply Agreement

Customer Supply Agreement	9 Months Ended
	Sep. 30, 2020
Additional Term of Contract [Abstract]
Customer Supply Agreement	Customer Supply Agreement On September 30, 2020, the Company and Cabot Norit Americas, Inc., ("Cabot") entered into a supply agreement (the "Supply Agreement") pursuant to which the Company agrees to sell and deliver to Cabot, and Cabot agrees to purchase and accept from the Company certain lignite-based AC products ("Furnace Products"). The term of the Supply Agreement is for 15 years with 10-year renewal terms that are automatic unless either party provides three years prior notice of intention not to renew before the end of any term. In addition to the sale by the Company and purchase by Cabot of Furnace Products, the Company and Cabot have agreed to additional terms whereby Cabot will reimburse the Company for certain capital expenditures incurred by the Company that are necessary to manufacture the Furnace Products. Reimbursements will be in the form of revenues earned from capital expenditures incurred that will benefit both the Company and Cabot (referred to as "Shared Capital") and capital expenditures incurred that will benefit Cabot exclusively (referred to as "Specific Capital"). Both the Company and Cabot must mutually agree with all Shared Capital and Specific Capital expenditures that are necessary to support operational needs in advance of procurement and commissioning. Revenues will be earned on Shared Capital ("Shared Capital revenues") based on the percentage of Furnace Products produced and sold divided by the Company’s total products produced and sold multiplied by a mutually agreed to factor, which is based on the cost of Shared Capital assets placed in service amortized as an annuity over the expected asset life (lives) with interest at a rate that was mutually agreed to by both the Company and Cabot. Shared Capital revenues are recognized and billable beginning on the first day of a half year (either January 1 or July 1 of a calendar year) following the placed in service date of a Shared Capital asset(s). Revenues will be earned on Specific Capital ("Specific Capital revenues") and are based on a mutually agreed to factor, which is based on the cost of Specific Capital assets placed in service amortized as an annuity over five years with interest at a rate

Acquisition of Marshall Mine

Acquisition of Marshall Mine	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Acquisition of Marshall Mine	Acquisition of Marshall Mine Concurrently with the execution of the Supply Agreement, on September 30, 2020, the Company entered into an agreement to purchase (the "Purchase Agreement") from Cabot 100% of the membership interests in Marshall Mine, LLC (the "Marshall Mine Acquisition") for a nominal purchase price. Marshall Mine, LLC owns a lignite mine located outside of Marshall, Texas (the "Marshall Mine"). The Company independently determined to immediately commence activities to shutter the Marshall Mine and will incur the associated reclamation costs. In conjunction with the execution of the Supply Agreement and the Purchase Agreement, on September 30, 2020, the Company entered into a reclamation contract (the "Reclamation Contract") with a third party that provides a capped cost, subject to certain contingencies, in the amount of approximately $19.7 million plus an obligation to pay certain direct costs of approximately $3.6 million (collectively, the "Reclamation Costs") over the estimated reclamation period of 10 years (the "Reclamation Period"). Under the terms of the Supply Agreement, Cabot is obligated to reimburse the Company for $10.2 million of Reclamation Costs (the "Reclamation Reimbursements"), which are payable semi-annually over 13 years and inclusive of interest. In the event that Cabot has a change in control as described in the Supply Agreement, all outstanding balances of the Reclamation Reimbursements shall be due and payable in full. See further discussion of the Reclamation Costs and Reclamation Reimbursements in Note 4. The Marshall Mine Acquisition included the acquisition of certain assets that will be consumed and the assumption of certain liabilities that will be paid in reclamation of the Marshall Mine in addition to the incurrence of an obligation for the Reclamation Costs. The Company determined that the Marshall Mine Acquisition should be treated as an asset acquisition as it did not meet the definition of a business. That is, the Company concluded that the Marshall Mine does not have any economic reserves, as the Company has commenced full reclamation as of September 30, 2020, and therefore lacks inputs. As the Marshall Mine Acquisition represents a transaction with a customer of net assets acquired and liabilities assumed from Cabot, the Company has accounted for the excess of the fair value of liabilities assumed over assets acquired as upfront consideration transferred to a customer, Cabot (the "Upfront Customer Consideration"). The amount of the Upfront Customer Consideration is also recognized net of an additional asset recognized in the Marshall Mine Acquisition, which is comprised of a receivable from Cabot (the "Cabot Receivable") for the Reclamation Reimbursements. The Cabot Receivable is further discussed in Note 4. The total Upfront Customer Consideration will be amortized on a straight-line basis over the expected 15-year contractual period of the Supply Agreement as a reduction to revenue. The Company paid a nominal amount to Cabot in the form of cash for the Marshall Mine; in addition, the Company assumed liabilities whose fair value exceeded the fair value of assets acquired. The net assets acquired and liabilities assumed, followed by the Cabot Receivable, and the excess of fair value of liabilities acquired over assets assumed and recognized as the Upfront Customer Consideration is as follows (in thousands), as of the transaction date of September 30, 2020: (in thousands) Amount Assets acquired: Property, plant and equipment $ 3,863 Spare parts 100 Liabilities assumed: Accounts payable and accrued expenses (673) Asset retirement obligation (21,328) Net assets acquired and liabilities assumed from Marshall Mine acquisition (18,038) Cabot receivable 9,749 Upfront Customer Consideration $ 8,289 The following table summarizes the final purchase price allocation. Subsequent to the Acquisition Date, the Company completed additional analysis and adjustments were made to the preliminary purchase price allocations as noted in the table below: Fair value of assets acquired: As Originally Reported Adjustments As Adjusted Cash $ 3,284 $ — $ 3,284 Receivables 6,409 — 6,409 Inventories 22,100 (356) 21,744 Prepaid expenses and other current assets 2,992 61 3,053 Spare parts 3,359 — 3,359 Property, plant and equipment 43,033 (377) 42,656 Mine leases and development 2,500 200 2,700 Mine reclamation asset — 2,402 2,402 Intangible assets 4,000 100 4,100 Other assets 168 — 168 Amount attributable to assets acquired 87,845 2,030 89,875 Fair value of liabilities assumed: Accounts payable 4,771 — 4,771 Accrued liabilities 7,354 254 7,608 Equipment lease liabilities 8,211 — 8,211 Mine reclamation liability 626 1,776 2,402 Other liabilities 437 — 437 Amount attributable to liabilities assumed 21,399 2,030 23,429 Net assets acquired $ 66,446 $ — $ 66,446 Adjustments to the preliminary purchase price allocation primarily related to changes in fair values assigned to property, plant and equipment, intangible assets, mine reclamation liability and the related mine reclamation asset as a result of the final valuation report from the Company's third-party valuation firm issued in May 2019. During the three months ended June 30, 2019 based on new information of facts and circumstances that existed as of the Acquisition Date, the Company revised its estimates used as of the Acquisition Date related to the net realizable value of certain finished goods inventory items as well as values assigned to certain prepaid and accrued expense items. The following table represents the intangible assets, as adjusted for purchase price adjustments noted above, identified as part of the Carbon Solutions Acquisition: (in thousands) Amount Weighted Average Useful Life (years) Customer relationships $ 2,200 5 Developed technology 1,600 5 Trade name 300 2 Total intangibles acquired $ 4,100 Refer to Note 5 regarding subsequent impairment taken on the long-lived assets acquired above.

Marshall Mine Asset Retirement

Marshall Mine Asset Retirement Obligation and related Cabot Receivable	9 Months Ended
	Sep. 30, 2020
Asset Retirement Obligation and related Long-Term Receivable [Abstract]
Marshall Mine Asset Retirement Obligation and related Cabot Receivable	Marshall Mine Asset Retirement Obligation and related Cabot Receivable Asset Retirement Obligation In connection with the Supply Agreement, Purchase Agreement and the Reclamation Contract, the Company assumed the obligation to reclaim and restore the land associated with the Marshall Mine. The Company determined that the Marshall Mine does not have any remaining economic reserves. As of September 30, 2020, the Company recorded an asset retirement obligation (the "Marshall Mine ARO") for the total Reclamation Costs of $21.3 million as measured at the expected future cash flows of $23.7 million, inclusive of contingency costs, discounted to their present value using a discount rate based on a credit-adjusted, risk-free rate of 7.0%. Cabot Receivable As previously disclosed, under the terms of the related Supply Agreement, Cabot is obligated to pay Reclamation Reimbursements to the Company for $10.2 million of the Reclamation Costs, inclusive of interest. As of September 30, 2020, the Company recorded the Cabot Receivable for the Reclamation Reimbursements at its estimated fair value, which is measured using a discounted cash flows valuation model that considers the estimated credit risk associated with the obligor’s (Cabot’s) future performance. Interest will be accreted on a monthly basis and recognized as interest income. There were no significant related fees or costs associated with the Cabot Receivable. As of September 30, 2020, the Company recorded the Cabot Receivable at its estimated fair value of $9.7 million, reflecting a discount rate of approximately 1.5% or $0.5 million. Allowances for this asset are assessed periodically, and no allowance was deemed necessary as of September 30, 2020. Surety Bond As the owner of the Marshall Mine, the Company is required to post a surety bond to ensure performance of its reclamation activities. On September 30, 2020, the Company and a third party entered into a surety bond indemnification agreement (the "Surety Agreement") pursuant to which the Company secured and posted a $30.0 million surety bond (the "Bond") with the local regulatory agency. The Bond will remain in place until the Marshall Mine is fully reclaimed, and it may be reduced in amount from time to time as the Company progresses with its reclamation activities. For the obligations due under the Reclamation Contract, the Company was required to post collateral of $5.0 million dollars as of September 30, 2020 and an additional $5.0 million dollars as of March 31, 2021.

Impairment

Impairment	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment	Impairment As part of its periodic review of the carrying value of long-lived assets, the Company assessed its long-lived assets for potential impairment. In assessing impairment of its PGI segment's and certain other long-lived asset groups, the Company considered factors such as the significant decline in both the PGI segment's trailing twelve months revenues and current and future years’ forecasted revenues. These factors are largely due to the significant drop in coal-fired power dispatch that began in 2019 amid historically low prices of alternative power generation sources such as natural gas leading to an increase in natural gas usage as well as other competing energy sources. As of June 30, 2020, the Company completed an undiscounted cash flow analysis of its PGI segment's and certain other long-lived assets (the "Asset Group"), which are comprised of its manufacturing plant and related assets and its lignite mine assets, and estimated the undiscounted cash flows from the Asset Group at $54.7 million, which was less than the carrying value of the Asset Group of $58.3 million. Accordingly, the Company completed an assessment of the Asset Group’s fair value and estimated the fair value of the Asset Group at $32.2 million. This resulted in an impairment and write-down of the Asset Group (the "Impairment Charge") of $26.1 million as of June 30, 2020, which is reflected as "Impairment of long-lived assets" in the Condensed Consolidated Statements of Operations for the nine months ended September 30, 2020. The Impairment Charge was allocated to the PGI segment and Other in the amounts of $23.2 million and $2.9 million, respectively, for the nine months ended September 30, 2020. The following table summarizes the allocation to the Asset Group of the Impairment Charge of $26.1 million recorded as of June 30, 2020: (in thousands) Property, plant and equipment, net $ 18,986 Intangible assets, net 1,445 Other long-term assets, net 5,672 Total impairment $ 26,103 The Company engaged an independent third party to perform the valuation of the Asset Group in order to determine the estimated fair value of the Asset Group. This valuation was based on the use of several established valuation models including an expected future discounted cash flow model using Level 3 inputs under ASC 820 - Fair Value Measurement. The cash flows are those expected to be generated by market participants discounted at the risk-free rate of interest. Because of the continued future uncertainty surrounding the level of coal-fired dispatch, the impact of historically low natural gas prices and other estimates impacting the expected future cash flow, it is reasonably possible that the expected future cash flows may change in the near term and may result in the Company recording additional impairment of the Asset Group.

COVID-19

COVID-19	9 Months Ended
	Sep. 30, 2020
CARES Act, Grant Income [Abstract]
COVID-19	COVID-19 In response to the COVID-19 outbreak, in March 2020, the federal government passed the Coronavirus Aid, Relief, and Economic Security Act (the "CARES Act"). The CARES Act provided, among other things, the creation of the Paycheck Protection Program ("PPP"), which is sponsored and administered by the U.S. Small Business Administration ("SBA"). On April 20, 2020, the Company entered into a loan (the "PPP Loan") under the PPP, evidenced by a promissory note, with BOK, NA dba Bank of Oklahoma ("BOK") providing for $3.3 million in proceeds, which was funded to the Company on April 21, 2020. The PPP Loan matures April 21, 2022 and provides for 18 monthly payments of principal and interest commencing on November 21, 2020. The interest rate on the PPP Loan is 1.00%. The PPP Loan is unsecured and contains customary events of default relating to, among other things, payment defaults, making materially false and misleading representations to the SBA or BOK, or breaching the terms of the PPP Loan. The occurrence of an event of default may result in the repayment of all amounts outstanding, collection of all amounts owing from the Company, or filing suit and obtaining judgment against the Company. The PPP Loan principal may be forgiven subject to the terms of the PPP and approval by the SBA. The Company recorded the PPP Loan as a debt obligation under the guidance of ASC 470 - Debt and will accrue interest over the 18-month term of the PPP Loan beginning November 21, 2020.

Equity Method Investments

Equity Method Investments	9 Months Ended
	Sep. 30, 2020
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, 2020 and December 31, 2019. 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 also qualify for Section 45 tax credits. Tinuum Group has been determined to be a 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) 2020 2019 2020 2019 Gross profit $ 101 $ 16,810 $ 11,979 $ 96,189 Operating, selling, general and administrative expenses 13,781 11,076 38,476 23,421 (Loss) income from operations (13,680) 5,734 (26,497) 72,768 Other income (expenses) 5,739 (450) 11,526 (427) Loss attributable to noncontrolling interest 25,023 22,355 63,117 51,022 Net income available to members $ 17,082 $ 27,639 $ 48,146 $ 123,363 ADES equity earnings from Tinuum Group $ 7,260 $ 11,746 $ 20,462 $ 50,757 For the three and nine months ended September 30, 2020 and the three months ended September 30, 2019, the Company recognized its pro-rata share of Tinuum Group's net income available to its members for the respective period. For the nine months ended September 30, 2019, the Company recognized its pro-rata share of Tinuum Group's net income available to its members for the period, less the amount necessary to recover the cumulative earnings short-fall balance as of the end of the immediately preceding period, which was December 31, 2018. For the nine months ended September 30, 2019, the difference between the Company's proportionate share of Tinuum Group's net income available to members (at its equity interest of 42.5%) 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. For the three and nine months ended September 30, 2020, the Company recognized equity earnings from Tinuum Group of $7.3 million and $20.5 million, respectively. For the three and nine months ended September 30, 2019, the Company recognized equity earnings from Tinuum Group of $11.7 million and $50.8 million, respectively. The following tables present the Company's investment balance, equity earnings and cash distributions in excess of the investment balance, if any, for the three and nine months ended September 30, 2020 and 2019 ( in thousands ): Description Date(s) Investment balance ADES equity earnings Cash distributions Memorandum Account: Cash distributions and equity earnings in (excess) of investment balance Beginning balance 12/31/2019 $ 32,280 $ — $ — $ — ADES proportionate share of income from Tinuum Group First Quarter 6,438 6,438 — — Cash distributions from Tinuum Group First Quarter (13,764) — 13,764 — Total investment balance, equity earnings and cash distributions 3/31/2020 $ 24,954 $ 6,438 $ 13,764 $ — ADES proportionate share of income from Tinuum Group Second Quarter $ 6,764 $ 6,764 $ — $ — Cash distributions from Tinuum Group Second Quarter (13,600) — 13,600 — Total investment balance, equity earnings and cash distributions 6/30/2020 $ 18,118 $ 6,764 $ 13,600 $ — ADES proportionate share of income from Tinuum Group Third Quarter $ 7,260 $ 7,260 $ — $ — Cash distributions from Tinuum Group Third Quarter (7,862) — 7,862 — Total investment balance, equity earnings and cash distributions 9/30/2020 $ 17,516 $ 7,260 $ 7,862 $ — 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 12/31/2018 $ — $ — $ — $ (1,672) Impact of adoption of accounting standards (1) First Quarter 37,232 — — — ADES proportionate share of income from Tinuum Group First Quarter 21,439 21,439 — — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) First Quarter (1,672) (1,672) — 1,672 Cash distributions from Tinuum Group First Quarter (16,788) — 16,788 — Total investment balance, equity earnings and cash distributions 3/31/2019 $ 40,211 $ 19,767 $ 16,788 $ — ADES proportionate share of income from Tinuum Group Second Quarter $ 19,244 $ 19,244 $ — $ — Cash distributions from Tinuum Group Second Quarter (17,000) — 17,000 — Total investment balance, equity earnings and cash distributions 6/30/2019 $ 42,455 $ 19,244 $ 17,000 $ — ADES proportionate share of income from Tinuum Group Third Quarter $ 11,746 $ 11,746 $ — $ — Cash distributions from Tinuum Group Third Quarter (16,468) — 16,468 — Total investment balance, equity earnings and cash distributions 9/30/2019 $ 37,733 $ 11,746 $ 16,468 $ — (1) Tinuum Group adopted Accounting Standards Codification Topic ("ASC") 606 - Revenue from Contracts with Customers and ASC 842 - Leases as of January 1, 2019. As a result of Tinuum Group’s adoption of these standards, the Company recorded a cumulative adjustment of $27.4 million, net of the impact of income taxes, related to the Company's percentage of Tinuum Group's cumulative effect adjustment, which increased the Company's Retained earnings as of January 1, 2019. Tinuum Services, LLC The Company has a 50% voting and economic interest in Tinuum Services. The Company has determined that Tinuum Services is not a VIE and has further evaluated it for consolidation 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, 2020 and December 31, 2019 was $5.3 million and $6.8 million, respectively. The following table summarizes the results of operations of Tinuum Services: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Gross loss $ (22,764) $ (27,834) $ (65,441) $ (77,761) Operating, selling, general and administrative expenses 42,435 51,927 131,703 151,789 Loss from operations (65,199) (79,761) (197,144) (229,550) Other income (expenses) (363) (460) (978) (1,018) Loss attributable to noncontrolling interest 70,075 85,586 209,118 243,163 Net income $ 4,513 $ 5,365 $ 10,996 $ 12,595 ADES equity earnings from Tinuum Services $ 2,257 $ 2,682 $ 5,498 $ 6,297 Included in the Consolidated Statements of Operations of Tinuum Services for the three and nine months ended September 30, 2020 and 2019, 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 in 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) 2020 2019 2020 2019 Earnings from Tinuum Group $ 7,260 $ 11,746 $ 20,462 $ 50,757 Earnings from Tinuum Services 2,257 2,682 5,498 6,297 Earnings (loss) from other 1 (2) (1) (3) Earnings from equity method investments $ 9,518 $ 14,426 $ 25,959 $ 57,051 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 in the Condensed Consolidated Statements of Cash Flows as "Distributions from equity method investees, return on investment" within Operating cash flows. Nine Months Ended September 30, (in thousands) 2020 2019 Distributions from equity method investees, return on investment Tinuum Group $ 35,226 $ 50,256 Tinuum Services 7,002 6,550 $ 42,228 $ 56,806

Acquisition

Acquisition	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Acquisition	Acquisition of Marshall Mine Concurrently with the execution of the Supply Agreement, on September 30, 2020, the Company entered into an agreement to purchase (the "Purchase Agreement") from Cabot 100% of the membership interests in Marshall Mine, LLC (the "Marshall Mine Acquisition") for a nominal purchase price. Marshall Mine, LLC owns a lignite mine located outside of Marshall, Texas (the "Marshall Mine"). The Company independently determined to immediately commence activities to shutter the Marshall Mine and will incur the associated reclamation costs. In conjunction with the execution of the Supply Agreement and the Purchase Agreement, on September 30, 2020, the Company entered into a reclamation contract (the "Reclamation Contract") with a third party that provides a capped cost, subject to certain contingencies, in the amount of approximately $19.7 million plus an obligation to pay certain direct costs of approximately $3.6 million (collectively, the "Reclamation Costs") over the estimated reclamation period of 10 years (the "Reclamation Period"). Under the terms of the Supply Agreement, Cabot is obligated to reimburse the Company for $10.2 million of Reclamation Costs (the "Reclamation Reimbursements"), which are payable semi-annually over 13 years and inclusive of interest. In the event that Cabot has a change in control as described in the Supply Agreement, all outstanding balances of the Reclamation Reimbursements shall be due and payable in full. See further discussion of the Reclamation Costs and Reclamation Reimbursements in Note 4. The Marshall Mine Acquisition included the acquisition of certain assets that will be consumed and the assumption of certain liabilities that will be paid in reclamation of the Marshall Mine in addition to the incurrence of an obligation for the Reclamation Costs. The Company determined that the Marshall Mine Acquisition should be treated as an asset acquisition as it did not meet the definition of a business. That is, the Company concluded that the Marshall Mine does not have any economic reserves, as the Company has commenced full reclamation as of September 30, 2020, and therefore lacks inputs. As the Marshall Mine Acquisition represents a transaction with a customer of net assets acquired and liabilities assumed from Cabot, the Company has accounted for the excess of the fair value of liabilities assumed over assets acquired as upfront consideration transferred to a customer, Cabot (the "Upfront Customer Consideration"). The amount of the Upfront Customer Consideration is also recognized net of an additional asset recognized in the Marshall Mine Acquisition, which is comprised of a receivable from Cabot (the "Cabot Receivable") for the Reclamation Reimbursements. The Cabot Receivable is further discussed in Note 4. The total Upfront Customer Consideration will be amortized on a straight-line basis over the expected 15-year contractual period of the Supply Agreement as a reduction to revenue. The Company paid a nominal amount to Cabot in the form of cash for the Marshall Mine; in addition, the Company assumed liabilities whose fair value exceeded the fair value of assets acquired. The net assets acquired and liabilities assumed, followed by the Cabot Receivable, and the excess of fair value of liabilities acquired over assets assumed and recognized as the Upfront Customer Consideration is as follows (in thousands), as of the transaction date of September 30, 2020: (in thousands) Amount Assets acquired: Property, plant and equipment $ 3,863 Spare parts 100 Liabilities assumed: Accounts payable and accrued expenses (673) Asset retirement obligation (21,328) Net assets acquired and liabilities assumed from Marshall Mine acquisition (18,038) Cabot receivable 9,749 Upfront Customer Consideration $ 8,289 The following table summarizes the final purchase price allocation. Subsequent to the Acquisition Date, the Company completed additional analysis and adjustments were made to the preliminary purchase price allocations as noted in the table below: Fair value of assets acquired: As Originally Reported Adjustments As Adjusted Cash $ 3,284 $ — $ 3,284 Receivables 6,409 — 6,409 Inventories 22,100 (356) 21,744 Prepaid expenses and other current assets 2,992 61 3,053 Spare parts 3,359 — 3,359 Property, plant and equipment 43,033 (377) 42,656 Mine leases and development 2,500 200 2,700 Mine reclamation asset — 2,402 2,402 Intangible assets 4,000 100 4,100 Other assets 168 — 168 Amount attributable to assets acquired 87,845 2,030 89,875 Fair value of liabilities assumed: Accounts payable 4,771 — 4,771 Accrued liabilities 7,354 254 7,608 Equipment lease liabilities 8,211 — 8,211 Mine reclamation liability 626 1,776 2,402 Other liabilities 437 — 437 Amount attributable to liabilities assumed 21,399 2,030 23,429 Net assets acquired $ 66,446 $ — $ 66,446 Adjustments to the preliminary purchase price allocation primarily related to changes in fair values assigned to property, plant and equipment, intangible assets, mine reclamation liability and the related mine reclamation asset as a result of the final valuation report from the Company's third-party valuation firm issued in May 2019. During the three months ended June 30, 2019 based on new information of facts and circumstances that existed as of the Acquisition Date, the Company revised its estimates used as of the Acquisition Date related to the net realizable value of certain finished goods inventory items as well as values assigned to certain prepaid and accrued expense items. The following table represents the intangible assets, as adjusted for purchase price adjustments noted above, identified as part of the Carbon Solutions Acquisition: (in thousands) Amount Weighted Average Useful Life (years) Customer relationships $ 2,200 5 Developed technology 1,600 5 Trade name 300 2 Total intangibles acquired $ 4,100 Refer to Note 5 regarding subsequent impairment taken on the long-lived assets acquired above.

Inventories, net

Inventories, net	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net The following table summarizes the Company's inventories recorded at the lower of average cost or net realizable value as of September 30, 2020 and December 31, 2019: As of (in thousands) September 30, 2020 December 31, 2019 Product inventory $ 9,535 $ 13,515 Raw material inventory 884 1,945 $ 10,419 $ 15,460

Debt Obligations

Debt Obligations	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Debt Obligations	Debt Obligations As of (in thousands) September 30, 2020 December 31, 2019 Senior Term Loan due December 2021, related party $ 22,000 $ 40,000 Less: net unamortized debt issuance costs (640) (1,163) Less: net unamortized debt discount (660) (1,200) Senior Term Loan due December 2021, net 20,700 37,637 Finance lease obligations 5,841 6,729 PPP Loan 3,305 — 29,846 44,366 Less: Current maturities (24,360) (23,932) Total long-term debt $ 5,486 $ 20,434 Senior Term Loan On December 7, 2018, the Company, and ADA-ES, Inc. ("ADA"), a wholly-owned subsidiary, and certain other subsidiaries of the Company as guarantors, The Bank of New York Mellon as administrative agent, and Apollo Credit Strategies Master Fund Ltd and Apollo A-N Credit Fund (Delaware) L.P. (collectively "Apollo"), affiliates of a beneficial owner of greater than five percent of the Company's common stock and a related party, entered into the Senior Term Loan in the amount of $70.0 million less original issue discount of $2.1 million. Proceeds from the Senior Term Loan were used to fund the Carbon Solutions Acquisition as disclosed in Note 8. The Company also paid debt issuance costs of $2.0 million related to the Senior Term Loan. The Senior Term Loan has a term of 36 months and bears interest at a rate equal to 3-month LIBOR (subject to a 1.5% floor) + 4.75% per annum, which is adjusted quarterly to the current 3-month LIBOR rate, and interest is payable quarterly in arrears. Quarterly principal payments of $6.0 million were required beginning in March 2019, and the Company may prepay the Senior Term Loan at any time without penalty. The Senior Term Loan is secured by substantially all the assets of the Company, including the cash flows from Tinuum Group and Tinuum Services (collectively, the "Tinuum Entities"), but excluding the Company's equity interests in the Tinuum entities. The Senior Term Loan includes, among others, the following covenants: (1) Beginning December 31, 2018 and as of the end of each fiscal quarter thereafter, the Company must maintain a minimum cash balance of $5.0 million and shall not permit "expected future net cash flows from the refined coal business" (as defined in the Senior Term Loan) to be less than 1.75 times the outstanding principal amount of the Senior Term Loan; (2) Beginning in January 2019, annual collective dividends and buybacks of Company shares in an aggregate amount, not to exceed $30.0 million, is permitted so long as (a) no default or event of default exists under the Senior Term Loan and (b) expected future net cash flows from the refined coal business as of the end of the most recent fiscal quarter exceed $100.0 million. Waiver and Limited Consent on Senior Term Loan Pursuant to entering into the PPP Loan, on April 20, 2020, the Company and Apollo executed the First Amendment to the Senior Term Loan, which permitted the Company to enter into the PPP Loan. On September 30, 2020, the Company and Apollo entered into a limited consent, which permitted the Company to (i) enter into the Surety Agreement, open the collateral bank accounts and post collateral required under the Surety Agreement, and (ii) acquire the membership interests in Marshall Mine, LLC., as described in Note 3. Line of Credit On September 29, 2020, ADA-ES, Inc. ("ADA"), a wholly-owned subsidiary of the Company, as borrower, the Company, as guarantor, and a bank (the "Lender") entered into an amendment to the 2013 Loan and Security Agreement (the "Line of Credit"). This amendment extended the maturity date of the Line of Credit to March 31, 2021 and retained covenants from the prior amendments to the Line of Credit, which included ADA's ability to enter into the Senior Term Loan as a guarantor so long as the principal amount of the Senior Term Loan did not exceed $70.0 million and the revision of covenants that were consistent with the Senior Term Loan covenants, including maintaining a minimum cash balance of $5.0 million. As of September 30, 2020, there were no outstanding borrowings under the Line of Credit.

Leases

Leases	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Leases	Leases As of September 30, 2020, the Company has obligations under finance and operating leases in the amounts of $5.8 million and $3.5 million, respectively. As of September 30, 2020, the Company has right of use ("ROU") assets, net of accumulated amortization, under finance leases and operating leases of $2.6 million and $2.3 million, respectively. Finance leases ROU assets under finance leases and finance lease liabilities are included in Property, plant and equipment and Current portion and Long-term portion of borrowings, respectively, in the Condensed Consolidated Balance Sheets as of September 30, 2020. and December 31, 2019. Interest expense related to finance lease liabilities and amortization of ROU assets under finance leases are included in Interest expense and Depreciation, amortization, depletion and accretion, respectively, in the Condensed Consolidated Statement of Operations for the three and nine months ended September 30, 2020 and September 30, 2019. Operating leases ROU assets under operating leases and operating lease liabilities are included in Other long-term assets and Other liabilities and Other long-term liabilities, respectively, in the Condensed Consolidated Balance Sheet as of September 30, 2020 and December 31, 2019. Lease expense for operating leases for the three and nine months ended September 30, 2020 was $1.1 million and $3.5 million, respectively, of which $1.0 million and $2.9 million, respectively, is included in Consumables - cost of revenue, exclusive of depreciation and amortization, and $0.1 million and $0.6 million, respectively, is included in General and administrative in the Condensed Consolidated Statement of Operations. Lease expense for operating leases for the three and nine months ended September 30, 2019 was $1.1 million and $3.3 million, respectively, of which $1.0 million and $3.1 million, respectively, is included in Consumables - cost of revenue, exclusive of depreciation and amortization, and $0.1 million and $0.3 million, respectively, is included in General and administrative in the Condensed Consolidated Statement of Operations. Lease financial information as of and for the three and nine months ended September 30, 2020 and 2019 is provided in the following table: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Finance lease cost: Amortization of right-of-use assets $ 258 $ 1,277 $ 1,237 $ 2,371 Interest on lease liabilities 88 82 275 270 Operating lease cost 412 908 1,941 2,764 Short-term lease cost 671 198 1,377 558 Variable lease cost (1) 10 52 147 227 Total lease cost $ 1,439 $ 2,517 $ 4,977 $ 6,190 Other Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 275 $ 270 Operating cash flows from operating leases $ 1,678 $ 2,435 Financing cash flows from finance leases $ 1,026 $ 1,016 Right-of-use assets obtained in exchange for new finance lease liabilities $ 158 $ — Right-of-use assets obtained in exchange for new operating lease liabilities $ 59 $ 1,309 Weighted-average remaining lease term - finance leases 3.7 years 4.4 years Weighted-average remaining lease term - operating leases 2.0 years 2.5 years Weighted-average discount rate - finance leases 6.1 % 6.1 % Weighted-average discount rate - operating leases 8.5 % 8.6 % (1) Primarily includes common area maintenance, property taxes and insurance payable to lessors.
Leases	Leases As of September 30, 2020, the Company has obligations under finance and operating leases in the amounts of $5.8 million and $3.5 million, respectively. As of September 30, 2020, the Company has right of use ("ROU") assets, net of accumulated amortization, under finance leases and operating leases of $2.6 million and $2.3 million, respectively. Finance leases ROU assets under finance leases and finance lease liabilities are included in Property, plant and equipment and Current portion and Long-term portion of borrowings, respectively, in the Condensed Consolidated Balance Sheets as of September 30, 2020. and December 31, 2019. Interest expense related to finance lease liabilities and amortization of ROU assets under finance leases are included in Interest expense and Depreciation, amortization, depletion and accretion, respectively, in the Condensed Consolidated Statement of Operations for the three and nine months ended September 30, 2020 and September 30, 2019. Operating leases ROU assets under operating leases and operating lease liabilities are included in Other long-term assets and Other liabilities and Other long-term liabilities, respectively, in the Condensed Consolidated Balance Sheet as of September 30, 2020 and December 31, 2019. Lease expense for operating leases for the three and nine months ended September 30, 2020 was $1.1 million and $3.5 million, respectively, of which $1.0 million and $2.9 million, respectively, is included in Consumables - cost of revenue, exclusive of depreciation and amortization, and $0.1 million and $0.6 million, respectively, is included in General and administrative in the Condensed Consolidated Statement of Operations. Lease expense for operating leases for the three and nine months ended September 30, 2019 was $1.1 million and $3.3 million, respectively, of which $1.0 million and $3.1 million, respectively, is included in Consumables - cost of revenue, exclusive of depreciation and amortization, and $0.1 million and $0.3 million, respectively, is included in General and administrative in the Condensed Consolidated Statement of Operations. Lease financial information as of and for the three and nine months ended September 30, 2020 and 2019 is provided in the following table: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Finance lease cost: Amortization of right-of-use assets $ 258 $ 1,277 $ 1,237 $ 2,371 Interest on lease liabilities 88 82 275 270 Operating lease cost 412 908 1,941 2,764 Short-term lease cost 671 198 1,377 558 Variable lease cost (1) 10 52 147 227 Total lease cost $ 1,439 $ 2,517 $ 4,977 $ 6,190 Other Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 275 $ 270 Operating cash flows from operating leases $ 1,678 $ 2,435 Financing cash flows from finance leases $ 1,026 $ 1,016 Right-of-use assets obtained in exchange for new finance lease liabilities $ 158 $ — Right-of-use assets obtained in exchange for new operating lease liabilities $ 59 $ 1,309 Weighted-average remaining lease term - finance leases 3.7 years 4.4 years Weighted-average remaining lease term - operating leases 2.0 years 2.5 years Weighted-average discount rate - finance leases 6.1 % 6.1 % Weighted-average discount rate - operating leases 8.5 % 8.6 % (1) Primarily includes common area maintenance, property taxes and insurance payable to lessors.

Revenues

Revenues	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenues	Revenues 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. Trade receivables, net The following table shows the components of the Company's Trade receivables, net: As of (in thousands) September 30, 2020 December 31, 2019 Trade receivables $ 9,950 $ 8,057 Less: Allowance for doubtful accounts (598) (627) Trade receivables, net $ 9,352 $ 7,430 For the three and nine months ended September 30, 2020 and 2019, the Company recognized zero bad debt expense, respectively. Upfront Customer Consideration As described in Note 3, as of September 30, 2020, the Company recorded an asset of $8.3 million representing upfront consideration transferred to a customer in connection with the Supply Agreement. The amount is included in Other long-term assets, net on the Company's Consolidated Balance Sheet as of September 30, 2020. Disaggregation of Revenue and Earnings from Equity Method Investments During the three and nine months ended September 30, 2020 and 2019, all performance obligations related to revenues recognized were satisfied at a point in time. The Company disaggregates its revenues by major components as well as between its two reportable segments, which are further discussed in Note 18 to the Condensed Consolidated Financial Statements. The following tables disaggregate revenues by major component for the three and nine months ended September 30, 2020 and 2019 (in thousands): Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Segment Segment PGI RC Other Total PGI RC Other Total Revenue component Consumables $ 13,442 $ — $ 2,402 $ 15,844 $ 28,987 $ — $ 4,244 $ 33,231 License royalties, related party — 3,627 — 3,627 — 9,986 — 9,986 Revenues from customers 13,442 3,627 2,402 19,471 28,987 9,986 4,244 43,217 Earnings from equity method investments — 9,518 — 9,518 — 25,959 — 25,959 Total revenues from customers and earnings from equity method investments $ 13,442 $ 13,145 $ 2,402 $ 28,989 $ 28,987 $ 35,945 $ 4,244 $ 69,176 Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Segment Segment PGI RC Other Total PGI RC Other Total Revenue component Consumables $ 14,010 $ — $ 738 $ 14,748 $ 39,612 $ — $ 1,631 $ 41,243 License royalties, related party — 4,385 — 4,385 — 12,796 — 12,796 Revenues from customers 14,010 4,385 738 19,133 39,612 12,796 1,631 54,039 Earnings from equity method investments — 14,426 — 14,426 — 57,051 — 57,051 Total revenues from customers and earnings from equity method investments $ 14,010 $ 18,811 $ 738 $ 33,559 $ 39,612 $ 69,847 $ 1,631 $ 111,090

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
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 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. There were no significant legal proceedings as of September 30, 2020. Restricted Cash As of September 30, 2020, the Company had long-term restricted cash of $10.0 million, which consisted of minimum cash balance requirements of $5.0 million and $5.0 million under the Senior Term Loan and the Surety Agreement related to the Marshall Mine, respectively. As of December 31, 2019, the Company had long-term restricted cash of $5.0 million related to minimum cash requirements under the Senior Term Loan. Other Commitments and Contingencies

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Stock Repurchase Programs In November 2018, the Company's Board of Directors (the "Board") authorized the Company to purchase up to $20.0 million of its outstanding common stock under a stock repurchase program (the "Stock Repurchase Program"), which was to remain in effect until December 31, 2019 unless otherwise modified by the Board. As of November 2019, $2.9 million remained outstanding related to the Stock Repurchase Program. In November 2019, the Board authorized an incremental $7.1 million to the Stock Repurchase Program and provided that it will remain in effect until all amounts are utilized or it is otherwise modified by the Board. For the three and nine months ended September 30, 2020, under the Stock Repurchase Program, the Company purchased zero and 20,613 shares, respectively, of its common stock for cash of zero and $0.2 million, respectively, inclusive of commissions and fees. For the three and nine months ended September 30, 2019, under the Stock Repurchase Program, the Company purchased 8,152 and 256,743 shares, respectively, of its common stock for cash of $0.1 million and $2.9 million, respectively, inclusive of commissions and fees. As of September 30, 2020, the Company had $7.0 million remaining under the Stock Repurchase Program. Quarterly Cash Dividend Dividends declared and paid quarterly on all outstanding shares of common stock during the three and nine months ended September 30, 2020 and 2019 were as follows: 2020 2019 Per share Date paid Per share Date paid Dividends declared during quarter ended: March 31 $ 0.25 March 10, 2020 $ 0.25 March 7, 2019 June 30 $ — $ 0.25 June 7, 2019 September 30 $ — $ 0.25 September 6, 2019 $ 0.25 $ 0.75 A portion of the dividends declared remains accrued subsequent to the payment dates and represents 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 Sheets as of September 30, 2020 and December 31, 2019. Tax Asset Protection Plan U.S. 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 the Company 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 the Company 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 "TAPP") designed to protect the Company’s ability to utilize its net operating losses and tax credits. The TAPP 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 9, 2020, the Board approved the Third Amendment to the TAPP ("Third Amendment") that amends the TAPP, as previously amended by the First and Second Amendments that were approved the Board on April 6, 2018 and April 5, 2019, respectively. The Third 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 2020 annual meeting of stockholders, the Company's stockholders approved the Second Amendment, thus the Final Expiration Date will be the close of business on December 31, 2021.

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company grants equity-based awards to employees, non-employee directors, and consultants that may include, but are not limited to, RSA's, restricted stock units ("RSU's"), performance stock units ("PSU's") and stock options. Stock-based compensation expense related to manufacturing employees and administrative employees is included within the Cost of revenue and Payroll and benefits line items, respectively, in the Condensed Consolidated Statements of Operations. Stock-based compensation expense related to non-employee directors and consultants 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, 2020 and 2019 was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 RSA expense $ 411 $ 468 $ 1,892 $ 1,326 PSU expense 15 — 178 — Total stock-based compensation expense $ 426 $ 468 $ 2,070 $ 1,326 The amount of unrecognized compensation cost as of September 30, 2020, and the expected weighted-average period over which the cost will be recognized is as follows: As of September 30, 2020 (in thousands) Unrecognized Compensation Cost Expected Weighted- RSA expense $ 2,181 1.71 PSU expense 131 2.44 Total unrecognized stock-based compensation expense $ 2,312 1.75 Restricted Stock Restricted stock is typically granted with vesting terms of three A summary of RSA activity under the Company's various stock compensation plans for the nine months ended September 30, 2020 is presented below: Restricted Stock Weighted-Average Grant Date Fair Value Non-vested at January 1, 2020 451,344 $ 10.65 Granted 309,976 $ 5.20 Vested (306,137) $ 10.08 Forfeited (7,565) $ 7.87 Non-vested at September 30, 2020 447,618 $ 7.31 Stock Options Stock options generally vest over three five A summary of stock option activity for the nine months ended September 30, 2020 is presented below: Number of Options Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average Options outstanding, January 1, 2020 300,000 $ 13.87 Options granted — — Options exercised — — Options expired / forfeited (300,000) 13.87 Options outstanding, September 30, 2020 — $ — $ — — Options vested and exercisable, September 30, 2020 — $ — $ — — 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. A summary of PSU activity for the nine months ended September 30, 2020 is presented below: Units Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average PSU's outstanding, January 1, 2020 — $ — Granted 50,127 6.17 Vested / Settled — — Forfeited / Canceled — — PSU's outstanding, September 30, 2020 50,127 $ 6.17 $ 204 2.44

Supplemental Financial Informat

Supplemental Financial Information	9 Months Ended
	Sep. 30, 2020
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, net as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) September 30, December 31, Prepaid expenses and other assets: Federal and state income tax benefits $ 9,373 $ — Prepaid federal and state income taxes 4,715 4,228 Prepaid expenses 1,633 1,708 Other 1,167 1,896 $ 16,888 $ 7,832 Other long-term assets, net: Upfront Customer Consideration (1) $ 8,290 $ — Cabot receivable 8,828 — Right of use assets, operating leases, net 2,256 5,073 Spare parts, net 3,846 3,453 Mine development costs, net 4,356 7,084 Mine reclamation asset, net 1,307 2,451 Highview Investment 552 552 Other long-term assets 1,771 1,718 $ 31,206 $ 20,331 (1) See further discussion of Upfront Customer Consideration in Note 3. Spare parts include critical spares required to support plant operations. Parts and supply costs are determined using the lower of cost or estimated replacement cost. Parts are recorded as maintenance expenses in the period in which they are consumed. Mine development costs include acquisition costs, the cost of other development work and mitigation costs related to the Company's mining operations and are depleted over the estimated life of the related mine reserves, which is 21 years. The Company performs an evaluation of the recoverability of the carrying value of mine development costs to determine if facts and circumstances indicate that their carrying value may be impaired and if any adjustment is warranted. Indicators of impairment were present during the second quarter of 2020. See Note 5 for further discussion. Mine reclamation asset, net represents an asset retirement obligation asset and is depreciated over the estimated life of the mine. The Company holds a long-term investment (the "Highview Investment") in Highview Enterprises Limited ("Highview"), a London, England based developmental stage company specializing in power storage. The Company accounts for the Highview Investment as an investment recorded at cost, less impairment, plus or minus observable changes in price for identical or similar investments of the same issuer. The Highview Investment is evaluated for indicators of impairment such as an event or change in circumstances that may have a significant adverse effect on the fair value of the investment. There were no changes to the carrying value of the Highview Investment for the three and nine months ended September 30, 2020 as there were no indicators of impairment or observable price changes for identical or similar investments. 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: Current portion of operating lease obligations $ 2,043 $ 2,382 Accrued interest 91 213 Income and other taxes payable 1,603 678 Other 365 1,038 $ 4,102 $ 4,311 Other long-term liabilities: Operating lease obligations, long-term $ 1,471 $ 2,810 Mine reclamation liability (1) 24,183 2,721 Other 58 229 $ 25,712 $ 5,760 (1) As discussed in Note 3, $21.3 million relates to Marshall Mine ARO. 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) 2020 2019 2020 2019 Interest on Senior Term Loan $ 339 $ 940 $ 1,453 $ 3,344 Debt discount and debt issuance costs 355 473 1,064 1,324 453A interest 94 234 254 882 Other 93 82 282 270 $ 881 $ 1,729 $ 3,053 $ 5,820

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes For the three and nine months ended September 30, 2020 and 2019, 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) 2020 2019 2020 2019 Income tax expense $ 854 $ 6,595 $ 1,315 $ 14,928 Effective tax rate 15 % 63 % (7) % 36 % The effective rate for the three and nine months ended September 30, 2020 was different from the federal statutory rate primarily from changes in the valuation allowance on deferred tax assets, most notably an increase of $5.1 million for the nine months ended September 30, 2020. The increase in the valuation allowance was a result of a reduction in forecasts as of September 30, 2020 from forecasts as of December 31, 2019 of current and future years' taxable income. 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 deferred tax assets, 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.

Business Segment Information

Business Segment Information	9 Months Ended
	Sep. 30, 2020
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, 2020, the Company's CODM was the Company's CEO. The Company's operating and reportable segments are identified by products and services provided. As of September 30, 2020, the Company has two reportable segments: (1) Refined Coal ("RC"); and (2) Power Generation and Industrials ("PGI"). 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 2019 Form 10-K. • Segment revenues include equity method earnings and losses from the Company's equity method investments. • Segment operating income (loss) includes segment revenues and allocation of certain "Corporate general and administrative expenses," which include Payroll and benefits, Legal and professional fees and General and administrative. • RC segment operating income includes interest expense directly attributable to the RC segment. As of September 30, 2020 and December 31, 2019, substantially all of the Company's material assets are located in the U.S. and substantially all of 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, 2020 and 2019: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Revenues: Refined Coal: Earnings in equity method investments $ 9,518 $ 14,426 $ 25,959 $ 57,051 License royalties, related party 3,627 4,385 9,986 12,796 13,145 18,811 35,945 69,847 Power Generation and Industrials: Consumables 13,442 14,010 28,987 39,612 13,442 14,010 28,987 39,612 Total segment reporting revenues 26,587 32,821 64,932 109,459 Adjustments to reconcile to reported revenues: Earnings in equity method investments (9,518) (14,426) (25,959) (57,051) Corporate and other 2,402 738 4,244 1,631 Total reported revenues $ 19,471 $ 19,133 $ 43,217 $ 54,039 Segment operating income (loss): Refined Coal (1) $ 12,817 $ 18,158 $ 34,454 $ 68,137 Power Generation and Industrials (2) (1,270) (977) (33,584) (8,301) Total segment operating income $ 11,547 $ 17,181 $ 870 $ 59,836 (1) Included in RC segment operating income for the three and nine months ended September 30, 2020 is 453A interest expense of $0.1 million and $0.3 million, respectively. Included in RC segment operating income for the three and nine months ended September 30, 2019 is 453A interest expense of $0.2 million and $0.9 million, respectively. (2) Included in PGI segment operating loss for the three and nine months ended September 30, 2020 is zero and $23.2 million, respectively, of impairment expense on the Asset Group, and zero and $0.4 million, respectively, of expenses related to sequestration of certain of our employees at our manufacturing plant in Louisiana. Included in PGI segment operating loss for the three and nine months ended September 30, 2020 and 2019 is $1.4 million and $4.9 million, and $1.9 million and $4.5 million, respectively, of depreciation, amortization, and depletion expense on mine and plant long-lived assets. Included in PGI segment operating loss for the nine months ended September 30, 2019 was $4.7 million of costs recognized as a result of the step-up in inventory fair value recorded from the Carbon Solutions Acquisition. A reconciliation of reportable segment operating income to the Company's consolidated income (loss) before income tax expense is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Total reported segment operating income $ 11,547 $ 17,181 $ 870 $ 59,836 Other operating loss (1) (2,010) (658) (7,065) (1,409) 9,537 16,523 (6,195) 58,427 Adjustments to reconcile to income (loss) before income tax expense attributable to the Company: Corporate payroll and benefits (587) (768) (2,444) (2,004) Corporate legal and professional fees (1,176) (1,737) (3,850) (5,254) Corporate general and administrative (1,116) (2,278) (4,273) (5,427) Corporate depreciation and amortization (148) (21) (337) (41) Corporate interest expense, net (680) (1,413) (2,446) (4,668) Other income (expense), net (1) 212 128 334 Income (loss) before income tax expense $ 5,829 $ 10,518 $ (19,417) $ 41,367 (1) Included in Other operating loss for the three and nine months ended September 30, 2020 was zero and $2.9 million, respectively, of impairment expense on the Asset Group. 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) $ 26,985 $ 43,953 Power Generation and Industrials 70,772 80,912 Total segment assets 97,757 124,865 All Other and Corporate (2) 57,897 48,934 Consolidated $ 155,654 $ 173,799 (1) Includes $22.9 million and $39.2 million of investments in equity method investees, respectively. (2) Includes the Company's deferred tax assets.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair value of financial instruments The carrying amounts of financial instruments, including cash, cash equivalents and restricted cash, 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, 2020 As of December 31, 2019 (in thousands) Carrying Value Fair Value Carrying Value Fair Value Financial Instruments: Highview Investment $ 552 $ 552 $ 552 $ 552 Highview Obligation $ 216 $ 216 $ 220 $ 220 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 four financial institutions as of September 30, 2020. If an 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, 2020 and December 31, 2019, the Company had no financial instruments carried and measured at fair value on a recurring basis. Assets and Liabilities Measured at Fair Value on a Non-Recurring Basis As disclosed in Note 3, the Company completed the asset acquisition of Marshall Mine, LLC. The estimated fair values of the assets acquired and liabilities assumed were determined based on Level 3 inputs. As disclosed in Note 5, the Company recorded an impairment charge related to the Asset Group based on a valuation models that included an expected future discounted cash flow model using Level 3 inputs . As disclosed in Note 8, the Company completed the Carbon Solutions Acquisition for purchase consideration of $66.5 million. The estimated fair values of the assets acquired and liabilities assumed were determined based on Level 3 inputs. The Company has applied the measurement alternative for investments without readily determinable fair values under ASC Topic 321 - Investments in Equity Securities

Restructuring and Other Compens

Restructuring and Other Compensation	9 Months Ended
	Sep. 30, 2020
Restructuring and Other Compensation [Abstract]
Restructuring and Other Compensation	Restructuring and Other Compensation Restructuring In December 2018, the Company recorded restructuring charges in connection with the departures of certain executives of Carbon Solutions in conjunction with the Carbon Solutions Acquisition. As part of the Carbon Solutions Acquisition, the Company also assumed a salary severance liability for an additional executive of Carbon Solutions in the amount of $0.6 million. There were no material restructuring activities during the three and nine months ended September 30, 2020. 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. Other Compensation On March 27, 2020, the Company's CEO resigned from the Company effective June 30, 2020. Pursuant to a settlement agreement executed between the Company and the CEO, the Company was obligated to pay severance compensation to the CEO in the form of salary continuance, cash bonus, contingent upon the Company achieving a performance metric, healthcare benefits, RSAs and PSUs, which in the aggregate was $1.4 million. As of June 30, 2020, the Company recorded a liability for the total severance compensation and corresponding expense under the caption "Payroll and benefits" in the Condensed Consolidated Statements of Operations. The following table summarizes the Company's change in restructuring and other compensation accruals for the nine months ended September 30, 2020: (in thousands) Severance Remaining accrual as of December 31, 2019 $ 254 Expense provision 1,403 Cash payments and other (956) Change in estimates — Remaining accrual as of September 30, 2020 $ 701

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2020
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, 2020. Invested RC Facility On October 20, 2020, the Company announced that Tinuum Group completed a lease for an additional RC facility. The RC facility is located at a coal plant that has historically burned in excess of 4.0 million tons of coal per year. With this addition, Tinuum Group has 22 invested facilities in full-time operation.

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2020
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 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 in consolidation for all periods presented in this Quarterly Report.
Earnings (Loss) Per Share	Basic earnings (loss) per share is computed using the two-class method, which is an earnings allocation formula that determines earnings (loss) per share for common stock and any participating securities according to dividend and participating rights in undistributed earnings (losses). 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 (loss) 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.
Use of Estimates	The preparation of financial statements in conformity with U.S. GAAP requires management to make 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 2019 Form 10-K except for assumptions regarding impairment of long-lived assets and the valuation of assets acquired and liabilities assumed in an asset acquisition. 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, 2020, Tinuum Group has 21 invested RC facilities of which 9 are leased to a single customer. A majority of these leases are periodically renewed. Further, the ability to generate Section 45 tax credits related to Tinuum's RC facilities e xpires in 2021. The loss of a single customer by Tinuum Group or the expiration of Section 45 tax credits would have a significant adverse impact on Tinuum Group's financial position, results of operations and cash flows, which in turn would have a 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. Such reclassifications had no effect on the Company’s results of operations or financial position in any of the periods presented.
New Accounting Guidance	Not Yet Adopted 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 "smaller reporting companies" (as defined by the Securities and Exchange Commission) for fiscal years beginning after December 15, 2022, 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 and does not believe this standard will have a material impact on the Company's financial statements and disclosures. In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740) Simplifying the Accounting for Income Taxes ("ASU 2019-12"). The amendments in ASU 2019-12 simplify various aspects related to accounting for income taxes by removing certain exceptions contained in Topic 740 and also clarify and amends existing guidance in Topic 740 to improve consistent application. ASU 2019-12 is effective for public business entities beginning after December 15, 2020, including interim periods within those years, and early adoption is permitted. The Company is currently evaluating the provisions of this guidance and assessing its impact on the Company's financial statements and disclosures and does not believe this standard will have a material impact on the Company's financial statements and disclosures.
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, 2020, the Company's CODM was the Company's CEO. The Company's operating and reportable segments are identified by products and services provided. As of September 30, 2020, the Company has two reportable segments: (1) Refined Coal ("RC"); and (2) Power Generation and Industrials ("PGI"). 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 2019 Form 10-K. • Segment revenues include equity method earnings and losses from the Company's equity method investments. • Segment operating income (loss) includes segment revenues and allocation of certain "Corporate general and administrative expenses," which include Payroll and benefits, Legal and professional fees and General and administrative. • RC segment operating income includes interest expense directly attributable to the RC segment.
Fair Value of Financial Instruments	The carrying amounts of financial instruments, including cash, cash equivalents and restricted cash, accounts receivable, accounts payable and accrued expenses, approximate fair value due to the short maturity of these instruments.

Basis of Presentation (Tables)

Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table sets forth the calculations of basic and diluted earnings (loss) per share: Three Months Ended September 30, Nine Months Ended September 30, (in thousands, except per share amounts) 2020 2019 2020 2019 Net income (loss) $ 4,975 $ 3,923 $ (20,732) $ 26,439 Less: Dividends and undistributed income (loss) allocated to participating securities — 5 (10) 37 Income (loss) attributable to common stockholders $ 4,975 $ 3,918 $ (20,722) $ 26,402 Basic weighted-average common shares outstanding 18,093 18,112 18,014 18,184 Add: dilutive effect of equity instruments 10 227 — 210 Diluted weighted-average shares outstanding 18,103 18,339 18,014 18,394 Earnings (loss) per share - basic $ 0.27 $ 0.22 $ (1.15) $ 1.45 Earnings (loss) per share - diluted $ 0.27 $ 0.21 $ (1.15) $ 1.44

Acquisition of Marshall Mine (T

Acquisition of Marshall Mine (Tables)	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Summary of Purchase Consideration and Allocation	The net assets acquired and liabilities assumed, followed by the Cabot Receivable, and the excess of fair value of liabilities acquired over assets assumed and recognized as the Upfront Customer Consideration is as follows (in thousands), as of the transaction date of September 30, 2020: (in thousands) Amount Assets acquired: Property, plant and equipment $ 3,863 Spare parts 100 Liabilities assumed: Accounts payable and accrued expenses (673) Asset retirement obligation (21,328) Net assets acquired and liabilities assumed from Marshall Mine acquisition (18,038) Cabot receivable 9,749 Upfront Customer Consideration $ 8,289 The following table summarizes the final purchase price allocation. Subsequent to the Acquisition Date, the Company completed additional analysis and adjustments were made to the preliminary purchase price allocations as noted in the table below: Fair value of assets acquired: As Originally Reported Adjustments As Adjusted Cash $ 3,284 $ — $ 3,284 Receivables 6,409 — 6,409 Inventories 22,100 (356) 21,744 Prepaid expenses and other current assets 2,992 61 3,053 Spare parts 3,359 — 3,359 Property, plant and equipment 43,033 (377) 42,656 Mine leases and development 2,500 200 2,700 Mine reclamation asset — 2,402 2,402 Intangible assets 4,000 100 4,100 Other assets 168 — 168 Amount attributable to assets acquired 87,845 2,030 89,875 Fair value of liabilities assumed: Accounts payable 4,771 — 4,771 Accrued liabilities 7,354 254 7,608 Equipment lease liabilities 8,211 — 8,211 Mine reclamation liability 626 1,776 2,402 Other liabilities 437 — 437 Amount attributable to liabilities assumed 21,399 2,030 23,429 Net assets acquired $ 66,446 $ — $ 66,446

Impairment (Tables)

Impairment (Tables)	9 Months Ended
	Sep. 30, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Impaired Intangible Assets	The following table summarizes the allocation to the Asset Group of the Impairment Charge of $26.1 million recorded as of June 30, 2020: (in thousands) Property, plant and equipment, net $ 18,986 Intangible assets, net 1,445 Other long-term assets, net 5,672 Total impairment $ 26,103

Equity Method Investments (Tabl

Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Method Investments	The following table summarizes the results of operations of Tinuum Group: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Gross profit $ 101 $ 16,810 $ 11,979 $ 96,189 Operating, selling, general and administrative expenses 13,781 11,076 38,476 23,421 (Loss) income from operations (13,680) 5,734 (26,497) 72,768 Other income (expenses) 5,739 (450) 11,526 (427) Loss attributable to noncontrolling interest 25,023 22,355 63,117 51,022 Net income available to members $ 17,082 $ 27,639 $ 48,146 $ 123,363 ADES equity earnings from Tinuum Group $ 7,260 $ 11,746 $ 20,462 $ 50,757 The following tables present the Company's investment balance, equity earnings and cash distributions in excess of the investment balance, if any, for the three and nine months ended September 30, 2020 and 2019 ( in thousands ): Description Date(s) Investment balance ADES equity earnings Cash distributions Memorandum Account: Cash distributions and equity earnings in (excess) of investment balance Beginning balance 12/31/2019 $ 32,280 $ — $ — $ — ADES proportionate share of income from Tinuum Group First Quarter 6,438 6,438 — — Cash distributions from Tinuum Group First Quarter (13,764) — 13,764 — Total investment balance, equity earnings and cash distributions 3/31/2020 $ 24,954 $ 6,438 $ 13,764 $ — ADES proportionate share of income from Tinuum Group Second Quarter $ 6,764 $ 6,764 $ — $ — Cash distributions from Tinuum Group Second Quarter (13,600) — 13,600 — Total investment balance, equity earnings and cash distributions 6/30/2020 $ 18,118 $ 6,764 $ 13,600 $ — ADES proportionate share of income from Tinuum Group Third Quarter $ 7,260 $ 7,260 $ — $ — Cash distributions from Tinuum Group Third Quarter (7,862) — 7,862 — Total investment balance, equity earnings and cash distributions 9/30/2020 $ 17,516 $ 7,260 $ 7,862 $ — 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 12/31/2018 $ — $ — $ — $ (1,672) Impact of adoption of accounting standards (1) First Quarter 37,232 — — — ADES proportionate share of income from Tinuum Group First Quarter 21,439 21,439 — — Recovery of prior cash distributions in excess of investment balance (prior to cash distributions) First Quarter (1,672) (1,672) — 1,672 Cash distributions from Tinuum Group First Quarter (16,788) — 16,788 — Total investment balance, equity earnings and cash distributions 3/31/2019 $ 40,211 $ 19,767 $ 16,788 $ — ADES proportionate share of income from Tinuum Group Second Quarter $ 19,244 $ 19,244 $ — $ — Cash distributions from Tinuum Group Second Quarter (17,000) — 17,000 — Total investment balance, equity earnings and cash distributions 6/30/2019 $ 42,455 $ 19,244 $ 17,000 $ — ADES proportionate share of income from Tinuum Group Third Quarter $ 11,746 $ 11,746 $ — $ — Cash distributions from Tinuum Group Third Quarter (16,468) — 16,468 — Total investment balance, equity earnings and cash distributions 9/30/2019 $ 37,733 $ 11,746 $ 16,468 $ — (1) Tinuum Group adopted Accounting Standards Codification Topic ("ASC") 606 - Revenue from Contracts with Customers and ASC 842 - Leases as of January 1, 2019. As a result of Tinuum Group’s adoption of these standards, the Company recorded a cumulative adjustment of $27.4 million, net of the impact of income taxes, related to the Company's percentage of Tinuum Group's cumulative effect adjustment, which increased the Company's Retained earnings as of January 1, 2019. The following table summarizes the results of operations of Tinuum Services: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Gross loss $ (22,764) $ (27,834) $ (65,441) $ (77,761) Operating, selling, general and administrative expenses 42,435 51,927 131,703 151,789 Loss from operations (65,199) (79,761) (197,144) (229,550) Other income (expenses) (363) (460) (978) (1,018) Loss attributable to noncontrolling interest 70,075 85,586 209,118 243,163 Net income $ 4,513 $ 5,365 $ 10,996 $ 12,595 ADES equity earnings from Tinuum Services $ 2,257 $ 2,682 $ 5,498 $ 6,297 The following table details the components of the Company's respective equity method investments included in 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) 2020 2019 2020 2019 Earnings from Tinuum Group $ 7,260 $ 11,746 $ 20,462 $ 50,757 Earnings from Tinuum Services 2,257 2,682 5,498 6,297 Earnings (loss) from other 1 (2) (1) (3) Earnings from equity method investments $ 9,518 $ 14,426 $ 25,959 $ 57,051 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 in the Condensed Consolidated Statements of Cash Flows as "Distributions from equity method investees, return on investment" within Operating cash flows. Nine Months Ended September 30, (in thousands) 2020 2019 Distributions from equity method investees, return on investment Tinuum Group $ 35,226 $ 50,256 Tinuum Services 7,002 6,550 $ 42,228 $ 56,806

Acquisition (Tables)

Acquisition (Tables)	9 Months Ended
	Sep. 30, 2020
Business Combinations [Abstract]
Schedule of Purchase Price Allocation	The net assets acquired and liabilities assumed, followed by the Cabot Receivable, and the excess of fair value of liabilities acquired over assets assumed and recognized as the Upfront Customer Consideration is as follows (in thousands), as of the transaction date of September 30, 2020: (in thousands) Amount Assets acquired: Property, plant and equipment $ 3,863 Spare parts 100 Liabilities assumed: Accounts payable and accrued expenses (673) Asset retirement obligation (21,328) Net assets acquired and liabilities assumed from Marshall Mine acquisition (18,038) Cabot receivable 9,749 Upfront Customer Consideration $ 8,289 The following table summarizes the final purchase price allocation. Subsequent to the Acquisition Date, the Company completed additional analysis and adjustments were made to the preliminary purchase price allocations as noted in the table below: Fair value of assets acquired: As Originally Reported Adjustments As Adjusted Cash $ 3,284 $ — $ 3,284 Receivables 6,409 — 6,409 Inventories 22,100 (356) 21,744 Prepaid expenses and other current assets 2,992 61 3,053 Spare parts 3,359 — 3,359 Property, plant and equipment 43,033 (377) 42,656 Mine leases and development 2,500 200 2,700 Mine reclamation asset — 2,402 2,402 Intangible assets 4,000 100 4,100 Other assets 168 — 168 Amount attributable to assets acquired 87,845 2,030 89,875 Fair value of liabilities assumed: Accounts payable 4,771 — 4,771 Accrued liabilities 7,354 254 7,608 Equipment lease liabilities 8,211 — 8,211 Mine reclamation liability 626 1,776 2,402 Other liabilities 437 — 437 Amount attributable to liabilities assumed 21,399 2,030 23,429 Net assets acquired $ 66,446 $ — $ 66,446
Summary of Finite-Lived Intangible Assets Acquired	The following table represents the intangible assets, as adjusted for purchase price adjustments noted above, identified as part of the Carbon Solutions Acquisition: (in thousands) Amount Weighted Average Useful Life (years) Customer relationships $ 2,200 5 Developed technology 1,600 5 Trade name 300 2 Total intangibles acquired $ 4,100

Inventories, net (Tables)

Inventories, net (Tables)	9 Months Ended
	Sep. 30, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory	The following table summarizes the Company's inventories recorded at the lower of average cost or net realizable value as of September 30, 2020 and December 31, 2019: As of (in thousands) September 30, 2020 December 31, 2019 Product inventory $ 9,535 $ 13,515 Raw material inventory 884 1,945 $ 10,419 $ 15,460

Debt Obligations (Tables)

Debt Obligations (Tables)	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Schedule of Borrowings	As of (in thousands) September 30, 2020 December 31, 2019 Senior Term Loan due December 2021, related party $ 22,000 $ 40,000 Less: net unamortized debt issuance costs (640) (1,163) Less: net unamortized debt discount (660) (1,200) Senior Term Loan due December 2021, net 20,700 37,637 Finance lease obligations 5,841 6,729 PPP Loan 3,305 — 29,846 44,366 Less: Current maturities (24,360) (23,932) Total long-term debt $ 5,486 $ 20,434

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2020
Leases [Abstract]
Lease, Cost	Lease financial information as of and for the three and nine months ended September 30, 2020 and 2019 is provided in the following table: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Finance lease cost: Amortization of right-of-use assets $ 258 $ 1,277 $ 1,237 $ 2,371 Interest on lease liabilities 88 82 275 270 Operating lease cost 412 908 1,941 2,764 Short-term lease cost 671 198 1,377 558 Variable lease cost (1) 10 52 147 227 Total lease cost $ 1,439 $ 2,517 $ 4,977 $ 6,190 Other Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 275 $ 270 Operating cash flows from operating leases $ 1,678 $ 2,435 Financing cash flows from finance leases $ 1,026 $ 1,016 Right-of-use assets obtained in exchange for new finance lease liabilities $ 158 $ — Right-of-use assets obtained in exchange for new operating lease liabilities $ 59 $ 1,309 Weighted-average remaining lease term - finance leases 3.7 years 4.4 years Weighted-average remaining lease term - operating leases 2.0 years 2.5 years Weighted-average discount rate - finance leases 6.1 % 6.1 % Weighted-average discount rate - operating leases 8.5 % 8.6 % (1) Primarily includes common area maintenance, property taxes and insurance payable to lessors.

Revenues (Tables)

Revenues (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue from Contract with Customer [Abstract]
Schedule of Accounts Receivable	The following table shows the components of the Company's Trade receivables, net: As of (in thousands) September 30, 2020 December 31, 2019 Trade receivables $ 9,950 $ 8,057 Less: Allowance for doubtful accounts (598) (627) Trade receivables, net $ 9,352 $ 7,430
Schedule of Disaggregation of Revenue	The following tables disaggregate revenues by major component for the three and nine months ended September 30, 2020 and 2019 (in thousands): Three Months Ended September 30, 2020 Nine Months Ended September 30, 2020 Segment Segment PGI RC Other Total PGI RC Other Total Revenue component Consumables $ 13,442 $ — $ 2,402 $ 15,844 $ 28,987 $ — $ 4,244 $ 33,231 License royalties, related party — 3,627 — 3,627 — 9,986 — 9,986 Revenues from customers 13,442 3,627 2,402 19,471 28,987 9,986 4,244 43,217 Earnings from equity method investments — 9,518 — 9,518 — 25,959 — 25,959 Total revenues from customers and earnings from equity method investments $ 13,442 $ 13,145 $ 2,402 $ 28,989 $ 28,987 $ 35,945 $ 4,244 $ 69,176 Three Months Ended September 30, 2019 Nine Months Ended September 30, 2019 Segment Segment PGI RC Other Total PGI RC Other Total Revenue component Consumables $ 14,010 $ — $ 738 $ 14,748 $ 39,612 $ — $ 1,631 $ 41,243 License royalties, related party — 4,385 — 4,385 — 12,796 — 12,796 Revenues from customers 14,010 4,385 738 19,133 39,612 12,796 1,631 54,039 Earnings from equity method investments — 14,426 — 14,426 — 57,051 — 57,051 Total revenues from customers and earnings from equity method investments $ 14,010 $ 18,811 $ 738 $ 33,559 $ 39,612 $ 69,847 $ 1,631 $ 111,090

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2020
Equity [Abstract]
Schedule of Dividends Declared	Dividends declared and paid quarterly on all outstanding shares of common stock during the three and nine months ended September 30, 2020 and 2019 were as follows: 2020 2019 Per share Date paid Per share Date paid Dividends declared during quarter ended: March 31 $ 0.25 March 10, 2020 $ 0.25 March 7, 2019 June 30 $ — $ 0.25 June 7, 2019 September 30 $ — $ 0.25 September 6, 2019 $ 0.25 $ 0.75

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Share-based Payment Arrangement [Abstract]
Allocation of Compensation Expense	Total stock-based compensation expense for the three and nine months ended September 30, 2020 and 2019 was as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 RSA expense $ 411 $ 468 $ 1,892 $ 1,326 PSU expense 15 — 178 — Total stock-based compensation expense $ 426 $ 468 $ 2,070 $ 1,326
Schedule of Unrecognized Compensation Cost	The amount of unrecognized compensation cost as of September 30, 2020, and the expected weighted-average period over which the cost will be recognized is as follows: As of September 30, 2020 (in thousands) Unrecognized Compensation Cost Expected Weighted- RSA expense $ 2,181 1.71 PSU expense 131 2.44 Total unrecognized stock-based compensation expense $ 2,312 1.75
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, 2020 is presented below: Restricted Stock Weighted-Average Grant Date Fair Value Non-vested at January 1, 2020 451,344 $ 10.65 Granted 309,976 $ 5.20 Vested (306,137) $ 10.08 Forfeited (7,565) $ 7.87 Non-vested at September 30, 2020 447,618 $ 7.31
Summary of Option Activity	A summary of stock option activity for the nine months ended September 30, 2020 is presented below: Number of Options Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average Options outstanding, January 1, 2020 300,000 $ 13.87 Options granted — — Options exercised — — Options expired / forfeited (300,000) 13.87 Options outstanding, September 30, 2020 — $ — $ — — Options vested and exercisable, September 30, 2020 — $ — $ — —
Summary of Performance Shares Units	A summary of PSU activity for the nine months ended September 30, 2020 is presented below: Units Weighted-Average Aggregate Intrinsic Value (in thousands) Weighted-Average PSU's outstanding, January 1, 2020 — $ — Granted 50,127 6.17 Vested / Settled — — Forfeited / Canceled — — PSU's outstanding, September 30, 2020 50,127 $ 6.17 $ 204 2.44

Supplemental Financial Inform_2

Supplemental Financial Information (Tables)	9 Months Ended
	Sep. 30, 2020
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, net as presented in the Condensed Consolidated Balance Sheets: As of (in thousands) September 30, December 31, Prepaid expenses and other assets: Federal and state income tax benefits $ 9,373 $ — Prepaid federal and state income taxes 4,715 4,228 Prepaid expenses 1,633 1,708 Other 1,167 1,896 $ 16,888 $ 7,832 Other long-term assets, net: Upfront Customer Consideration (1) $ 8,290 $ — Cabot receivable 8,828 — Right of use assets, operating leases, net 2,256 5,073 Spare parts, net 3,846 3,453 Mine development costs, net 4,356 7,084 Mine reclamation asset, net 1,307 2,451 Highview Investment 552 552 Other long-term assets 1,771 1,718 $ 31,206 $ 20,331 (1) See further discussion of Upfront Customer Consideration in Note 3.
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: Current portion of operating lease obligations $ 2,043 $ 2,382 Accrued interest 91 213 Income and other taxes payable 1,603 678 Other 365 1,038 $ 4,102 $ 4,311 Other long-term liabilities: Operating lease obligations, long-term $ 1,471 $ 2,810 Mine reclamation liability (1) 24,183 2,721 Other 58 229 $ 25,712 $ 5,760 (1) As discussed in Note 3, $21.3 million relates to Marshall Mine ARO.
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) 2020 2019 2020 2019 Interest on Senior Term Loan $ 339 $ 940 $ 1,453 $ 3,344 Debt discount and debt issuance costs 355 473 1,064 1,324 453A interest 94 234 254 882 Other 93 82 282 270 $ 881 $ 1,729 $ 3,053 $ 5,820

Income Taxes (Tables)

Income Taxes (Tables)	9 Months Ended
	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Schedule of Income Tax Expense and Effective Tax Rates	For the three and nine months ended September 30, 2020 and 2019, 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) 2020 2019 2020 2019 Income tax expense $ 854 $ 6,595 $ 1,315 $ 14,928 Effective tax rate 15 % 63 % (7) % 36 %

Business Segment Information (T

Business Segment Information (Tables)	9 Months Ended
	Sep. 30, 2020
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, 2020 and 2019: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Revenues: Refined Coal: Earnings in equity method investments $ 9,518 $ 14,426 $ 25,959 $ 57,051 License royalties, related party 3,627 4,385 9,986 12,796 13,145 18,811 35,945 69,847 Power Generation and Industrials: Consumables 13,442 14,010 28,987 39,612 13,442 14,010 28,987 39,612 Total segment reporting revenues 26,587 32,821 64,932 109,459 Adjustments to reconcile to reported revenues: Earnings in equity method investments (9,518) (14,426) (25,959) (57,051) Corporate and other 2,402 738 4,244 1,631 Total reported revenues $ 19,471 $ 19,133 $ 43,217 $ 54,039 Segment operating income (loss): Refined Coal (1) $ 12,817 $ 18,158 $ 34,454 $ 68,137 Power Generation and Industrials (2) (1,270) (977) (33,584) (8,301) Total segment operating income $ 11,547 $ 17,181 $ 870 $ 59,836 (1) Included in RC segment operating income for the three and nine months ended September 30, 2020 is 453A interest expense of $0.1 million and $0.3 million, respectively. Included in RC segment operating income for the three and nine months ended September 30, 2019 is 453A interest expense of $0.2 million and $0.9 million, respectively. (2) Included in PGI segment operating loss for the three and nine months ended September 30, 2020 is zero and $23.2 million, respectively, of impairment expense on the Asset Group, and zero and $0.4 million, respectively, of expenses related to sequestration of certain of our employees at our manufacturing plant in Louisiana. Included in PGI segment operating loss for the three and nine months ended September 30, 2020 and 2019 is $1.4 million and $4.9 million, and $1.9 million and $4.5 million, respectively, of depreciation, amortization,
Reconciliation of Reportable Segment Amounts to Consolidated Balances	A reconciliation of reportable segment operating income to the Company's consolidated income (loss) before income tax expense is as follows: Three Months Ended September 30, Nine Months Ended September 30, (in thousands) 2020 2019 2020 2019 Total reported segment operating income $ 11,547 $ 17,181 $ 870 $ 59,836 Other operating loss (1) (2,010) (658) (7,065) (1,409) 9,537 16,523 (6,195) 58,427 Adjustments to reconcile to income (loss) before income tax expense attributable to the Company: Corporate payroll and benefits (587) (768) (2,444) (2,004) Corporate legal and professional fees (1,176) (1,737) (3,850) (5,254) Corporate general and administrative (1,116) (2,278) (4,273) (5,427) Corporate depreciation and amortization (148) (21) (337) (41) Corporate interest expense, net (680) (1,413) (2,446) (4,668) Other income (expense), net (1) 212 128 334 Income (loss) before income tax expense $ 5,829 $ 10,518 $ (19,417) $ 41,367 (1) Included in Other operating loss for the three and nine months ended September 30, 2020 was zero and $2.9 million, respectively, of impairment expense on the Asset Group.
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) $ 26,985 $ 43,953 Power Generation and Industrials 70,772 80,912 Total segment assets 97,757 124,865 All Other and Corporate (2) 57,897 48,934 Consolidated $ 155,654 $ 173,799 (1) Includes $22.9 million and $39.2 million of investments in equity method investees, respectively. (2) Includes the Company's deferred tax assets.

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
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, 2020 As of December 31, 2019 (in thousands) Carrying Value Fair Value Carrying Value Fair Value Financial Instruments: Highview Investment $ 552 $ 552 $ 552 $ 552 Highview Obligation $ 216 $ 216 $ 220 $ 220

Restructuring and Other Compe_2

Restructuring and Other Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Restructuring and Other Compensation [Abstract]
Schedule of Restructuring Reserve by Type of Cost	The following table summarizes the Company's change in restructuring and other compensation accruals for the nine months ended September 30, 2020: (in thousands) Severance Remaining accrual as of December 31, 2019 $ 254 Expense provision 1,403 Cash payments and other (956) Change in estimates — Remaining accrual as of September 30, 2020 $ 701

Basis of Presentation - Calcula

Basis of Presentation - Calculations of Basic and Diluted Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounting Policies [Abstract]
Net income (loss)	$ 4,975	$ (23,814)	$ (1,893)	$ 3,923	$ 8,114	$ 14,402	$ (20,732)	$ 26,439
Less: Dividends and undistributed income (loss) allocated to participating securities	0			5			(10)	37
Income (loss) attributable to common stockholders	$ 4,975			$ 3,918			$ (20,722)	$ 26,402
Basic weighted-average common shares outstanding (in shares)	18,093			18,112			18,014	18,184
Add: dilutive effect of equity instruments (in shares)	10			227			0	210
Diluted weighted-average shares outstanding (in shares)	18,103			18,339			18,014	18,394
Earnings (loss) per share - basic (in dollars per share)	$ 0.27			$ 0.22			$ (1.15)	$ 1.45
Earnings (loss) per share - diluted (in dollars per share)	$ 0.27			$ 0.21			$ (1.15)	$ 1.44
Restricted Stock and Employee Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares excluded from diluted shares outstanding (in shares)	500			300			900	300

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Details)	Sep. 30, 2020debt_instrument
Tinuum Group, LLC | Customer Concentration Risk
Concentration Risk [Line Items]
Number of instruments held	9
Tinuum Group, LLC
Concentration Risk [Line Items]
Number of instruments held	21

Customer Supply Agreement (Deta

Customer Supply Agreement (Details)	Sep. 30, 2020
Additional Term of Contract [Abstract]
Term of contract	15 years
Additional term of contract	10 years
Period of termination notice	3 years

Acquisition of Marshall Mine -

Acquisition of Marshall Mine - Additional Information (Details) $ in Millions	Sep. 30, 2020USD ($)
Business Acquisition [Line Items]
Reclamation reimbursements	$ 10.2
Term of contract	15 years
Marshall Mine
Business Acquisition [Line Items]
Membership interest	100.00%
Capped cost	$ 19.7
Direct cost	$ 3.6
Estimated reclamation period	10 years
Term of contract	15 years
Marshall Mine | Cabot
Business Acquisition [Line Items]
Reclamation reimbursements	$ 10.2

Acquisition of Marshall Mine _2

Acquisition of Marshall Mine - Allocation (Details) - Marshall Mine $ in Thousands	Sep. 30, 2020USD ($)
Fair value of assets acquired:
Property, plant and equipment	$ 3,863
Spare parts	100
Fair value of liabilities assumed:
Accounts payable and accrued expenses	(673)
Asset retirement obligation	(21,328)
Net assets acquired	(18,038)
Cabot receivable	9,749
Upfront Customer Consideration	$ 8,289

Marshall Mine Asset Retiremen_2

Marshall Mine Asset Retirement Obligation and related Cabot Receivable - ARO (Details)	Sep. 30, 2020USD ($)
Asset Retirement Obligation and related Long-Term Receivable [Abstract]
Reclamation costs	$ 21,300,000
Expected future cash flows	$ 23,700,000
Risk-free rate	7.00%
Reclamation reimbursements	$ 10,200,000
Long-term receivable	$ 9,700,000
Discount rate	1.50%
Effect of discounting	$ 500,000
Allowance for credit losses	$ 0

Marshall Mine Asset Retiremen_3

Marshall Mine Asset Retirement Obligation and related Cabot Receivable - Bonds (Details) - USD ($) $ in Millions	Mar. 31, 2021	Sep. 30, 2020
Asset Retirement Obligation and related Long-Term Receivable [Abstract]
Surety bond amount		$ 30
Collateral posted		$ 5
Forecast
Guarantor Obligations [Line Items]
Collateral to be posted	$ 5

Impairment - Additional Informa

Impairment - Additional Information (Details) - USD ($)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of long-lived assets	$ 0	$ 0		$ 26,103,000	$ 0
Assets at carrying value	155,654,000			155,654,000		$ 173,799,000
Power Generation and Industrials
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of long-lived assets			$ 26,103,000
Assets, total			54,700,000
Assets at carrying value			58,300,000
Property, plant and equipment, net			18,986,000
Operating Segments
Impaired Long-Lived Assets Held and Used [Line Items]
Assets at carrying value	97,757,000			97,757,000		124,865,000
Operating Segments | Power Generation and Industrials
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of long-lived assets			26,100,000	23,200,000
Assets at carrying value	70,772,000			70,772,000		80,912,000
Assets at fair value			$ 32,200,000
Property, plant and equipment, net	0			23,200,000
Expected impairment charge				0
Corporate and Other
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment of long-lived assets	0			2,900,000
Assets at carrying value	$ 57,897,000			$ 57,897,000		$ 48,934,000

Impairment - Components (Detail

Impairment - Components (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Sep. 30, 2020	Sep. 30, 2019
Impaired Long-Lived Assets Held and Used [Line Items]
Total impairment	$ 0	$ 0		$ 26,103	$ 0
Power Generation and Industrials
Impaired Long-Lived Assets Held and Used [Line Items]
Property, plant and equipment, net			$ 18,986
Intangible assets, net			1,445
Other long-term assets, net			5,672
Total impairment			$ 26,103

COVID-19 (Details)

COVID-19 (Details) - USD ($) $ in Millions	Apr. 20, 2020	Sep. 30, 2020	Sep. 30, 2020
CARES Act, Grant Income [Abstract]
Payroll tax payments deferred under the CARES Act		$ 0.3	$ 0.3
Debt Instrument [Line Items]
Payroll tax payments deferred under the CARES Act		$ 0.3	$ 0.3
Promissory Note | PPP Loan
Debt Instrument [Line Items]
Face amount	$ 3.3
Term	18 months
Interest rate, stated percentage	1.00%

Equity Method Investments - Nar

Equity Method Investments - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investments	$ 9,518	$ 14,426	$ 25,959	$ 57,051
Equity method investments	$ 22,885		$ 22,885				$ 39,155
Tinuum Group, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest, percent	42.50%		42.50%				42.50%
Earnings from equity method investments	$ 7,260	11,746	$ 20,462	50,757
Equity method investments	$ 17,516	37,733	$ 17,516	37,733	$ 18,118	$ 24,954	$ 32,280	$ 42,455	$ 40,211	$ 0
Tinuum Services, LLC
Schedule of Equity Method Investments [Line Items]
Ownership interest, percent	50.00%		50.00%
Earnings from equity method investments	$ 2,257	2,682	$ 5,498	6,297
Equity method investments	$ 5,300		$ 5,300				$ 6,800
Percent of losses removed from net income, attributable to noncontrolling interest	100.00%		100.00%
Equity Method Investment | Tinuum Group, LLC
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investments	$ 7,300	$ 11,700	$ 20,500	$ 50,800

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, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Operating, selling, general and administrative expenses	$ 22,296			$ 21,524			$ 85,748	$ 64,245
Net income (loss)	4,975	$ (23,814)	$ (1,893)	3,923	$ 8,114	$ 14,402	(20,732)	26,439
ADES equity earnings	9,518			14,426			25,959	57,051
Distributions from equity method investees, return on investment							42,228	56,806
Tinuum Group, LLC
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
ADES equity earnings	7,260			11,746			20,462	50,757
Distributions from equity method investees, return on investment							35,226	50,256
Tinuum Services, LLC
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
ADES equity earnings	2,257			2,682			5,498	6,297
Distributions from equity method investees, return on investment							7,002	6,550
Earnings (loss) from other
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
ADES equity earnings	1			(2)			(1)	(3)
Equity Method Investment | Tinuum Group, LLC
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Gross profit (loss)	101			16,810			11,979	96,189
Operating, selling, general and administrative expenses	13,781			11,076			38,476	23,421
Loss (income) from operations	(13,680)			5,734			(26,497)	72,768
Other income (expenses)	5,739			(450)			11,526	(427)
Loss attributable to noncontrolling interest	25,023			22,355			63,117	51,022
Net income (loss)	17,082			27,639			48,146	123,363
ADES equity earnings	7,300			11,700			20,500	50,800
Equity Method Investment | Tinuum Services, LLC
Equity Method Investment, Financial Statement, Reported Amounts [Abstract]
Gross profit (loss)	(22,764)			(27,834)			(65,441)	(77,761)
Operating, selling, general and administrative expenses	42,435			51,927			131,703	151,789
Loss (income) from operations	(65,199)			(79,761)			(197,144)	(229,550)
Other income (expenses)	(363)			(460)			(978)	(1,018)
Loss attributable to noncontrolling interest	70,075			85,586			209,118	243,163
Net income (loss)	$ 4,513			$ 5,365			$ 10,996	$ 12,595

Equity Method Investments - Rol

Equity Method Investments - Rollforward of CCS Investment (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Equity Method Investments [Roll Forward]
Beginning balance			$ 39,155
Total investment balance, equity earnings (loss) and cash distributions	$ 22,885
Retained earnings	32,014						$ 57,336
Tinuum Group, LLC
Equity Method Investments [Roll Forward]
Beginning balance	18,118	$ 24,954	32,280	$ 42,455	$ 40,211	$ 0
Impact of adoption of accounting standards									$ 37,232
ADES proportionate share of income from Tinuum Group	7,260	6,764	6,438	11,746	19,244	21,439
Recovery of prior cash distributions in excess of investment balance (prior to cash distributions)						1,672
Cash distributions from Tinuum Group	7,862	13,600	13,764	16,468	17,000	16,788
Total investment balance, equity earnings (loss) and cash distributions	17,516	18,118	24,954	37,733	42,455	40,211
Tinuum Group, LLC | Difference between Revenue Guidance in Effect before and after Topic 606
Equity Method Investments [Roll Forward]
Retained earnings								$ 27,400
Tinuum Group, LLC | ADES equity earnings (loss)
Equity Method Investments [Roll Forward]
Beginning balance	6,764	6,438	0	19,244	19,767	0
Impact of adoption of accounting standards									0
ADES proportionate share of income from Tinuum Group	7,260	6,764	6,438	11,746	19,244	21,439
Recovery of prior cash distributions in excess of investment balance (prior to cash distributions)						1,672
Cash distributions from Tinuum Group	0	0	0	0	0	0
Total investment balance, equity earnings (loss) and cash distributions	7,260	6,764	6,438	11,746	19,244	19,767
Tinuum Group, LLC | Cash distributions
Equity Method Investments [Roll Forward]
Beginning balance	13,600	13,764	0	17,000	16,788	0
Impact of adoption of accounting standards									0
ADES proportionate share of income from Tinuum Group	0	0	0	0	0	0
Recovery of prior cash distributions in excess of investment balance (prior to cash distributions)						0
Cash distributions from Tinuum Group	7,862	13,600	13,764	16,468	17,000	16,788
Total investment balance, equity earnings (loss) and cash distributions	7,862	13,600	13,764	16,468	17,000	16,788
Tinuum Group, LLC | Memorandum Account: Cash distributions and equity loss in (excess) of investment balance
Equity Method Investments [Roll Forward]
Beginning balance	0	0	0	0	0	1,672
Impact of adoption of accounting standards									$ 0
ADES proportionate share of income from Tinuum Group	0	0	0	0	0	0
Recovery of prior cash distributions in excess of investment balance (prior to cash distributions)						1,672
Cash distributions from Tinuum Group	0	0	0	0	0	0
Total investment balance, equity earnings (loss) and cash distributions	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0

Acquisition - Additional Inform

Acquisition - Additional Information (Details) - ADA Carbon Solutions, LLC $ in Millions	Dec. 07, 2018USD ($)
Business Acquisition [Line Items]
Purchase price	$ 75
Consideration transferred	66.5
Cash acquired from acquisition	3.3
Fair value of liabilities assumed	11.8
Acquisition related costs	4.5
Senior Term Loan due December 2021, net | Term Loan
Business Acquisition [Line Items]
Proceeds from issuance of debt	$ 70

Acquisition - Schedules (Detail

Acquisition - Schedules (Details) - ADA Carbon Solutions, LLC - USD ($) $ in Thousands	Dec. 07, 2018	Sep. 30, 2020
Fair value of assets acquired:
Cash	$ 3,284	$ 3,284
Receivables	6,409	6,409
Inventories	22,100	21,744
Prepaid expenses and other current assets	2,992	3,053
Spare parts	3,359	3,359
Property, plant and equipment	43,033	42,656
Mine leases and development	2,500	2,700
Mine reclamation asset	0	2,402
Intangible assets	4,000	4,100
Other assets	168	168
Amount attributable to assets acquired	87,845	89,875
Fair value of liabilities assumed:
Accounts payable	4,771	4,771
Accrued liabilities	7,354	7,608
Equipment lease liabilities	8,211	8,211
Mine reclamation liability	626	2,402
Other liabilities	437	437
Amount attributable to liabilities assumed	21,399	23,429
Adjustments
Cash		0
Receivables		0
Inventories		(356)
Prepaid expenses and other current assets		61
Spare parts		0
Property, plant and equipment		(377)
Mine leases and development		200
Mine reclamation asset		2,402
Intangible assets		100
Other assets		0
Amount attributable to assets acquired		2,030
Accounts payable		0
Accrued liabilities		254
Equipment lease liabilities		0
Mine reclamation liability		1,776
Other liabilities		0
Amount attributable to liabilities assumed		2,030
Net assets acquired	$ 66,446	66,446
Net assets acquired		0
Customer relationships
Fair value of assets acquired:
Intangible assets		2,200
Adjustments
Weighted Average Useful Life (years)	5 years
Developed technology
Fair value of assets acquired:
Intangible assets		1,600
Adjustments
Weighted Average Useful Life (years)	5 years
Trade name
Fair value of assets acquired:
Intangible assets		$ 300
Adjustments
Weighted Average Useful Life (years)	2 years

Inventories, net (Details)

Inventories, net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Product inventory	$ 9,535	$ 13,515
Raw material inventory	884	1,945
Inventories	$ 10,419	$ 15,460

Debt Obligations - Schedule of

Debt Obligations - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019	Dec. 07, 2018
Debt Instrument [Line Items]
Finance lease obligations	$ 5,841	$ 6,729
PPP Loan	3,305	0
Long-term Debt	29,846	44,366
Less: Current maturities	(24,360)	(23,932)
Total long-term debt	5,486	20,434
Senior Term Loan due December 2021, net
Debt Instrument [Line Items]
Less: net unamortized debt issuance costs	(640)	(1,163)	$ (2,000)
Less: net unamortized debt discount	(660)	(1,200)	$ (2,100)
Senior Term Loan due December 2021, net	20,700	37,637
Senior Term Loan due December 2021, net | Senior Term Loan due December 2021, related party
Debt Instrument [Line Items]
Senior Term Loan due December 2021, related party	$ 22,000	$ 40,000

Debt Obligations - Senior Term

Debt Obligations - Senior Term Loan (Details)	Dec. 07, 2018USD ($)	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Senior Term Loan
Debt Instrument [Line Items]
Less: net unamortized debt discount	$ 2,100,000	$ 660,000	$ 1,200,000
Debt issuance costs	$ 2,000,000	$ 640,000	$ 1,163,000
Term	36 months
Interest rate, stated percentage	4.75%
Minimum cash balance required				$ 5,000,000
Expected future net cash flows from refined coal business		1.75
Maximum annual collective dividends and buybacks		$ 30,000,000
Minimum requirement from future net cash flows from refined coal business		$ 100,000,000
Senior Term Loan | Beginning on March 1, 2019
Debt Instrument [Line Items]
Periodic payment, principal	$ 6,000,000
Senior Term Loan | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
ADA Carbon Solutions, LLC | Term Loan | Senior Term Loan
Debt Instrument [Line Items]
Proceeds from issuance of debt	$ 70,000,000
Senior Term Loan due December 2021, related party | Minimum
Debt Instrument [Line Items]
Percent of common stock owned	5.00%

Debt Obligations - Line of Cred

Debt Obligations - Line of Credit (Details) - USD ($)	Sep. 30, 2020	Sep. 29, 2020	Dec. 31, 2018
Debt Instrument [Line Items]
Line of credit	$ 0
Senior Term Loan
Debt Instrument [Line Items]
Minimum cash balance required			$ 5,000,000
Senior Term Loan | ADA-ES, Inc.
Debt Instrument [Line Items]
Face amount		$ 70,000,000

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Long-term lease liabilities	$ 5,841		$ 5,841		$ 6,729
Operating lease, liability	3,500		3,500
Finance lease, right of use asset	2,600		2,600
Operating lease, right of use asset	2,256		2,256		$ 5,073
Operating lease, expense	1,100	$ 1,100	3,500	$ 3,300
General and Administrative Expense
Lessee, Lease, Description [Line Items]
Operating lease, expense	100	100	600	300
Consumables
Lessee, Lease, Description [Line Items]
Operating lease, expense	$ 1,000	$ 1,000	$ 2,900	$ 3,100

Leases - Lease Liabilities (Det

Leases - Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Lease, cost
Amortization of right-of-use assets	$ 258	$ 1,277	$ 1,237	$ 2,371
Interest on lease liabilities	88	82	275	270
Operating lease cost	412	908	1,941	2,764
Short-term lease cost	671	198	1,377	558
Variable lease cost	10	52	147	227
Total lease cost	$ 1,439	$ 2,517	4,977	6,190
Operating cash flows from finance leases			275	270
Operating cash flows from operating leases			1,678	2,435
Financing cash flows from finance leases			1,026	1,016
Right-of-use assets obtained in exchange for new finance lease liabilities			158	0
Right-of-use assets obtained in exchange for new operating lease liabilities			$ 59	$ 1,309
Weighted-average remaining lease term - finance leases	3 years 8 months 12 days	4 years 4 months 24 days	3 years 8 months 12 days	4 years 4 months 24 days
Weighted-average remaining lease term - operating leases	2 years	2 years 6 months	2 years	2 years 6 months
Weighted-average discount rate - finance leases	6.10%	6.10%	6.10%	6.10%
Weighted-average discount rate - operating leases	8.50%	8.60%	8.50%	8.60%

Revenues - Narrative (Details)

Revenues - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)segment	Sep. 30, 2019USD ($)
Revenue from Contract with Customer [Abstract]
Collection terms			Credit terms are generally net 30 from the date of invoice.
Provision for debt expense	$ 0	$ 0	$ 0	$ 0
Number of operating segments | segment			2
Marshall Mine
Business Acquisition [Line Items]
Upfront consideration	$ 8.3		$ 8.3

Revenues - Trade Receivables (D

Revenues - Trade Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total	$ 10,273	$ 7,430
Trade Accounts Receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Trade receivables	9,950	8,057
Less: Allowance for doubtful accounts	(598)	(627)
Total	$ 9,352	$ 7,430

Revenues - Disaggregation of Re

Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation of Revenue [Line Items]
Revenue component	$ 19,471	$ 19,133	$ 43,217	$ 54,039
Earnings from equity method investments	9,518	14,426	25,959	57,051
Total revenues from customers and earnings from equity method investments	19,471	19,133	43,217	54,039
Total revenues from customers and earnings from equity method investments	28,989	33,559	69,176	111,090
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues from customers and earnings from equity method investments	26,587	32,821	64,932	109,459
Consumables
Disaggregation of Revenue [Line Items]
Revenue component	15,844	14,748	33,231	41,243
License royalties, related party
Disaggregation of Revenue [Line Items]
Revenue component	3,627	4,385	9,986	12,796
Power Generation and Industrials
Disaggregation of Revenue [Line Items]
Revenue component	13,442	14,010	28,987	39,612
Earnings from equity method investments	0	0	0	0
Power Generation and Industrials | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues from customers and earnings from equity method investments	13,442	14,010	28,987	39,612
Power Generation and Industrials | Consumables
Disaggregation of Revenue [Line Items]
Revenue component	13,442	14,010	28,987	39,612
Power Generation and Industrials | Consumables | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue component	13,442	14,010	28,987	39,612
Power Generation and Industrials | License royalties, related party
Disaggregation of Revenue [Line Items]
Revenue component	0	0	0	0
Refined Coal
Disaggregation of Revenue [Line Items]
Revenue component	3,627	4,385	9,986	12,796
Earnings from equity method investments	9,518	14,426	25,959	57,051
Refined Coal | Operating Segments
Disaggregation of Revenue [Line Items]
Earnings from equity method investments	9,518	14,426	25,959	57,051
Total revenues from customers and earnings from equity method investments	13,145	18,811	35,945	69,847
Refined Coal | Consumables
Disaggregation of Revenue [Line Items]
Revenue component	0	0	0	0
Refined Coal | License royalties, related party
Disaggregation of Revenue [Line Items]
Revenue component	3,627	4,385	9,986	12,796
Other
Disaggregation of Revenue [Line Items]
Revenue component	2,402	738	4,244	1,631
Earnings from equity method investments	0	0	0	0
Other | Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues from customers and earnings from equity method investments	2,402	738	4,244	1,631
Other | Consumables
Disaggregation of Revenue [Line Items]
Revenue component	2,402	738	4,244	1,631
Other | License royalties, related party
Disaggregation of Revenue [Line Items]
Revenue component	$ 0	$ 0	$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details)	Sep. 30, 2020USD ($)entity	Dec. 31, 2019USD ($)
Debt Instrument [Line Items]
Restricted cash, long-term	$ 10,000,000	$ 5,000,000
Tinuum Group, LLC
Related Party Transaction [Line Items]
Number of entities affiliated with related parties | entity	2
Limited guarantees, percent	50.00%
Liabilities or expense	$ 0
Senior Term Loan due December 2021, net
Debt Instrument [Line Items]
Restricted cash, long-term	5,000,000	$ 5,000,000
Surety Agreement
Debt Instrument [Line Items]
Restricted cash, long-term	$ 5,000,000

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Nov. 30, 2019	Nov. 30, 2018	May 05, 2017
Maximum
Class of Stock [Line Items]
Requirement to own shares outstanding as percent							4.99%
Common Stock
Class of Stock [Line Items]
Remaining authorized amount	$ 7,000,000		$ 7,000,000		$ 2,900,000
Authorized incremental amount					$ 7,100,000
Stock repurchased (in shares)	0	8,152	20,613	256,743
Stock repurchased	$ 0	$ 100,000	$ 200,000	$ 2,900,000
Common Stock | Maximum
Class of Stock [Line Items]
Authorized amount						$ 20,000,000

Stockholders' Equity - Dividend

Stockholders' Equity - Dividends (Details) - $ / shares	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Equity [Abstract]
Dividends declared (in dollars per share)	$ 0	$ 0	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.75

Stock-Based Compensation - Allo

Stock-Based Compensation - Allocation of Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 426	$ 468	$ 2,070	$ 1,326
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	411	468	1,892	1,326
Performance share units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 15	$ 0	$ 178	$ 0

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Unrecognized Compensation Cost (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 2,312
Expected Weighted-Average Period of Recognition (in years)	1 year 9 months
Restricted stock awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 2,181
Expected Weighted-Average Period of Recognition (in years)	1 year 8 months 15 days
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized Compensation Cost	$ 131
Expected Weighted-Average Period of Recognition (in years)	2 years 5 months 8 days

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details)	9 Months Ended
	Sep. 30, 2020
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

Stock-Based Compensation - Su_2

Stock-Based Compensation - Summary of Non-vested Restricted Stock Activity (Details) - Restricted stock awards	9 Months Ended
	Sep. 30, 2020$ / sharesshares
Number of SAR's Outstanding and Exercisable
Non-vested shares, Beginning balance (in shares) | shares	451,344
Granted (in shares) | shares	309,976
Vested (in shares) | shares	(306,137)
Forfeited (in shares) | shares	(7,565)
Non-vested shares, Ending balance (in shares) | shares	447,618
Units
Non-vested shares, Weighted-Average Grant Date Fair Value, Beginning Balance (in dollars per share) | $ / shares	$ 10.65
Granted, Weighted-Average Grant Date Fair Value (in dollars per share) | $ / shares	5.20
Vested in period, Weighted-Average Grant Date Fair Value (in dollars per share) | $ / shares	10.08
Forfeited, Weighted-Average Grant Date Fair Value (in dollars per share) | $ / shares	7.87
Non-vested shares, Weighted-Average Grant Date Fair Value, Ending Balance (in dollars per share) | $ / shares	$ 7.31

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, 2020USD ($)$ / sharesshares
Employee and Director Options
Options outstanding, start of year (in shares) | shares	300,000
Options granted (in shares) | shares	0
Options exercised (in shares) | shares	0
Options expired / forfeited (in shares) | shares	(300,000)
Options outstanding, end of year (in shares) | shares	0
Options vested and exercisable (in shares) | shares	0
Weighted Average Exercise Price
Options outstanding, start of year (in dollars per share) | $ / shares	$ 13.87
Options granted (in dollars per share) | $ / shares	0
Options exercised (in dollars per share) | $ / shares	0
Options expired / forfeited (in dollars per share) | $ / shares	13.87
Options outstanding, end of year (in dollars per share) | $ / shares	0
Options vested and exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 0
Options outstanding, intrinsic value | $	$ 0
Options exercisable, intrinsic value | $	$ 0

Stock-Based Compensation - Su_4

Stock-Based Compensation - Summary of Non-vested PSUs (Details) - Performance share units $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)$ / sharesshares
Number of SAR's Outstanding and Exercisable
Non-vested shares, Beginning balance (in shares) | shares	0
Granted (in shares) | shares	50,127
Vested / Settled (in shares) | shares	0
Forfeited / Canceled (in shares) | shares	0
Non-vested shares, Ending balance (in shares) | shares	50,127
Units
Non-vested shares, Weighted-Average Grant Date Fair Value, Beginning Balance (in dollars per share) | $ / shares	$ 0
Granted, Weighted-Average Grant Date Fair Value (in dollars per share) | $ / shares	6.17
Vested / Settled in period, Weighted-Average Grant Date Fair Value (in dollars per share) | $ / shares	0
Forfeited, Weighted-Average Grant Date Fair Value (in dollars per share) | $ / shares	0
Non-vested shares, Weighted-Average Grant Date Fair Value, Ending Balance (in dollars per share) | $ / shares	$ 6.17
Outstanding, Aggregate Intrinsic Value | $	$ 204
Outstanding, Weighted Average Remaining Contractual Term (in years)	2 years 5 months 8 days

Supplemental Financial Inform_3

Supplemental Financial Information - Prepaid expenses and other assets and Other assets (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Prepaid expenses and other assets:
Federal and state income tax benefits	$ 9,373	$ 0
Prepaid federal and state income taxes	4,715	4,228
Prepaid expenses	1,633	1,708
Other	1,167	1,896
Other current assets	16,888	7,832
Other long-term assets, net:
Upfront Customer Consideration	8,290	0
Cabot receivable	8,828	0
Right of use assets, operating leases, net	2,256	5,073
Spare parts, net	3,846	3,453
Mine development costs, net	4,356	7,084
Mine reclamation asset, net	1,307	2,451
Highview Investment	552	552
Other long-term assets	1,771	1,718
Total	$ 31,206	$ 20,331
Mine reserves, amortization period	21 years

Supplemental Financial Inform_4

Supplemental Financial Information - Other Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Other current liabilities:
Current portion of operating lease obligations	$ 2,043	$ 2,382
Accrued interest	91	213
Income and other taxes payable	1,603	678
Other	365	1,038
Other current liabilities	4,102	4,311
Other long-term liabilities:
Operating lease obligations, long-term	1,471	2,810
Mine reclamation liability (1)	24,183	2,721
Other	58	229
Other long-term liabilities	25,712	$ 5,760
Marshall Mine
Business Acquisition [Line Items]
Asset retirement obligation	$ 21,328

Supplemental Financial Inform_5

Supplemental Financial Information - Supplemental Income Statement, Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Interest on Senior Term Loan	$ 339	$ 940	$ 1,453	$ 3,344
Debt discount and debt issuance costs	355	473	1,064	1,324
453A interest	94	234	254	882
Other	93	82	282	270
Interest expense	$ 881	$ 1,729	$ 3,053	$ 5,820

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income tax expense	$ 854	$ 6,595	$ 1,315	$ 14,928
Effective tax rate	15.00%	63.00%	(7.00%)	36.00%
Increase in valuation allowance			$ 5,100

Business Segment Information -

Business Segment Information - Segment Operating Results (Details)	3 Months Ended		6 Months Ended	9 Months Ended
	Sep. 30, 2020USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2020USD ($)	Sep. 30, 2020USD ($)segment	Sep. 30, 2019USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment				2
Revenues:
Earnings in equity method investments	$ 9,518,000	$ 14,426,000		$ 25,959,000	$ 57,051,000
Total revenues	19,471,000	19,133,000		43,217,000	54,039,000
Total reported revenues	19,471,000	19,133,000		43,217,000	54,039,000
Segment operating income (loss):
Total segment operating income	(2,825,000)	(2,391,000)		(42,531,000)	(10,206,000)
453A interest	94,000	234,000		254,000	882,000
Depreciation, amortization, depletion and accretion				5,807,000	4,902,000
Decrease in inventories				4,688,000	4,566,000
Refined Coal
Revenues:
Earnings in equity method investments	9,518,000	14,426,000		25,959,000	57,051,000
Total revenues	3,627,000	4,385,000		9,986,000	12,796,000
Refined Coal | RMC6, LLC (RCM6)
Segment operating income (loss):
453A interest	100,000	200,000		300,000	900,000
Power Generation and Industrials
Revenues:
Earnings in equity method investments	0	0		0	0
Total revenues	13,442,000	14,010,000		28,987,000	39,612,000
Segment operating income (loss):
Impairment expense on mine and plant long-lived assets			$ 18,986,000
Consumables
Revenues:
Total revenues	15,844,000	14,748,000		33,231,000	41,243,000
Consumables | Refined Coal
Revenues:
Total revenues	0	0		0	0
Consumables | Power Generation and Industrials
Revenues:
Total revenues	13,442,000	14,010,000		28,987,000	39,612,000
Operating Segments
Revenues:
Total reported revenues	26,587,000	32,821,000		64,932,000	109,459,000
Segment operating income (loss):
Total segment operating income	11,547,000	17,181,000		870,000	59,836,000
Operating Segments | Refined Coal
Revenues:
Earnings in equity method investments	9,518,000	14,426,000		25,959,000	57,051,000
License royalties, related party	3,627,000	4,385,000		9,986,000	12,796,000
Total reported revenues	13,145,000	18,811,000		35,945,000	69,847,000
Segment operating income (loss):
Total segment operating income	12,817,000	18,158,000		34,454,000	68,137,000
Operating Segments | Power Generation and Industrials
Revenues:
Total reported revenues	13,442,000	14,010,000		28,987,000	39,612,000
Segment operating income (loss):
Total segment operating income	(1,270,000)	(977,000)		(33,584,000)	(8,301,000)
Impairment expense on mine and plant long-lived assets	0			23,200,000
Severance costs		0			400,000
Depreciation, amortization, depletion and accretion	1,400,000	1,900,000		4,900,000	4,500,000
Decrease in inventories				4,700,000
Operating Segments | Consumables | Power Generation and Industrials
Revenues:
Total revenues	13,442,000	14,010,000		28,987,000	39,612,000
Intersegment Eliminations | Refined Coal
Revenues:
Earnings in equity method investments	(9,518,000)	(14,426,000)		(25,959,000)	(57,051,000)
Corporate and Other
Revenues:
Total reported revenues	2,402,000	738,000		4,244,000	1,631,000
Segment operating income (loss):
Total segment operating income	$ (2,010,000)	$ (658,000)		$ (7,065,000)	$ (1,409,000)

Business Segment Information _2

Business Segment Information - Reconciliation of Reportable Segment Amounts (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Segment Reporting Information [Line Items]
Consolidated operating income	$ (2,825,000)	$ (2,391,000)	$ (42,531,000)	$ (10,206,000)
Adjustments to reconcile to income (loss) before income tax expense attributable to the Company:
Corporate payroll and benefits	(2,285,000)	(2,651,000)	(8,839,000)	(8,005,000)
Corporate legal and professional fees	(1,321,000)	(2,907,000)	(4,386,000)	(7,105,000)
Corporate general and administrative	(1,900,000)	(1,984,000)	(6,693,000)	(5,894,000)
Corporate depreciation and amortization	(1,777,000)	(2,043,000)	(5,807,000)	(4,902,000)
Other income (expense), net	17,000	212,000	208,000	342,000
Income (loss) before income tax expense	5,829,000	10,518,000	(19,417,000)	41,367,000
Impairment expense	0	0	26,103,000	0
Operating Segments
Segment Reporting Information [Line Items]
Consolidated operating income	11,547,000	17,181,000	870,000	59,836,000
All Other and Corporate
Segment Reporting Information [Line Items]
Consolidated operating income	(2,010,000)	(658,000)	(7,065,000)	(1,409,000)
Adjustments to reconcile to income (loss) before income tax expense attributable to the Company:
Impairment expense	0		2,900,000
Segment Reconciling Items
Segment Reporting Information [Line Items]
Consolidated operating income	9,537,000	16,523,000	(6,195,000)	58,427,000
Adjustments to reconcile to income (loss) before income tax expense attributable to the Company:
Corporate payroll and benefits	(587,000)	(768,000)	(2,444,000)	(2,004,000)
Corporate legal and professional fees	(1,176,000)	(1,737,000)	(3,850,000)	(5,254,000)
Corporate general and administrative	(1,116,000)	(2,278,000)	(4,273,000)	(5,427,000)
Corporate depreciation and amortization	(148,000)	(21,000)	(337,000)	(41,000)
Corporate interest expense, net	(680,000)	(1,413,000)	(2,446,000)	(4,668,000)
Other income (expense), net	(1,000)	212,000	128,000	334,000
Income (loss) before income tax expense	$ 5,829,000	$ 10,518,000	$ (19,417,000)	$ 41,367,000

Business Segment Information _3

Business Segment Information - Segment Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Assets	$ 155,654		$ 173,799
Equity method investments	22,885		39,155
Power Generation and Industrials
Segment Reporting Information [Line Items]
Assets		$ 58,300
Operating Segments
Segment Reporting Information [Line Items]
Assets	97,757		124,865
Operating Segments | Refined Coal
Segment Reporting Information [Line Items]
Assets	26,985		43,953
Operating Segments | Power Generation and Industrials
Segment Reporting Information [Line Items]
Assets	70,772		80,912
All Other and Corporate
Segment Reporting Information [Line Items]
Assets	$ 57,897		$ 48,934

Fair Value Measurements - Estim

Fair Value Measurements - Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Highview Investment	$ 552	$ 552
Carrying Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Highview Investment	552	552
Highview Obligation	216	220
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Highview Investment	552	552
Highview Obligation	$ 216	$ 220

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) $ in Millions	Dec. 07, 2018USD ($)
ADA Carbon Solutions, LLC
Business Combination, Separately Recognized Transactions [Line Items]
Consideration transferred	$ 66.5

Restructuring and Other Compe_3

Restructuring and Other Compensation - Restructuring (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Dec. 31, 2018	Sep. 30, 2020	Sep. 30, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 0	$ 0
Employee Severance | ADA Carbon Solutions, LLC
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 0.6

Restructuring and Other Compe_4

Restructuring and Other Compensation - Other Compensation (Details) $ in Millions	9 Months Ended
	Sep. 30, 2020USD ($)
CEO
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Compensation expense	$ 1.4

Restructuring and Other Compe_5

Restructuring and Other Compensation - Utilization of Restructuring Accruals (Details) - Employee Severance $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Restructuring Reserve [Roll Forward]
Remaining accrual as of December 31, 2019	$ 254
Expense provision	1,403
Cash payments and other	(956)
Change in estimates	0
Remaining accrual as of September 30, 2020	$ 701

Subsequent Events (Details)

Subsequent Events (Details) - Subsequent Event - RC Project - Tinuum Group, LLC T in Millions	Oct. 20, 2020Tfacilities
Subsequent Event [Line Items]
Tons of coal burned per year | T	4
Number of facilities in full-time operation | facilities	22