Alpha Metallurgical Resources (AMR) 10-K 23 Feb 23 2022 FY Annual report Financial data

Cover

Cover - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2022	Feb. 16, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-38735
Entity Registrant Name	ALPHA METALLURGICAL RESOURCES, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	81-3015061
Entity Address, Address Line One	340 Martin Luther King Jr. Blvd.
Entity Address, City or Town	Bristol
Entity Address, State or Province	TN
Entity Address, Postal Zip Code	37620
City Area Code	423
Local Phone Number	573-0300
Title of 12(b) Security	Common Stock, par value $0.01 per share
Trading Symbol	AMR
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1.6
Entity Common Stock, Shares Outstanding		15,170,451
Documents Incorporated by Reference	Part III incorporates certain information by reference from the registrant’s definitive proxy statement for the 2023 annual meeting of stockholders (the “Proxy Statement”), which will be filed no later than 120 days after the close of the registrant’s fiscal year ended December 31, 2022.
Entity Central Index Key	0001704715
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2022
Audit Information [Abstract]
Auditor Name	RSM US LLP
Auditor Location	Atlanta, Georgia
Auditor Firm ID	49

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Revenues:
Coal revenues	$ 4,092,987	$ 2,252,624	$ 1,413,124
Other revenues	8,605	6,062	3,063
Total revenues	4,101,592	2,258,686	1,416,187
Costs and expenses:
Cost of coal sales (exclusive of items shown separately below)	2,285,969	1,677,782	1,281,011
Depreciation, depletion and amortization	107,620	110,047	139,885
Accretion on asset retirement obligations	23,765	26,520	26,504
Amortization of acquired intangibles, net	19,498	13,244	9,214
Asset impairment and restructuring	0	(561)	83,878
Selling, general and administrative expenses (exclusive of depreciation, depletion and amortization shown separately above)	71,618	63,901	57,356
Total other operating loss (income):
Mark-to-market adjustment for acquisition-related obligations	8,880	19,525	(8,750)
Other expense (income)	3,363	(10,972)	(2,223)
Total costs and expenses	2,520,713	1,899,486	1,586,875
Income (loss) from operations	1,580,879	359,200	(170,688)
Other (expense) income:
Interest expense	(21,802)	(69,654)	(74,528)
Interest income	3,187	336	7,027
Equity loss in affiliates	(14,346)	(4,149)	(3,473)
Miscellaneous income (loss), net	6,832	6,465	(1,972)
Total other expense, net	(26,129)	(67,002)	(72,946)
Income (loss) from continuing operations before income taxes	1,554,750	292,198	(243,634)
Income tax (expense) benefit	(106,205)	(3,408)	2,164
Net income (loss) from continuing operations	1,448,545	288,790	(241,470)
Discontinued operations:
Loss from discontinued operations	0	0	(205,429)
Net income (loss)	$ 1,448,545	$ 288,790	$ (446,899)
Basic income (loss) per common share:
Income (loss) from continuing operations (in dollars per share)	$ 82.82	$ 15.66	$ (13.20)
Loss from discontinued operations (in dollars per share)	0	0	(11.22)
Net income (loss) (in dollars per share)	82.82	15.66	(24.42)
Diluted income (loss) per common share:
Income (loss) from continuing operations (in dollars per share)	79.49	15.30	(13.20)
Loss from discontinuing operations (in dollars per share)	0	0	(11.22)
Net income (loss) (in dollars per share)	$ 79.49	$ 15.30	$ (24.42)
Weighted average shares - basic (in shares)	17,490,886	18,441,175	18,298,362
Weighted average shares - diluted (in shares)	18,222,397	18,871,682	18,298,362

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Statement of Other Comprehensive Income [Abstract]
Net income (loss)	$ 1,448,545	$ 288,790	$ (446,899)
Employee benefit plans:
Current period actuarial gain (loss)	56,485	47,461	(60,647)
Income tax	(12,888)	0	0
Current period actuarial (loss) gain, net of income tax	43,597	47,461	(60,647)
Less: reclassification adjustments for amounts reclassified to earnings due to amortization of net actuarial loss and settlements	3,555	6,021	7,278
Income tax	(811)	0	0
Less: reclamation adjustments for amounts reclassified to earnings due to amortization of net actuarial (gain) loss and settlements, net of income tax	2,744	6,021	7,278
Total other comprehensive income (loss), net of tax	46,341	53,482	(53,369)
Total comprehensive income (loss)	$ 1,494,886	$ 342,272	$ (500,268)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 301,906	$ 81,211
Short-term investments	46,052	0
Trade accounts receivable, net of allowance for doubtful accounts of $239 and $393 as of December 31, 2022 and 2021, respectively	407,210	489,241
Inventories, net	200,574	129,382
Short-term deposits	84,748	425
Short-term restricted cash	24,547	11,977
Prepaid expenses and other current assets	49,384	35,750
Total current assets	1,114,421	747,986
Property, plant, and equipment, net of accumulated depreciation and amortization of $491,186 and $443,856 as of December 31, 2022 and 2021, respectively	442,645	362,218
Owned and leased mineral rights, net of accumulated depletion and amortization of $77,333 and $52,444 as of December 31, 2022 and 2021, respectively	451,062	444,302
Other acquired intangibles, net of accumulated amortization of $53,719 and $34,221 as of December 31, 2022 and 2021, respectively	55,102	74,197
Long-term restricted investments	105,735	30,949
Long-term restricted cash	28,941	89,426
Deferred income taxes	11,378	0
Other non-current assets	103,195	108,634
Total assets	2,312,479	1,857,712
Current liabilities:
Current portion of long-term debt	3,078	2,989
Trade accounts payable	106,037	90,093
Acquisition-related obligations - current	28,254	22,405
Accrued expenses and other current liabilities	265,256	180,442
Total current liabilities	402,625	295,929
Long-term debt	7,897	445,562
Acquisition-related obligations - long-term	0	19,000
Workers’ compensation and black lung obligations	188,247	231,876
Pension obligations	110,836	159,930
Asset retirement obligations	142,048	132,013
Deferred income taxes	10,874	317
Other non-current liabilities	20,197	26,176
Total liabilities	882,724	1,310,803
Commitments and Contingencies (Note 22)
Stockholders’ Equity
Preferred stock - par value $0.01, 5.0 million shares authorized, none issued	0	0
Common stock - par value $0.01, 50.0 million shares authorized, 21.7 million issued and 15.5 million outstanding at December 31, 2022 and 20.8 million issued and 18.4 million outstanding at December 31, 2021	217	208
Additional paid-in capital	815,442	784,743
Accumulated other comprehensive loss	(12,162)	(58,503)
Treasury stock, at cost: 6.2 million shares at December 31, 2022 and 2.4 million shares at December 31, 2021	(649,061)	(107,800)
Retained earnings (accumulated deficit)	1,275,319	(71,739)
Total stockholders’ equity	1,429,755	546,909
Total liabilities and stockholders’ equity	$ 2,312,479	$ 1,857,712

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 239	$ 393
Less accumulated depreciation and amortization	491,186	443,856
Owned and leased mineral rights, accumulated depletion and amortization	77,333	52,444
Other acquired intangibles, accumulated amortization	$ 53,719	$ 34,221
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	21,700,000	20,800,000
Common stock, shares outstanding (in shares)	15,500,000	18,400,000
Treasury stock, shares at cost (in shares)	6,200,000	2,400,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating activities:
Net income (loss)	$ 1,448,545	$ 288,790	$ (446,899)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	107,620	110,047	151,455
Amortization of acquired intangibles, net	19,498	13,244	10,075
Accretion of acquisition-related obligations discount	233	1,258	3,342
Amortization of debt issuance costs and accretion of debt discount	8,282	12,338	14,772
Mark-to-market adjustment for acquisition-related obligations	8,880	19,525	(8,750)
Loss on sale of business	0	0	36,113
Loss on sale	43	(9,911)	(2,401)
Accretion on asset retirement obligations	23,765	26,520	30,658
Employee benefit plans, net	(4,492)	(1,751)	14,439
Deferred income taxes	(14,521)	(163)	33,123
Asset impairment and restructuring	0	(561)	256,518
Stock-based compensation	7,484	5,315	4,896
Equity loss in affiliates	14,346	4,149	3,473
Other, net	(994)	(6,570)	(5,972)
Changes in operating assets and liabilities
Trade accounts receivable, net	82,774	(336,240)	91,190
Inventories, net	(63,169)	(21,331)	48,689
Prepaid expenses and other current assets	(12,031)	61,581	28,152
Deposits	(84,314)	26,853	(17,926)
Other non-current assets	11,268	(250)	(6,753)
Trade accounts payable	3,721	25,154	(28,620)
Accrued expenses and other current liabilities	(6,872)	15,961	15,428
Acquisition-related obligations	(22,264)	(18,121)	(32,560)
Asset retirement obligations	(18,699)	(16,306)	(19,375)
Other non-current liabilities	(25,098)	(24,588)	(43,831)
Net cash provided by operating activities	1,484,005	174,943	129,236
Investing activities:
Capital expenditures	(164,309)	(83,300)	(153,990)
Proceeds on disposal of assets	3,623	8,224	4,023
Cash paid for business acquired	(24,878)	0	0
Cash paid on sale of business	0	0	(52,192)
Capital contributions to equity affiliates	(19,556)	(6,677)	(3,443)
Purchases of investment securities	(269,420)	(17,985)	(21,129)
Maturity of investment securities	149,397	13,265	16,685
Other, net	(4,214)	(3,382)	77
Net cash used in investing activities	(329,357)	(89,855)	(209,969)
Financing activities:
Proceeds from borrowings on long-term debt	0	0	57,500
Repurchases of long-term debt	0	(18,415)	0
Principal repayments of long-term debt	(450,622)	(119,097)	(76,491)
Dividend and dividend equivalents paid	(13,360)	0	0
Common stock repurchases and related expenses	(521,803)	(786)	(209)
Proceeds from exercise of warrants	5,643	0	0
Other, net	(1,726)	(8,747)	(3,176)
Net cash used in financing activities	(981,868)	(147,045)	(22,376)
Net increase (decrease) in cash and cash equivalents and restricted cash	172,780	(61,957)	(103,109)
Cash and cash equivalents and restricted cash at beginning of period	182,614	244,571	347,680
Cash and cash equivalents and restricted cash at end of period	355,394	182,614	244,571
Supplemental cash flow information:
Cash paid for interest	25,895	63,061	49,294
Cash paid for income taxes	139,663	176	5
Cash received for income tax refunds	6	64,498	68,801
Supplemental disclosure of noncash investing and financing activities:
Financing leases and capital financing - equipment	9,833	787	4,411
Accrued capital expenditures	18,456	9,964	7,493
Accrued common stock repurchases	3,016	0	0
Accrued dividend payable	88,128	0	0
Reconciliation of Cash and Cash Equivalents and Restricted Cash
Cash and cash equivalents	301,906	81,211	139,227
Short-term restricted cash	24,547	11,977	9,311
Long-term restricted cash	28,941	89,426	96,033
Total cash and cash equivalents and restricted cash shown in the Consolidated Statements of Cash Flows	$ 355,394	$ 182,614	$ 244,571

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Treasury Stock at Cost	Retained Earnings (Accumulated Deficit)	Retained Earnings (Accumulated Deficit) Cumulative Effect, Period of Adoption, Adjustment
Beginning balance at Dec. 31, 2019	$ 696,122	$ (440)	$ 205	$ 775,707	$ (58,616)	$ (107,984)	$ 86,810	$ (440)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(446,899)						(446,899)
Other comprehensive income (loss), net	(53,369)				(53,369)
Stock-based compensation, issuance of common stock for share vesting, and common stock reissuances	4,897		1	3,717		1,179
Common stock repurchases and related expenses	(209)					(209)
Ending balance at Dec. 31, 2020	200,102		206	779,424	(111,985)	(107,014)	(360,529)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	288,790						288,790
Other comprehensive income (loss), net	53,482				53,482
Stock-based compensation, issuance of common stock for share vesting, and common stock reissuances	5,315		2	5,313
Common stock repurchases and related expenses	(786)					(786)
Warrants exercises	6			6
Ending balance at Dec. 31, 2021	546,909		208	784,743	(58,503)	(107,800)	(71,739)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,448,545						1,448,545
Other comprehensive income (loss), net	46,341				46,341
Stock-based compensation, issuance of common stock for share vesting, and common stock reissuances	7,484		2	5,415		2,067
Exercise of stock options	1,172			1,172
Common stock repurchases and related expenses	(543,328)					(543,328)
Warrants exercises	24,119		7	24,112
Cash dividend and dividend equivalents declared ($6.185 per share)	(101,487)						(101,487)
Ending balance at Dec. 31, 2022	$ 1,429,755		$ 217	$ 815,442	$ (12,162)	$ (649,061)	$ 1,275,319

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares				3 Months Ended	12 Months Ended
	Nov. 04, 2022	Aug. 04, 2022	May 03, 2022	Dec. 31, 2022	Dec. 31, 2022
Statement of Stockholders' Equity [Abstract]
Dividend per share (in dollars per share)	$ 5.418	$ 0.392	$ 0.375	$ 0.418	$ 6.185

Business and Basis of Presentat

Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business and Basis of Presentation	Business and Basis of Presentation Business Alpha Metallurgical Resources, Inc. (“Alpha” or the “Company”), previously named Contura Energy, Inc., is a Tennessee-based mining company with operations across Virginia and West Virginia. With customers across the globe, high-quality reserves and significant port capacity, Alpha is a leading U.S. supplier of metallurgical coal products for the steel industry. The Company was formed to acquire and operate certain of Alpha Natural Resources, Inc.’s core coal operations, as part of the Alpha Natural Resources, Inc. bankruptcy reorganization. The Company began operations on July 26, 2016 and currently operates mines in the Central Appalachia region. A merger with ANR, Inc. and Alpha Natural Resources Holdings, Inc. (together, the "Merger Companies”) was completed on November 9, 2018 (the “Merger”) pursuant to terms of the definitive merger agreement (the “Merger Agreement”). Upon the consummation of the transactions contemplated by the Merger Agreement, the Company began trading on the New York Stock Exchange under the ticker “CTRA.” Effective February 1, 2021, the Company changed its corporate name from Contura Energy, Inc. to Alpha Metallurgical Resources, Inc. to more accurately reflect its strategic focus on the production of metallurgical coal. Following the effectiveness of its name change, the Company’s ticker symbol on the New York Stock Exchange changed from “CTRA” to “AMR” effective on February 4, 2021. Basis of Presentation Together, the consolidated balance sheets and consolidated statements of operations, comprehensive income (loss), cash flows and stockholders’ equity for the Company are referred to as the “Financial Statements.” The Financial Statements are also referred to as “Consolidated” and references across periods are generally labeled “Balance Sheets,” “Statements of Operations,” and “Statements of Cash Flows.” The Company’s former NAPP operations results of operations and financial position are reported as discontinued operations in the Consolidated Financial Statements for the year ended December 31, 2020. Refer to Note 3 for further information on discontinued operations. The Consolidated Financial Statements include all wholly owned subsidiaries’ results of operations for the years ended December 31, 2022, 2021, and 2020. All significant intercompany transactions have been eliminated in consolidation. The accompanying Consolidated Financial Statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). Reclassifications Certain immaterial amounts as of and for the years ended December 31, 2022 and 2021 in the Consolidated Financials Statements and notes to the Consolidated Financials Statements have been recast to reclassify discontinued operations and present the related amounts within continuing operations as part of the All Other category. Additionally, certain amounts in the prior year Consolidated Statements of Stockholders’ Equity have been reclassified to conform to the current year presentation. COVID-19 Pandemic In the first quarter of 2020, the COVID-19 virus was declared a pandemic by the World Health Organization. The COVID-19 pandemic has had negative impacts on the Company’s business, results of operations, financial condition and cash flows. In 2021, the Company experienced an increase in employee absences due to COVID-19, although COVID-related absences within the Company decreased in 2022. Indirectly, through some of the Company’s third-party vendors, the Company and the Company’s customers have experienced some supply chain disruptions due to the COVID-19 pandemic. The continued impact of the COVID-19 pandemic on the Company’s operational and financial performance will depend on certain developments, including the duration of the virus, the global economic impacts of the virus, its impact on the Company’s customers and suppliers, and the range of governmental and community reactions to the pandemic, which cannot be fully predicted. Health and safety are core values of the Company and are the foundation for how the Company manages every

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Use of Estimates The preparation of the Company’s Consolidated Financial Statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates and assumptions include inventories; mineral reserves and resources; long-lived asset impairments; reclamation obligations; post-employment and other employee benefit obligations; useful lives, depletion and amortization; reserves for workers’ compensation and black lung claims; deferred income taxes; income taxes payable; income taxes refundable and receivable; reserves for contingencies and litigation; fair value of financial instruments; and fair value adjustments for acquisition accounting. Estimates are based on facts and circumstances believed to be reasonable at the time; however, actual results could differ from those estimates. Cash and Cash Equivalents Cash and cash equivalents consist of cash held with reputable depository institutions and highly liquid, short-term investments, such as highly-rated money market funds, with original maturities of three months or less. Cash and cash equivalents are stated at cost, which approximates fair value. Restricted Cash Amounts included in restricted cash represent cash and cash equivalents that are restricted as to withdrawal as required by certain agreements entered into by the Company and provide collateral to secure the certain obligations which have been written on the Company’s behalf. Refer to Note 22 for further information. Investments Short-term investments consist of U.S government securities. Restricted investments consist of Federal Deposit Insurance Company (“FDIC”) insured certificates of deposit, corporate fixed income, and U.S. government securities that are restricted as to withdrawal as required by certain agreements entered into by the Company and provide collateral to secure certain obligations which have been written on the Company’s behalf. All investments are classified as trading securities as of December 31, 2022 and 2021. Trading securities are recorded initially at cost and are adjusted to fair value at each reporting period with unrealized gains and losses recorded in current period earnings or loss. Refer to Note 22 for further information. Deposits Deposits represent cash deposits held at third parties as required by certain agreements entered into by the Company to provide cash collateral to secure the following obligations which have been written on the Company’s behalf. Refer to Note 22 for further information. Trade Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable are recorded at their invoiced amounts and do not bear interest. The Company markets its coal primarily to international and domestic steel producers and electric utilities in the United States. Credit is extended based on an evaluation of a customer’s financial condition, including a review of third-party credit score information. Collateral is generally not required. Accounts receivable balances are monitored against approved credit limits. Credit limits are monitored and adjusted as considered necessary based on changes to a customer’s credit profile. If a customer’s credit deteriorates, the Company may reduce credit risk exposure by reducing credit limits, obtaining letters of credit, obtaining credit insurance, or requiring pre-payment for shipments. Credit losses have historically not been material. Account balances are written-off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. Refer to Note 23 for further information. Inventories Coal is reported as inventory at the point in time the coal is extracted from the mine. Raw coal represents coal stockpiles that may be sold in current condition or may be further processed prior to shipment to a customer. Saleable coal represents coal stockpiles that require no further processing prior to shipment to a customer. Coal inventories are valued at the lower of average cost or net realizable value. The cost of coal inventories is determined based on the average cost of production, which includes labor, supplies, equipment costs, operating overhead, depreciation, and other related costs. Net realizable value considers the projected future sales price of the product, less estimated preparation and selling costs. Material and supplies inventories are valued at average cost, less an allowance for obsolete and surplus items. Refer to Note 7 for further information. Discontinued Operations In accordance with Accounting Standards Codification (“ASC”) 205-20-45, the Company treats a disposal transaction as a discontinued operation when the disposal of a component or group of components represents a strategic shift that will have a major effect on the Company’s operations and financial results. In the period in which the discontinued operations criteria are met, the assets and liabilities of the discontinued operations are separately presented on the Company's Consolidated Balance Sheets and the results of operations, including any gain or loss recognized, are reclassified to discontinued operations on the Company’s Consolidated Statement of Operations. Refer to Note 3 for further information. Advanced Mining Royalties Lease rights to coal reserves are often acquired in exchange for royalty payments. Advance mining royalties are advance payments made to lessors under terms of mineral lease agreements that are recoupable against future production royalties. These advance payments are deferred and charged to operations as the coal reserves are mined. The Company regularly reviews recoverability of advance mining royalties and establishes or adjusts the allowance for advance mining royalties as necessary using the specific identification method. Advance royalty balances are generally charged off against the allowance when they are no longer recoupable. Refer to Note 11 for further information. Property, Plant, and Equipment, Net Costs for mine development incurred to expand capacity of operating mines or to develop new mines are capitalized and charged to operations on the units-of-production method over the estimated proven and probable reserve tons directly benefiting from the capital expenditures. Mine development costs include costs incurred for site preparation and development of the mines during the development stage less any incidental revenue generated during the development stage. Mining equipment, buildings, and other fixed assets are stated at cost and depreciated on a straight-line basis over estimated useful lives ranging from one Owned and Leased Mineral Rights Owned and leased mineral rights, net of accumulated depletion and amortization, for the years ended December 31, 2022 and 2021 were $451,062 and $444,302, respectively, and are reported in assets in the Company’s Consolidated Balance Sheets. These amounts include $20,284 and $10,354 of asset retirement obligation assets, net of accumulated amortization, associated with active mining operations for the years ended December 31, 2022 and 2021, respectively. During the year ended December 31, 2020, the Company recorded a long-lived asset impairment which reduced the carrying value of owned and leased mineral rights, net, by $41,579. Refer to Note 8 for further information on long-lived asset impairment. Costs to obtain owned and leased mineral rights are capitalized and amortized to operations as depletion expense using the units-of-production method. Only proven and probable reserves are included in the depletion base. Depletion expense is included in Depreciation, depletion and amortization in the accompanying Consolidated Statements of Operations and was $23,078, $23,541, and ($13,746) for the years ended December 31, 2022, 2021, and 2020 respectively. Depletion expense for the years ended December 31, 2022, 2021, and 2020 includes a credit of ($3,016), an expense of $5,782, and a credit of ($34,377), respectively, related to revisions to asset retirement obligations. Refer to Note 16 for further disclosures related to asset retirement obligations. Leases In accordance with ASC 842, the Company recognizes right of use assets and lease liabilities on the Consolidated Balance Sheets for all leases with a term longer than 12 months. Some of these leases include both lease and non-lease components which are accounted for as a single lease component as the Company has elected the practical expedient to combine these components for all leases. The discount rates used to determine the present value of the lease assets and liabilities are based on the Company’s incremental borrowing rate at the lease commencement date and commensurate with the remaining lease term. As the rates implicit in most of the Company’s leases are not readily determinable, the Company uses a collateralized incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future payments. The Company uses the portfolio approach and groups leases by short-term and long-term categories, applying the corresponding incremental borrowing rates to these categories of leases. For leases with a term of 12 months or less, no right of use assets or liabilities are recognized on the Consolidated Balance Sheets and the Company recognizes the lease expense on a straight-line basis over the lease term. Additionally, the Company recognizes variable lease payments as an expense in the period incurred. The Company has elected to show net instead of gross amounts for right-of-use assets and liabilities within its Consolidated Statements of Cash Flows. Refer to Note 12 for further information. Acquired Intangibles The Company has recognized assets for acquired mine permits which were valued based on the replacement cost and lost profits method as of the Merger date. The balances of such assets as of December 31, 2022 and 2021, net of accumulated amortization, were $55,102 and $74,197, respectively, and are included within Other acquired intangibles, net of accumulated amortization, on the Company’s Consolidated Balance Sheets. During the year ended December 31, 2020, the Company recorded long-lived asset impairments which reduced the carrying value of acquired mine permits, net, by $21,144. Refer to Note 8 for further information. The acquired mine permits are amortized over the estimated life of the associated mine. Amortization expense is included in Amortization of acquired intangibles, net in the accompanying Consolidated Statements of Operations and was $19,498, $13,571, and $14,887 for the years ended December 31, 2022, 2021, and 2020, respectively. Additionally, the Company previously recognized assets for acquired above market-priced coal supply agreements and liabilities for acquired below market-priced coal supply agreements. The agreements were amortized over the actual number of tons shipped over the life of each contract. Amortization expense is included in Amortization of acquired intangibles, net in the accompanying Consolidated Statements of Operations and was $0, ($327), and ($5,673) for the years ended December 31, 2022, 2021, and 2020, respectively. Future net amortization expense related to acquired intangibles is expected to be $8,526, $6,705, $5,893, $5,373, $4,792, and $23,813 for 2023, 2024, 2025, 2026, 2027, and after 2027, respectively. Goodwill Goodwill represents the excess of the purchase price over the fair value of the net identifiable tangible and intangible assets of acquired companies. In December 2022, primarily to secure the supply of certain underground mining equipment parts needed for its operations, the Company purchased substantially all of the assets of a mining equipment component manufacturing and rebuilding business for $24,878, which included $7,787 of working capital, $6,355 of property, plant, and equipment, and $10,736 of goodwill. The acquired goodwill, related primarily to the acquired workforce and expected cost synergies, was allocated to the Company’s Met reportable segment. Goodwill is not amortized; instead, it is tested for impairment annually as of October 31 of each year or more frequently if indicators of impairment exist. The Company assesses goodwill for impairment on a qualitative basis. If the Company determines that more likely than not the fair value of a reporting unit containing goodwill exceeds its carrying amount, no further impairment testing is required. If the qualitative assessment indicates that an impairment potentially exists, then the Company quantitatively tests goodwill for impairment by comparing the fair value of the reporting unit to its carrying amount. If the fair value of the reporting unit is lower than its carrying amount, its goodwill is written down by the lesser of the amount by which the reporting units carrying amount exceeded its fair value or its carrying amount of goodwill. Asset Impairment Long-lived assets, such as property, plant, and equipment, mineral rights, and acquired intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset groups may not be recoverable. Recoverability of assets or asset groups to be held and used is measured by a comparison of the carrying amount of an asset or asset group to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. Long-lived assets located in a close geographic area are grouped together for purposes of impairment testing when, after considering revenue and cost interdependencies, circumstances indicate the assets are used together to produce future cash flows. The Company’s asset groups generally consist of the assets and applicable liabilities of one or more mines and preparation plants and associated coal reserves for which cash flows are largely independent of cash flows of other mines, preparation plants, and associated coal reserves. If the carrying amount of an asset or asset group exceeds its estimated future cash flows, the potential impairment is equal to the amount by which the carrying amount of the asset or asset group exceeds the fair value of the asset or asset group. The Company estimates the fair value of an asset group generally using discounted cash flow analysis based on estimates of future sales volumes, coal prices, production costs, and a risk-adjusted cost of capital. These estimates generally constitute unobservable Level 3 inputs under the fair value hierarchy. The amount of impairment, if any, is allocated to the long-lived assets on a pro-rata basis, except that the carrying value of the individual long-lived assets are not reduced below their estimated fair value. Refer to Note 8 for further information. Asset Retirement Obligations Minimum standards for mine reclamation have been established by various regulatory agencies and dictate the reclamation requirements at the Company’s operations. The Company’s asset retirement obligations consist principally of costs to reclaim acreage disturbed at surface operations and estimated costs to reclaim support acreage, treat mine water discharge, and perform other related functions at underground mines. The Company records these reclamation obligations at fair value in the period in which the legal obligation associated with the retirement of the long-lived asset is incurred. Changes to the liability at operations that are not currently being reclaimed are offset by increasing or decreasing the carrying amount of the related long-lived asset. Changes to the liability at operations that are currently being reclaimed are recorded to depreciation, depletion, and amortization. Over time, the liability is accreted and any capitalized cost is depreciated or depleted over the useful life of the related asset. To settle the liability, the obligation is paid, and any difference between the liability and the amount of cash paid is recorded within Depreciation, depletion and amortization within the Consolidated Statements of Operations at the time the reclamation work is completed. The Company annually reviews its estimated future cash flows for its asset retirement obligations. Refer to Note 16 for further information. Income Taxes The Company recognizes deferred tax assets and liabilities using enacted tax rates for the effect of temporary differences between the book and tax bases of recorded assets and liabilities. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax assets will not be realized. In evaluating its ability to recover deferred tax assets within the jurisdiction in which they arise, the Company considers all available positive and negative evidence, including the expected reversals of deferred tax liabilities, projected future taxable income, taxable income available via carryback to prior years, tax planning strategies, and results of recent operations. The Company assesses the realizability of its deferred tax assets, including scheduling the reversal of its deferred tax assets and liabilities, to determine the amount of valuation allowance needed. Scheduling the reversal of deferred tax asset and liability balances requires judgment and estimation. The Company believes the deferred tax liabilities relied upon as future taxable income in its assessment will reverse in the same period and jurisdiction and are of the same character as the temporary differences giving rise to the deferred tax assets that will be realized. Refer to Note 18 for further information. Deferred Financing Costs The costs to obtain new debt financing or amend existing financing agreements are generally deferred and amortized to interest expense over the life of the related indebtedness or credit facility using the effective interest method. Unamortized deferred financing costs are presented in the Consolidated Balance Sheets as a direct deduction from the carrying amount of the debt liability, consistent with debt discounts or premiums. Unamortized deferred financing costs associated with undrawn credit facilities are included in the Consolidated Balance Sheets within Other non-current assets. Revenue Recognition In accordance with ASC 606 Revenue from Contracts with Customers (“ASC 606”), the Company measures revenue based on the consideration specified in a contract with a customer and recognizes revenue as a result of satisfying its promise to transfer goods or services in a contract with a customer using the following general revenue recognition five-step model: (1) identify the contract; (2) identify performance obligations; (3) determine transaction price; (4) allocate transaction price; and (5) recognize revenue. Freight and handling costs paid to third-party carriers and invoiced to coal customers are recorded as freight and handling costs and freight and handling fulfillment revenues within cost of coal sales and coal revenues, respectively. Refer to Note 4 for further information. Workers’ Compensation and Pneumoconiosis (Black Lung) Benefits Workers’ Compensation As of December 31, 2022, the Company’s subsidiaries generally utilize high-deductible insurance programs for workers’ compensation claims at its operations with the exception of certain subsidiaries in which the Company is a qualified self-insurer for workers’ compensation obligations. The liabilities for workers’ compensation claims are estimates of the ultimate losses incurred based on the Company’s experience and include a provision for incurred but not reported losses. Adjustments to the probable ultimate liabilities are made annually based on an actuarial study and adjustments to the liability are recorded based on the results of this study. These short-term and long-term obligations are included in the Consolidated Balance Sheets within Accrued expenses and other current liabilities and Workers’ compensation and black lung obligations, respectively, with the related expected insurance receivables within Prepaid expenses and other current assets and Other non-current assets. As of December 31, 2022 and 2021, the workers’ compensation liability was net of a discount of $22,824 and $23,442, respectively, related to fair value adjustments associated with acquisition accounting. Refer to Note 19 for further information. Black Lung Benefits The Company is required by federal and state statutes to provide benefits to employees for awards related to black lung. As of December 31, 2022, certain of the Company’s subsidiaries are insured for black lung obligations by a third-party insurance provider and certain subsidiaries are self-insured for state black lung obligations. Certain other subsidiaries are self-insured for federal black lung benefits and may fund benefit payments through a Section 501(c)(21) tax-exempt trust fund. Charges are made to operations for black lung claims, as determined by an independent actuary at the present value of the actuarially computed liability for such benefits over the employee’s applicable term of service. The Company recognizes in its Consolidated Balance sheets the amount of the Company’s unfunded Accumulated Benefit Obligation (“ABO”) at the end of the year. The actuarial gains and losses recognized in accumulated other comprehensive income (loss) are amortized into components of net periodic benefit cost over the expected lifetime of active participants (the Company does not use a corridor method). These short-term and long-term obligations are included in the Consolidated Balance Sheets within Accrued expenses and other current liabilities and Workers’ compensation and black lung obligations, respectively. Refer to Note 19 for further information. Pension The Company is required to recognize the overfunded or underfunded status of a defined benefit pension plan as an asset or liability in its Consolidated Balance Sheets and to recognize changes in that funded status in the year in which the changes occur through other comprehensive (loss) income. The actuarial gains and losses recognized in accumulated other comprehensive income (loss) are amortized into components of net periodic benefit cost over the average future lifetime of participants expected to have benefits (the Company does not use a corridor method). The Company is required to measure plan assets and benefit obligations as of the date of the Company’s fiscal year-end Consolidated Balance Sheet and provide the required disclosures as of the end of each fiscal year. Refer to Note 19 for information. Postretirement Life Insurance Benefits As part of the Alpha Natural Resources, Inc. bankruptcy reorganization plan and the Retiree Committee Settlement Agreement, the Company assumed the liability for life insurance benefits for certain disabled and non-union retired employees. Provisions are made for estimated benefits based on annual evaluations prepared by independent actuaries. Adjustments to the probable ultimate liabilities are made annually based on an actuarial study and adjustments to the liability are recorded based on the results of this study. These obligations are included in the Consolidated Balance Sheets as Accrued expenses and other current liabilities and Other non-current liabilities. Refer to Note 19 for further information. Net Income (Loss) per Share Basic net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of outstanding common shares for the period. Diluted (loss) earnings per share reflects the potential dilution that could occur if instruments that may require the issuance of common shares in the future were settled and the underlying common shares were issued. Diluted (loss) earnings per share is computed by increasing the weighted-average number of outstanding common shares computed in basic earnings (loss) per share to include the additional common shares that would be outstanding after issuance and adjusting net income (loss) for changes that would result from the issuance. Only those securities that are dilutive are included in the calculation. In periods of loss, the number of shares used to calculate diluted earnings is the same as basic earnings per share. Refer to Note 6 for further information. Stock-Based Compensation The Company recognizes expense for stock-based compensation awards based on their grant-date fair value. The expense is recorded over the respective service period of the underlying award. Liability classified stock-based compensation awards are remeasured each reporting period at fair value until the award is settled. The Company recognizes forfeitures of stock-based compensation awards as they occur. Refer to Note 20 for further information. Warrants On July 26, 2016 (the “Initial Issue Date”), the Company issued warrants, which are classified as equity instruments, and are exercisable for cash or on a cashless basis at any time from the Initial Issue Date until July 26, 2023, and no fractional shares will be issued upon warrant exercises. The exercise price and the warrant share number will be adjusted in respect of certain dilutive events with respect to common stock (namely, dividends or distributions on the common stock, share splits and combinations, above-market tender offers for common stock by the Company or a subsidiary thereof, and discounted issuances of common stock or rights or options to purchase common stock or securities convertible or exchangeable into common stock). Additionally, in the case of any reorganization (i.e., a consolidation, merger, or sale of all or substantially all of the consolidated assets of Alpha) pursuant to which the common stock is converted into cash, securities or other property, the warrants would become exercisable for such property. Refer to Note 9 for additional information. Equity Method Investments Investments in unconsolidated affiliates that the Company has the ability to exercise significant influence over, but not control, are accounted for under the equity method of accounting. Under the equity method of accounting, the Company records its proportionate share of the entity’s net income or loss at each reporting period in the Consolidated Statements of Operations in other (expense) income, with a corresponding entry to increase or decrease the carrying value of the investment. The carrying value of the Company’s equity method investments was $23,070 and $20,460 as of December 31, 2022 and 2021, respectively. Recently Adopted Accounting Guidance Reference Rate Reform: In December 2022, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2022-06, Deferral of the Sunset Date of Topic 848 (“ASU 2022-06”). This update defers the sunset date of ASC 848 to December 31, 2024. The amendments are effective immediately for all entities and are applied prospectively. As the Company previously adopted ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of Effects of Reference Rate Reform on Financial Reporting during the first quarter of 2020, ASU 2022-06 did not have an impact on the Company’s Consolidated Financial Statements and related disclosures. Government Assistance : In November 2021, the FASB issued ASU 2021-10 , Disclosures by Business Entities about Government Assistance (“ASU 2021-10”). This update requires business entities to make annual disclosures about transactions with a government accounted for by analogizing to a grant or contribution accounting model. The required annual disclosures include the nature of the transaction, the related accounting policy, the financial statement line items affected and the amounts reflected in the current period financial statements, and any significant terms and conditions. The amendments are effective for fiscal years beginning after December 15, 2021, for all entities, with early application permitted. The Company adopted ASU 2021-10 during the fourth quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures. Liabilities: In September 2022, the FASB issued ASU 2022-04, Liabilities - Supplier Finance Programs (Subtopic 405-50): Disclosure of Supplier Finance Program Obligations (“ASU 2022-04”). This update enhances transparency about an entity’s use of supplier finance programs. The ASU requires entities to disclose information about the key terms of the program, outstanding confirmed amounts as of the end of the period, a rollforward of such amounts during each annual period, and a description of where in the financial statements outstanding amounts are presented. The amendments are effective for fiscal years beginning after December 15, 2022, with early application permitted. The Company adopted ASU 2022-04 during the third quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures. Fair Value Measurement: In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions (“ASU 2022-03”). This update clarifies how the fair value of equity securities subject to contractual sale restrictions is determined. Per the update, a contractual restriction on the sale of an equity security is not considered part of the unit of account of the equity security and is not considered in measuring fair value. Additionally, the update requires entities with investments in equity securities subject to contractual sale restrictions to disclose certain qualitative and quantitative information about such securities. The amendments are effective for fiscal years beginning after December 15, 2023, with early application permitted. The Company adopted ASU 2022-03 during the second quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures. Financial Instruments: In March 2022, the FASB issued ASU 2022-02, Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures (“ASU 2022-02”). This update eliminates the troubled debt restructuring model for creditors that have adopted Topic 326. All loan modifications will now be accounted for under general loan modification guidance and, on a prospective basis, entities will be subject to new disclosure requirements covering modifications of receivables to borrowers experiencing financial difficulty. In addition, entities will be required to prospectively disclose current-period gross write-off information by year of origination. The amendments are effective for fiscal years beginning after December 15, 2022, with early application permitted. The Company adopted ASU 2022-02 during the first quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures.

Discontinued Operations

Discontinued Operations	12 Months Ended
	Dec. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	Discontinued Operations The Company has no discontinued operations as of or for the years ended December 31, 2022 and 2021. Certain immaterial amounts as of and for the years ended December 31, 2022 and 2021 in the Consolidated Financials Statements and notes to the Consolidated Financials Statements have been recast to reclassify discontinued operations and present the related amounts within continuing operations as part of the All Other category. Discontinued operations consisted of activity related to the Company’s former NAPP operations for the year ended December 31, 2020. Former NAPP Operations On November 11, 2020, the Company entered into a unit purchase agreement (the “UPA”) to sell its thermal coal mining operations located in Pennsylvania consisting primarily of its Cumberland mining complex and related property (“Cumberland Transaction”) to a third-party purchaser Iron Senergy Holdings, LLC (“Iron Senergy”). The Cumberland Transaction closed on December 10, 2020. In accordance with terms of the UPA, the Company transferred its equity interests in certain subsidiaries (Cumberland Contura, LLC, Contura Coal Resources, LLC, Contura Pennsylvania Land, LLC, Emerald Contura, LLC, and Contura Pennsylvania Terminal, LLC) along with total consideration of $49,987 to Iron Senergy. Pursuant to the terms of the UPA, the Company also retained certain assets and liabilities associated with its former NAPP operations. The mining permits associated with the Cumberland mining operations were obtained by Iron Senergy at closing. The following table presents the details of the Cumberland Transaction: Year Ended December 31, 2020 Cash $ 19,987 Surety bonding collateral 30,000 Total consideration $ 49,987 Transaction costs 2,205 Carrying value of assets and liabilities (1) (16,079) Loss on sale $ 36,113 (1) Assets and liabilities were primarily comprised of property, plant and equipment, net of $32,872, deferred longwall move expenses of $15,173, and coal and supplies inventory of $5,112 and asset retirement obligations of $39,573, severance of $17,143, black lung obligations of $8,290, and subsidence liability of $3,559. In connection with the UPA, the Company entered into certain agreements with Iron Senergy under which Iron Senergy will sell to the Company all of the coal that the Company is obligated to sell to customers under Cumberland coal supply agreements (“Cumberland CSAs”) which existed as of the transaction closing date but did not transfer to Iron Senergy at closing (each, a “Cumberland Back-to-Back Coal Supply Agreement”). Each Cumberland Back-to-Back Coal Supply Agreement has economic terms identical to, but offsetting, the related Cumberland CSA. If a Cumberland customer subsequently consents to assign a Cumberland CSA to Iron Senergy after closing, the related Cumberland CSA will immediately and automatically transfer to Iron Senergy and the related Cumberland Back-to-Back Coal Supply Agreements executed by the parties shall thereupon terminate as set forth therein. As the Company does not control the purchased coal prior to customer delivery, the Company will record coal purchases and sales under the related agreements on a net basis. Per terms of the Cumberland Back-to-Back Coal Supply Agreements, the Company is required to purchase and sell 401 tons of coal in 2023 totaling $15,478. For the years ended December 31, 2022, 2021, and 2020 the Company purchased and sold 1,617, 2,591, and 104 tons, respectively, totaling $62,171, $100,338, and $3,997, respectively, under the Cumberland Back-to-Back Coal Supply Agreements. During the fourth quarter of 2022, one Cumberland Back-to-Back Coal Supply Agreement initially scheduled to be fully performed by December 31, 2022 was extended into 2023 and is expected to be fully performed by the end of the second quarter of 2023. Major Financial Statement Components of Discontinued Operations The major components of net loss from discontinued operations before income taxes in the Consolidated Statements of Operations for the year ended December 31, 2020 are as follows: Year Ended December 31, 2020 (1) Revenues: Total revenues $ 235,509 Costs and expenses: Cost of coal sales (exclusive of items shown separately below) 215,390 Depreciation, depletion and amortization 11,570 Accretion on asset retirement obligations 4,154 Asset impairment and restructuring (2) 172,640 Selling, general and administrative expenses (3) 1,623 Other income (926) Other non-major expense items, net 374 Loss on sale 36,113 Loss from discontinued operations before income taxes $ (205,429) (1) Includes minor residual activity related to the Company’s former PRB operations. (2) Refer to Note 8. (3) Represents professional and legal fees. Refer to the Consolidated Statements of Operations and Note 6 for net loss per share information related to discontinued operations. The major components of cash flows related to discontinued operations were as follows: Year Ended December 31, 2020 Depreciation, depletion and amortization $ 11,570 Capital expenditures $ 34,411 Other significant operating non-cash items related to discontinued operations: Accretion on asset retirement obligations $ 4,154 Asset impairment and restructuring $ 172,640

Revenue

Revenue	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Disaggregation of Revenue from Contracts with Customers ASC 606 requires that entities disclose disaggregated revenue information in categories (such as type of good or service, geography, market, type of contract, etc.) that depict how the nature, amount, timing, and uncertainty of revenue and cash flow are affected by economic factors. ASC 606 explains that the extent to which an entity’s revenue is disaggregated depends on the facts and circumstances that pertain to the entity’s contracts with customers and that some entities may need to use more than one type of category to meet the objective for disaggregating revenue. The Company earns revenues primarily through the sale of coal produced at Company operations and coal purchased from third parties. The Company extracts, processes and markets met and thermal coal from deep and surface mines for sale to steel and coke producers, industrial customers, and electric utilities. The Company conducts mining operations only in the United States with mines in Central Appalachia. The Company has one reportable segment: Met. In addition to the one reportable segment, the All Other category includes general corporate overhead and corporate assets and liabilities, the former CAPP - Thermal operations, and the elimination of certain intercompany activity, as well as expenses associated with certain idled/closed mines. Refer to Note 24 for further segment information. The Company has disaggregated revenue between met coal and thermal coal and export and domestic revenues which depicts the pricing and contract differences between the two. Export revenue generally is derived by spot or short term contracts with pricing determined at the time of shipment or based on a market index; whereas domestic revenue is characterized by contracts that typically have a term of one year or longer and typically the pricing is fixed. The following tables disaggregate the Company’s coal revenues by product category and by market to depict how the nature, amount, timing, and uncertainty of the Company’s coal revenues and cash flows are affected by economic factors: Year Ended December 31, 2022 Met Coal Thermal Coal Total Export coal revenues $ 3,195,516 $ 107,961 $ 3,303,477 Domestic coal revenues 687,795 101,715 789,510 Total coal revenues $ 3,883,311 $ 209,676 $ 4,092,987 Year Ended December 31, 2021 Met Coal Thermal Coal Total Export coal revenues $ 1,675,147 $ 30,879 $ 1,706,026 Domestic coal revenues 396,160 150,438 546,598 Total coal revenues $ 2,071,307 $ 181,317 $ 2,252,624 Year Ended December 31, 2020 Met Coal Thermal Coal Total Export coal revenues $ 870,121 $ 27,904 $ 898,025 Domestic coal revenues 362,654 152,445 515,099 Total coal revenues $ 1,232,775 $ 180,349 $ 1,413,124 Performance Obligations The Company considers each individual transfer of coal on a per shipment basis to the customer a performance obligation. The pricing terms of the Company’s contracts with customers include fixed pricing, variable pricing, or a combination of both fixed and variable pricing. All the Company’s revenue derived from contracts with customers is recognized at a point in time. The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied as of December 31, 2022. 2023 2024 2025 2026 2027 Total Estimated coal revenues (1) $ 128,341 $ 37,250 $ — $ — $ — $ 165,591 (1) Amounts only include estimated coal revenues associated with contracts with customers with fixed pricing with original expected duration of more than one year. The Company has elected not to disclose the aggregate amount of the transaction price allocated to the performance obligations that are unsatisfied (or partially unsatisfied) as of the end of the reporting period for performance obligations with either of the following conditions: 1) the remaining performance obligation is part of a contract that has an original expected duration of one year or less; or 2) the remaining performance obligation has variable consideration that is allocated entirely to a wholly unsatisfied performance obligation.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Loss	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss The following tables summarize the changes to accumulated other comprehensive loss during the years ended December 31, 2022, 2021, and 2020: Balance January 1, 2022 Other comprehensive income before reclassifications Amounts reclassified from accumulated other comprehensive loss Balance December 31, 2022 Employee benefit costs $ (58,503) $ 43,597 $ 2,744 $ (12,162) Balance January 1, 2021 Other comprehensive income before reclassifications Amounts reclassified from accumulated other comprehensive loss Balance December 31, 2021 Employee benefit costs $ (111,985) $ 47,461 $ 6,021 $ (58,503) Balance January 1, 2020 Other comprehensive loss before reclassifications Amounts reclassified from accumulated other comprehensive loss Balance December 31, 2020 Employee benefit costs $ (58,616) $ (60,647) $ 7,278 $ (111,985) The following table summarizes the amounts reclassified from accumulated other comprehensive loss and the Consolidated Statements of Operations line items affected by the reclassification during the years ended December 31, 2022, 2021, and 2020: Details about accumulated other comprehensive loss components Amounts reclassified from accumulated other comprehensive loss Affected line item in the Consolidated Statements of Operations Year Ended December 31, 2022 2021 2020 Employee benefit costs: Amortization of actuarial loss (1) $ 3,311 $ 5,653 $ 3,929 Miscellaneous income (loss), net Settlement (1) 244 368 3,349 Miscellaneous income (loss), net Total before income tax $ 3,555 $ 6,021 $ 7,278 Income tax (811) — — Income tax (expense) benefit Total, net of income tax $ 2,744 $ 6,021 $ 7,278 (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit costs for certain employee benefit plans. Refer to Note 19.

Net Income (Loss) per Share

Net Income (Loss) per Share	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Net Income (Loss) per Share	Net Income (Loss) per Share The number of shares used to calculate basic net income (loss) per common share is based on the weighted average number of the Company’s outstanding common shares during the respective period. The number of shares used to calculate diluted net income (loss) per common share is based on the number of common shares used to calculate basic net income (loss) per common share plus the dilutive effect of stock options and other stock-based instruments held by the Company’s employees and directors during the period, and the Company’s outstanding warrants. The dilutive effect of outstanding stock-based instruments is determined by application of the treasury stock method. The stock options and warrants become dilutive for diluted net income (loss) per common share calculations when the market price of the Company’s common stock exceeds the exercise price. As discussed below, dilutive securities are not included in the computation of diluted net loss per common share for the year ended December 31, 2020 as the impact would be anti-dilutive. For the years ended December 31, 2022, 2021, and 2020, respectively, 0, 717,992, and 1,317,351 warrants, stock options, and other stock-based instruments were excluded from the computation of dilutive net income (loss) per common share because they would have been anti-dilutive. When applying the treasury stock method, anti-dilution generally occurs when the exercise prices or unrecognized compensation cost per share are higher than the Company’s average stock price during an applicable period. Anti-dilution also occurs in periods of a net loss, and the dilutive impact of all share-based compensation awards are excluded. For the year ended December 31, 2020, the weighted average share impact of stock options and other stock-based instruments that were excluded from the calculation of diluted shares due to the Company incurring a net loss for the period was 142,250. The following table presents the net income (loss) per common share for the years ended December 31, 2022, 2021, and 2020: Year Ended December 31, 2022 2021 2020 Net income (loss) Income (loss) from continuing operations $ 1,448,545 $ 288,790 $ (241,470) Loss from discontinued operations — — (205,429) Net income (loss) $ 1,448,545 $ 288,790 $ (446,899) Basic Weighted average common shares outstanding - basic 17,490,886 18,441,175 18,298,362 Basic income (loss) per common share: Income (loss) from continuing operations $ 82.82 $ 15.66 $ (13.20) Loss from discontinued operations — — (11.22) Net income (loss) $ 82.82 $ 15.66 $ (24.42) Diluted Weighted average common shares outstanding - basic 17,490,886 18,441,175 18,298,362 Diluted effect of warrants 275,715 35,574 — Diluted effect of stock options 4,171 1,753 — Diluted effect of other stock-based instruments 451,625 393,180 — Weighted average common shares outstanding - diluted 18,222,397 18,871,682 18,298,362 Diluted income (loss) per common share: Income (loss) from continuing operations $ 79.49 $ 15.30 $ (13.20) Loss from discontinued operations — — (11.22) Net income (loss) $ 79.49 $ 15.30 $ (24.42)

Inventories, net

Inventories, net	12 Months Ended
	Dec. 31, 2022
Inventory Disclosure [Abstract]
Inventories, net	Inventories, net Inventories, net consisted of the following: December 31, 2022 2021 Raw coal $ 57,382 $ 20,347 Saleable coal 91,474 81,240 Materials, supplies and other, net 51,718 27,795 Total inventories, net $ 200,574 $ 129,382

Asset Impairment and Restructur

Asset Impairment and Restructuring	12 Months Ended
	Dec. 31, 2022
Restructuring and Related Activities [Abstract]
Asset Impairment and Restructuring	Asset Impairment and Restructuring Long-lived Asset Impairment for the Year Ended December 31, 2021 During the year ended December 31, 2021, long-lived asset impairment of $60 was recorded in the All Other category to reduce the carrying value of property, plant, and equipment, net, due to capital spending during the period at previously impaired locations requiring the impairment of certain additional assets not considered recoverable. Long-lived Asset Impairment for the Year Ended December 31, 2020 During the year ended December 31, 2020, weakening coal market conditions due in part to the impact of the global COVID-19 Pandemic, as well as the following events resulted in quarterly impairment testing: • During the second quarter of 2020, the Company announced that it would take certain strategic actions with respect to two of its thermal coal mining complexes in an effort to strengthen its financial performance and improve forecasted liquidity. The Company announced that an underground mine and preparation plant located in West Virginia would be idled during the third quarter of 2020. In addition, the Company decided not to move forward with the construction of a new refuse impoundment at its Cumberland mine in Pennsylvania and would therefore no longer spend the significant capital required in connection with the project. As a result, the Cumberland mine was expected to cease production by the end of 2022. On December 10, 2020, the Company sold its Cumberland mining operations. Refer to Note 3 for further details. • During the fourth quarter of 2020, changes in mine plans and the determination that certain mineral reserves previously forecasted to be mined were no longer considered economic due to poor geologic conditions reduced forecasted cash flows for one Met and one All Other asset group to amounts below those required for full recoverability. The Company performed long-lived asset impairment tests as of November 30, 2020, August 31, 2020, May 31, 2020, and February 29, 2020. In total, the Company determined that indicators of impairment with respect to five long-lived asset groups within its Met reporting segment, three long-lived asset groups within its All Other category, and one long-lived asset group within discontinued operations existed during the year ended December 31, 2020. The following tables present the details of the long-lived asset impairments Year Ended December 31, 2020 First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended Continuing operations: Met $ 32,951 $ — $ — $ 13,366 $ 46,317 All Other 758 17,390 219 16,270 34,637 Total from continuing operations $ 33,709 $ 17,390 $ 219 $ 29,636 $ 80,954 Discontinued operations: $ — $ 144,348 $ 3,297 $ — $ 147,645 Total long-lived asset impairment: $ 33,709 $ 161,738 $ 3,516 $ 29,636 $ 228,599 Year Ended December 31, 2020 First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended Continuing operations: Mineral rights, net $ 21,825 $ 2,241 $ — $ 17,513 $ 41,579 Property, plant, and equipment, net 6,066 6,496 219 5,450 18,231 Acquired mine permits, net 5,818 8,653 — 6,673 21,144 Total from continuing operations $ 33,709 $ 17,390 $ 219 $ 29,636 $ 80,954 Discontinued operations: Mineral rights, net $ — $ 16,364 $ — $ — $ 16,364 Property, plant, and equipment, net — 127,984 3,297 — 131,281 Total from discontinued operations $ — $ 144,348 $ 3,297 $ — $ 147,645 Total long-lived asset impairment: Mineral rights, net $ 21,825 $ 18,605 $ — $ 17,513 $ 57,943 Property, plant, and equipment, net 6,066 134,480 3,516 5,450 149,512 Acquired mine permits, net 5,818 8,653 — 6,673 21,144 Total long-lived asset impairment $ 33,709 $ 161,738 $ 3,516 $ 29,636 $ 228,599 Restructuring As a result of the strategic actions announced in the second quarter of 2020 and subsequent changes to severance and employee-related benefits, the Company recorded restructuring expense of ($621) in the All Other category during the year ended December 31, 2021. As a result of the strategic actions discussed above, the Company recorded restructuring expense during the year ended December 31, 2020 as follows: Year Ended December 31, 2020 Total Restructuring Continuing Operations (3) Discontinued Operations Severance and employee-related benefits (1) $ 26,037 $ 2,117 $ 23,920 Other costs (2) 1,882 807 1,075 Total restructuring expense $ 27,919 $ 2,924 $ 24,995 (1) Severance and employee-related benefits were considered probable and estimable based on provisions of contractual agreements and existing employee benefit plans. (2) Includes accelerated amortization of deferred longwall move expenses of $668, allowance for advanced mining royalties of $407, and allowance for obsolete materials and supplies inventory of $807.

Capital Stock

Capital Stock	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Capital Stock	Capital Stock Share Repurchase Program On March 4, 2022, the Company’s Board of Directors (the “Board”) adopted a share repurchase program that permitted the Company to repurchase up to an aggregate amount of $150,000 of the Company's common stock. On May 3, 2022, the Board amended the share repurchase program to increase the aggregate amount the Company is permitted to repurchase to $600,000 of the Company's common stock. On November 4, 2022, the Board amended the share repurchase program to increase the aggregate amount the Company is permitted to repurchase to $1,000,000 of the Company’s common stock. Share repurchases may be made from time to time through open market transactions, block trades, tender offers, or otherwise, and the program has no expiration date. The share repurchase program does not obligate the Company to acquire any particular amount of common stock or to acquire shares on any particular timetable, and the program may be suspended at any time at the Company’s discretion. Repurchases under the program are subject to market and business conditions, available liquidity, the Company’s cash needs, restrictions under agreements or obligations, legal or regulatory requirements or restrictions and other relevant factors. As of December 31, 2022, the Company had repurchased an aggregate of 3,544,413 shares under the program for an aggregate purchase price of approximately $516,952 (comprised of $516,845 of share repurchases and $107 of related fees). Refer to Note 25 for subsequent event disclosures related to an increase in the aggregate amount permitted to be repurchased under the share repurchase program. Dividend Program On May 3, 2022, the Board adopted a dividend policy. Pursuant to this policy, the Board initially intended to pay aggregate cash dividends of $1.50 per share of common stock per year, with $0.375 per share paid each quarter. Subsequently, during the year ended December 31, 2022, the Board increased the quarterly dividend amounts and also declared a one-time, special dividend. In addition, pursuant to the terms of certain stock-based compensation awards under the Company’s Management Incentive Plan (the “MIP”) and Long-Term Incentive Plan (the “LTIP”), dividend equivalent amounts for each quarterly dividend will become payable at various vesting dates with respect to each underlying outstanding award. The Board declared the following dividends on the Company’s common stock during the year ended December 31, 2022: Total Dividend per Share (1) Total Dividends Paid (2) Declaration Date Holders of Record Date Payable Date $ 0.375 $ 6,773 May 3, 2022 June 15, 2022 July 1, 2022 0.392 6,522 August 4, 2022 September 15, 2022 October 3, 2022 5.418 84,748 November 4, 2022 December 15, 2022 January 3, 2023 $ 6.185 $ 98,043 (1) The fourth quarter dividend declared on November 4, 2022 includes the quarterly cash dividend of $0.418 per share and the one-time, special dividend of $5.00 per share. (2) Excludes dividend equivalents paid or accrued of $3,444 as of December 31, 2022. As of December 31, 2022, a related $84,748 balance was held on deposit to facilitate the dividend payment on January 3, 2023. The Company expects any future dividend payments will be targeted to be paid in the first month of each calendar quarter. Any decisions as to whether and when to pay future cash dividends will, however, be made by the Board and depend on the Company’s future earnings and financial condition and other relevant factors. Refer to Note 25 for subsequent event disclosures related to the Company’s dividend program. Warrants On July 26, 2016, the Company issued 810,811 warrants. Pursuant to the terms in the underlying warrants agreement (refer to Note 2), the exercise price was adjusted from $46.911 per share to $46.804 per share as of the June 15, 2022 dividend record date while the warrant share number remained unchanged, at 1.15. Subsequently, as of the September 15, 2022 and December 15, 2022 dividend record dates, the exercise price was adjusted to $46.679 per share and $45.086 per share, respectively, and the warrant share number was adjusted to 1.16 and 1.20, respectively. Refer to Note 25 for subsequent event disclosures related to the Company’s dividend program which could result in an additional adjustment to the warrants exercise price and warrants share number. As of December 31, 2022, 190,838 warrants remained outstanding, with a total of 229,006 shares underlying the un-exercised warrants. For the year ended December 31, 2022, the Company issued 702,182 shares of common stock resulting from exercises of its warrants and, pursuant to the terms of the underlying warrants agreement, withheld 187,857 of the issued shares, in satisfaction of the warrant exercise price and in lieu of fractional shares, which were subsequently reclassified as treasury stock in the amount of $18,509. As of December 31, 2021, 801,246 warrants were outstanding, with a total of 921,433 shares underlying the un-exercised warrants. For the year ended December 31, 2021, the Company issued 143 shares of common stock resulting from exercises of

Property, Plant, and Equipment,

Property, Plant, and Equipment, Net	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment, Net	Property, Plant, and Equipment, net Property, plant, and equipment, net, consisted of the following: December 31, 2022 2021 Plant and mining equipment $ 723,056 $ 642,874 Mine development 130,144 115,357 Land 27,937 26,389 Office equipment, software and other 3,111 1,462 Construction in progress 49,583 19,992 Total property, equipment and mine development costs $ 933,831 $ 806,074 Less accumulated depreciation and amortization (491,186) (443,856) Total property, plant, and equipment, net $ 442,645 $ 362,218 Included in plant and mining equipment are assets under financing leases totaling $13,139 and $8,611 with accumulated depreciation of $7,710 and $5,624 as of December 31, 2022 and December 31, 2021, respectively. Depreciation and amortization expense associated with property, plant, equipment, and non-mineral asset retirement obligation assets, net, was $84,542, $86,506, and $153,631 for the years ended December 31, 2022, 2021, and 2020 respectively. Depreciation expense for the years ended December 31, 2022, 2021, and 2020 includes a credit of ($1,344), ($307), and ($3,689), respectively, related to revisions to asset retirement obligations. Refer to Note 16 for further disclosures related to asset retirement obligations. During the years ended December 31, 2021 and 2020, the Company recorded long-lived asset impairments which reduced the carrying value of property, plant, and equipment, net, by $60 and $18,231, respectively. Refer to Note 8 for further information.

Other Non-Current Assets

Other Non-Current Assets	12 Months Ended
	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Other Non-Current Assets	Other Non-Current Assets Other non-current assets consisted of the following: December 31, 2022 2021 Advanced mining royalties $ 7,476 $ 10,788 Long-term deposits 1,363 1,371 Equity method investments 23,070 20,460 Workers’ compensation receivables 44,734 51,355 Goodwill 10,736 — Other 15,816 24,660 Total other non-current assets $ 103,195 $ 108,634

Leases

Leases	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Leases	Leases The Company’s lease population consists primarily of vehicle and heavy equipment leases and leases for office equipment. The Company’s building and land leases relate to corporate office space and certain site offices. The Company determines whether a contract contains a lease based on whether the Company obtains the right to control the use of specifically identifiable property, plant, and equipment for a period of time in exchange for consideration. For the years ended December 31, 2022, 2021, and 2020 the Company identified no instances requiring significant judgment in determining whether any contracts entered into during the period were or were not leases. Additionally, the Company had no material sublease agreements within the scope of ASC 842 or lease agreements for which the Company was the lessor for the years ended December 31, 2022, 2021, and 2020. Renewal options in the Company’s lease population primarily relate to month-to-month extensions on vehicle leases and are immaterial both individually and in the aggregate. The Company includes renewal options that are reasonably certain to be exercised in the measurement of lease liabilities. As of December 31, 2022, the Company does not intend to exercise any termination options on existing leases. As of December 31, 2022 and 2021, the Company had the following right-of-use assets and lease liabilities within the Company’s Consolidated Balance Sheets: December 31, 2022 December 31, 2021 Assets Balance Sheet Classification Financing lease assets Property, plant, and equipment, net $ 5,429 $ 2,987 Operating lease right-of-use assets Other non-current assets 4,488 5,003 Total lease assets $ 9,917 $ 7,990 Liabilities Balance Sheet Classification Financing lease liabilities - current Current portion of long-term debt $ 1,052 $ 1,878 Operating lease liabilities - current Accrued expenses and other current liabilities 612 547 Financing lease liabilities - long-term Long-term debt 3,744 791 Operating lease liabilities - long-term Other non-current liabilities 3,876 4,456 Total lease liabilities $ 9,284 $ 7,672 Total lease costs and other lease information for the years ended December 31, 2022, 2021, and 2020 included the following: Year Ended December 31, 2022 2021 2020 Lease cost (1) Financing lease cost: Amortization of leased assets $ 2,644 $ 2,061 $ 3,238 Interest on lease liabilities 315 245 358 Operating lease cost 1,113 1,383 2,105 Short-term lease cost 1,234 786 1,518 Total lease cost $ 5,306 $ 4,475 $ 7,219 (1) The Company had no variable lease costs or sublease income for the years ended December 31, 2022, 2021, and 2020. Year Ended December 31, 2022 2021 2020 Other information Cash paid for amounts included in the measurement of lease liabilities $ 5,556 $ 4,478 $ 7,157 Operating cash flows from financing leases $ 315 $ 245 $ 358 Operating cash flows from operating leases $ 2,347 $ 2,169 $ 3,623 Financing cash flows from financing leases $ 2,894 $ 2,064 $ 3,176 Right-of-use assets obtained in exchange for new financing lease liabilities $ 4,728 $ 703 $ 221 Right-of-use assets obtained in exchange for new operating lease liabilities $ 48 $ 275 $ (12) Lease Term and Discount Rate Weighted-average remaining lease term in years - financing leases 5.90 1.75 1.94 Weighted-average remaining lease term in years - operating leases 7.10 7.88 8.45 Weighted-average discount rate - financing leases 13.5 % 9.6 % 6.1 % Weighted-average discount rate - operating leases 11.6 % 11.3 % 11.5 % The Company has elected to show net instead of gross amounts for right-of-use assets and liabilities within its Consolidated Statements of Cash Flows. The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Consolidated Balance Sheets as of December 31, 2022: Financing Leases Operating Leases Lease cost 2023 $ 1,597 $ 1,099 2024 1,335 955 2025 1,225 897 2026 691 884 2027 360 714 Thereafter 1,800 2,062 Total future minimum lease payments $ 7,008 $ 6,611 Imputed interest (2,212) (2,123) Present value of future minimum lease payments $ 4,796 $ 4,488
Leases	Leases The Company’s lease population consists primarily of vehicle and heavy equipment leases and leases for office equipment. The Company’s building and land leases relate to corporate office space and certain site offices. The Company determines whether a contract contains a lease based on whether the Company obtains the right to control the use of specifically identifiable property, plant, and equipment for a period of time in exchange for consideration. For the years ended December 31, 2022, 2021, and 2020 the Company identified no instances requiring significant judgment in determining whether any contracts entered into during the period were or were not leases. Additionally, the Company had no material sublease agreements within the scope of ASC 842 or lease agreements for which the Company was the lessor for the years ended December 31, 2022, 2021, and 2020. Renewal options in the Company’s lease population primarily relate to month-to-month extensions on vehicle leases and are immaterial both individually and in the aggregate. The Company includes renewal options that are reasonably certain to be exercised in the measurement of lease liabilities. As of December 31, 2022, the Company does not intend to exercise any termination options on existing leases. As of December 31, 2022 and 2021, the Company had the following right-of-use assets and lease liabilities within the Company’s Consolidated Balance Sheets: December 31, 2022 December 31, 2021 Assets Balance Sheet Classification Financing lease assets Property, plant, and equipment, net $ 5,429 $ 2,987 Operating lease right-of-use assets Other non-current assets 4,488 5,003 Total lease assets $ 9,917 $ 7,990 Liabilities Balance Sheet Classification Financing lease liabilities - current Current portion of long-term debt $ 1,052 $ 1,878 Operating lease liabilities - current Accrued expenses and other current liabilities 612 547 Financing lease liabilities - long-term Long-term debt 3,744 791 Operating lease liabilities - long-term Other non-current liabilities 3,876 4,456 Total lease liabilities $ 9,284 $ 7,672 Total lease costs and other lease information for the years ended December 31, 2022, 2021, and 2020 included the following: Year Ended December 31, 2022 2021 2020 Lease cost (1) Financing lease cost: Amortization of leased assets $ 2,644 $ 2,061 $ 3,238 Interest on lease liabilities 315 245 358 Operating lease cost 1,113 1,383 2,105 Short-term lease cost 1,234 786 1,518 Total lease cost $ 5,306 $ 4,475 $ 7,219 (1) The Company had no variable lease costs or sublease income for the years ended December 31, 2022, 2021, and 2020. Year Ended December 31, 2022 2021 2020 Other information Cash paid for amounts included in the measurement of lease liabilities $ 5,556 $ 4,478 $ 7,157 Operating cash flows from financing leases $ 315 $ 245 $ 358 Operating cash flows from operating leases $ 2,347 $ 2,169 $ 3,623 Financing cash flows from financing leases $ 2,894 $ 2,064 $ 3,176 Right-of-use assets obtained in exchange for new financing lease liabilities $ 4,728 $ 703 $ 221 Right-of-use assets obtained in exchange for new operating lease liabilities $ 48 $ 275 $ (12) Lease Term and Discount Rate Weighted-average remaining lease term in years - financing leases 5.90 1.75 1.94 Weighted-average remaining lease term in years - operating leases 7.10 7.88 8.45 Weighted-average discount rate - financing leases 13.5 % 9.6 % 6.1 % Weighted-average discount rate - operating leases 11.6 % 11.3 % 11.5 % The Company has elected to show net instead of gross amounts for right-of-use assets and liabilities within its Consolidated Statements of Cash Flows. The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Consolidated Balance Sheets as of December 31, 2022: Financing Leases Operating Leases Lease cost 2023 $ 1,597 $ 1,099 2024 1,335 955 2025 1,225 897 2026 691 884 2027 360 714 Thereafter 1,800 2,062 Total future minimum lease payments $ 7,008 $ 6,611 Imputed interest (2,212) (2,123) Present value of future minimum lease payments $ 4,796 $ 4,488

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Accrued Expenses and Other Current Liabilities	Accrued Expenses and Other Current Liabilities Accrued expenses and other current liabilities consisted of the following: December 31, 2022 2021 Wages and benefits $ 69,458 $ 53,564 Workers’ compensation 11,651 13,312 Black lung 9,664 7,295 Taxes other than income taxes 24,959 31,234 Asset retirement obligations 36,963 32,159 Accrued interest and fees 1,062 14,489 Dividend payable 86,118 — Freight accrual 7,181 15,085 Other 18,200 13,304 Total accrued expenses and other current liabilities $ 265,256 $ 180,442

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt Long-term debt consisted of the following: December 31, 2022 2021 Term Loan Credit Facility - due June 2024 $ — $ 449,435 Other (1) 10,975 5,311 Debt discount and issuance costs — (6,195) Total long-term debt $ 10,975 $ 448,551 Less current portion (3,078) (2,989) Long-term debt, net of current portion $ 7,897 $ 445,562 (1) Includes financing leases, refer to Note 12 for additional information. Term Loan Credit Facility - due June 2024 On June 14, 2019, the Company entered into a credit agreement with Cantor Fitzgerald Securities, as administrative agent and collateral agent, and the other lenders party thereto (as defined therein) (the “Term Loan Credit Agreement”) that provided for a senior secured term loan facility in the aggregate principal amount of $561,800 with a maturity date of June 14, 2024 (the “Term Loan Credit Facility”). Principal repayments equal to approximately $1,405 were due each March, June, September and December (commencing with September 30, 2019) with the final principal repayment installment to be paid on the maturity date and in an amount equal to the aggregate principal amount outstanding on such date. The Term Loan Credit Facility bore an interest rate per annum based on the character of the loan (defined as either “Base Rate Loan” or “Eurocurrency Rate Loan”). Each loan type bore interest at a rate per annum comprised of a base rate (as defined) plus an applicable percentage (6.00% for Base Rate Loans and 7.00% for Eurocurrency Rate Loans on or prior to the second anniversary of the Closing Date and 7.00% or 8.00% thereafter (the “Applicable Rate”)). The Eurocurrency base rate was subject to a 2.00% floor. Interest accrued on each Base Rate Loan was payable in arrears on the last business day of each March, June, September and December and the maturity date. Interest accrued on each Eurocurrency Rate Loan was payable in arrears on the last day of each interest period as defined therein. During the three months ending September 30, 2021, the Company repurchased and permanently retired, through privately negotiated transactions, $18,724 of outstanding principal borrowings under the Term Loan Credit Facility. These borrowings were repurchased at a discount resulting in an aggregate purchase price of $18,415. As the participating lenders were existing shareholders (related parties) of the Company as of the repurchase date, the Company analyzed various factors regarding each of the transactions and concluded such repurchases were at a reasonable market rate and reflected the terms of an arm’s length transaction per the requirements of the Term Loan Credit Facility. Additionally, during the third and fourth quarters of 2021, the Company made voluntary prepayments of $81,000 of outstanding principal borrowings under the Term Loan Credit Facility. As of December 31, 2021, the carrying value of the Term Loan Credit Facility was $443,241, all of which was classified as long-term within the Consolidated Balance Sheets. As of December 31, 2022, there were no outstanding borrowings under the Term Loan Credit Facility as a result of the Company’s voluntary prepayments of $449,435 of outstanding principal borrowings during the first and second quarters of 2022. Effective with the final voluntary prepayment on June 3, 2022, the Credit Agreement was terminated, and the Company was released of all underlying obligations including the Credit Agreement covenants. Second Amended and Restated Asset-Based Revolving Credit Agreement On December 6, 2021, the Company entered into the Second Amended and Restated Asset-Based Revolving Credit Agreement with Citibank N.A as administrative agent, collateral agent, swingline lender, and L/C issuer and the other lenders party thereto (the “Lenders”), and BMO Harris Bank N.A and Eclipse Business Capital LLC as co-collateral agents. The Second Amended and Restated Asset-Based Revolving Credit Agreement (“ABL Agreement”) amended and restated the Amended and Restated Asset-Based Revolving Credit Agreement dated November 9, 2018, in its entirety, and includes a senior secured asset-based revolving credit facility (the “ABL Facility”). Under the ABL Facility, the Company may borrow cash from the Lenders (as defined therein) or cause the L/C Issuers (as defined therein) to issue letters of credit, on a revolving basis, in an aggregate amount of up to $155,000, of which no more than $150,000 may represent outstanding letters of credit ($125,000 on a committed basis and another $25,000 on an uncommitted cash collateralized basis) with the facility having a maturity date of December 6, 2024. The ABL Agreement extended the maturity date of the facility from the previous maturity of April 3, 2022. Under the terms of the ABL Agreement, letters of credit fees will be calculated at 5.25%, while any future borrowings will bear interest based on the character of the loan (defined as either secured overnight financing rate “SOFR” Loan (“SOFR Loan”) or “Base Rate Loan”) plus an applicable rate of 4.50% for SOFR Loans and 3.50% for Base Rate Loans. Pursuant to terms of the ABL Agreement at each notice period, the Company elects the character of the loan, the interest period, and may provide notice of continuation or conversion of the borrowed principal amount with the ability to repay the borrowed principal amount in advance of the maturity date without penalty. As of December 31, 2022 and 2021, no borrowings were outstanding under the ABL Facility. The ABL Agreement provides that a specified percentage of billed and unbilled receivables and raw and clean inventory meeting certain criteria are eligible to be counted for purposes of collateralizing the amount of financing available, subject to certain terms and conditions. Availability under the ABL Facility is calculated on a monthly basis and fluctuates based on qualifying amounts of coal inventory and trade accounts receivable (the “Borrowing Base”) and the facility's covenant limitations related to the Fixed Charge Coverage Ratio (as defined therein). In accordance with the terms of the ABL Facility, the Company may be required to collateralize the ABL Facility to the extent outstanding borrowings and letters of credit under the ABL Facility exceed the Borrowing Base after considering covenant limitations. Any letter of credit issued under the ABL Facility will bear a commitment fee rate of 0.50%, and a fronting fee of 0.25% of the face amount under each letter of credit. As of December 31, 2022 and 2021, the Company had $61,877 and $121,037 letters of credit outstanding under the ABL Facility, respectively. The ABL Facility is guaranteed by substantially all of Alpha’s direct and indirect subsidiaries (together with Alpha, the “Loan Parties”) and secured by all or substantially all assets of the Loan Parties, including equity in Alpha’s direct domestic subsidiaries, as collateral for the obligations under the ABL Facility. The ABL Facility has a first lien on ABL priority collateral and previously had a second lien on Term Loan priority collateral. As noted above, the Term Loan Credit Facility was voluntarily prepaid in full on June 3, 2022, and in connection therewith, the Term Loan priority collateral was released in connection therewith, and the ABL Facility’s lien on the Term Loan priority collateral is no longer second. The ABL Agreement, as amended, and related documents contain negative and affirmative covenants including certain financial covenants. The Company is in compliance with all covenants under these agreements as of December 31, 2022. Future Maturities Future maturities of long-term debt as of December 31, 2022 are as follows: 2023 $ 3,078 2024 3,076 2025 2,879 2026 468 2027 171 After 2027 1,303 Total long-term debt $ 10,975

Acquisition-Related Obligations

Acquisition-Related Obligations	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Acquisition-Related Obligations	Acquisition-Related Obligations Acquisition-related obligations consisted of the following: December 31, 2022 2021 Contingent Revenue Obligation $ 27,719 $ 35,005 Environmental Settlement Obligations 535 6,633 Discount — (233) Total acquisition-related obligations $ 28,254 $ 41,405 Less current portion (28,254) (22,405) Acquisition-related obligations, net of current portion $ — $ 19,000 The Company entered into various settlement agreements with Alpha Natural Resources, Inc. and/or the Alpha Natural Resources, Inc. bankruptcy successor ANR, Inc. and third parties as part of the Alpha Natural Resources, Inc. bankruptcy reorganization process. The Company assumed acquisition-related obligations through those settlement agreements which became effective on July 26, 2016, the effective date of Alpha Natural Resources, Inc.’s plan of reorganization. Additionally, as a result of the Merger, the Company assumed certain acquisition-related obligations pursuant to the terms stipulated within the bankruptcy settlement previously entered into by the Merger Companies. Contingent Revenue Obligation As a result of the Merger, the Company assumed a contingent revenue payment obligation (the “Contingent Revenue Obligation”) to certain of the Merger Companies’ creditors pursuant to the terms stipulated within the bankruptcy settlement previously entered into by the Merger Companies. Pursuant to terms of the obligation, the annual obligation will be limited to revenues derived from legacy operations for the Merger Companies and will not include revenues related to legacy Alpha Metallurgical Resources, Inc. operations. The Contingent Revenue Obligation consists of a contingent revenue payment of 1.5% of annual gross revenues of the legacy operations for the Merger Companies up to $500,000 and 1.0% of annual gross revenue of the legacy operations for the Merger Companies in excess of $500,000 through the period ended December 31, 2022. The corresponding final payment is expected to be paid from a short-term restricted cash escrow account during the second quarter of 2023. As of December 31, 2022 and 2021, the carrying value of the Contingent Revenue Obligation was $27,719 and $35,005, with $27,719 and $16,005 classified as current, respectively, and classified as an acquisition-related obligation in the Consolidated Balance Sheets. Refer to Note 17 for further disclosures related to the fair value assignment and methods used. During the second quarter of 2022, the Company paid $16,166 pursuant to terms of the Contingent Revenue Obligation. Refer to Note 21 for disclosures related to a Contingent Revenue Obligation repurchase transaction with a related party during the fourth quarter of 2021. Additionally, during the second quarter of 2021, the Company paid $11,396 pursuant to terms of the Contingent Revenue Obligation. Environmental Settlement Obligations As a result of the Merger, the Company assumed certain environmental settlement obligations (the “Environmental Settlement Obligations”) pursuant to the terms stipulated within the bankruptcy settlement previously entered into by the Merger Companies. These obligations include payments to a third-party environmental agency and the funding of certain reclamation related projects through 2023. As of December 31, 2022 and 2021, the carrying value of the Environmental Settlement Obligations was $535 and $6,400, net of discounts of $0 and $233, all of which was classified as a current acquisition-related obligation in the Consolidated Balance Sheets.

Asset Retirement Obligations

Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations	Asset Retirement Obligations The following table summarizes the changes in asset retirement obligations for the years ended December 31, 2022 and 2021: Total asset retirement obligations at December 31, 2020 $ 165,064 Accretion for the period 26,520 Sites added during the period 2,125 Revisions in estimated cash flows (1) (12,744) Expenditures for the period (16,793) Total asset retirement obligations at December 31, 2021 $ 164,172 Accretion for the period 23,765 Sites added during the period 9,602 Revisions in estimated cash flows 304 Expenditures for the period (18,832) Total asset retirement obligations at December 31, 2022 $ 179,011 Less current portion (2) (36,963) Long-term portion $ 142,048 (1) The revisions in estimated cash flows resulted primarily from discount rate adjustments and changes in mine plans. (2) Included within Accrued expenses and other current liabilities on the Company’s Consolidated Balance Sheets. Refer to Note 13.

Fair Value of Financial Instrum

Fair Value of Financial Instruments and Fair Value Measurements	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments and Fair Value Measurements	Fair Value of Financial Instruments and Fair Value Measurements The estimated fair values of financial instruments are determined based on relevant market information. These estimates involve uncertainty and cannot be determined with precision. The carrying amounts for cash and cash equivalents, trade accounts receivable, net, prepaid expenses and other current assets, restricted cash, deposits, trade accounts payable, accrued expenses and other current liabilities, and environmental settlement obligations approximate fair value as of December 31, 2022 and 2021 due to the short maturity of these instruments. The following table sets forth by level, within the fair value hierarchy, the Company’s long-term debt at fair value as of December 31, 2021: December 31, 2021 Carrying (1) Total Fair Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Term Loan Credit Facility - due June 2024 $ 443,241 $ 447,561 $ — $ 447,561 $ — (1) Net of debt discounts and debt issuance costs. The following table sets forth by level, within the fair value hierarchy, the Company’s financial and non-financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2022 and 2021. Financial and non-financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the determination of fair value for assets and liabilities and their placement within the fair value hierarchy levels. December 31, 2022 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 27,719 $ — $ — $ 27,719 Trading securities (1) $ 151,787 $ — $ 151,787 $ — (1) Includes $46,052 classified as Short-term investments and $105,735 classified as Long-term restricted investments on the Company’s Consolidated Balance Sheets. December 31, 2021 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 35,005 $ — $ — $ 35,005 Trading securities (1) $ 30,949 $ 27,075 $ 3,874 $ — (1) Classified as Long-term restricted investments on the Company’s Consolidated Balance Sheets. The following tables are reconciliations of the financial and non-financial assets and liabilities that were accounted for at fair value on a recurring basis and that were categorized within Level 3 of the fair value hierarchy: December 31, 2021 Payments Loss Recognized in Earnings Transfer In (Out) of Level 3 Fair Value Hierarchy December 31, 2022 Contingent Revenue Obligation $ 35,005 $ (16,166) $ 8,880 $ — $ 27,719 (1) The loss recognized in earnings resulted primarily from an increase in forecasted future revenue as of December 31, 2022. December 31, 2020 Payments Loss Recognized in Earnings Transfer In (Out) of Level 3 Fair Value Hierarchy December 31, 2021 Contingent Revenue Obligation $ 28,967 $ (13,487) $ 19,525 $ — $ 35,005 (1) The loss recognized in earnings resulted primarily from an increase in forecasted future revenue as of December 31, 2021. The following methods and assumptions were used to estimate the fair values of the assets and liabilities in the tables above: Level 1 Fair Value Measurements Trading Securities - Typically includes money market funds. The fair value is based on observable market data. Level 2 Fair Value Measurements Term Loan Credit Facility - due June 2024 - The fair value was based on the average between bid and ask prices provided by a third-party. As the fair value is based on observable market inputs and due to limited trading volume in the Term Loan Credit Facility, the Company has classified the fair value within Level 2 of the fair value hierarchy. Effective June 3, 2022, the Term Loan Credit Facility was terminated. Refer to Note 14 for additional information. Trading Securities - Typically includes certificates of deposit, corporate fixed income and U.S. government securities. The fair values are obtained from a third-party pricing service provider. The fair values provided by the pricing service provider are based on observable market inputs including credit spreads and broker-dealer quotes, among other inputs. The Company classifies the prices obtained from the pricing services within Level 2 of the fair value hierarchy because the underlying inputs are directly observable from active markets. However, the pricing models used entail a certain amount of subjectivity and therefore differing judgments in how the underlying inputs are modeled could result in different estimates of fair value. Level 3 Fair Value Measurements Contingent Revenue Obligation - The fair value of the Contingent Revenue Obligation was estimated using a Black-Scholes pricing model. The inputs included in the Black-Scholes pricing model are the Company's forecasted future revenue, the stated royalty rate, the remaining periods in the obligation, annual risk-free interest rate based on the U.S. Constant Maturity Treasury Curve and annualized volatility. The annualized volatility was calculated by observing volatilities for comparable companies with adjustments for the Company's size and leverage. As the royalty period ended on December 31, 2022, the fair value of the remaining obligation represents the actual final calculated payment to be made during the second quarter of 2023. Refer to Note 15 for additional information. The range of significant unobservable inputs used to value the Contingent Revenue Obligation as of December 31, 2021 are set forth in the following table: December 31, 2021 Forecasted future revenue $1.5 - $2.0 billion Stated royalty rate 1.0% - 1.5% Annualized volatility 18.4% - 39.3% (29.9%)

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Significant components of income tax expense (benefit) from continuing operations were as follows: Year Ended December 31, 2022 2021 2020 Current tax expense (benefit): Federal $ 114,106 $ 2,422 $ (35,187) State 6,620 1,149 (99) Total current $ 120,726 $ 3,571 $ (35,286) Deferred tax (benefit) expense: Federal $ (1,726) $ (3) $ 33,348 State (12,795) (160) (226) Total deferred $ (14,521) $ (163) $ 33,122 Total income tax expense (benefit): Federal $ 112,380 $ 2,419 $ (1,839) State (6,175) 989 (325) Total $ 106,205 $ 3,408 $ (2,164) A reconciliation of statutory federal income tax expense (benefit) on income (loss) from continuing operations to the actual income tax expense (benefit) is as follows: Year Ended December 31, 2022 2021 2020 Federal statutory income tax expense (benefit) $ 326,497 $ 61,362 $ (51,163) Increase (reductions) in taxes due to: Percentage depletion allowance (50,277) (11,864) (2,039) Foreign-derived intangible income deduction (69,917) (1,453) — Change in valuation allowances (119,082) (78,043) 59,929 State taxes, net of federal tax impact 14,625 12,440 (9,640) State apportioned tax rate change, net of federal tax impact 273 8,751 (1,235) Capital loss carryforward expiration 140 10,552 — Other, net 3,946 1,663 1,984 Income tax expense (benefit) $ 106,205 $ 3,408 $ (2,164) Deferred income taxes result from temporary differences between the reporting of amounts for financial statement purposes and income tax purposes. The net deferred tax assets and liabilities included in the Consolidated Balance Sheets include the following amounts: Year Ended December 31, 2022 2021 Deferred tax assets: Asset retirement obligations $ 39,200 $ 36,252 Reserves and accruals not currently deductible 10,572 9,610 Workers’ compensation benefit obligations 38,099 47,105 Pension obligations 23,826 34,956 Equity method investments 1,555 1,846 Net operating loss carryforwards 43,716 137,865 Capital loss carryforwards 48,940 49,476 Acquisition-related obligations 6,194 9,156 Other 7,171 7,100 Gross deferred tax assets 219,273 333,366 Less valuation allowance (53,801) (172,883) Deferred tax assets $ 165,472 $ 160,483 Deferred tax liabilities: Property, plant and mineral reserves $ (148,189) $ (134,075) Acquired intangibles, net (11,995) (16,408) Prepaid expenses (4,215) (4,955) Restricted cash (556) (5,362) Other (13) — Total deferred tax liabilities (164,968) (160,800) Net deferred tax assets (liabilities) $ 504 $ (317) Changes in the valuation allowance were as follows: Year Ended December 31, 2022 2021 2020 Valuation allowance beginning of period $ 172,883 $ 263,387 $ 133,020 (Decrease) increase in valuation allowance recorded to income tax expense (benefit) (119,082) (78,043) 117,829 (Decrease) increase in valuation allowance not affecting income tax expense (benefit) — (12,461) 12,538 Valuation allowance end of period $ 53,801 $ 172,883 $ 263,387 At December 31, 2022, the Company has regular tax net operating loss carryforwards for federal income tax purposes of approximately $1,139,000. This includes approximately $1,007,000 that are available to offset regular federal taxable income subject to an annual Internal Revenue Code Section 382 limitation of approximately $1,000 and $132,000 that are subject to an annual Section 382 limitation of approximately $17,500. These federal net operating loss carryforwards were generated before 2018 and will expire between years 2030 and 2037. The Company has capital loss carryforwards of approximately $223,000. The capital loss carryforwards will expire between years 2024 and 2025. A valuation allowance is recorded against the capital loss carryforwards and certain state net operating loss carryforwards. During the third quarter of the year ended December 31, 2020, the Company recorded a decrease in unrecognized tax benefits of approximately $20,788 as a result of the issuance of final regulatory guidance from the Internal Revenue Service (“IRS”). The decrease in unrecognized tax benefits did not impact the Company’s effective tax rate for the year ended December 31, 2020. The Company’s policy is to classify interest and penalties related to uncertain tax positions as part of income tax expense. As of December 31, 2022 and 2021, the Company had no accrued interest and penalties. The following reconciliation illustrates the Company’s liability for uncertain tax positions: Year Ended December 31, 2022 2021 2020 Unrecognized tax benefits - beginning of period $ — $ — $ 20,788 Reductions for tax positions of prior years — — (20,788) Unrecognized tax benefits - end of period $ — $ — $ — As of December 31, 2022, tax years 2019 – 2022 remain open to federal and state examination. During the third quarter of 2021, the IRS concluded its audit of the Company’s 2016 federal income tax return and associated net operating loss (“NOL”) carryback claim. The audit conclusion did not result in any material impact to the financial statements or related disclosures. Following the conclusion of the audit, the Company received the $64,160 carryback claim tax refund and $5,425 of accrued interest. On August 16, 2022, the Inflation Reduction Act of 2022 (“IRA”) was signed into law. Among other provisions, the IRA enacted a 15% corporate alternative minimum tax and a 1% excise tax on repurchases of corporate stock for tax years beginning after December 31, 2022. The Company is currently assessing the impact of the IRA but does not expect it to have a material impact on our results of operations.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2022
Compensation Related Costs [Abstract]
Employee Benefit Plans	Employee Benefit Plans The Company provides several types of benefits for its employees, including defined benefit and defined contribution pension plans, workers’ compensation and black lung benefits, and postretirement life insurance. The Company does not participate in any multi-employer plans. The components of net periodic benefit (credit) cost other than the service cost component for black lung are included in the line item Miscellaneous income (loss), net, in the Consolidated Statements of Operations. Company Administered Defined Benefit Pension Plans In connection with the Merger, the Company assumed three qualified non-contributory defined benefit pension plans, which cover certain salaried and non-union hourly employees. The qualified non-contributory defined benefit pension plans are collectively referred to as the “Pension Plans.” Benefits are frozen under these plans. Participants accrued benefits either based on certain formulas, the participant’s compensation prior to retirement, or plan specified amounts for each year of service with the Company. One of the Company’s frozen qualified non-contributory defined benefit pension plans utilizes a cash balance formula for certain of its participants. The cash balance formula provides guaranteed rates of interest on accumulated balances of 6% for balances accumulated prior to 2004 and 4% on balances accumulated thereafter. Annual funding contributions to the Pension Plans are made as recommended by consulting actuaries based upon the ERISA funding standards. Projected contributions are based on the latest available data and include the impact of the funding relief granted by the American Rescue Plan Act ("ARPA") and the application of the interest rate stabilization guidance under ARPA. Plan assets consist of equity securities, fixed income funds, commingled short-term funds, private equity funds, and a guaranteed insurance contract. Effective in 2019, two of the qualified non-contributory defined benefit pension plans were amended to offer certain eligible participants the option to elect to receive lump sum benefits, which resulted in a partial plan settlement and the accelerated recognition of a portion of the accumulated other comprehensive loss during the years ended December 31, 2022, 2021, and 2020. Refer to the disclosures below for further information on the partial plan settlements. The following tables set forth the Pension Plans’ accumulated benefit obligations, fair value of plan assets and funded status for the years ended December 31, 2022 and 2021. Year Ended December 31, 2022 2021 Change in benefit obligations: Accumulated benefit obligation at beginning of period: $ 668,055 $ 723,448 Interest cost 15,981 13,566 Actuarial gain (1) (182,441) (34,922) Benefits paid (30,378) (30,222) Settlement (2,775) (3,815) Accumulated benefit obligation at end of period $ 468,442 $ 668,055 Change in fair value of plan assets: Fair value of plan assets at beginning of period $ 508,125 $ 504,777 Actual return on plan assets (120,796) 30,814 Employer contributions 3,430 6,571 Benefits paid (30,378) (30,222) Settlement (2,775) (3,815) Fair value of plan assets at end of period $ 357,606 $ 508,125 Funded status $ (110,836) $ (159,930) Accrued benefit cost at end of period (2) $ (110,836) $ (159,930) (1) For the year ended December 31, 2022, the actuarial gain was primarily attributable to the loss on plan assets and the change in the weighted-average discount rate actuarial assumption used in determining the benefit obligations. For the year ended December 31, 2021, the actuarial gain was primarily attributable to the change in the weighted-average discount rate actuarial assumption used in determining the benefit obligations. (2) Amounts are classified as long-term on the Consolidated Balance Sheets as there are sufficient plan assets to make expected benefit payments to plan participants in the succeeding twelve months. Gross amounts related to benefit obligations recognized in accumulated other comprehensive loss consisted of the following as of December 31, 2022 and 2021: December 31, 2022 2021 Net actuarial loss $ 12,683 $ 47,950 The following table details the components of net periodic benefit credit: Year Ended December 31, 2022 2021 2020 Interest cost $ 15,981 $ 13,566 $ 18,730 Expected return on plan assets (28,733) (28,732) (27,064) Amortization of net actuarial loss 2,111 3,217 2,012 Settlement 244 412 1,636 Net periodic benefit credit $ (10,397) $ (11,537) $ (4,686) Other changes in plan assets and benefit obligations recognized in other comprehensive (loss) income are as follows: Year Ended December 31, 2022 2021 2020 Actuarial (gain) loss $ (32,912) $ (37,004) $ 45,663 Amortization of net actuarial loss (2,111) (3,217) (2,012) Settlement (244) (412) (1,636) Total recognized in other comprehensive (loss) income $ (35,267) $ (40,633) $ 42,015 The following table presents information applicable to plans with accumulated benefit obligations in excess of plan assets: Year Ended December 31, 2022 2021 Projected benefit obligation $ 468,442 $ 668,055 Accumulated benefit obligation $ 468,442 $ 668,055 Fair value of plan assets $ 357,606 $ 508,125 The weighted-average actuarial assumption used in determining the benefit obligations as of December 31, 2022 and 2021 was as follows: December 31, 2022 2021 Discount rate 5.42 % 2.92 % The weighted-average actuarial assumptions used to determine net periodic benefit credit for the years ended December 31, 2022, 2021, and 2020 were as follows: Year Ended December 31, 2022 2021 2020 Discount rate for benefit obligation 2.92 % 2.62 % 3.35 % Discount rate for interest cost 2.44 % 1.96 % 2.92 % Expected long-term rate of return on plan assets 5.80 % 5.80 % 5.90 % The discount rate assumptions were determined from a high-quality corporate bond yield-curve timing of the Company’s projected cash out flows. The expected long-term rate of return on assets of the Pension Plans is established each year in consultation with the plans’ actuaries and outside investment advisors. This rate is determined by taking into consideration the Pension Plans’ target asset allocation, expected long-term rates of return on each major asset class by reference to long-term historic ranges, inflation assumptions, and the expected additional value from active management of the Pension Plans’ assets. For the determination of net periodic benefit cost in 2023, the Company will utilize an expected long-term rate of return on plan assets of 6.20%. Assets of the Pension Plans are held in trusts and are invested in accordance with investment guidelines that have been established by the Company’s Benefits Committee in consultation with outside investment advisors. The target allocation for 2023 and the actual asset allocation as reported at December 31, 2022 are as follows: Target Allocation Percentages 2023 Percentage of Plan Assets 2022 Equity securities 58.0 % 55.0 % Fixed income funds 42.0 % 41.0 % Other — % 4.0 % Total 100.0 % 100.0 % The asset allocation targets have been set with the expectation that the Pension Plans’ assets will fund the expected liabilities within an appropriate level of risk. In determining the appropriate target asset allocations, the Benefits Committee considers the demographics of the Pension Plans’ participants, the funded status of each plan, the Company’s contribution philosophy, the Company’s business and financial profile, and other associated risk factors. The Pension Plans’ assets are periodically rebalanced among the major asset categories to maintain the asset allocation within a specified range of the target allocation percentage. The target allocation between equity securities and fixed income funds is determined by reference to the funded status percentage for each of the Pension Plans. The plan administrator uses a one-way de-risking glide path whereby the fixed income funds allocation increases as the funded status improves. At a 90.0% funded status level, the glide path calls for a 50/50 equity securities and fixed income funds mix. During the year ended December 31, 2021, one of the Pension Plans funded status levels reached 90.0% and the related plan assets were adjusted accordingly to the new allocation. The Company contributed $3,430 to the pension plans during the year ended December 31, 2022. The Company expects to contribute $25,011 to the Pension Plans in 2023, which includes amounts above the estimated minimum required contributions for the 2023 plan year. The following represents expected future pension benefit payments for the next ten years: 2023 $ 31,084 2024 31,103 2025 31,136 2026 31,215 2027 31,264 2028-2032 153,885 $ 309,687 The fair values of the Company’s Pension Plans’ assets as of December 31, 2022, by asset category are as follows: Asset Category Total Quoted Market Prices in Active Market for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Equity securities: Multi-asset fund (1) $ 198,262 $ — $ 198,262 $ — Fixed income funds: Bond fund (2) 144,197 — 144,197 — Commingled short-term fund (3) 1,339 — 1,339 — Other types of investments: Guaranteed insurance contract 11,912 — — 11,912 Total $ 355,710 $ — $ 343,798 $ 11,912 Receivable (4) 1,145 Total assets at fair value 356,855 Private equity funds measured at net asset value practical expedient (5) 751 Total plan assets $ 357,606 (1) This fund contains equities (domestic and international), real estate and bonds. (2) This fund contains bonds representing a diversity of sectors and maturities. This fund also includes mortgage-backed securities and U.S. Treasuries. (3) This fund contains cash and highly liquid short-term investments in a collective investment fund. (4) Receivable for investments sold at December 31, 2022, which approximates fair value. (5) In accordance with Accounting Standards Update 2015-07, investments that are measured at fair value using the net asset value per share practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the total value of assets of the plans. Changes in Level 3 plan assets for the period ended December 31, 2022 were as follows: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Guaranteed Insurance Contract Beginning balance, December 31, 2021 $ 11,652 Actual return on plan assets: Relating to assets still held at the reporting date 562 Purchases, sales and settlements (302) Ending balance, December 31, 2022 $ 11,912 The fair values of the Company’s Pension Plans’ assets as of December 31, 2021, by asset category are as follows: Asset Category Total Quoted Market Prices in Active Market for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Equity securities: Multi-asset fund (1) $ 284,568 $ — $ 284,568 $ — Fixed income funds: Bond fund (2) 208,466 — 208,466 — Commingled short-term fund (3) 1,384 — 1,384 — Other types of investments: Guaranteed insurance contract 11,652 — — 11,652 Total $ 506,070 $ — $ 494,418 $ 11,652 Receivable (4) 876 Total assets at fair value 506,946 Private equity funds measured at net asset value practical expedient (5) 1,179 Total plan assets $ 508,125 (1) This fund contains equities (domestic and international), real estate and bonds. (2) This fund contains bonds representing a diversity of sectors and maturities. This fund also includes mortgage-backed securities and U.S. Treasuries. (3) This fund contains cash and highly liquid short-term investments in a collective investment fund. (4) Receivable for investments sold at December 31, 2021, which approximates fair value. (5) In accordance with Accounting Standards Update 2015-07, investments that are measured at fair value using the net asset value per share practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the total value of assets of the plans. Changes in Level 3 plan assets for the period ended December 31, 2021 were as follows: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Guaranteed Insurance Contract Beginning balance, December 31, 2020 $ 11,454 Actual return on plan assets: Relating to assets still held at the reporting date 528 Purchases, sales and settlements (330) Ending balance, December 31, 2021 $ 11,652 The following is a description of the valuation methodologies used for assets measured at fair value: Level 1 Plan Assets: Assets consist of individual security positions that are easily traded on recognized market exchanges. These securities are priced and traded daily, and therefore the fund is valued daily. Level 2 Plan Assets: Funds consist of individual security positions that are mostly securities easily traded on recognized market exchanges. These securities are priced and traded daily, and therefore the fund is valued daily. Level 3 Plan Assets: Assets are valued monthly or quarterly based on the Market Value provided by managers of the underlying fund investments. The Market Value provided typically reflects the fair value of each underlying fund investment, including unrealized gains and losses. Workers’ Compensation and Pneumoconiosis (Black Lung) The Company is required by federal and state statutes to provide benefits to employees for awards related to workers’ compensation and black lung. The Company’s subsidiaries utilize high-deductible third-party insurance for worker’s compensation and black lung obligations with the exception of certain subsidiaries in which the Company is a qualified self-insurer for workers’ compensation and/or black lung obligations. The Company’s subsidiaries that are self-insured for black lung benefits may fund certain benefit payments through a Section 501(c) (21) tax-exempt trust fund. Pursuant to the Merger Agreement, the Company assumed a reinsurance contract with a third party. In 2017, the Merger Companies made a lump sum payment in exchange for a reinsurance company’s agreement to administer and pay certain future workers’ compensation and state black lung obligations in the state of Kentucky. Pursuant to the Merger Agreement, the Company assumed the estimated liability for these future claims. As the liabilities are paid by the insurance company, the prepaid insurance amounts will be reduced by a corresponding amount. The Company accrues for workers’ compensation liability by recognizing costs when it is probable that a covered liability has been incurred and the cost can be reasonably estimated. The Company’s estimates of these costs are adjusted based upon actuarial studies and include a provision for incurred but not reported losses. Actual losses may differ from these estimates, which could increase or decrease the Company’s costs. Additionally, the liability for black lung benefits is estimated by an independent actuary by prorating the accrual of actuarially projected benefits over the employee’s applicable term of service. Adjustments to the probable ultimate liability for workers’ compensation and black lung are made annually based on actuarial valuations. For the Company’s subsidiaries that are insured with a high-deductible insurance plan for workers’ compensation and black lung claims, the insurance premium expense for the years ended December 31, 2022, 2021 and 2020 was $9,274, $8,630, and $7,000, respectively. Workers’ Compensation The table below presents workers’ compensation amounts recognized in the Consolidated Balance Sheets: December 31, 2022 2021 Current liabilities $ 11,651 $ 13,312 Long-term liabilities 107,028 124,693 Total liabilities $ 118,679 $ 138,005 Less expected insurance receivable (1) (46,866) (53,664) Workers’ compensation obligations, net of expected insurance receivables $ 71,813 $ 84,341 (1) Included within Prepaid expenses and other current assets and Other non-current assets in the Consolidated Balance Sheets. Workers’ compensation (credit) expense for high-deductible insurance plans for the years ended December 31, 2022, 2021, and 2020 was ($1,995), $664, and $1,275, respectively, included within Cost of coal sales in the Consolidated Statements of Operations. Black Lung The divestiture of the Company’s former NAPP operations during the fourth quarter of 2020 (refer to Note 3) resulted in a partial plan settlement of $8,290 and the accelerated recognition of a portion of the accumulated other comprehensive loss of $1,563 during the three months ended December 31, 2020. Refer to the disclosures below for further information on the partial plan settlement. As a result of the strategic actions impacting certain mines during the three months ended June 30, 2020 (refer to Note 8), black lung obligations were revalued for curtailment and remeasured with an updated discount rate as of May 31, 2020, which resulted in an increase in the liability for black lung obligations of approximately $7,400 with the offset to accumulated other comprehensive loss and a slight increase in net periodic expense to be recognized subsequent to the remeasurement date. Refer to the disclosures below for further information. The following tables set forth the accumulated black lung benefit obligations, fair value of plan assets and funded status for the years ended December 31, 2022 and 2021: Year Ended December 31, 2022 2021 Change in benefit obligation: Accumulated benefit obligation at beginning of period $ 117,142 $ 127,506 Service cost 2,642 2,972 Interest cost 2,722 2,463 Actuarial gain (1) (21,060) (9,759) Benefits paid (8,025) (6,040) Accumulated benefit obligation at end of period $ 93,421 $ 117,142 Change in fair value of plan assets: Fair value of plan assets at beginning of period $ 2,664 $ 2,720 Actual return on plan assets (126) (56) Benefits paid (8,025) (6,040) Employer contributions 8,025 6,040 Fair value of plan assets at end of period (2) 2,538 2,664 Funded status $ (90,883) $ (114,478) Accrued benefit cost at end of period $ (90,883) $ (114,478) (1) For the years ended December 31, 2022 and 2021, the actuarial gain was primarily attributable to the change in the weighted-average discount rate actuarial assumption used in determining the benefit obligations. (2) Assets of the plan are held in a Section 501(c)(21) tax-exempt trust fund and consist primarily of government debt securities. All assets are classified as Level 1 and valued based on quoted market prices. The table below presents amounts recognized in the Consolidated Balance Sheets: December 31, 2022 2021 Current liabilities $ 9,664 $ 7,295 Long-term liabilities 81,219 107,183 Total liabilities $ 90,883 $ 114,478 Gross amounts related to the black lung benefit obligations recognized in accumulated other comprehensive loss consisted of the following as of December 31, 2022 and 2021: December 31, 2022 2021 Net actuarial (gain) loss $ (10,198) $ 11,940 The following table details the components of the net periodic benefit cost for the black lung benefit obligations: Year Ended December 31, 2022 2021 2020 Service cost $ 2,642 $ 2,972 $ 2,361 Interest cost 2,722 2,463 3,240 Expected return on plan assets (53) (54) (54) Amortization of net actuarial loss 1,257 2,453 1,942 Settlement — — 1,563 Net periodic benefit cost $ 6,568 $ 7,834 $ 9,052 Summary net periodic benefit cost: Continuing operations $ 6,568 $ 7,834 $ 7,670 Discontinued operations (1) — — 1,382 Total net periodic benefit cost $ 6,568 $ 7,834 $ 9,052 (1) The discontinued operations consisted of activity related to the Company’s former NAPP operations. Refer to Note 3. Other changes in the black lung plan assets and benefit obligations recognized in other comprehensive (loss) income are as follows: Year Ended December 31, 2022 2021 2020 Actuarial (gain) loss $ (20,881) $ (9,649) $ 14,567 Amortization of net actuarial loss (1,257) (2,453) (1,942) Settlement — — (1,563) Total recognized in other comprehensive (loss) income $ (22,138) $ (12,102) $ 11,062 The weighted-average assumptions related to black lung obligations used to determine the benefit obligation as of December 31, 2022 and 2021 were as follows: December 31, 2022 2021 Discount rate 5.42 % 2.96 % Federal black lung income benefit trend rate 2.50 % 2.00 % Federal black lung medical benefit trend rate 5.00 % 5.00 % The weighted-average assumptions related to black lung benefit obligations used to determine net periodic benefit cost were as follows: Year Ended December 31, 2022 2021 2020 Discount rate for benefit obligation 2.96 % 2.75 % 3.47 % Discount rate for service cost 3.24 % 3.15 % 3.56 % Discount rate for interest cost 2.37 % 1.96 % 2.61 % Federal black lung income benefit trend rate 2.50 % 2.00 % 2.50 % Federal black lung medical benefit trend rate 5.00 % 5.00 % 5.00 % Black lung benefit expense inflation rate (1) — % — % 2.00 % Expected return on plan assets 2.00 % 2.00 % 2.00 % (1) Effective in 2021, the annual claim administration expenses are incorporated into the annual service cost component of the net periodic benefit cost for the black lung benefit obligations. Estimated future cash payments related to black lung benefit obligations for the next 10 years ending after December 31, 2022 are as follows: Year ending December 31: 2023 $ 9,664 2024 9,218 2025 9,009 2026 8,923 2027 8,828 2028-2032 20,454 $ 66,096 Postretirement Life Insurance Benefits As part of the Alpha Natural Resources, Inc. bankruptcy reorganization process and the Retiree Committee Settlement Agreement, the Company assumed the unfunded liability for life insurance benefits for certain disabled and non-union retired employees. Provisions are made for estimated benefits and adjustments to the probable ultimate liabilities are made annually based on an actuarial study prepared by independent actuaries. As of December 31, 2022 and 2021, the postretirement life insurance benefit obligation was $8,761, including a current portion $648, and $11,610, including a current portion $602, respectively, which are included in the Consolidated Balance Sheets as Other non-current liabilities and Accrued expenses and other current liabilities. Defined Contribution and Profit-Sharing Plans The Company sponsors defined contribution plans to assist its eligible employees in providing for retirement. Generally, under the terms of these plans, employees make voluntary contributions through payroll deductions and the Company makes matching and/or discretionary contributions, as defined by each plan. The Company’s total contributions to these plans for the years ended December 31, 2022, 2021, and 2020 were $19,385, $10,275, and $3,613 respectively. During the third quarter of 2022, the Company announced a year-end discretionary employer contribution under the Alpha Metallurgical Resources 401(k) Retirement Savings Plan (the “Plan”) equal to the 2% of the Plan participants’ annual salaries. Effective in June 2021, the Company’s matching contributions under the Plan were reinstated after being suspended due to weak market conditions during the second quarter of 2020. Self-insured Medical Plan

Stock-Based Compensation Awards

Stock-Based Compensation Awards	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Stock-Based Compensation Awards	Stock-Based Compensation Awards The MIP is currently authorized for the issuance of awards of up to 1,201,202 shares of common stock, and as of December 31, 2022, there were 64,296 shares of common stock available for grant under the MIP. The LTIP is currently authorized for the issuance of awards of up to 1,500,000 shares of common stock, and as of December 31, 2022, there were 845,961 shares of common stock available for grant under the LTIP. Pursuant to the Merger Agreement, the Company assumed the ANR Inc. 2017 Equity Incentive Plan (the “ANR EIP”), which had underlying ANR shares that were converted to 89,766 Contura Energy, Inc. shares. The ANR EIP is not authorized for additional issuance of awards of shares of common stock, and as of December 31, 2022, there were no shares of common stock available for grant under the ANR EIP. As of December 31, 2022, the Company had four types of stock-based awards outstanding: time-based restricted stock units, performance-based restricted stock units, stock options, and performance-based cash awards. Upon vesting and settlement or exercise of the stock-based awards outstanding, the Company issues authorized and unissued shares of the Company’s common stock to the recipient. Stock-based compensation expense totaled $9,841, $7,468, and $5,540 for the years ended December 31, 2022, 2021, and 2020, respectively. For the years ended December 31, 2022, 2021, and 2020, approximately 92%, 89%, and 83%, respectively, of stock-based compensation expense was reported as selling, general and administrative expenses, and the remainder was recorded as cost of coal sales. The Company is authorized to repurchase common shares from employees (upon the election by the employee) to satisfy the employees’ statutory tax withholdings upon the vesting of stock grants. Shares that are repurchased to satisfy the employees’ statutory tax withholdings are recorded in treasury stock at cost. During the year ended December 31, 2022, the Company repurchased 94,460 shares of its common stock issued pursuant to awards under the MIP and LTIP for a total purchase amount of $7,867, or $83.28 average price paid per share. During the year ended December 31, 2021, the Company repurchased 50,363 shares of its common stock issued pursuant to awards under the MIP and LTIP for a total purchase amount of $785, or $15.60 average price paid per share. During the year ended December 31, 2020, the Company repurchased 43,559 shares of its common stock issued pursuant to awards under the MIP, LTIP and ANR EIP for a total purchase amount of $209, or $4.79 average price paid per share. 2022 Awards Granted During the year ended December 31, 2022, the Company granted certain key employees and non-employee directors 95,111 time-based restricted stock units under the MIP and LTIP with a weighted average grant date fair value of $96.60 based on the Company’s closing stock price at the trading day before the date of the grant. The awards granted to key employees on January 25, 2022 will vest ratably over a three-year period from the date of the grant in accordance with the vesting schedule, subject to the participant’s continuous service with the Company through each applicable vesting date. The restricted stock units granted to non-employee directors on May 3, 2022 will vest on the first to occur of (i) May 2, 2023, (ii) the director’s service as a member of the Board is terminated, for any reason other than removal for cause, as of a date that is more than six months after the date of grant, and (iii) a change in control. The award granted to the Chief Executive Officer (“CEO”) on November 18, 2022, in advance of his transition to Executive Chairman on January 1, 2023, will vest over the course of 2023 in accordance with the vesting schedule, subject to the participant’s continuous service with the Company through each applicable vesting date. All unvested restricted stock units will immediately vest upon involuntary departure from the Board. Additionally, during the year ended December 31, 2022, the Company granted certain key employees 60,857 performance-based restricted stock units under the LTIP, which represent the number of shares of common stock that may be issued based on the achievement of targeted performance levels related to pre-established relative total shareholder return goals and annually determined operational goals over a three year period. These awards are scheduled to cliff vest on the third anniversary of the date of the grant, subject to the participant’s continuous service with the Company through the applicable vesting date and the satisfaction of the performance criteria. These performance-based restricted stock units have the potential to be earned from 0% to 200% of the targeted performance level, depending on actual results. Upon vesting and settlement of these awards, the Company will issue authorized and previously unissued shares of the Company’s common stock to the recipient. The 36,515 operational performance-based restricted stock units were valued based on the Company’s closing stock price on the trading day before the date of the grant and had a weighted average grant date fair value of $60.37. For the awards with operational performance conditions, the Company reassesses at each reporting date whether achievement of each of the performance conditions was probable and adjusts the accrual of stock-based compensation expense as needed. The 24,342 relative total shareholder return performance-based restricted stock units were valued relative to the stock price performance of a comparator group and had a weighted average grant date fair value of $97.33 based on a Monte Carlo simulation. The Monte Carlo simulation incorporated the assumptions as presented in the following table: Relative performance-based restricted stock units Start price (1) $ 53.29 Valuation date stock price (2) $ 61.09 Expected volatility (3) 106.48 % Risk-free interest rate (4) 1.26 % Expected dividend yield (5) — % (1) The start price for the Company represented the average closing stock price over the twenty trading days ending on December 31, 2021, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represented the closing price on the grant date. (3) The expected volatility assumption was based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equaled the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that had a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represented the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Additionally, during the year ended December 31, 2022, the Company granted certain key employees performance-based cash incentive awards under the LTIP with a target award amount of $1,105. The cash to be awarded is based on the achievement of pre-established relative total shareholder return goals over a three-year period. These awards are scheduled to cliff vest on the third anniversary of the date of the grant, subject to the participant’s continuous service with the Company through the applicable vesting date and the satisfaction of the performance criteria. These awards have the potential to be distributed from 0% to 200% of the targeted performance level, depending on actual results. Upon vesting of these awards, the Company issues cash to the recipient. These awards are classified as a liability, and the Company reassesses at each reporting date the fair value of the award and adjusts the accruals of stock-based compensation expense as appropriate based on a Monte Carlo simulation. As of December 31, 2022, the liability for these awards totaled $374. The performance-based cash incentive awards were valued relative to the stock price performance of a comparator group and had a weighted average grant date fair value as a percent of target dollar value of 61.97% based on a Monte Carlo simulation. The Monte Carlo simulation incorporates the assumptions as presented in the following table: Performance-based cash incentive awards Start price (1) $ 53.29 Valuation date stock price (2) $ 61.09 Expected volatility (3) 106.48 % Risk-free interest rate (4) 1.26 % Expected dividend yield (5) — % (1) The start price for the Company represents the average closing stock price over the twenty trading days ending on December 31, 2021, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represents the closing price at each reporting date. (3) The expected volatility assumption is based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equals the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that have a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represents the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. 2021 Awards Granted During the year ended December 31, 2021, the Company granted certain key employees and non-employee directors 223,496 time-based restricted stock units under the MIP and LTIP with a weighted average grant date fair value of $12.03 based on the Company’s closing stock price at the trading day before the date of the grant. The awards granted to key employees will vest ratably over a three-year period from the date of the grant in accordance with the vesting schedule, subject to the participant’s continuous service with the Company through each applicable vesting date. The restricted stock units granted to non-employee directors on February 10, 2021 will vest on the first to occur of (i) April 30, 2021, (ii) the director’s separation from service due to the director’s death or physical or mental incapacity to perform his or her usual duties, such condition likely to remain continuously and permanently, as determined by the Company, and (iii) a change in control. The restricted stock units granted to non-employee directors on May 1, 2021 will vest on the first to occur of (i) April 30, 2022, (ii) the director’s service as a member of the Board is terminated, for any reason other than removal for cause, as of a date that is more than six months after the date of grant, and (iii) a change in control. Additionally, during the year ended December 31, 2021, the Company granted certain key employees 167,587 performance-based restricted stock units under the LTIP, which represent the number of shares of common stock that may be issued based on the achievement of targeted performance levels related to pre-established relative total shareholder return goals and annually determined operational goals over a three year period. These awards are scheduled to cliff vest on the third anniversary of the date of the grant, subject to the participant’s continuous service with the Company through the applicable vesting date and the satisfaction of the performance criteria. These performance-based restricted stock units have the potential to be earned from 0% to 200% of the targeted performance level, depending on actual results. Upon vesting and settlement of these awards, the Company will issue authorized and previously unissued shares of the Company’s common stock to the recipient. The 100,552 operational performance-based restricted stock units were valued based on the Company’s closing stock price on the trading day before the date of the grant and had a weighted average grant date fair value of $12.00. For the awards with operational performance conditions, the Company reassesses at each reporting date whether achievement of each of the performance conditions was probable and adjusts the accrual of stock-based compensation expense as needed. The 67,035 relative total shareholder return performance-based restricted stock units were valued relative to the stock price performance of a comparator group and had a weighted average grant date fair value of $16.18 based on a Monte Carlo simulation. The Monte Carlo simulation incorporated the assumptions as presented in the following table: Relative performance-based restricted stock units Start price (1) $ 11.81 Valuation date stock price (2) $ 11.34 Expected volatility (3) 98.54 % Risk-free interest rate (4) 0.18 % Expected dividend yield (5) — % (1) The start price for the Company represented the average closing stock price over the twenty trading days ending on December 31, 2020, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represented the closing price on the grant date. (3) The expected volatility assumption was based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equaled the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that had a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represented the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Additionally, during the year ended December 31, 2021, the Company granted certain key employees performance-based cash incentive awards under the LTIP with a target award amount of $927. The cash to be awarded is based on the achievement of pre-established relative total shareholder return goals over a three-year period. These awards are scheduled to cliff vest on the third anniversary of the date of the grant, subject to the participant’s continuous service with the Company through the applicable vesting date and the satisfaction of the performance criteria. These awards have the potential to be distributed from 0% to 200% of the targeted performance level, depending on actual results. Upon vesting of these awards, the Company issues cash to the recipient. These awards are classified as a liability, and the Company reassesses at each reporting date the fair value of the award and adjusts the accruals of stock-based compensation expense as appropriate based on a Monte Carlo simulation. As of December 31, 2022 and 2021, the liability for these awards totaled $812 and $255, respectively. The performance-based cash incentive awards were valued relative to the stock price performance of a comparator group and had a weighted average grant date fair value as a percent of target dollar value of 51.73% based on a Monte Carlo simulation. The Monte Carlo simulation incorporates the assumptions as presented in the following table: Performance-based cash incentive awards Start price (1) $ 11.81 Valuation date stock price (2) $ 11.34 Expected volatility (3) 98.54 % Risk-free interest rate (4) 0.18 % Expected dividend yield (5) — % (1) The start price for the Company represents the average closing stock price over the twenty trading days ending on December 31, 2020, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represents the closing price at each reporting date. (3) The expected volatility assumption is based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equals the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that have a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represents the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. 2020 Awards Granted During the year ended December 31, 2020, the Company granted certain key employees and non-employee directors 402,620 time-based restricted stock units under the MIP and LTIP with a weighted average grant date fair value of $6.17 based on the Company’s closing stock price at the trading day before the date of the grant. The awards granted to key employees will vest ratably over a three-year period from the date of the grant in accordance with the vesting schedule, subject to the participant’s continuous service with the Company through each applicable vesting date. The awards granted to non-employee directors will vest on the first to occur of (i) April 30, 2021, (ii) the director’s separation from service due to the director’s death or physical or mental incapacity to perform his or her usual duties, such condition likely to remain continuously and permanently, as determined by the Company, (iii) a change in control, and (iv) the director's service as a member of the Board is terminated as of a date that is after October 31, 2021 but prior to May 1, 2022 for any reason other than removal for cause. Additionally, during the year ended December 31, 2020, the Company granted the CEO 302,795 performance-based restricted stock units under the LTIP which represent the number of shares of common stock that may be issued based on the achievement of targeted performance levels related to pre-established relative total shareholder return goals and annually determined operational goals over a three year period. This award was scheduled to cliff vest on the third anniversary of the date of the grant, subject to the participant’s continuous service with the Company through the applicable vesting date and the satisfaction of the performance criteria. These performance-based restricted stock units had the potential to be earned from 0% to 200% of the targeted performance level, depending on actual results. Upon vesting of this award, the Company would issue authorized and previously unissued shares of the Company’s common stock to the recipient. The 151,398 operational performance-based restricted stock units were valued based on the Company’s closing stock price on the trading day before the date of the grant and had a weighted average grant date fair value of $6.36. For the awards with operational performance conditions, the Company reassessed at each reporting date whether achievement of each of the performance conditions was probable and adjusted the accrual of stock-based compensation expense as needed. The 151,397 relative total shareholder return performance-based restricted stock units were valued relative to the stock price performance of a comparator group and had a weighted average grant date fair value of $8.53 based on a Monte Carlo simulation. The Monte Carlo simulation incorporated the assumptions as presented in the following table: Relative performance-based restricted stock units Start price (1) $ 7.59 Valuation date stock price (2) $ 6.33 Expected volatility (3) 55.27 % Risk-free interest rate (4) 1.37 % Expected dividend yield (5) — % (1) The start price for the Company represented the average closing stock price over the twenty trading days ending on December 31, 2019, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represented the closing price on the grant date. (3) The expected volatility assumption was based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equaled the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that had a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represented the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. During the first quarter of 2021, the 302,795 performance-based restricted stock units granted under the LTIP were voluntarily forfeited by the CEO in conjunction with an amendment to his employment agreement and the shares were canceled and allocated back to the LTIP for future issuance. The amendment also included an amendment to the participant’s time-based restricted stock granted under the MIP, such that the ratable vesting initially scheduled to occur on the second and third anniversaries of the award shall instead both occur on the second anniversary of the award. Additionally, during the year ended December 31, 2020, the Company granted certain key employees performance-based cash incentive awards under the LTIP with a target award amount of $2,755. The cash to be awarded is based on the achievement of pre-established relative total shareholder return goals over a three-year period. These awards are scheduled to cliff vest on the third anniversary of the date of the grant, subject to the participant’s continuous service with the Company through the applicable vesting date and the satisfaction of the performance criteria. These awards have the potential to be distributed from 0% to 200% of the targeted performance level, depending on actual results. Upon vesting of these awards, the Company issues cash to the recipient. These awards are classified as a liability, and the Company reassesses at each reporting date the fair value of the award and adjusts the accruals of stock-based compensation expense as appropriate based on a Monte Carlo simulation. As of December 31, 2022 and 2021, the liability for these awards totaled $3,968 and $2,542, respectively. The performance-based cash incentive awards were valued relative to the stock price performance of a comparator group and had a weighted average grant date fair value as a percent of target dollar value of 82.45% based on a Monte Carlo simulation. The Monte Carlo simulation incorporates the assumptions as presented in the following table: Performance-based cash incentive awards Start price (1) $ 7.59 Valuation date stock price (2) $ 6.33 Expected volatility (3) 55.27 % Risk-free interest rate (4) 1.37 % Expected dividend yield (5) — % (1) The start price for the Company represents the average closing stock price over the twenty trading days ending on December 31, 2019, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represents the closing price at each reporting date. (3) The expected volatility assumption is based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equals the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that have a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represents the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Restricted Stock Units Time-Based Restricted Stock Units Time-based restricted stock unit activity for the year ended December 31, 2022 is summarized in the following table: Time-based restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value Non-vested shares outstanding at December 31, 2021 392,275 $ 11.54 Granted 95,111 $ 96.60 Vested (1) (237,643) $ 14.80 Forfeited (1,374) $ 6.36 Non-vested shares outstanding at December 31, 2022 248,369 $ 41.02 (1) Includes 4,254 shares with deferred settlement pursuant to the award agreements. As of December 31, 2022, there was $4,672 of unrecognized compensation cost related to non-vested time-based restricted stock units which is expected to be recognized as expense over a weighted-average period of 1.03 years. The total fair value of shares vested, including awards with deferred settlements, during the years ended December 31, 2022, 2021, and 2020, was $20,275, $5,544, and $809, respectively. Performance-Based Restricted Stock Units Relative performance-based restricted stock unit activity for the year ended December 31, 2022 based on target achievement of the performance criteria is summarized in the following table: Relative performance-based restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value Non-vested shares outstanding at December 31, 2021 113,586 $ 36.47 Granted 24,342 $ 97.33 Vested — $ — Canceled (1) (46,551) $ 65.70 Non-vested shares outstanding at December 31, 2022 91,377 $ 37.80 (1) Shares were canceled and allocated back to the LTIP for future issuance as the 2019 award’s performance metric was not achieved, including 25,364 shares for employees that had previously only met the continued employment vesting criteria. As of December 31, 2022, there was $2,025 of unrecognized compensation cost related to non-vested relative performance-based restricted stock units which is expected to be recognized as expense over a weighted-average period of 1.88 years. Absolute performance-based restricted stock unit activity for the year ended December 31, 2022 based on target achievement of the performance criteria is summarized in the following table: Absolute performance-based restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value Non-vested shares outstanding at December 31, 2021 15,532 $ 50.60 Granted — $ — Vested — $ — Canceled (1) (15,532) $ 50.60 Non-vested shares outstanding at December 31, 2022 — $ — (1) Shares were canceled and allocated back to the LTIP for future issuance as the 2019 award’s performance metric was not achieved, including 8,459 shares for employees that had previously only met the continued employment vesting criteria. As of December 31, 2022, there was no unrecognized compensation cost related to non-vested absolute performance-based restricted stock units. Operational performance-based restricted stock unit activity for the year ended December 31, 2022 based on target achievement of the performance criteria is summarized in the following table: Operational performance-based restricted stock unit activity: Number of Shares Weighted-Average Fair Value Non-vested shares outstanding at December 31, 2021 100,552 $ 12.00 Granted 36,515 $ 60.37 Vested — $ — Forfeited or Canceled — $ — Non-vested shares outstanding at December 31, 2022 137,067 $ 24.89 As of December 31, 2022, there was $1,011 of unrecognized compensation cost related to non-vested operational performance-based restricted stock units, based on the probability of achievement as of December 31, 2022, which is expected to be recognized as expense over a weighted-average period of 1.63 years. Stock Options 30-Day Volume-Weighted Average Price (“VWAP”) Stock Options 30-day VWAP stock option activity for the year ended December 31, 2022 is summarized in the following table: Number of Shares Weighted-Average Exercise Price Per Share Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (1) Outstanding at December 31, 2021 23,225 $ 60.20 5.12 $ 20 Exercisable at December 31, 2021 23,225 $ 60.20 5.12 $ 20 Granted — $ — Exercised (19,818) $ 59.18 $ 1,484 Forfeited or Expired — $ — Outstanding at December 31, 2022 3,407 $ 66.13 4.18 $ 273 Exercisable at December 31, 2022 3,407 $ 66.13 4.18 $ 273 (1) The aggregate intrinsic value of outstanding and exercisable options is calculated as the difference between the exercise price and the Company’s stock price at each reporting period end. The aggregate intrinsic value of exercised options is calculated as the difference between the exercise price and the Company’s stock price on the exercise date. As of December 31, 2022, there was no unrecognized compensation cost related to the 30-day VWAP stock options. Performance-Based Cash Incentive Awards Performance-based cash incentive award activity for the year ended December 31, 2022 based on target achievement of the performance criteria is summarized in the following table: Performance-based cash incentive award activity: Target Dollar Value Weighted-Average Fair Value as a % of Target Dollar Value Non-vested awards outstanding at December 31, 2021 $ 2,991 162.03 % Granted 1,105 61.97 % Vested — — % Forfeited (138) 150.25 % Non-vested awards outstanding at December 31, 2022 $ 3,958 166.29 % As of December 31, 2022, there was $1,471 of unrecognized compensation cost related to non-vested performance-based cash incentive awards, based on the probability of achievement as of December 31, 2022, which is expected to be recognized as expense over a weighted-average period of 1.52 years.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions On December 7, 2022, the Company’s subsidiary, Maxxim Rebuild Co., LLC (“Maxxim”) acquired certain assets of Industrial Plating & Machine, Inc. (“IPM”), as well as its Bluefield, West Virginia manufacturing facility. As part of the transaction, the Company entered into an employment agreement with Joseph Shannon Remines, IPM’s president, pursuant to which Mr. Remines would be employed by Maxxim as Vice-President, and pursuant to which he would continue to be employed at the Bluefield facility. The initial term of the agreement is three years, with automatic one-year renewals thereafter unless either party gives 90 days’ prior notice. The agreement provides Mr. Remines with a base salary, an opportunity for sales bonuses if gross revenues at the facility exceed certain thresholds, as well as participation in the Company’s other benefits programs, including the Annual Incentive Bonus Plan and the LTIP. Mr. Remines also is an owner of the company that leases the real property for the Bluefield facility under a lease with an initial term of five years, with an option in favor of Maxxim to extend the term for an additional five years and for one-year extensions thereafter. The initial base rental under the lease is $360,000 per year. Additionally, Mr. Remines continues to own IPM, which also operates a chroming business at a separate facility, which Maxxim did not acquire. The Company will continue to do business with IPM related to the chroming business, which is not material. Under his employment agreement, Mr. Remines is subject to numerous restrictions and conditions to avoid a conflict of interest or the ability to engage in self-dealing. Mr. Remines and his companies have also entered into a non-competition agreement with the Company in connection with the transaction. The Board reviewed and approved the transaction in advance, and, although Mr. Remines does not meet the definition of a "related person," the Board also approved the nature of the arrangements with Mr. Remines described above. During the year ended December 31, 2021, the Company, through a privately negotiated transaction with an underlying Contingent Revenue Obligation creditor, repurchased 7.75% of the outstanding rights of the Contingent Revenue Obligation at an aggregate purchase price of $2,091. The underlying Contingent Revenue Obligation creditor was an existing shareholder (related party) as of the repurchase date. Refer to Note 15 for additional disclosures on this acquisition-related obligation. Additionally, during the year ended December 31, 2021, the Company repurchased at a discount certain outstanding principal borrowings made under the Term Loan Credit Facility from existing shareholders through privately negotiated transactions. Refer to Note 14 for additional disclosures on long-term debt.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies (a) General Estimated losses from loss contingencies are accrued by a charge to income when information available indicates that it is probable that an asset has been impaired or a liability has been incurred and the amount of the loss can be reasonably estimated. If a loss contingency is not probable or reasonably estimable, disclosure of the loss contingency is made in the Consolidated Financial Statements when it is at least reasonably possible that a loss may be incurred and that the loss could be material. (b) Commitments and Contingencies Commitments The Company leases coal mining and other equipment under long-term financing and operating leases with varying terms. Refer to Note 12 for further information on leases. In addition, the Company leases mineral interests and surface rights from landowners under various terms and royalty rates. Coal royalty expense was $226,366, $113,685, and $67,992 for the years ended December 31, 2022, 2021, and 2020, respectively. Minimum royalty obligations under coal leases total $15,556, $14,688, $13,608, $13,489, $12,916, and $62,118 for 2023, 2024, 2025, 2026, 2027, and after 2027, respectively. Other Commitments As of December 31, 2022, the Company has obligations under certain coal purchase agreements that contain minimum quantities to be purchased in 2023 totaling an estimated $149,763. The Company also has obligations under certain unconditional purchase obligations totaling $109,358, $98,602, and $4,887 in 2023, 2024, and 2025, respectively, including transportation commitments, minimum equipment purchase commitments, diesel fuel purchase commitments, and electricity purchase commitments. Contingencies Extensive regulation of the impacts of mining on the environment and of maintaining workplace safety has had, and is expected to continue to have, a significant effect on the Company’s costs of production and results of operations. Further regulations, legislation or litigation in these areas may also cause the Company’s sales or profitability to decline by increasing costs or by hindering the Company’s ability to continue mining at existing operations or to permit new operations. During the normal course of business, contract-related matters arise between the Company and its customers. When a loss related to such matters is considered probable and can reasonably be estimated, the Company records a liability. Refer to Note 3 for disclosures on the Cumberland Back-to-Back Coal Supply Agreements. (c) Guarantees and Financial Instruments with Off-Balance Sheet Risk In the normal course of business, the Company is a party to certain guarantees and financial instruments with off-balance sheet risk, such as bank letters of credit, performance or surety bonds, and other guarantees and indemnities related to the obligations of affiliated entities which are not reflected in the Company’s Consolidated Balance Sheets. However, the underlying liabilities that they secure, such as asset retirement obligations, workers’ compensation liabilities, and royalty obligations, are reflected in the Company’s Consolidated Balance Sheets. The Company is required to provide financial assurance in order to perform the post-mining reclamation required by its mining permits, pay workers’ compensation claims under workers’ compensation laws in various states, pay federal black lung benefits, and perform certain other obligations. In order to provide the required financial assurance, the Company generally uses surety bonds for post-mining reclamation and workers’ compensation obligations. The Company can also use bank letters of credit to collateralize certain obligations. As of December 31, 2022, the Company had $61,877 in letters of credit outstanding under the Second Amended and Restated Asset-Based Revolving Credit Agreement. Additionally, as of December 31, 2022, the Company had $50 in letters of credit outstanding under the Credit and Security Agreement dated June 30, 2017, and related amendments, between ANR, Inc. and First Tennessee Bank National Association. As of December 31, 2022, the Company had outstanding surety bonds with a total face amount of $165,575 to secure various obligations and commitments. To secure the Company’s reclamation-related obligations, the Company has $35,040 of collateral in the form of restricted cash, restricted investments, and deposits supporting these obligations as of December 31, 2022. The Company meets frequently with its surety providers and has discussions with certain providers regarding the extent of and the terms of their participation in the program. These discussions may cause the Company to shift surety bonds between providers or to alter the terms of their participation in our program. To the extent that surety bonds become unavailable or the Company’s surety bond providers require additional collateral, the Company would seek to secure its obligations with letters of credit, cash deposits or other suitable forms of collateral. The Company’s failure to maintain, or inability to acquire, surety bonds or to provide a suitable alternative would have a material adverse effect on its liquidity. These failures could result from a variety of factors including lack of availability, higher cost or unfavorable market terms of new surety bonds, and the exercise by third-party surety bond issuers of their right to refuse to renew the surety. Amounts included in restricted cash provide collateral to secure the following obligations: December 31, 2022 2021 Workers’ compensation and black lung obligations $ 15,334 $ 70,637 Reclamation-related obligations 3,220 10,449 Financial payments and other performance obligations 10,387 8,340 Contingent Revenue Obligation escrow 24,547 11,977 Total restricted cash $ 53,488 $ 101,403 Less current portion (24,547) (11,977) Restricted cash, net of current portion $ 28,941 $ 89,426 Amounts included in restricted investments provide collateral to secure the following obligations: December 31, 2022 2021 Workers’ compensation and black lung obligations $ 72,136 $ 2,716 Reclamation-related obligations 31,718 26,225 Financial payments and other performance obligations 1,881 2,008 Total restricted investments (1) $ 105,735 $ 30,949 (1) Classified as trading securities as of December 31, 2022 and 2021. Amounts included in deposits provide collateral to secure the following obligations: December 31, 2022 2021 Reclamation-related obligations $ 102 $ 118 Financial payments and other performance obligations 391 403 Other operating agreements (1) 85,618 1,275 Total deposits (2) $ 86,111 $ 1,796 (1) Includes $84,748 related to the Company’s dividend payable. Refer to Note 9 for additional information. (2) Included within Short-term deposits and Other non-current assets on the Company’s Consolidated Balance Sheets. DCMWC Reauthorization Process In July 2019, the U.S. Department of Labor (Division of Coal Mine Workers’ Compensation or “DCMWC”) began implementing a new authorization process for all self-insured coal mine operators. As requested by the DCMWC, the Company filed an application and supporting documentation for reauthorization to self-insure certain of its black lung obligations in October 2019. As a result of this application, the DCMWC notified the Company in a letter dated February 21, 2020 that the Company was reauthorized to self-insure certain of its black lung obligations for a period of one-year from February 21, 2020. The DCMWC reauthorization is contingent, however, upon the Company’s providing collateral of $65,700 to secure certain of its black lung obligations. This proposed collateral requirement is an increase from the approximate $2,600 in collateral that the Company currently provides to secure these self-insured black lung obligations. The reauthorization process provided the Company with the right to appeal the security determination in writing within 30 days of the date of the notification, which appeal period the DCMWC agreed to extend to May 22, 2020. The Company exercised this right of appeal in connection with the substantial increase in the amount of required collateral. In February 2021, the U.S. Department of Labor (“DOL”) withdrew its Federal Register notice seeking comments on its bulletin describing its new method of calculating collateral requirements. The Department removed the bulletin from its website in May 2021. On February 10, 2022, a telephone conference was held with DCMWC and DOL decision makers wherein the Company presented facts and arguments in support of its appeal. No ruling has been made on the appeal, but during the call the Company indicated that it would be willing to allocate an additional $10,000 in collateral. If the Company’s appeal is unsuccessful, the Company may be required to provide additional letters of credit to receive the self-insurance reauthorization from the DCMWC or alternatively insure these black lung obligations through a third-party provider that would likely also require the Company to provide additional collateral. In January 2023, the DOL proposed for public comment new regulations which, if adopted, would substantially increase the collateral required to secure self-insured federal black lung obligations. Under the proposed 120% minimum collateral requirement, the Company estimates it could be required to provide approximately $80,000 to $100,000 of collateral to secure certain of its black lung obligations. A significant increase in these collateral obligations would have a materially adverse effect on the Company’s liquidity. (d) Legal Proceedings The Company is party to legal proceedings from time to time. These proceedings, as well as governmental examinations, could involve various business units and a variety of claims including, but not limited to, contract disputes, personal injury claims, property damage claims (including those resulting from blasting, trucking and flooding), environmental and safety issues, securities-related matters and employment matters. While some legal matters may specify the damages claimed by the plaintiffs, many seek an unquantified amount of damages. Even when the amount of damages claimed against the Company or its subsidiaries is stated, (i) the claimed amount may be exaggerated or unsupported; (ii) the claim may be based on a novel legal theory or involve a large number of parties; (iii) there may be uncertainty as to the likelihood of a class being certified or

Concentration of Credit Risk an

Concentration of Credit Risk and Major Customers	12 Months Ended
	Dec. 31, 2022
Risks and Uncertainties [Abstract]
Concentration of Credit Risk and Major Customers	Concentration of Credit Risk and Major Customers The Company markets produced, processed, and purchased coal to customers in the United States and in international markets. The following table presents additional information on our total revenues and top customers: Year Ended December 31, 2022 2021 2020 Total coal revenues $ 4,092,987 $ 2,252,624 $ 1,413,124 Total revenues $ 4,101,592 $ 2,258,686 $ 1,416,187 Top customer as % of total revenues 25 % 13 % 16 % Top 10 customers as % of total revenues 70 % 64 % 63 % Number of customers exceeding 10% of total revenues 1 2 2 Number of customers exceeding 10% of total trade accounts receivable, net 2 3 3 Domestic revenue as % of coal revenues 19 % 24 % 36 % Export revenue as % of coal revenues 81 % 76 % 64 % Countries with export revenue exceeding 10% of total revenues India India, China, Brazil India, Brazil Met coal as % of coal sales volume 87 % 83 % 80 % Thermal coal as % of coal sales volume 13 % 17 % 20 %

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
Segment Information	Segment Information The Company extracts, processes and markets met and thermal coal from deep and surface mines for sale to steel and coke producers, industrial customers, and electric utilities. The Company conducts mining operations only in the United States with mines in Central Appalachia. The Company has one reportable segment: Met, which consists of six active mines and two preparation plants in Virginia, seventeen active mines and five preparation plants in West Virginia, as well as expenses associated with certain idled/closed mines. In addition to the one reportable segment, the All Other category includes general corporate overhead and corporate assets and liabilities, the former CAPP - Thermal operations consisting of one active mine and one preparation plant in West Virginia, and the elimination of certain intercompany activity, as well as expenses associated with certain idled/closed mines. Certain immaterial amounts as of and for the years ended December 31, 2022 and 2021 in the Consolidated Financials Statements and notes to the Consolidated Financials Statements have been recast to reclassify discontinued operations and present the related amounts within continuing operations as part of the All Other category. Reportable segment operating results are regularly reviewed by the Chief Operating Decision Maker (“CODM”), who is the Chief Executive Officer of the Company. Segment operating results and capital expenditures for the year ended December 31, 2022 were as follows: Year Ended December 31, 2022 Met All Other Consolidated Total revenues $ 4,023,688 $ 77,904 $ 4,101,592 Depreciation, depletion, and amortization $ 100,584 $ 7,036 $ 107,620 Amortization of acquired intangibles, net $ 15,699 $ 3,799 $ 19,498 Adjusted EBITDA $ 1,776,642 $ (36,030) $ 1,740,612 Capital expenditures $ 160,679 $ 3,630 $ 164,309 Segment operating results and capital expenditures for the year ended December 31, 2021 were as follows: Year Ended December 31, 2021 Met All Other Consolidated Total revenues $ 2,176,080 $ 82,606 $ 2,258,686 Depreciation, depletion, and amortization $ 99,963 $ 10,084 $ 110,047 Amortization of acquired intangibles, net $ 13,671 $ (427) $ 13,244 Adjusted EBITDA $ 567,270 $ (32,789) $ 534,481 Capital expenditures $ 79,185 $ 4,115 $ 83,300 Segment operating results and capital expenditures from continuing operations for the year ended December 31, 2020 were as follows: Year Ended December 31, 2020 Met All Other Consolidated Total revenues $ 1,264,496 $ 151,691 $ 1,416,187 Depreciation, depletion, and amortization $ 124,060 $ 15,825 $ 139,885 Amortization of acquired intangibles, net $ 12,889 $ (3,675) $ 9,214 Adjusted EBITDA $ 120,281 $ (36,880) $ 83,401 Capital expenditures $ 111,745 $ 7,834 $ 119,579 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the year ended December 31, 2022: Year Ended December 31, 2022 Met All Other Consolidated Net income (loss) $ 1,647,104 $ (198,559) $ 1,448,545 Interest expense 202 21,600 21,802 Interest income (541) (2,646) (3,187) Income tax expense — 106,205 106,205 Depreciation, depletion and amortization 100,584 7,036 107,620 Non-cash stock compensation expense 4 7,480 7,484 Mark-to-market adjustment - acquisition-related obligations — 8,880 8,880 Accretion on asset retirement obligations 13,590 10,175 23,765 Amortization of acquired intangibles, net 15,699 3,799 19,498 Adjusted EBITDA $ 1,776,642 $ (36,030) $ 1,740,612 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the year ended December 31, 2021: Year Ended December 31, 2021 Met All Other Consolidated Net income (loss) $ 439,859 $ (151,069) $ 288,790 Interest expense 184 69,470 69,654 Interest income (6) (330) (336) Income tax expense — 3,408 3,408 Depreciation, depletion and amortization 99,963 10,084 110,047 Non-cash stock compensation expense 28 5,287 5,315 Mark-to-market adjustment - acquisition-related obligations — 19,525 19,525 Gain on settlement of acquisition-related obligations — (1,125) (1,125) Accretion on asset retirement obligations 13,571 12,949 26,520 Asset impairment and restructuring — (561) (561) Amortization of acquired intangibles, net 13,671 (427) 13,244 Adjusted EBITDA $ 567,270 $ (32,789) $ 534,481 The following table presents a reconciliation of net loss from continuing operations to Adjusted EBITDA for the year ended December 31, 2020: Year Ended December 31, 2020 Met All Other Consolidated Net loss from continuing operations $ (77,519) $ (163,951) $ (241,470) Interest expense (2,014) 76,542 74,528 Interest income (63) (6,964) (7,027) Income tax benefit — (2,164) (2,164) Depreciation, depletion and amortization 124,060 15,825 139,885 Non-cash stock compensation expense 289 4,607 4,896 Mark-to-market adjustment - acquisition-related obligations — (8,750) (8,750) Accretion on asset retirement obligations 14,214 12,290 26,504 Asset impairment and restructuring 46,317 37,561 83,878 Management restructuring costs (1) 501 440 941 Loss on partial settlement of benefit obligations 1,607 1,359 2,966 Amortization of acquired intangibles, net 12,889 (3,675) 9,214 Adjusted EBITDA $ 120,281 $ (36,880) $ 83,401 (1) Management restructuring costs are related to severance expense associated with senior management changes during the three months ended March 31, 2020. No asset information has been disclosed as the CODM does not regularly review asset information by reportable segment.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2022
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsOn February 21, 2023, the Board declared a quarterly cash dividend of $0.44 per share which will be payable on April 3, 2023 for holders of record as of March 15, 2023. The quarterly cash dividend was increased to $0.44 from the previous quarterly cash dividend of $0.418 per share. On February 21, 2023, the Board also approved a $200,000 increase to the existing common share repurchase program, bringing the total authorization to repurchase the Company’s stock to $1,200,000. Refer to Note 9 for information regarding the Company’s dividend program and share repurchase program.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2022
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation Together, the consolidated balance sheets and consolidated statements of operations, comprehensive income (loss), cash flows and stockholders’ equity for the Company are referred to as the “Financial Statements.” The Financial Statements are also referred to as “Consolidated” and references across periods are generally labeled “Balance Sheets,” “Statements of Operations,” and “Statements of Cash Flows.” The Company’s former NAPP operations results of operations and financial position are reported as discontinued operations in the Consolidated Financial Statements for the year ended December 31, 2020. Refer to Note 3 for further information on discontinued operations. The Consolidated Financial Statements include all wholly owned subsidiaries’ results of operations for the years ended December 31, 2022, 2021, and 2020. All significant intercompany transactions have been eliminated in consolidation.
Reclassifications	Reclassifications Certain immaterial amounts as of and for the years ended December 31, 2022 and 2021 in the Consolidated Financials Statements and notes to the Consolidated Financials Statements have been recast to reclassify discontinued operations and present the related amounts within continuing operations as part of the All Other category. Additionally, certain amounts in the prior year Consolidated Statements of Stockholders’ Equity have been reclassified to conform to the current year presentation.
Use of Estimates	Use of Estimates The preparation of the Company’s Consolidated Financial Statements requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Significant items subject to such estimates and assumptions include inventories; mineral reserves and resources; long-lived asset impairments; reclamation obligations; post-employment and other employee benefit obligations; useful lives, depletion and amortization; reserves for workers’ compensation and black lung claims; deferred income taxes; income taxes payable; income taxes refundable and receivable; reserves for contingencies and litigation; fair value of financial instruments; and fair value adjustments for acquisition accounting. Estimates are based on facts and circumstances believed to be reasonable at the time; however, actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents Cash and cash equivalents consist of cash held with reputable depository institutions and highly liquid, short-term investments, such as highly-rated money market funds, with original maturities of three months or less. Cash and cash equivalents are stated at cost, which approximates fair value.
Restricted Cash	Restricted CashAmounts included in restricted cash represent cash and cash equivalents that are restricted as to withdrawal as required by certain agreements entered into by the Company and provide collateral to secure the certain obligations which have been written on the Company’s behalf. Refer to Note 22 for further information.
Investments	Investments Short-term investments consist of U.S government securities. Restricted investments consist of Federal Deposit Insurance Company (“FDIC”) insured certificates of deposit, corporate fixed income, and U.S. government securities that are restricted as to withdrawal as required by certain agreements entered into by the Company and provide collateral to secure certain obligations which have been written on the Company’s behalf.
Deposits	DepositsDeposits represent cash deposits held at third parties as required by certain agreements entered into by the Company to provide cash collateral to secure the following obligations which have been written on the Company’s behalf. Refer to Note 22 for further information.
Trade Accounts Receivable and Allowance for Doubtful Accounts	Trade Accounts Receivable and Allowance for Doubtful Accounts Trade accounts receivable are recorded at their invoiced amounts and do not bear interest. The Company markets its coal primarily to international and domestic steel producers and electric utilities in the United States. Credit is extended based on an evaluation of a customer’s financial condition, including a review of third-party credit score information. Collateral is generally not required. Accounts receivable balances are monitored against approved credit limits. Credit limits are monitored and adjusted as considered necessary based on changes to a customer’s credit profile. If a customer’s credit deteriorates, the Company may reduce credit risk exposure by reducing credit limits, obtaining letters of credit, obtaining credit insurance, or requiring pre-payment for shipments. Credit losses have historically not been material. Account balances are written-off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. Refer to Note 23 for further information.
Inventories	Inventories Coal is reported as inventory at the point in time the coal is extracted from the mine. Raw coal represents coal stockpiles that may be sold in current condition or may be further processed prior to shipment to a customer. Saleable coal represents coal stockpiles that require no further processing prior to shipment to a customer.
Discontinued Operations	Discontinued Operations In accordance with Accounting Standards Codification (“ASC”) 205-20-45, the Company treats a disposal transaction as a discontinued operation when the disposal of a component or group of components represents a strategic shift that will have a major effect on the Company’s operations and financial results. In the period in which the discontinued operations criteria are met, the assets and liabilities of the discontinued operations are separately presented on the Company's Consolidated Balance Sheets and the results of operations, including any gain or loss recognized, are reclassified to discontinued operations on the Company’s Consolidated Statement of Operations. Refer to Note 3 for further information.
Advanced Mining Royalties	Advanced Mining Royalties Lease rights to coal reserves are often acquired in exchange for royalty payments. Advance mining royalties are advance payments made to lessors under terms of mineral lease agreements that are recoupable against future production royalties. These advance payments are deferred and charged to operations as the coal reserves are mined. The Company regularly reviews recoverability of advance mining royalties and establishes or adjusts the allowance for advance mining royalties as necessary using the specific identification method. Advance royalty balances are generally charged off against the allowance when they are no longer recoupable. Refer to Note 11 for further information.
Property, Plant and Equipment, Net	Property, Plant, and Equipment, Net Costs for mine development incurred to expand capacity of operating mines or to develop new mines are capitalized and charged to operations on the units-of-production method over the estimated proven and probable reserve tons directly benefiting from the capital expenditures. Mine development costs include costs incurred for site preparation and development of the mines during the development stage less any incidental revenue generated during the development stage. Mining equipment, buildings, and other fixed assets are stated at cost and depreciated on a straight-line basis over estimated useful lives ranging from one
Owned and Leased Mineral Rights	Costs to obtain owned and leased mineral rights are capitalized and amortized to operations as depletion expense using the units-of-production method. Only proven and probable reserves are included in the depletion base.
Leases	LeasesIn accordance with ASC 842, the Company recognizes right of use assets and lease liabilities on the Consolidated Balance Sheets for all leases with a term longer than 12 months. Some of these leases include both lease and non-lease components which are accounted for as a single lease component as the Company has elected the practical expedient to combine these components for all leases. The discount rates used to determine the present value of the lease assets and liabilities are based on the Company’s incremental borrowing rate at the lease commencement date and commensurate with the remaining lease term. As the rates implicit in most of the Company’s leases are not readily determinable, the Company uses a collateralized incremental borrowing rate based on the information available at the lease commencement date in determining the present value of future payments. The Company uses the portfolio approach and groups leases by short-term and long-term categories, applying the corresponding incremental borrowing rates to these categories of leases. For leases with a term of 12 months or less, no right of use assets or liabilities are recognized on the Consolidated Balance Sheets and the Company recognizes the lease expense on a straight-line basis over the lease term. Additionally, the Company recognizes variable lease payments as an expense in the period incurred. The Company has elected to show net instead of gross amounts for right-of-use assets and liabilities within its Consolidated Statements of Cash Flows.
Acquired Intangibles	Acquired IntangiblesThe Company has recognized assets for acquired mine permits which were valued based on the replacement cost and lost profits method as of the Merger date.The acquired mine permits are amortized over the estimated life of the associated mine. Amortization expense is included in Amortization of acquired intangibles, net in the accompanying Consolidated Statements of Operations and was $19,498, $13,571, and $14,887 for the years ended December 31, 2022, 2021, and 2020, respectively. Additionally, the Company previously recognized assets for acquired above market-priced coal supply agreements and liabilities for acquired below market-priced coal supply agreements. The agreements were amortized over the actual number of tons shipped over the life of each contract.
Goodwill	Goodwill Goodwill represents the excess of the purchase price over the fair value of the net identifiable tangible and intangible assets of acquired companies. In December 2022, primarily to secure the supply of certain underground mining equipment parts needed for its operations, the Company purchased substantially all of the assets of a mining equipment component manufacturing and rebuilding business for $24,878, which included $7,787 of working capital, $6,355 of property, plant, and equipment, and $10,736 of goodwill. The acquired goodwill, related primarily to the acquired workforce and expected cost synergies, was allocated to the Company’s Met reportable segment. Goodwill is not amortized; instead, it is tested for impairment annually as of October 31 of each year or more frequently if indicators of impairment exist.
Asset Impairment	Asset ImpairmentLong-lived assets, such as property, plant, and equipment, mineral rights, and acquired intangibles subject to amortization, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset groups may not be recoverable. Recoverability of assets or asset groups to be held and used is measured by a comparison of the carrying amount of an asset or asset group to the estimated undiscounted future cash flows expected to be generated by the asset or asset group. Long-lived assets located in a close geographic area are grouped together for purposes of impairment testing when, after considering revenue and cost interdependencies, circumstances indicate the assets are used together to produce future cash flows. The Company’s asset groups generally consist of the assets and applicable liabilities of one or more mines and preparation plants and associated coal reserves for which cash flows are largely independent of cash flows of other mines, preparation plants, and associated coal reserves. If the carrying amount of an asset or asset group exceeds its estimated future cash flows, the potential impairment is equal to the amount by which the carrying amount of the asset or asset group exceeds the fair value of the asset or asset group. The Company estimates the fair value of an asset group generally using discounted cash flow analysis based on estimates of future sales volumes, coal prices, production costs, and a risk-adjusted cost of capital. These estimates generally constitute unobservable Level 3 inputs under the fair value hierarchy. The amount of impairment, if any, is allocated to the long-lived assets on a pro-rata basis, except that the carrying value of the individual long-lived assets are not reduced below their estimated fair value.
Asset Retirement Obligations	Asset Retirement ObligationsMinimum standards for mine reclamation have been established by various regulatory agencies and dictate the reclamation requirements at the Company’s operations. The Company’s asset retirement obligations consist principally of costs to reclaim acreage disturbed at surface operations and estimated costs to reclaim support acreage, treat mine water discharge, and perform other related functions at underground mines. The Company records these reclamation obligations at fair value in the period in which the legal obligation associated with the retirement of the long-lived asset is incurred. Changes to the liability at operations that are not currently being reclaimed are offset by increasing or decreasing the carrying amount of the related long-lived asset. Changes to the liability at operations that are currently being reclaimed are recorded to depreciation, depletion, and amortization. Over time, the liability is accreted and any capitalized cost is depreciated or depleted over the useful life of the related asset. To settle the liability, the obligation is paid, and any difference between the liability and the amount of cash paid is recorded within Depreciation, depletion and amortization within the Consolidated Statements of Operations at the time the reclamation work is completed. The Company annually reviews its estimated future cash flows for its asset retirement obligations.
Income Taxes	Income TaxesThe Company recognizes deferred tax assets and liabilities using enacted tax rates for the effect of temporary differences between the book and tax bases of recorded assets and liabilities. Deferred tax assets are reduced by a valuation allowance if it is more likely than not that some portion or all of the deferred tax assets will not be realized. In evaluating its ability to recover deferred tax assets within the jurisdiction in which they arise, the Company considers all available positive and negative evidence, including the expected reversals of deferred tax liabilities, projected future taxable income, taxable income available via carryback to prior years, tax planning strategies, and results of recent operations. The Company assesses the realizability of its deferred tax assets, including scheduling the reversal of its deferred tax assets and liabilities, to determine the amount of valuation allowance needed. Scheduling the reversal of deferred tax asset and liability balances requires judgment and estimation. The Company believes the deferred tax liabilities relied upon as future taxable income in its assessment will reverse in the same period and jurisdiction and are of the same character as the temporary differences giving rise to the deferred tax assets that will be realized.
Deferred Financing Costs	Deferred Financing Costs The costs to obtain new debt financing or amend existing financing agreements are generally deferred and amortized to
Revenue Recognition	Revenue Recognition In accordance with ASC 606 Revenue from Contracts with Customers (“ASC 606”), the Company measures revenue based on the consideration specified in a contract with a customer and recognizes revenue as a result of satisfying its promise to transfer goods or services in a contract with a customer using the following general revenue recognition five-step model: (1) identify the contract; (2) identify performance obligations; (3) determine transaction price; (4) allocate transaction price; and (5) recognize revenue. Freight and handling costs paid to third-party carriers and invoiced to coal customers are recorded as freight and handling costs and freight and handling fulfillment revenues within cost of coal sales and coal revenues, respectively.
Workers' Compensation and Pneumoconiosis (Black Lung) Benefits, Pension and Postretirement Life Insurance Benefits	Workers’ Compensation and Pneumoconiosis (Black Lung) Benefits Workers’ Compensation As of December 31, 2022, the Company’s subsidiaries generally utilize high-deductible insurance programs for workers’ compensation claims at its operations with the exception of certain subsidiaries in which the Company is a qualified self-insurer for workers’ compensation obligations. The liabilities for workers’ compensation claims are estimates of the ultimate losses incurred based on the Company’s experience and include a provision for incurred but not reported losses. Adjustments to the probable ultimate liabilities are made annually based on an actuarial study and adjustments to the liability are recorded based on the results of this study. These short-term and long-term obligations are included in the Consolidated Balance Sheets within Accrued expenses and other current liabilities and Workers’ compensation and black lung obligations, respectively, with the related expected insurance receivables within Prepaid expenses and other current assets and Other non-current assets. As of December 31, 2022 and 2021, the workers’ compensation liability was net of a discount of $22,824 and $23,442, respectively, related to fair value adjustments associated with acquisition accounting. Refer to Note 19 for further information. Black Lung Benefits The Company is required by federal and state statutes to provide benefits to employees for awards related to black lung. As of December 31, 2022, certain of the Company’s subsidiaries are insured for black lung obligations by a third-party insurance provider and certain subsidiaries are self-insured for state black lung obligations. Certain other subsidiaries are self-insured for federal black lung benefits and may fund benefit payments through a Section 501(c)(21) tax-exempt trust fund. Charges are made to operations for black lung claims, as determined by an independent actuary at the present value of the actuarially computed liability for such benefits over the employee’s applicable term of service. The Company recognizes in its Consolidated Balance sheets the amount of the Company’s unfunded Accumulated Benefit Obligation (“ABO”) at the end of the year. The actuarial gains and losses recognized in accumulated other comprehensive income (loss) are amortized into components of net periodic benefit cost over the expected lifetime of active participants (the Company does not use a corridor method). These short-term and long-term obligations are included in the Consolidated Balance Sheets within Accrued expenses and other current liabilities and Workers’ compensation and black lung obligations, respectively. Refer to Note 19 for further information. Pension The Company is required to recognize the overfunded or underfunded status of a defined benefit pension plan as an asset or liability in its Consolidated Balance Sheets and to recognize changes in that funded status in the year in which the changes occur through other comprehensive (loss) income. The actuarial gains and losses recognized in accumulated other comprehensive income (loss) are amortized into components of net periodic benefit cost over the average future lifetime of participants expected to have benefits (the Company does not use a corridor method). The Company is required to measure plan assets and benefit obligations as of the date of the Company’s fiscal year-end Consolidated Balance Sheet and provide the required disclosures as of the end of each fiscal year. Refer to Note 19 for information.
Net Income (Loss) Per Share	Net Income (Loss) per Share  Basic net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of outstanding common shares for the period. Diluted (loss) earnings per share reflects the potential dilution that could occur if instruments that may require the issuance of common shares in the future were settled and the underlying common shares were issued. Diluted (loss) earnings per share is computed by increasing the weighted-average number of outstanding common shares computed in basic earnings (loss) per share to include the additional common shares that would be outstanding after issuance and adjusting net income (loss) for changes that would result from the issuance. Only those securities that are dilutive are included in the calculation. In periods of loss, the number of shares used to calculate diluted earnings is the same as basic earnings per share.
Stock-Based Compensation	Stock-Based CompensationThe Company recognizes expense for stock-based compensation awards based on their grant-date fair value. The expense is recorded over the respective service period of the underlying award. Liability classified stock-based compensation awards are remeasured each reporting period at fair value until the award is settled. The Company recognizes forfeitures of stock-based compensation awards as they occur.
Warrants	Warrants On July 26, 2016 (the “Initial Issue Date”), the Company issued warrants, which are classified as equity instruments, and are exercisable for cash or on a cashless basis at any time from the Initial Issue Date until July 26, 2023, and no fractional shares will be issued upon warrant exercises. The exercise price and the warrant share number will be adjusted in respect of certain dilutive events with respect to common stock (namely, dividends or distributions on the common stock, share splits and combinations, above-market tender offers for common stock by the Company or a subsidiary thereof, and discounted issuances of common stock or rights or options to purchase common stock or securities convertible or exchangeable into common stock). Additionally, in the case of any reorganization (i.e., a consolidation, merger, or sale of all or substantially all of the consolidated assets of Alpha) pursuant to which the common stock is converted into cash, securities or other property, the warrants would become exercisable for such property. Refer to Note 9 for additional information.
Equity Method Investments	Equity Method InvestmentsInvestments in unconsolidated affiliates that the Company has the ability to exercise significant influence over, but not control, are accounted for under the equity method of accounting. Under the equity method of accounting, the Company records its proportionate share of the entity’s net income or loss at each reporting period in the Consolidated Statements of Operations in other (expense) income, with a corresponding entry to increase or decrease the carrying value of the investment.
Recently Adopted Accounting Guidance and Recent Accounting Guidance Issued Not Yet Effective	Recently Adopted Accounting Guidance Reference Rate Reform: In December 2022, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) 2022-06, Deferral of the Sunset Date of Topic 848 (“ASU 2022-06”). This update defers the sunset date of ASC 848 to December 31, 2024. The amendments are effective immediately for all entities and are applied prospectively. As the Company previously adopted ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of Effects of Reference Rate Reform on Financial Reporting during the first quarter of 2020, ASU 2022-06 did not have an impact on the Company’s Consolidated Financial Statements and related disclosures. Government Assistance : In November 2021, the FASB issued ASU 2021-10 , Disclosures by Business Entities about Government Assistance (“ASU 2021-10”). This update requires business entities to make annual disclosures about transactions with a government accounted for by analogizing to a grant or contribution accounting model. The required annual disclosures include the nature of the transaction, the related accounting policy, the financial statement line items affected and the amounts reflected in the current period financial statements, and any significant terms and conditions. The amendments are effective for fiscal years beginning after December 15, 2021, for all entities, with early application permitted. The Company adopted ASU 2021-10 during the fourth quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures. Liabilities: In September 2022, the FASB issued ASU 2022-04, Liabilities - Supplier Finance Programs (Subtopic 405-50): Disclosure of Supplier Finance Program Obligations (“ASU 2022-04”). This update enhances transparency about an entity’s use of supplier finance programs. The ASU requires entities to disclose information about the key terms of the program, outstanding confirmed amounts as of the end of the period, a rollforward of such amounts during each annual period, and a description of where in the financial statements outstanding amounts are presented. The amendments are effective for fiscal years beginning after December 15, 2022, with early application permitted. The Company adopted ASU 2022-04 during the third quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures. Fair Value Measurement: In June 2022, the FASB issued ASU 2022-03, Fair Value Measurement (Topic 820): Fair Value Measurement of Equity Securities Subject to Contractual Sale Restrictions (“ASU 2022-03”). This update clarifies how the fair value of equity securities subject to contractual sale restrictions is determined. Per the update, a contractual restriction on the sale of an equity security is not considered part of the unit of account of the equity security and is not considered in measuring fair value. Additionally, the update requires entities with investments in equity securities subject to contractual sale restrictions to disclose certain qualitative and quantitative information about such securities. The amendments are effective for fiscal years beginning after December 15, 2023, with early application permitted. The Company adopted ASU 2022-03 during the second quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures. Financial Instruments: In March 2022, the FASB issued ASU 2022-02, Financial Instruments - Credit Losses (Topic 326): Troubled Debt Restructurings and Vintage Disclosures (“ASU 2022-02”). This update eliminates the troubled debt restructuring model for creditors that have adopted Topic 326. All loan modifications will now be accounted for under general loan modification guidance and, on a prospective basis, entities will be subject to new disclosure requirements covering modifications of receivables to borrowers experiencing financial difficulty. In addition, entities will be required to prospectively disclose current-period gross write-off information by year of origination. The amendments are effective for fiscal years beginning after December 15, 2022, with early application permitted. The Company adopted ASU 2022-02 during the first quarter of 2022. The adoption of this ASU did not have a material impact on the Company’s Consolidated Financial Statements and related disclosures.

Discontinued Operations (Tables

Discontinued Operations (Tables)	12 Months Ended
	Dec. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	The following table presents the details of the Cumberland Transaction: Year Ended December 31, 2020 Cash $ 19,987 Surety bonding collateral 30,000 Total consideration $ 49,987 Transaction costs 2,205 Carrying value of assets and liabilities (1) (16,079) Loss on sale $ 36,113 (1) Assets and liabilities were primarily comprised of property, plant and equipment, net of $32,872, deferred longwall move expenses of $15,173, and coal and supplies inventory of $5,112 and asset retirement obligations of $39,573, severance of $17,143, black lung obligations of $8,290, and subsidence liability of $3,559. The major components of net loss from discontinued operations before income taxes in the Consolidated Statements of Operations for the year ended December 31, 2020 are as follows: Year Ended December 31, 2020 (1) Revenues: Total revenues $ 235,509 Costs and expenses: Cost of coal sales (exclusive of items shown separately below) 215,390 Depreciation, depletion and amortization 11,570 Accretion on asset retirement obligations 4,154 Asset impairment and restructuring (2) 172,640 Selling, general and administrative expenses (3) 1,623 Other income (926) Other non-major expense items, net 374 Loss on sale 36,113 Loss from discontinued operations before income taxes $ (205,429) (1) Includes minor residual activity related to the Company’s former PRB operations. (2) Refer to Note 8. (3) Represents professional and legal fees. The major components of cash flows related to discontinued operations were as follows: Year Ended December 31, 2020 Depreciation, depletion and amortization $ 11,570 Capital expenditures $ 34,411 Other significant operating non-cash items related to discontinued operations: Accretion on asset retirement obligations $ 4,154 Asset impairment and restructuring $ 172,640

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2022
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following tables disaggregate the Company’s coal revenues by product category and by market to depict how the nature, amount, timing, and uncertainty of the Company’s coal revenues and cash flows are affected by economic factors: Year Ended December 31, 2022 Met Coal Thermal Coal Total Export coal revenues $ 3,195,516 $ 107,961 $ 3,303,477 Domestic coal revenues 687,795 101,715 789,510 Total coal revenues $ 3,883,311 $ 209,676 $ 4,092,987 Year Ended December 31, 2021 Met Coal Thermal Coal Total Export coal revenues $ 1,675,147 $ 30,879 $ 1,706,026 Domestic coal revenues 396,160 150,438 546,598 Total coal revenues $ 2,071,307 $ 181,317 $ 2,252,624 Year Ended December 31, 2020 Met Coal Thermal Coal Total Export coal revenues $ 870,121 $ 27,904 $ 898,025 Domestic coal revenues 362,654 152,445 515,099 Total coal revenues $ 1,232,775 $ 180,349 $ 1,413,124
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	The following table includes estimated revenue expected to be recognized in the future related to performance obligations that are unsatisfied as of December 31, 2022. 2023 2024 2025 2026 2027 Total Estimated coal revenues (1) $ 128,341 $ 37,250 $ — $ — $ — $ 165,591 (1) Amounts only include estimated coal revenues associated with contracts with customers with fixed pricing with original expected duration of more than one year. The Company has elected not to disclose the aggregate amount of the transaction price allocated to the performance obligations that are unsatisfied (or partially unsatisfied) as of the end of the reporting period for performance obligations with either of the following conditions: 1) the remaining performance obligation is part of a contract that has an original expected duration of one year or less; or 2) the remaining performance obligation has variable consideration that is allocated entirely to a wholly unsatisfied performance obligation.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Loss (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Schedule of Accumulated Other Comprehensive Loss	The following tables summarize the changes to accumulated other comprehensive loss during the years ended December 31, 2022, 2021, and 2020: Balance January 1, 2022 Other comprehensive income before reclassifications Amounts reclassified from accumulated other comprehensive loss Balance December 31, 2022 Employee benefit costs $ (58,503) $ 43,597 $ 2,744 $ (12,162) Balance January 1, 2021 Other comprehensive income before reclassifications Amounts reclassified from accumulated other comprehensive loss Balance December 31, 2021 Employee benefit costs $ (111,985) $ 47,461 $ 6,021 $ (58,503) Balance January 1, 2020 Other comprehensive loss before reclassifications Amounts reclassified from accumulated other comprehensive loss Balance December 31, 2020 Employee benefit costs $ (58,616) $ (60,647) $ 7,278 $ (111,985) The following table summarizes the amounts reclassified from accumulated other comprehensive loss and the Consolidated Statements of Operations line items affected by the reclassification during the years ended December 31, 2022, 2021, and 2020: Details about accumulated other comprehensive loss components Amounts reclassified from accumulated other comprehensive loss Affected line item in the Consolidated Statements of Operations Year Ended December 31, 2022 2021 2020 Employee benefit costs: Amortization of actuarial loss (1) $ 3,311 $ 5,653 $ 3,929 Miscellaneous income (loss), net Settlement (1) 244 368 3,349 Miscellaneous income (loss), net Total before income tax $ 3,555 $ 6,021 $ 7,278 Income tax (811) — — Income tax (expense) benefit Total, net of income tax $ 2,744 $ 6,021 $ 7,278 (1) These accumulated other comprehensive loss components are included in the computation of net periodic benefit costs for certain employee benefit plans. Refer to Note 19.

Net Income (Loss) per Share (Ta

Net Income (Loss) per Share (Tables)	12 Months Ended
	Dec. 31, 2022
Earnings Per Share [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	The following table presents the net income (loss) per common share for the years ended December 31, 2022, 2021, and 2020: Year Ended December 31, 2022 2021 2020 Net income (loss) Income (loss) from continuing operations $ 1,448,545 $ 288,790 $ (241,470) Loss from discontinued operations — — (205,429) Net income (loss) $ 1,448,545 $ 288,790 $ (446,899) Basic Weighted average common shares outstanding - basic 17,490,886 18,441,175 18,298,362 Basic income (loss) per common share: Income (loss) from continuing operations $ 82.82 $ 15.66 $ (13.20) Loss from discontinued operations — — (11.22) Net income (loss) $ 82.82 $ 15.66 $ (24.42) Diluted Weighted average common shares outstanding - basic 17,490,886 18,441,175 18,298,362 Diluted effect of warrants 275,715 35,574 — Diluted effect of stock options 4,171 1,753 — Diluted effect of other stock-based instruments 451,625 393,180 — Weighted average common shares outstanding - diluted 18,222,397 18,871,682 18,298,362 Diluted income (loss) per common share: Income (loss) from continuing operations $ 79.49 $ 15.30 $ (13.20) Loss from discontinued operations — — (11.22) Net income (loss) $ 79.49 $ 15.30 $ (24.42)

Inventories, net (Tables)

Inventories, net (Tables)	12 Months Ended
	Dec. 31, 2022
Inventory Disclosure [Abstract]
Schedule of Inventory	Inventories, net consisted of the following: December 31, 2022 2021 Raw coal $ 57,382 $ 20,347 Saleable coal 91,474 81,240 Materials, supplies and other, net 51,718 27,795 Total inventories, net $ 200,574 $ 129,382

Asset Impairment and Restruct_2

Asset Impairment and Restructuring (Tables)	12 Months Ended
	Dec. 31, 2022
Restructuring and Related Activities [Abstract]
Details of Long-Lived Asset Impairments	The following tables present the details of the long-lived asset impairments Year Ended December 31, 2020 First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended Continuing operations: Met $ 32,951 $ — $ — $ 13,366 $ 46,317 All Other 758 17,390 219 16,270 34,637 Total from continuing operations $ 33,709 $ 17,390 $ 219 $ 29,636 $ 80,954 Discontinued operations: $ — $ 144,348 $ 3,297 $ — $ 147,645 Total long-lived asset impairment: $ 33,709 $ 161,738 $ 3,516 $ 29,636 $ 228,599 Year Ended December 31, 2020 First Quarter Second Quarter Third Quarter Fourth Quarter Year Ended Continuing operations: Mineral rights, net $ 21,825 $ 2,241 $ — $ 17,513 $ 41,579 Property, plant, and equipment, net 6,066 6,496 219 5,450 18,231 Acquired mine permits, net 5,818 8,653 — 6,673 21,144 Total from continuing operations $ 33,709 $ 17,390 $ 219 $ 29,636 $ 80,954 Discontinued operations: Mineral rights, net $ — $ 16,364 $ — $ — $ 16,364 Property, plant, and equipment, net — 127,984 3,297 — 131,281 Total from discontinued operations $ — $ 144,348 $ 3,297 $ — $ 147,645 Total long-lived asset impairment: Mineral rights, net $ 21,825 $ 18,605 $ — $ 17,513 $ 57,943 Property, plant, and equipment, net 6,066 134,480 3,516 5,450 149,512 Acquired mine permits, net 5,818 8,653 — 6,673 21,144 Total long-lived asset impairment $ 33,709 $ 161,738 $ 3,516 $ 29,636 $ 228,599
Restructuring and Related Costs	As a result of the strategic actions discussed above, the Company recorded restructuring expense during the year ended December 31, 2020 as follows: Year Ended December 31, 2020 Total Restructuring Continuing Operations (3) Discontinued Operations Severance and employee-related benefits (1) $ 26,037 $ 2,117 $ 23,920 Other costs (2) 1,882 807 1,075 Total restructuring expense $ 27,919 $ 2,924 $ 24,995 (1) Severance and employee-related benefits were considered probable and estimable based on provisions of contractual agreements and existing employee benefit plans. (2) Includes accelerated amortization of deferred longwall move expenses of $668, allowance for advanced mining royalties of $407, and allowance for obsolete materials and supplies inventory of $807.

Capital Stock (Tables)

Capital Stock (Tables)	12 Months Ended
	Dec. 31, 2022
Equity [Abstract]
Schedule of Dividends Declared	The Board declared the following dividends on the Company’s common stock during the year ended December 31, 2022: Total Dividend per Share (1) Total Dividends Paid (2) Declaration Date Holders of Record Date Payable Date $ 0.375 $ 6,773 May 3, 2022 June 15, 2022 July 1, 2022 0.392 6,522 August 4, 2022 September 15, 2022 October 3, 2022 5.418 84,748 November 4, 2022 December 15, 2022 January 3, 2023 $ 6.185 $ 98,043 (1) The fourth quarter dividend declared on November 4, 2022 includes the quarterly cash dividend of $0.418 per share and the one-time, special dividend of $5.00 per share.

Property, Plant, and Equipmen_2

Property, Plant, and Equipment, Net (Tables)	12 Months Ended
	Dec. 31, 2022
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant, and Equipment, Net	Property, plant, and equipment, net, consisted of the following: December 31, 2022 2021 Plant and mining equipment $ 723,056 $ 642,874 Mine development 130,144 115,357 Land 27,937 26,389 Office equipment, software and other 3,111 1,462 Construction in progress 49,583 19,992 Total property, equipment and mine development costs $ 933,831 $ 806,074 Less accumulated depreciation and amortization (491,186) (443,856) Total property, plant, and equipment, net $ 442,645 $ 362,218

Other Non-Current Assets (Table

Other Non-Current Assets (Tables)	12 Months Ended
	Dec. 31, 2022
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of Other Non-Current Assets	Other non-current assets consisted of the following: December 31, 2022 2021 Advanced mining royalties $ 7,476 $ 10,788 Long-term deposits 1,363 1,371 Equity method investments 23,070 20,460 Workers’ compensation receivables 44,734 51,355 Goodwill 10,736 — Other 15,816 24,660 Total other non-current assets $ 103,195 $ 108,634

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2022
Leases [Abstract]
Right-of-use Assets and Lease Liabilities	As of December 31, 2022 and 2021, the Company had the following right-of-use assets and lease liabilities within the Company’s Consolidated Balance Sheets: December 31, 2022 December 31, 2021 Assets Balance Sheet Classification Financing lease assets Property, plant, and equipment, net $ 5,429 $ 2,987 Operating lease right-of-use assets Other non-current assets 4,488 5,003 Total lease assets $ 9,917 $ 7,990 Liabilities Balance Sheet Classification Financing lease liabilities - current Current portion of long-term debt $ 1,052 $ 1,878 Operating lease liabilities - current Accrued expenses and other current liabilities 612 547 Financing lease liabilities - long-term Long-term debt 3,744 791 Operating lease liabilities - long-term Other non-current liabilities 3,876 4,456 Total lease liabilities $ 9,284 $ 7,672
Lease Costs and Other Information	Total lease costs and other lease information for the years ended December 31, 2022, 2021, and 2020 included the following: Year Ended December 31, 2022 2021 2020 Lease cost (1) Financing lease cost: Amortization of leased assets $ 2,644 $ 2,061 $ 3,238 Interest on lease liabilities 315 245 358 Operating lease cost 1,113 1,383 2,105 Short-term lease cost 1,234 786 1,518 Total lease cost $ 5,306 $ 4,475 $ 7,219 (1) The Company had no variable lease costs or sublease income for the years ended December 31, 2022, 2021, and 2020. Year Ended December 31, 2022 2021 2020 Other information Cash paid for amounts included in the measurement of lease liabilities $ 5,556 $ 4,478 $ 7,157 Operating cash flows from financing leases $ 315 $ 245 $ 358 Operating cash flows from operating leases $ 2,347 $ 2,169 $ 3,623 Financing cash flows from financing leases $ 2,894 $ 2,064 $ 3,176 Right-of-use assets obtained in exchange for new financing lease liabilities $ 4,728 $ 703 $ 221 Right-of-use assets obtained in exchange for new operating lease liabilities $ 48 $ 275 $ (12) Lease Term and Discount Rate Weighted-average remaining lease term in years - financing leases 5.90 1.75 1.94 Weighted-average remaining lease term in years - operating leases 7.10 7.88 8.45 Weighted-average discount rate - financing leases 13.5 % 9.6 % 6.1 % Weighted-average discount rate - operating leases 11.6 % 11.3 % 11.5 %
Finance Lease Maturity	The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Consolidated Balance Sheets as of December 31, 2022: Financing Leases Operating Leases Lease cost 2023 $ 1,597 $ 1,099 2024 1,335 955 2025 1,225 897 2026 691 884 2027 360 714 Thereafter 1,800 2,062 Total future minimum lease payments $ 7,008 $ 6,611 Imputed interest (2,212) (2,123) Present value of future minimum lease payments $ 4,796 $ 4,488
Operating Lease Maturity	The following table summarizes the maturity of the Company’s lease liabilities on an undiscounted cash flow basis and a reconciliation to the lease liabilities recognized in the Company’s Consolidated Balance Sheets as of December 31, 2022: Financing Leases Operating Leases Lease cost 2023 $ 1,597 $ 1,099 2024 1,335 955 2025 1,225 897 2026 691 884 2027 360 714 Thereafter 1,800 2,062 Total future minimum lease payments $ 7,008 $ 6,611 Imputed interest (2,212) (2,123) Present value of future minimum lease payments $ 4,796 $ 4,488

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2022
Payables and Accruals [Abstract]
Schedule of Accrued Expenses and Other Current Liabilities	Accrued expenses and other current liabilities consisted of the following: December 31, 2022 2021 Wages and benefits $ 69,458 $ 53,564 Workers’ compensation 11,651 13,312 Black lung 9,664 7,295 Taxes other than income taxes 24,959 31,234 Asset retirement obligations 36,963 32,159 Accrued interest and fees 1,062 14,489 Dividend payable 86,118 — Freight accrual 7,181 15,085 Other 18,200 13,304 Total accrued expenses and other current liabilities $ 265,256 $ 180,442

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2022
Debt Disclosure [Abstract]
Schedule of Long-term Debt Instruments	Long-term debt consisted of the following: December 31, 2022 2021 Term Loan Credit Facility - due June 2024 $ — $ 449,435 Other (1) 10,975 5,311 Debt discount and issuance costs — (6,195) Total long-term debt $ 10,975 $ 448,551 Less current portion (3,078) (2,989) Long-term debt, net of current portion $ 7,897 $ 445,562 (1) Includes financing leases, refer to Note 12 for additional information.
Schedule of Maturities of Long-term Debt	Future maturities of long-term debt as of December 31, 2022 are as follows: 2023 $ 3,078 2024 3,076 2025 2,879 2026 468 2027 171 After 2027 1,303 Total long-term debt $ 10,975

Acquisition-Related Obligatio_2

Acquisition-Related Obligations (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Acquisition-Related Obligations	Acquisition-related obligations consisted of the following: December 31, 2022 2021 Contingent Revenue Obligation $ 27,719 $ 35,005 Environmental Settlement Obligations 535 6,633 Discount — (233) Total acquisition-related obligations $ 28,254 $ 41,405 Less current portion (28,254) (22,405) Acquisition-related obligations, net of current portion $ — $ 19,000

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Summary of Changes in Asset Retirement Obligations	The following table summarizes the changes in asset retirement obligations for the years ended December 31, 2022 and 2021: Total asset retirement obligations at December 31, 2020 $ 165,064 Accretion for the period 26,520 Sites added during the period 2,125 Revisions in estimated cash flows (1) (12,744) Expenditures for the period (16,793) Total asset retirement obligations at December 31, 2021 $ 164,172 Accretion for the period 23,765 Sites added during the period 9,602 Revisions in estimated cash flows 304 Expenditures for the period (18,832) Total asset retirement obligations at December 31, 2022 $ 179,011 Less current portion (2) (36,963) Long-term portion $ 142,048 (1) The revisions in estimated cash flows resulted primarily from discount rate adjustments and changes in mine plans. (2) Included within Accrued expenses and other current liabilities on the Company’s Consolidated Balance Sheets. Refer to Note 13.

Fair Value of Financial Instr_2

Fair Value of Financial Instruments and Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value Measurements, Nonrecurring	The following table sets forth by level, within the fair value hierarchy, the Company’s long-term debt at fair value as of December 31, 2021: December 31, 2021 Carrying (1) Total Fair Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Term Loan Credit Facility - due June 2024 $ 443,241 $ 447,561 $ — $ 447,561 $ — (1) Net of debt discounts and debt issuance costs.
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth by level, within the fair value hierarchy, the Company’s financial and non-financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2022 and 2021. Financial and non-financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment, and may affect the determination of fair value for assets and liabilities and their placement within the fair value hierarchy levels. December 31, 2022 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 27,719 $ — $ — $ 27,719 Trading securities (1) $ 151,787 $ — $ 151,787 $ — (1) Includes $46,052 classified as Short-term investments and $105,735 classified as Long-term restricted investments on the Company’s Consolidated Balance Sheets. December 31, 2021 Total Fair Value Quoted Prices in Active Markets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Contingent Revenue Obligation $ 35,005 $ — $ — $ 35,005 Trading securities (1) $ 30,949 $ 27,075 $ 3,874 $ — (1) Classified as Long-term restricted investments on the Company’s Consolidated Balance Sheets. The following tables are reconciliations of the financial and non-financial assets and liabilities that were accounted for at fair value on a recurring basis and that were categorized within Level 3 of the fair value hierarchy: December 31, 2021 Payments Loss Recognized in Earnings Transfer In (Out) of Level 3 Fair Value Hierarchy December 31, 2022 Contingent Revenue Obligation $ 35,005 $ (16,166) $ 8,880 $ — $ 27,719 (1) The loss recognized in earnings resulted primarily from an increase in forecasted future revenue as of December 31, 2022. December 31, 2020 Payments Loss Recognized in Earnings Transfer In (Out) of Level 3 Fair Value Hierarchy December 31, 2021 Contingent Revenue Obligation $ 28,967 $ (13,487) $ 19,525 $ — $ 35,005
Schedule of Range of Significant Unobservable Inputs	Refer to Note 15 for additional information. The range of significant unobservable inputs used to value the Contingent Revenue Obligation as of December 31, 2021 are set forth in the following table: December 31, 2021 Forecasted future revenue $1.5 - $2.0 billion Stated royalty rate 1.0% - 1.5% Annualized volatility 18.4% - 39.3% (29.9%)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Significant components of income tax expense (benefit) from continuing operations were as follows: Year Ended December 31, 2022 2021 2020 Current tax expense (benefit): Federal $ 114,106 $ 2,422 $ (35,187) State 6,620 1,149 (99) Total current $ 120,726 $ 3,571 $ (35,286) Deferred tax (benefit) expense: Federal $ (1,726) $ (3) $ 33,348 State (12,795) (160) (226) Total deferred $ (14,521) $ (163) $ 33,122 Total income tax expense (benefit): Federal $ 112,380 $ 2,419 $ (1,839) State (6,175) 989 (325) Total $ 106,205 $ 3,408 $ (2,164)
Schedule of Effective Income Tax Rate Reconciliation	A reconciliation of statutory federal income tax expense (benefit) on income (loss) from continuing operations to the actual income tax expense (benefit) is as follows: Year Ended December 31, 2022 2021 2020 Federal statutory income tax expense (benefit) $ 326,497 $ 61,362 $ (51,163) Increase (reductions) in taxes due to: Percentage depletion allowance (50,277) (11,864) (2,039) Foreign-derived intangible income deduction (69,917) (1,453) — Change in valuation allowances (119,082) (78,043) 59,929 State taxes, net of federal tax impact 14,625 12,440 (9,640) State apportioned tax rate change, net of federal tax impact 273 8,751 (1,235) Capital loss carryforward expiration 140 10,552 — Other, net 3,946 1,663 1,984 Income tax expense (benefit) $ 106,205 $ 3,408 $ (2,164)
Schedule of Deferred Tax Assets and Liabilities	The net deferred tax assets and liabilities included in the Consolidated Balance Sheets include the following amounts: Year Ended December 31, 2022 2021 Deferred tax assets: Asset retirement obligations $ 39,200 $ 36,252 Reserves and accruals not currently deductible 10,572 9,610 Workers’ compensation benefit obligations 38,099 47,105 Pension obligations 23,826 34,956 Equity method investments 1,555 1,846 Net operating loss carryforwards 43,716 137,865 Capital loss carryforwards 48,940 49,476 Acquisition-related obligations 6,194 9,156 Other 7,171 7,100 Gross deferred tax assets 219,273 333,366 Less valuation allowance (53,801) (172,883) Deferred tax assets $ 165,472 $ 160,483 Deferred tax liabilities: Property, plant and mineral reserves $ (148,189) $ (134,075) Acquired intangibles, net (11,995) (16,408) Prepaid expenses (4,215) (4,955) Restricted cash (556) (5,362) Other (13) — Total deferred tax liabilities (164,968) (160,800) Net deferred tax assets (liabilities) $ 504 $ (317)
Summary of Valuation Allowance	Changes in the valuation allowance were as follows: Year Ended December 31, 2022 2021 2020 Valuation allowance beginning of period $ 172,883 $ 263,387 $ 133,020 (Decrease) increase in valuation allowance recorded to income tax expense (benefit) (119,082) (78,043) 117,829 (Decrease) increase in valuation allowance not affecting income tax expense (benefit) — (12,461) 12,538 Valuation allowance end of period $ 53,801 $ 172,883 $ 263,387
Schedule of Liability for Uncertain Tax Positions	The following reconciliation illustrates the Company’s liability for uncertain tax positions: Year Ended December 31, 2022 2021 2020 Unrecognized tax benefits - beginning of period $ — $ — $ 20,788 Reductions for tax positions of prior years — — (20,788) Unrecognized tax benefits - end of period $ — $ — $ —

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2022
Compensation Related Costs [Abstract]
Changes in Accumulated Benefits Obligations, Fair Value of Plan Assets and Funded Status of Plan	The following tables set forth the Pension Plans’ accumulated benefit obligations, fair value of plan assets and funded status for the years ended December 31, 2022 and 2021. Year Ended December 31, 2022 2021 Change in benefit obligations: Accumulated benefit obligation at beginning of period: $ 668,055 $ 723,448 Interest cost 15,981 13,566 Actuarial gain (1) (182,441) (34,922) Benefits paid (30,378) (30,222) Settlement (2,775) (3,815) Accumulated benefit obligation at end of period $ 468,442 $ 668,055 Change in fair value of plan assets: Fair value of plan assets at beginning of period $ 508,125 $ 504,777 Actual return on plan assets (120,796) 30,814 Employer contributions 3,430 6,571 Benefits paid (30,378) (30,222) Settlement (2,775) (3,815) Fair value of plan assets at end of period $ 357,606 $ 508,125 Funded status $ (110,836) $ (159,930) Accrued benefit cost at end of period (2) $ (110,836) $ (159,930) (1) For the year ended December 31, 2022, the actuarial gain was primarily attributable to the loss on plan assets and the change in the weighted-average discount rate actuarial assumption used in determining the benefit obligations. For the year ended December 31, 2021, the actuarial gain was primarily attributable to the change in the weighted-average discount rate actuarial assumption used in determining the benefit obligations. (2) Amounts are classified as long-term on the Consolidated Balance Sheets as there are sufficient plan assets to make expected benefit payments to plan participants in the succeeding twelve months. The following tables set forth the accumulated black lung benefit obligations, fair value of plan assets and funded status for the years ended December 31, 2022 and 2021: Year Ended December 31, 2022 2021 Change in benefit obligation: Accumulated benefit obligation at beginning of period $ 117,142 $ 127,506 Service cost 2,642 2,972 Interest cost 2,722 2,463 Actuarial gain (1) (21,060) (9,759) Benefits paid (8,025) (6,040) Accumulated benefit obligation at end of period $ 93,421 $ 117,142 Change in fair value of plan assets: Fair value of plan assets at beginning of period $ 2,664 $ 2,720 Actual return on plan assets (126) (56) Benefits paid (8,025) (6,040) Employer contributions 8,025 6,040 Fair value of plan assets at end of period (2) 2,538 2,664 Funded status $ (90,883) $ (114,478) Accrued benefit cost at end of period $ (90,883) $ (114,478) (1) For the years ended December 31, 2022 and 2021, the actuarial gain was primarily attributable to the change in the weighted-average discount rate actuarial assumption used in determining the benefit obligations. (2) Assets of the plan are held in a Section 501(c)(21) tax-exempt trust fund and consist primarily of government debt securities. All assets are classified as Level 1 and valued based on quoted market prices.
Schedule of Amounts Recognized in Accumulated Other Comprehensive (Income) Loss	Gross amounts related to benefit obligations recognized in accumulated other comprehensive loss consisted of the following as of December 31, 2022 and 2021: December 31, 2022 2021 Net actuarial loss $ 12,683 $ 47,950 December 31, 2022 2021 Net actuarial (gain) loss $ (10,198) $ 11,940
Schedule of Net Periodic Benefit Cost	The following table details the components of net periodic benefit credit: Year Ended December 31, 2022 2021 2020 Interest cost $ 15,981 $ 13,566 $ 18,730 Expected return on plan assets (28,733) (28,732) (27,064) Amortization of net actuarial loss 2,111 3,217 2,012 Settlement 244 412 1,636 Net periodic benefit credit $ (10,397) $ (11,537) $ (4,686) The following table details the components of the net periodic benefit cost for the black lung benefit obligations: Year Ended December 31, 2022 2021 2020 Service cost $ 2,642 $ 2,972 $ 2,361 Interest cost 2,722 2,463 3,240 Expected return on plan assets (53) (54) (54) Amortization of net actuarial loss 1,257 2,453 1,942 Settlement — — 1,563 Net periodic benefit cost $ 6,568 $ 7,834 $ 9,052 Summary net periodic benefit cost: Continuing operations $ 6,568 $ 7,834 $ 7,670 Discontinued operations (1) — — 1,382 Total net periodic benefit cost $ 6,568 $ 7,834 $ 9,052 (1) The discontinued operations consisted of activity related to the Company’s former NAPP operations. Refer to Note 3.
Schedule of Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income	Other changes in plan assets and benefit obligations recognized in other comprehensive (loss) income are as follows: Year Ended December 31, 2022 2021 2020 Actuarial (gain) loss $ (32,912) $ (37,004) $ 45,663 Amortization of net actuarial loss (2,111) (3,217) (2,012) Settlement (244) (412) (1,636) Total recognized in other comprehensive (loss) income $ (35,267) $ (40,633) $ 42,015 Other changes in the black lung plan assets and benefit obligations recognized in other comprehensive (loss) income are as follows: Year Ended December 31, 2022 2021 2020 Actuarial (gain) loss $ (20,881) $ (9,649) $ 14,567 Amortization of net actuarial loss (1,257) (2,453) (1,942) Settlement — — (1,563) Total recognized in other comprehensive (loss) income $ (22,138) $ (12,102) $ 11,062
Schedule of Benefit Obligations in Excess of Fair Value of Plan Assets	The following table presents information applicable to plans with accumulated benefit obligations in excess of plan assets: Year Ended December 31, 2022 2021 Projected benefit obligation $ 468,442 $ 668,055 Accumulated benefit obligation $ 468,442 $ 668,055 Fair value of plan assets $ 357,606 $ 508,125
Schedule of Assumptions Used	The weighted-average actuarial assumption used in determining the benefit obligations as of December 31, 2022 and 2021 was as follows: December 31, 2022 2021 Discount rate 5.42 % 2.92 % The weighted-average actuarial assumptions used to determine net periodic benefit credit for the years ended December 31, 2022, 2021, and 2020 were as follows: Year Ended December 31, 2022 2021 2020 Discount rate for benefit obligation 2.92 % 2.62 % 3.35 % Discount rate for interest cost 2.44 % 1.96 % 2.92 % Expected long-term rate of return on plan assets 5.80 % 5.80 % 5.90 % The weighted-average assumptions related to black lung obligations used to determine the benefit obligation as of December 31, 2022 and 2021 were as follows: December 31, 2022 2021 Discount rate 5.42 % 2.96 % Federal black lung income benefit trend rate 2.50 % 2.00 % Federal black lung medical benefit trend rate 5.00 % 5.00 % The weighted-average assumptions related to black lung benefit obligations used to determine net periodic benefit cost were as follows: Year Ended December 31, 2022 2021 2020 Discount rate for benefit obligation 2.96 % 2.75 % 3.47 % Discount rate for service cost 3.24 % 3.15 % 3.56 % Discount rate for interest cost 2.37 % 1.96 % 2.61 % Federal black lung income benefit trend rate 2.50 % 2.00 % 2.50 % Federal black lung medical benefit trend rate 5.00 % 5.00 % 5.00 % Black lung benefit expense inflation rate (1) — % — % 2.00 % Expected return on plan assets 2.00 % 2.00 % 2.00 % (1) Effective in 2021, the annual claim administration expenses are incorporated into the annual service cost component of the net periodic benefit cost for the black lung benefit obligations.
Schedule of Allocation of Plan Assets	The target allocation for 2023 and the actual asset allocation as reported at December 31, 2022 are as follows: Target Allocation Percentages 2023 Percentage of Plan Assets 2022 Equity securities 58.0 % 55.0 % Fixed income funds 42.0 % 41.0 % Other — % 4.0 % Total 100.0 % 100.0 %
Schedule of Estimated Cash Payments	The following represents expected future pension benefit payments for the next ten years: 2023 $ 31,084 2024 31,103 2025 31,136 2026 31,215 2027 31,264 2028-2032 153,885 $ 309,687 Estimated future cash payments related to black lung benefit obligations for the next 10 years ending after December 31, 2022 are as follows: Year ending December 31: 2023 $ 9,664 2024 9,218 2025 9,009 2026 8,923 2027 8,828 2028-2032 20,454 $ 66,096
Schedule of Changes in Fair Value of Plan Assets	The fair values of the Company’s Pension Plans’ assets as of December 31, 2022, by asset category are as follows: Asset Category Total Quoted Market Prices in Active Market for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Equity securities: Multi-asset fund (1) $ 198,262 $ — $ 198,262 $ — Fixed income funds: Bond fund (2) 144,197 — 144,197 — Commingled short-term fund (3) 1,339 — 1,339 — Other types of investments: Guaranteed insurance contract 11,912 — — 11,912 Total $ 355,710 $ — $ 343,798 $ 11,912 Receivable (4) 1,145 Total assets at fair value 356,855 Private equity funds measured at net asset value practical expedient (5) 751 Total plan assets $ 357,606 (1) This fund contains equities (domestic and international), real estate and bonds. (2) This fund contains bonds representing a diversity of sectors and maturities. This fund also includes mortgage-backed securities and U.S. Treasuries. (3) This fund contains cash and highly liquid short-term investments in a collective investment fund. (4) Receivable for investments sold at December 31, 2022, which approximates fair value. (5) In accordance with Accounting Standards Update 2015-07, investments that are measured at fair value using the net asset value per share practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the total value of assets of the plans. Changes in Level 3 plan assets for the period ended December 31, 2022 were as follows: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Guaranteed Insurance Contract Beginning balance, December 31, 2021 $ 11,652 Actual return on plan assets: Relating to assets still held at the reporting date 562 Purchases, sales and settlements (302) Ending balance, December 31, 2022 $ 11,912 The fair values of the Company’s Pension Plans’ assets as of December 31, 2021, by asset category are as follows: Asset Category Total Quoted Market Prices in Active Market for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Equity securities: Multi-asset fund (1) $ 284,568 $ — $ 284,568 $ — Fixed income funds: Bond fund (2) 208,466 — 208,466 — Commingled short-term fund (3) 1,384 — 1,384 — Other types of investments: Guaranteed insurance contract 11,652 — — 11,652 Total $ 506,070 $ — $ 494,418 $ 11,652 Receivable (4) 876 Total assets at fair value 506,946 Private equity funds measured at net asset value practical expedient (5) 1,179 Total plan assets $ 508,125 (1) This fund contains equities (domestic and international), real estate and bonds. (2) This fund contains bonds representing a diversity of sectors and maturities. This fund also includes mortgage-backed securities and U.S. Treasuries. (3) This fund contains cash and highly liquid short-term investments in a collective investment fund. (4) Receivable for investments sold at December 31, 2021, which approximates fair value. (5) In accordance with Accounting Standards Update 2015-07, investments that are measured at fair value using the net asset value per share practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in this table are intended to permit reconciliation of the fair value hierarchy to the total value of assets of the plans. Changes in Level 3 plan assets for the period ended December 31, 2021 were as follows: Fair Value Measurements Using Significant Unobservable Inputs (Level 3) Guaranteed Insurance Contract Beginning balance, December 31, 2020 $ 11,454 Actual return on plan assets: Relating to assets still held at the reporting date 528 Purchases, sales and settlements (330) Ending balance, December 31, 2021 $ 11,652
Schedule of Workers' Compensation	The table below presents workers’ compensation amounts recognized in the Consolidated Balance Sheets: December 31, 2022 2021 Current liabilities $ 11,651 $ 13,312 Long-term liabilities 107,028 124,693 Total liabilities $ 118,679 $ 138,005 Less expected insurance receivable (1) (46,866) (53,664) Workers’ compensation obligations, net of expected insurance receivables $ 71,813 $ 84,341 (1) Included within Prepaid expenses and other current assets and Other non-current assets in the Consolidated Balance Sheets.
Schedule of Amounts Recognized in Balance Sheet	The table below presents amounts recognized in the Consolidated Balance Sheets: December 31, 2022 2021 Current liabilities $ 9,664 $ 7,295 Long-term liabilities 81,219 107,183 Total liabilities $ 90,883 $ 114,478

Stock-Based Compensation Awar_2

Stock-Based Compensation Awards (Tables)	12 Months Ended
	Dec. 31, 2022
Share-Based Payment Arrangement [Abstract]
Schedule of Valuation Assumptions	The Monte Carlo simulation incorporated the assumptions as presented in the following table: Relative performance-based restricted stock units Start price (1) $ 53.29 Valuation date stock price (2) $ 61.09 Expected volatility (3) 106.48 % Risk-free interest rate (4) 1.26 % Expected dividend yield (5) — % (1) The start price for the Company represented the average closing stock price over the twenty trading days ending on December 31, 2021, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represented the closing price on the grant date. (3) The expected volatility assumption was based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equaled the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that had a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represented the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Performance-based cash incentive awards Start price (1) $ 53.29 Valuation date stock price (2) $ 61.09 Expected volatility (3) 106.48 % Risk-free interest rate (4) 1.26 % Expected dividend yield (5) — % (1) The start price for the Company represents the average closing stock price over the twenty trading days ending on December 31, 2021, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represents the closing price at each reporting date. (3) The expected volatility assumption is based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equals the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that have a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represents the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Relative performance-based restricted stock units Start price (1) $ 11.81 Valuation date stock price (2) $ 11.34 Expected volatility (3) 98.54 % Risk-free interest rate (4) 0.18 % Expected dividend yield (5) — % (1) The start price for the Company represented the average closing stock price over the twenty trading days ending on December 31, 2020, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represented the closing price on the grant date. (3) The expected volatility assumption was based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equaled the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that had a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represented the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Performance-based cash incentive awards Start price (1) $ 11.81 Valuation date stock price (2) $ 11.34 Expected volatility (3) 98.54 % Risk-free interest rate (4) 0.18 % Expected dividend yield (5) — % (1) The start price for the Company represents the average closing stock price over the twenty trading days ending on December 31, 2020, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represents the closing price at each reporting date. (3) The expected volatility assumption is based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equals the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that have a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represents the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Relative performance-based restricted stock units Start price (1) $ 7.59 Valuation date stock price (2) $ 6.33 Expected volatility (3) 55.27 % Risk-free interest rate (4) 1.37 % Expected dividend yield (5) — % (1) The start price for the Company represented the average closing stock price over the twenty trading days ending on December 31, 2019, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represented the closing price on the grant date. (3) The expected volatility assumption was based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equaled the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that had a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represented the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit. Performance-based cash incentive awards Start price (1) $ 7.59 Valuation date stock price (2) $ 6.33 Expected volatility (3) 55.27 % Risk-free interest rate (4) 1.37 % Expected dividend yield (5) — % (1) The start price for the Company represents the average closing stock price over the twenty trading days ending on December 31, 2019, assuming dividends distributed during this period were reinvested in additional shares of the Company’s stock on the ex-dividend date. (2) The valuation date stock price represents the closing price at each reporting date. (3) The expected volatility assumption is based on the historical volatility of the price of the Company’s stock. (4) The annual risk-free interest rate equals the yield on the semi-annual zero coupon U.S. Treasury rates converted to continuously compounded rates that have a term equal to the length of the remaining performance measurement period as of the valuation date. (5) The expected dividend yield represents the investments return to a share of the Company’s stock that is not available to the holder of the performance-based restricted stock unit.
Schedule of Restricted Stock Shares and Restricted Share Units Activity	Time-based restricted stock unit activity for the year ended December 31, 2022 is summarized in the following table: Time-based restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value Non-vested shares outstanding at December 31, 2021 392,275 $ 11.54 Granted 95,111 $ 96.60 Vested (1) (237,643) $ 14.80 Forfeited (1,374) $ 6.36 Non-vested shares outstanding at December 31, 2022 248,369 $ 41.02 (1) Includes 4,254 shares with deferred settlement pursuant to the award agreements.
Schedule of Performance Shares Activity	Relative performance-based restricted stock unit activity for the year ended December 31, 2022 based on target achievement of the performance criteria is summarized in the following table: Relative performance-based restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value Non-vested shares outstanding at December 31, 2021 113,586 $ 36.47 Granted 24,342 $ 97.33 Vested — $ — Canceled (1) (46,551) $ 65.70 Non-vested shares outstanding at December 31, 2022 91,377 $ 37.80 (1) Shares were canceled and allocated back to the LTIP for future issuance as the 2019 award’s performance metric was not achieved, including 25,364 shares for employees that had previously only met the continued employment vesting criteria. Absolute performance-based restricted stock unit activity for the year ended December 31, 2022 based on target achievement of the performance criteria is summarized in the following table: Absolute performance-based restricted stock unit activity: Number of Shares Weighted-Average Grant Date Fair Value Non-vested shares outstanding at December 31, 2021 15,532 $ 50.60 Granted — $ — Vested — $ — Canceled (1) (15,532) $ 50.60 Non-vested shares outstanding at December 31, 2022 — $ — (1) Shares were canceled and allocated back to the LTIP for future issuance as the 2019 award’s performance metric was not achieved, including 8,459 shares for employees that had previously only met the continued employment vesting criteria. Operational performance-based restricted stock unit activity for the year ended December 31, 2022 based on target achievement of the performance criteria is summarized in the following table: Operational performance-based restricted stock unit activity: Number of Shares Weighted-Average Fair Value Non-vested shares outstanding at December 31, 2021 100,552 $ 12.00 Granted 36,515 $ 60.37 Vested — $ — Forfeited or Canceled — $ — Non-vested shares outstanding at December 31, 2022 137,067 $ 24.89 Performance-based cash incentive award activity: Target Dollar Value Weighted-Average Fair Value as a % of Target Dollar Value Non-vested awards outstanding at December 31, 2021 $ 2,991 162.03 % Granted 1,105 61.97 % Vested — — % Forfeited (138) 150.25 % Non-vested awards outstanding at December 31, 2022 $ 3,958 166.29 %
Schedule of Stock Option Activity	30-day VWAP stock option activity for the year ended December 31, 2022 is summarized in the following table: Number of Shares Weighted-Average Exercise Price Per Share Weighted-Average Remaining Contractual Term (Years) Aggregate Intrinsic Value (1) Outstanding at December 31, 2021 23,225 $ 60.20 5.12 $ 20 Exercisable at December 31, 2021 23,225 $ 60.20 5.12 $ 20 Granted — $ — Exercised (19,818) $ 59.18 $ 1,484 Forfeited or Expired — $ — Outstanding at December 31, 2022 3,407 $ 66.13 4.18 $ 273 Exercisable at December 31, 2022 3,407 $ 66.13 4.18 $ 273

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Restrictions on Cash and Cash Equivalents	Amounts included in restricted cash provide collateral to secure the following obligations: December 31, 2022 2021 Workers’ compensation and black lung obligations $ 15,334 $ 70,637 Reclamation-related obligations 3,220 10,449 Financial payments and other performance obligations 10,387 8,340 Contingent Revenue Obligation escrow 24,547 11,977 Total restricted cash $ 53,488 $ 101,403 Less current portion (24,547) (11,977) Restricted cash, net of current portion $ 28,941 $ 89,426
Prepaid Expenses and Other Current Assets	Amounts included in restricted investments provide collateral to secure the following obligations: December 31, 2022 2021 Workers’ compensation and black lung obligations $ 72,136 $ 2,716 Reclamation-related obligations 31,718 26,225 Financial payments and other performance obligations 1,881 2,008 Total restricted investments (1) $ 105,735 $ 30,949 (1) Classified as trading securities as of December 31, 2022 and 2021. Amounts included in deposits provide collateral to secure the following obligations: December 31, 2022 2021 Reclamation-related obligations $ 102 $ 118 Financial payments and other performance obligations 391 403 Other operating agreements (1) 85,618 1,275 Total deposits (2) $ 86,111 $ 1,796 (1) Includes $84,748 related to the Company’s dividend payable. Refer to Note 9 for additional information. (2) Included within Short-term deposits and Other non-current assets on the Company’s Consolidated Balance Sheets.

Concentration of Credit Risk _2

Concentration of Credit Risk and Major Customers (Tables)	12 Months Ended
	Dec. 31, 2022
Risks and Uncertainties [Abstract]
Schedule of Concentration of Credit Risk and Major Customers	The following table presents additional information on our total revenues and top customers: Year Ended December 31, 2022 2021 2020 Total coal revenues $ 4,092,987 $ 2,252,624 $ 1,413,124 Total revenues $ 4,101,592 $ 2,258,686 $ 1,416,187 Top customer as % of total revenues 25 % 13 % 16 % Top 10 customers as % of total revenues 70 % 64 % 63 % Number of customers exceeding 10% of total revenues 1 2 2 Number of customers exceeding 10% of total trade accounts receivable, net 2 3 3 Domestic revenue as % of coal revenues 19 % 24 % 36 % Export revenue as % of coal revenues 81 % 76 % 64 % Countries with export revenue exceeding 10% of total revenues India India, China, Brazil India, Brazil Met coal as % of coal sales volume 87 % 83 % 80 % Thermal coal as % of coal sales volume 13 % 17 % 20 %

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2022
Segment Reporting [Abstract]
Schedule of Segment Operating Results and Capital Expenditures	Segment operating results and capital expenditures for the year ended December 31, 2022 were as follows: Year Ended December 31, 2022 Met All Other Consolidated Total revenues $ 4,023,688 $ 77,904 $ 4,101,592 Depreciation, depletion, and amortization $ 100,584 $ 7,036 $ 107,620 Amortization of acquired intangibles, net $ 15,699 $ 3,799 $ 19,498 Adjusted EBITDA $ 1,776,642 $ (36,030) $ 1,740,612 Capital expenditures $ 160,679 $ 3,630 $ 164,309 Segment operating results and capital expenditures for the year ended December 31, 2021 were as follows: Year Ended December 31, 2021 Met All Other Consolidated Total revenues $ 2,176,080 $ 82,606 $ 2,258,686 Depreciation, depletion, and amortization $ 99,963 $ 10,084 $ 110,047 Amortization of acquired intangibles, net $ 13,671 $ (427) $ 13,244 Adjusted EBITDA $ 567,270 $ (32,789) $ 534,481 Capital expenditures $ 79,185 $ 4,115 $ 83,300 Segment operating results and capital expenditures from continuing operations for the year ended December 31, 2020 were as follows: Year Ended December 31, 2020 Met All Other Consolidated Total revenues $ 1,264,496 $ 151,691 $ 1,416,187 Depreciation, depletion, and amortization $ 124,060 $ 15,825 $ 139,885 Amortization of acquired intangibles, net $ 12,889 $ (3,675) $ 9,214 Adjusted EBITDA $ 120,281 $ (36,880) $ 83,401 Capital expenditures $ 111,745 $ 7,834 $ 119,579
Reconciliation of Net Income (Loss) to Adjusted EBITDA	The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the year ended December 31, 2022: Year Ended December 31, 2022 Met All Other Consolidated Net income (loss) $ 1,647,104 $ (198,559) $ 1,448,545 Interest expense 202 21,600 21,802 Interest income (541) (2,646) (3,187) Income tax expense — 106,205 106,205 Depreciation, depletion and amortization 100,584 7,036 107,620 Non-cash stock compensation expense 4 7,480 7,484 Mark-to-market adjustment - acquisition-related obligations — 8,880 8,880 Accretion on asset retirement obligations 13,590 10,175 23,765 Amortization of acquired intangibles, net 15,699 3,799 19,498 Adjusted EBITDA $ 1,776,642 $ (36,030) $ 1,740,612 The following table presents a reconciliation of net income (loss) to Adjusted EBITDA for the year ended December 31, 2021: Year Ended December 31, 2021 Met All Other Consolidated Net income (loss) $ 439,859 $ (151,069) $ 288,790 Interest expense 184 69,470 69,654 Interest income (6) (330) (336) Income tax expense — 3,408 3,408 Depreciation, depletion and amortization 99,963 10,084 110,047 Non-cash stock compensation expense 28 5,287 5,315 Mark-to-market adjustment - acquisition-related obligations — 19,525 19,525 Gain on settlement of acquisition-related obligations — (1,125) (1,125) Accretion on asset retirement obligations 13,571 12,949 26,520 Asset impairment and restructuring — (561) (561) Amortization of acquired intangibles, net 13,671 (427) 13,244 Adjusted EBITDA $ 567,270 $ (32,789) $ 534,481 The following table presents a reconciliation of net loss from continuing operations to Adjusted EBITDA for the year ended December 31, 2020: Year Ended December 31, 2020 Met All Other Consolidated Net loss from continuing operations $ (77,519) $ (163,951) $ (241,470) Interest expense (2,014) 76,542 74,528 Interest income (63) (6,964) (7,027) Income tax benefit — (2,164) (2,164) Depreciation, depletion and amortization 124,060 15,825 139,885 Non-cash stock compensation expense 289 4,607 4,896 Mark-to-market adjustment - acquisition-related obligations — (8,750) (8,750) Accretion on asset retirement obligations 14,214 12,290 26,504 Asset impairment and restructuring 46,317 37,561 83,878 Management restructuring costs (1) 501 440 941 Loss on partial settlement of benefit obligations 1,607 1,359 2,966 Amortization of acquired intangibles, net 12,889 (3,675) 9,214 Adjusted EBITDA $ 120,281 $ (36,880) $ 83,401 (1) Management restructuring costs are related to severance expense associated with senior management changes during the three months ended March 31, 2020.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Property, Plant, and Equipment, Net (Details) - Mining equipment, buildings and other fixed assets	12 Months Ended
	Dec. 31, 2022
Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful lives	1 year
Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful lives	25 years

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Owned and Leased Mineral Rights (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Owned and leased mineral rights					$ 451,062	$ 444,302
Asset retirement obligation assets					20,284	10,354
Impairment of long-lived assets	$ 29,636	$ 219	$ 17,390	$ 33,709			$ 80,954
Depletion					23,078	23,541	(13,746)
Revisions to asset retirement obligations					(304)	12,744
Mineral rights, net
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets	$ 17,513	$ 0	$ 2,241	$ 21,825			41,579
Revisions to asset retirement obligations					$ (3,016)	$ 5,782	$ 34,377

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Acquired Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Impairment of long-lived assets	$ 29,636	$ 219	$ 17,390	$ 33,709			$ 80,954
Amortization of intangible assets					$ 19,498	$ 13,244	9,214
Future amortization expense, 2023					8,526
Future amortization expense, 2024					6,705
Future amortization expense, 2025					5,893
Future amortization expense, 2026					5,373
Future amortization expense, 2027					4,792
Future amortization expense, after 2027					23,813
Mine permits
Finite-Lived Intangible Assets [Line Items]
Impairment of long-lived assets	$ 6,673	$ 0	$ 8,653	$ 5,818			21,144
Mine permits
Finite-Lived Intangible Assets [Line Items]
Intangible assets, net					55,102	74,197
Amortization of intangible assets					19,498	13,571	14,887
Coal supply agreements
Finite-Lived Intangible Assets [Line Items]
Amortization of acquired intangibles, net					$ 0	$ (327)	$ (5,673)

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Goodwill (Details) - USD ($) $ in Thousands	1 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Goodwill	$ 10,736	$ 0
Mining Equipment Component Manufacturing and Rebuilding Business
Business Acquisition [Line Items]
Purchase price	24,878
Working capital	7,787
Property, plant, and equipment	6,355
Goodwill	$ 10,736

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Workers' Compensation (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Worker's compensation discount	$ 22,824	$ 23,442

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Equity Method Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Abstract]
Equity method investments	$ 23,070	$ 20,460

Discontinued Operations - Narra

Discontinued Operations - Narrative (Details) T in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) T	Dec. 31, 2022 USD ($) T	Dec. 31, 2021 USD ($) T	Dec. 31, 2020 USD ($) T
Cumberland Back-to-Back Coal Supply Agreement
Guarantor Obligations [Line Items]
Purchased and sold, tons | T		1,617	2,591	104
Purchased and sold		$ 62,171	$ 100,338	$ 3,997
Cumberland Back-to-Back Coal Supply Agreement | Forecast
Guarantor Obligations [Line Items]
Purchased and sold, tons | T	401
Purchased and sold	$ 15,478
Discontinued Operations, Disposed of by Sale | Cumberland Transaction
Guarantor Obligations [Line Items]
Consideration				$ 49,987

Discontinued Operations - Cumbe

Discontinued Operations - Cumberland Transaction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash	$ 0	$ 0	$ 52,192
Loss on sale	$ 0	$ 0	36,113
Cumberland Transaction | Discontinued Operations, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Cash			19,987
Surety bonding collateral			30,000
Total consideration			49,987
Transaction costs			2,205
Carrying value of assets and liabilities			(16,079)
Loss on sale			36,113
Property, plant and equipment, net			32,872
Deferred longwall move expenses			15,173
Coal and supplies inventory			5,112
Asset retirement obligations assumed			39,573
Severance			17,143
Black lung obligations			8,290
Subsidence liability			$ 3,559

Discontinued Operations - Major

Discontinued Operations - Major Components of Net Loss (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued Operation, Gain (Loss) on Disposal, Statement of Income or Comprehensive Income [Extensible Enumeration]	Loss from discontinued operations
Cumberland and PRB Transaction | Discontinued Operations
Revenues:
Total revenues	$ 235,509
Costs and expenses:
Cost of coal sales (exclusive of items shown separately below)	215,390
Depreciation, depletion and amortization	11,570
Accretion on asset retirement obligations	4,154
Asset impairment and restructuring	172,640
Selling, general and administrative expenses	1,623
Other income	(926)
Other non-major expense items, net	374
Loss on sale	36,113
Loss from discontinued operations before income taxes	$ (205,429)

Discontinued Operations - Maj_2

Discontinued Operations - Major Components of Cash Flows (Details) - Cumberland and PRB Transaction - Discontinued Operations $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Depreciation, depletion and amortization	$ 11,570
Capital expenditures	34,411
Other significant operating non-cash items related to discontinued operations:
Accretion on asset retirement obligations	4,154
Asset impairment and restructuring	$ 172,640

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue by Segment (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) segment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Revenue from Contract with Customer [Abstract]
Number of reportable segments | segment	1
Disaggregation of Revenue [Line Items]
Revenues	$ 4,092,987	$ 2,252,624	$ 1,413,124
Met Coal
Disaggregation of Revenue [Line Items]
Revenues	3,883,311	2,071,307	1,232,775
Thermal Coal
Disaggregation of Revenue [Line Items]
Revenues	209,676	181,317	180,349
Export coal revenues
Disaggregation of Revenue [Line Items]
Revenues	3,303,477	1,706,026	898,025
Export coal revenues | Met Coal
Disaggregation of Revenue [Line Items]
Revenues	3,195,516	1,675,147	870,121
Export coal revenues | Thermal Coal
Disaggregation of Revenue [Line Items]
Revenues	107,961	30,879	27,904
Domestic coal revenues
Disaggregation of Revenue [Line Items]
Revenues	789,510	546,598	515,099
Domestic coal revenues | Met Coal
Disaggregation of Revenue [Line Items]
Revenues	687,795	396,160	362,654
Domestic coal revenues | Thermal Coal
Disaggregation of Revenue [Line Items]
Revenues	$ 101,715	$ 150,438	$ 152,445

Revenue - Performance Obligatio

Revenue - Performance Obligations (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Disaggregation of Revenue [Line Items]
Estimated coal revenues	$ 165,591
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Disaggregation of Revenue [Line Items]
Estimated coal revenues	$ 128,341
Estimated coal revenues, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Disaggregation of Revenue [Line Items]
Estimated coal revenues	$ 37,250
Estimated coal revenues, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Disaggregation of Revenue [Line Items]
Estimated coal revenues	$ 0
Estimated coal revenues, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Disaggregation of Revenue [Line Items]
Estimated coal revenues	$ 0
Estimated coal revenues, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Disaggregation of Revenue [Line Items]
Estimated coal revenues	$ 0
Estimated coal revenues, period	1 year

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Loss - Changes to Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 546,909	$ 200,102	$ 696,122
Ending balance	1,429,755	546,909	200,102
Employee benefit costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(58,503)	(111,985)	(58,616)
Other comprehensive before income (loss) reclassifications	43,597	47,461	(60,647)
Amounts reclassified from accumulated other comprehensive loss	2,744	6,021	7,278
Ending balance	$ (12,162)	$ (58,503)	$ (111,985)

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Loss - Summary of Amounts Reclassified (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Employee benefit costs:
Income (loss) from continuing operations before income taxes	$ 1,554,750	$ 292,198	$ (243,634)
Income tax (expense) benefit	(106,205)	(3,408)	2,164
Net income (loss)	1,448,545	288,790	(446,899)
Reclassification out of Accumulated Other Comprehensive Income | Amortization of actuarial loss
Employee benefit costs:
Miscellaneous income	3,311	5,653	3,929
Reclassification out of Accumulated Other Comprehensive Income | Settlement
Employee benefit costs:
Miscellaneous income	244	368	3,349
Reclassification out of Accumulated Other Comprehensive Income | Employee benefit costs
Employee benefit costs:
Income (loss) from continuing operations before income taxes	3,555	6,021	7,278
Income tax (expense) benefit	(811)	0	0
Net income (loss)	$ 2,744	$ 6,021	$ 7,278

Net Income (Loss) per Share - N

Net Income (Loss) per Share - Narrative (Details) - shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Antidilutive securities excluded from computation of earnings per share (in shares)	0	717,992	1,317,351
Weighted-average antidilutive securities excluded from computation of earnings per share (in shares)		142,250

Net Income (Loss) per Share - S

Net Income (Loss) per Share - Schedule of Net Income (Loss) Per Common Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Net income (loss)
Income (loss) from continuing operations	$ 1,448,545	$ 288,790	$ (241,470)
Loss from discontinued operations	0	0	(205,429)
Net income (loss)	$ 1,448,545	$ 288,790	$ (446,899)
Basic
Weighted average common shares outstanding - basic (in shares)	17,490,886	18,441,175	18,298,362
Basic income (loss) per common share:
Income (loss) from continuing operations (in dollars per share)	$ 82.82	$ 15.66	$ (13.20)
Loss from discontinued operations (in dollars per share)	0	0	(11.22)
Net income (loss) (in dollars per share)	$ 82.82	$ 15.66	$ (24.42)
Diluted
Weighted average common shares outstanding - basic (in shares)	17,490,886	18,441,175	18,298,362
Weighted average common shares outstanding - diluted (in shares)	18,222,397	18,871,682	18,298,362
Diluted income (loss) per common share:
Income (loss) from continuing operations (in dollars per share)	$ 79.49	$ 15.30	$ (13.20)
Loss from discontinuing operations (in dollars per share)	0	0	(11.22)
Net income (loss) (in dollars per share)	$ 79.49	$ 15.30	$ (24.42)
Warrants
Diluted
Diluted effect of share-based payment awards (in shares)	275,715	35,574	0
Stock options
Diluted
Diluted effect of share-based payment awards (in shares)	4,171	1,753	0
Other stock-based instruments
Diluted
Diluted effect of share-based payment awards (in shares)	451,625	393,180	0

Inventories, net (Details)

Inventories, net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Inventory [Line Items]
Total inventories, net	$ 200,574	$ 129,382
Coal revenues
Inventory [Line Items]
Raw coal	57,382	20,347
Saleable coal	91,474	81,240
Materials, supplies and other, net
Inventory [Line Items]
Materials, supplies and other, net	$ 51,718	$ 27,795

Asset Impairment and Restruct_3

Asset Impairment and Restructuring - Narrative (Details) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2020 USD ($)	Sep. 30, 2020 USD ($)	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) assetGroup
Impaired Long-Lived Assets Held and Used [Line Items]
Total long-lived asset impairment	$ 29,636	$ 3,516	$ 161,738	$ 33,709		$ 228,599
Strategic Actions with Respect to Two Thermal Coal Mining Complexes
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring expense						$ 27,919
Discontinued Operations
Impaired Long-Lived Assets Held and Used [Line Items]
Number of assets impaired | assetGroup						1
Discontinued Operations | Strategic Actions with Respect to Two Thermal Coal Mining Complexes
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring expense						$ 24,995
All Other
Impaired Long-Lived Assets Held and Used [Line Items]
Total long-lived asset impairment					$ 60
Number of assets impaired | assetGroup						3
All Other | Strategic Actions with Respect to Two Thermal Coal Mining Complexes
Impaired Long-Lived Assets Held and Used [Line Items]
Restructuring expense					$ (621)
Operating segments | Met
Impaired Long-Lived Assets Held and Used [Line Items]
Number of assets impaired | assetGroup						5

Asset Impairment and Restruct_4

Asset Impairment and Restructuring - Long-Lived Asset Impairments (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2021	Dec. 31, 2020
Impaired Long-Lived Assets Held and Used [Line Items]
Impairment, Long-Lived Asset, Held-for-Use, Statement of Income or Comprehensive Income [Extensible Enumeration]						Asset impairment and restructuring
Long-lived asset impairment, continuing operations	$ 29,636	$ 219	$ 17,390	$ 33,709		$ 80,954
Long-lived asset impairment, discontinued operations	0	3,297	144,348	0		147,645
Total long-lived asset impairment	29,636	3,516	161,738	33,709		228,599
Mineral rights, net
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived asset impairment, continuing operations	17,513	0	2,241	21,825		41,579
Long-lived asset impairment, discontinued operations	0	0	16,364	0		16,364
Total long-lived asset impairment	17,513	0	18,605	21,825		57,943
Property, plant, and equipment, net
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived asset impairment, continuing operations	5,450	219	6,496	6,066	$ 60	18,231
Long-lived asset impairment, discontinued operations	0	3,297	127,984	0		131,281
Total long-lived asset impairment	5,450	3,516	134,480	6,066		149,512
Acquired mine permits, net
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived asset impairment, continuing operations	6,673	0	8,653	5,818		21,144
Total long-lived asset impairment	6,673	0	8,653	5,818		21,144
Operating segments | Met
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived asset impairment, continuing operations	13,366	0	0	32,951		46,317
All Other
Impaired Long-Lived Assets Held and Used [Line Items]
Long-lived asset impairment, continuing operations	$ 16,270	$ 219	$ 17,390	$ 758		$ 34,637
Total long-lived asset impairment					$ 60

Asset Impairment and Restruct_5

Asset Impairment and Restructuring - Restructuring Expense (Details) - Strategic Actions with Respect to Two Thermal Coal Mining Complexes - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Restructuring Cost and Reserve [Line Items]
Severance and employee-related benefits		$ 26,037
Other costs		1,882
Restructuring expense		27,919
Deferred longwall move expenses		668
Allowance for advanced mining royalties		407
Allowance for obsolete materials and supplies inventory		807
All Other
Restructuring Cost and Reserve [Line Items]
Restructuring expense	$ (621)
Continuing Operations
Restructuring Cost and Reserve [Line Items]
Severance and employee-related benefits		2,117
Other costs		807
Restructuring expense		2,924
Continuing Operations | All Other
Restructuring Cost and Reserve [Line Items]
Restructuring expense		2,924
Discontinued Operations
Restructuring Cost and Reserve [Line Items]
Severance and employee-related benefits		23,920
Other costs		1,075
Restructuring expense		$ 24,995

Capital Stock - Share Repurchas

Capital Stock - Share Repurchase Program (Details) - USD ($)	10 Months Ended	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Nov. 04, 2022	May 03, 2022	Mar. 04, 2022
Equity [Abstract]
Authorized share repurchases					$ 1,000,000,000	$ 600,000,000	$ 150,000,000
Number of shares repurchased	3,544,413
Total share repurchase price	$ 516,952,000	$ 521,803,000	$ 786,000	$ 209,000
Value of shares repurchased	516,845,000
Shares repurchased, fees	$ 107,000

Capital Stock - Dividend Progra

Capital Stock - Dividend Program (Details) - USD ($) $ / shares in Units, $ in Thousands

3 Months Ended

6 Months Ended

12 Months Ended

Feb. 21, 2023

Jan. 03, 2023

Nov. 04, 2022

Oct. 03, 2022

Aug. 04, 2022

Jul. 01, 2022

May 03, 2022

Dec. 31, 2022

Jan. 03, 2023

Dec. 31, 2022

Dec. 31, 2021

Dec. 31, 2020

Dividends Payable [Line Items]

Dividends intended but not yet declared (in dollars per share)

$ 0.375

Dividend per share (in dollars per share)

$ 5.418

$ 0.392

0.375

$ 0.418

$ 6.185

Dividends paid

$ 6,522

$ 6,773

$ 13,360

$ 0

$ 0

Subsequent Event

Dividends Payable [Line Items]

Dividend per share (in dollars per share)

$ 0.44

$ 6.185

Dividends paid

$ 84,748

$ 98,043

Annual Dividend

Dividends Payable [Line Items]

Dividends intended but not yet declared (in dollars per share)

$ 1.50

Special Dividend

Dividends Payable [Line Items]

Dividend per share (in dollars per share)

$ 5

Capital Stock - Dividend Declar

Capital Stock - Dividend Declared (Details) - USD ($) $ / shares in Units, $ in Thousands						3 Months Ended	12 Months Ended
	Nov. 04, 2022	Oct. 03, 2022	Aug. 04, 2022	Jul. 01, 2022	May 03, 2022	Dec. 31, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Dividends Payable [Line Items]
Dividend per share (in dollars per share)	$ 5.418		$ 0.392		$ 0.375	$ 0.418	$ 6.185
Dividends paid		$ 6,522		$ 6,773			$ 13,360	$ 0	$ 0
Dividend equivalent							3,444
Deposit for dividend payment						$ 84,748	$ 84,748
Special Dividend
Dividends Payable [Line Items]
Dividend per share (in dollars per share)	$ 5

Capital Stock - Warrants (Detai

Capital Stock - Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 15, 2022	Sep. 15, 2022	Jun. 15, 2022	Mar. 31, 2022	Jul. 26, 2016
Equity [Abstract]
Number of warrants outstanding (in shares)	190,838	801,246	801,370					810,811
Exercise price of warrants (in dollars per share)				$ 45.086	$ 46.679	$ 46.804	$ 46.911
Number of securities called by each warrant (in shares)				1.20	1.16	1.15
Number of securities called by outstanding warrants (in shares)	229,006	921,433	921,576
Shares issued upon exercise of warrants (in shares)	702,182	143	0
Shares withheld upon exercise of warrants (in shares)	187,857	17
Amount reclassified as treasury stock	$ 18,509

Property, Plant, and Equipmen_3

Property, Plant, and Equipment, Net - Schedule of Property, Plant, and Equipment, Net (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property, equipment and mine development costs	$ 933,831	$ 806,074
Less accumulated depreciation and amortization	(491,186)	(443,856)
Total property, plant, and equipment, net	442,645	362,218
Plant and mining equipment
Property, Plant and Equipment [Line Items]
Total property, equipment and mine development costs	723,056	642,874
Mine development
Property, Plant and Equipment [Line Items]
Total property, equipment and mine development costs	130,144	115,357
Land
Property, Plant and Equipment [Line Items]
Total property, equipment and mine development costs	27,937	26,389
Office equipment, software and other
Property, Plant and Equipment [Line Items]
Total property, equipment and mine development costs	3,111	1,462
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, equipment and mine development costs	$ 49,583	$ 19,992

Property, Plant, and Equipmen_4

Property, Plant, and Equipment, Net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended				12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Depreciation, depletion and amortization associated with property, plant and equipment					$ 84,542	$ 86,506	$ 153,631
Revisions to asset retirement obligations					(304)	12,744
Impairment of long-lived assets	$ 29,636	$ 219	$ 17,390	$ 33,709			80,954
Property, plant, and equipment, net
Property, Plant and Equipment [Line Items]
Impairment of long-lived assets	$ 5,450	$ 219	$ 6,496	$ 6,066		60	18,231
Depreciation expense
Property, Plant and Equipment [Line Items]
Revisions to asset retirement obligations					(1,344)	(307)	$ (3,689)
Plant and mining equipment
Property, Plant and Equipment [Line Items]
Financing leases included in plant and mining equipment					13,139	8,611
Financing leases, accumulated depreciation					$ 7,710	$ 5,624

Property, Plant, and Equipmen_5

Property, Plant, and Equipment, Net - Unconditional Purchase Obligations (Details) - Equipment purchase commitments $ in Thousands	Dec. 31, 2022 USD ($)
Recorded Unconditional Purchase Obligation [Line Items]
Unconditional purchase obligation, 2023	$ 40,015
Unconditional purchase obligation, 2024	0
Unconditional purchase obligation, 2025	$ 4,887

Other Non-Current Assets (Detai

Other Non-Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Advanced mining royalties	$ 7,476	$ 10,788
Long-term deposits	1,363	1,371
Equity method investments	23,070	20,460
Workers’ compensation receivables	44,734	51,355
Goodwill	10,736	0
Other	15,816	24,660
Total other non-current assets	$ 103,195	$ 108,634

Leases - Right-of-use Assets an

Leases - Right-of-use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets
Financing lease assets	$ 5,429	$ 2,987
Operating lease right-of-use assets	4,488	5,003
Total lease assets	$ 9,917	$ 7,990
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, plant, and equipment, net of accumulated depreciation and amortization of $491,186 and $443,856 as of December 31, 2022 and 2021, respectively	Property, plant, and equipment, net of accumulated depreciation and amortization of $491,186 and $443,856 as of December 31, 2022 and 2021, respectively
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other non-current assets	Other non-current assets
Liabilities
Financing lease liabilities - current	$ 1,052	$ 1,878
Operating lease liabilities - current	612	547
Financing lease liabilities - long-term	3,744	791
Operating lease liabilities - long-term	3,876	4,456
Total lease liabilities	$ 9,284	$ 7,672
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Current portion of long-term debt	Current portion of long-term debt
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other current liabilities	Accrued expenses and other current liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Long-term debt, net of current portion	Long-term debt, net of current portion
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other non-current liabilities	Other non-current liabilities

Leases - Lease Costs and Other

Leases - Lease Costs and Other Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Financing lease cost:
Amortization of leased assets	$ 2,644	$ 2,061	$ 3,238
Interest on lease liabilities	315	245	358
Operating lease cost	1,113	1,383	2,105
Short-term lease cost	1,234	786	1,518
Total lease cost	5,306	4,475	7,219
Variable lease income	0	0
Sublease income	0	0
Other information
Cash paid for amounts included in the measurement of lease liabilities	5,556	4,478	7,157
Operating cash flows from financing leases	315	245	358
Operating cash flows from operating leases	2,347	2,169	3,623
Financing cash flows from financing leases	2,894	2,064	3,176
Right-of-use assets obtained in exchange for new financing lease liabilities	4,728	703	221
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 48	$ 275	$ (12)
Lease Term and Discount Rate
Weighted-average remaining lease term in years - financing leases	5 years 10 months 24 days	1 year 9 months	1 year 11 months 8 days
Weighted-average remaining lease term in years - operating leases	7 years 1 month 6 days	7 years 10 months 17 days	8 years 5 months 12 days
Weighted-average discount rate - financing leases	13.50%	9.60%	6.10%
Weighted-average discount rate - operating leases	11.60%	11.30%	11.50%

Leases - Maturities of Lease Li

Leases - Maturities of Lease Liabilities (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Financing Leases
2023	$ 1,597
2024	1,335
2025	1,225
2026	691
2027	360
Thereafter	1,800
Total future minimum lease payments	7,008
Imputed interest	(2,212)
Present value of future minimum lease payments	4,796
Operating Leases
2023	1,099
2024	955
2025	897
2026	884
2027	714
Thereafter	2,062
Total future minimum lease payments	6,611
Imputed interest	(2,123)
Present value of future minimum lease payments	$ 4,488

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Wages and benefits	$ 69,458	$ 53,564
Workers’ compensation	11,651	13,312
Black lung	9,664	7,295
Taxes other than income taxes	24,959	31,234
Asset retirement obligations	36,963	32,159
Accrued interest and fees	1,062	14,489
Dividend payable	86,118	0
Freight accrual	7,181	15,085
Other	18,200	13,304
Accrued expenses and other current liabilities	$ 265,256	$ 180,442

Long-Term Debt - Schedule of Lo

Long-Term Debt - Schedule of Long-Term Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Debt discount and issuance costs	$ 0	$ (6,195)
Total long-term debt	10,975	448,551
Less current portion	(3,078)	(2,989)
Long-term debt, net of current portion	7,897	445,562
Term Loan | Term Loan Credit Facility - due June 2024
Debt Instrument [Line Items]
Total long-term debt, gross	0	449,435
Other
Debt Instrument [Line Items]
Total long-term debt, gross	$ 10,975	$ 5,311

Long-Term Debt - Term Loan Cred

Long-Term Debt - Term Loan Credit Facility (Details) - USD ($) $ in Thousands		3 Months Ended	6 Months Ended		12 Months Ended
	Jun. 14, 2019	Sep. 30, 2021	Jun. 30, 2022	Dec. 31, 2021	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Repurchase of debt, net of discount					$ 0	$ 18,415	$ 0
Outstanding borrowings					10,975
Term Loan Credit Facility - due June 2024 | Term Loan
Debt Instrument [Line Items]
Repurchased amount		$ 18,724
Repurchase of debt, net of discount		$ 18,415
Payment of borrowings			$ 449,435	$ 81,000
Term Loan | Term Loan Credit Facility - due June 2024
Debt Instrument [Line Items]
Aggregate amount of debt	$ 561,800
Principal payments due in March, June, September and December	$ 1,405
Outstanding borrowings				$ 443,241	$ 0	$ 443,241
Term Loan | Term Loan Credit Facility - due June 2024 | Base Rate | Debt Instrument, Interest Rate, Period One
Debt Instrument [Line Items]
Variable interest rate (as a percent)	6%
Term Loan | Term Loan Credit Facility - due June 2024 | Base Rate | Debt Instrument, Interest Rate, Period Two
Debt Instrument [Line Items]
Variable interest rate (as a percent)	7%
Term Loan | Term Loan Credit Facility - due June 2024 | Eurocurrency
Debt Instrument [Line Items]
Variable floor rate (as a percent)	2%
Term Loan | Term Loan Credit Facility - due June 2024 | Eurocurrency | Debt Instrument, Interest Rate, Period One
Debt Instrument [Line Items]
Variable interest rate (as a percent)	7%
Term Loan | Term Loan Credit Facility - due June 2024 | Eurocurrency | Debt Instrument, Interest Rate, Period Two
Debt Instrument [Line Items]
Variable interest rate (as a percent)	8%

Long-Term Debt - Second Amended

Long-Term Debt - Second Amended and Restated Asset-Based Revolving Credit Agreement (Details) - USD ($)	Dec. 06, 2021	Dec. 31, 2022	Dec. 31, 2021
Debt Instrument [Line Items]
Outstanding borrowings		$ 10,975,000
Line of Credit | New ABL Facility
Debt Instrument [Line Items]
Letter of credit fee (as a percent)	5.25%
Letters of credit outstanding		61,877,000	$ 121,037,000
Revolving Credit Facility | New ABL Facility
Debt Instrument [Line Items]
Amount of credit facility	$ 155,000,000
Revolving Credit Facility | Line of Credit | New ABL Facility
Debt Instrument [Line Items]
Outstanding borrowings		0	$ 0
Letters of credit outstanding		$ 61,877,000
Revolving Credit Facility | Line of Credit | New ABL Facility | SOFR
Debt Instrument [Line Items]
Variable interest rate (as a percent)	4.50%
Revolving Credit Facility | Line of Credit | New ABL Facility | Base Rate
Debt Instrument [Line Items]
Variable interest rate (as a percent)	3.50%
Letter of Credit | New ABL Facility
Debt Instrument [Line Items]
Amount of credit facility	$ 150,000,000
Amount of credit facility on committed basis	125,000,000
Amount of credit facility on uncommitted basis	$ 25,000,000
Commitment fee (as a percent)	0.50%
Fronting fee (as a percent)	0.25%

Long-Term Debt - Future Maturit

Long-Term Debt - Future Maturities (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Debt Disclosure [Abstract]
2023	$ 3,078
2024	3,076
2025	2,879
2026	468
2027	171
After 2027	1,303
Total long-term debt	$ 10,975

Acquisition-Related Obligatio_3

Acquisition-Related Obligations - Components (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Option, Quantitative Disclosures [Line Items]
Discount	$ 0	$ (233)
Total acquisition-related obligations	28,254	41,405
Less current portion	(28,254)	(22,405)
Acquisition-related obligations, net of current portion	0	19,000
Contingent Revenue Obligation
Fair Value, Option, Quantitative Disclosures [Line Items]
Total acquisition-related obligations	27,719	35,005
Total acquisition-related obligations	27,719	35,005
Less current portion	(27,719)	(16,005)
Environmental Settlement Obligations
Fair Value, Option, Quantitative Disclosures [Line Items]
Total acquisition-related obligations	535	6,633
Discount	0	(233)
Total acquisition-related obligations	$ 535	$ 6,400

Acquisition-Related Obligatio_4

Acquisition-Related Obligations - Narrative (Details) - USD ($)	3 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2022	Dec. 31, 2021	Nov. 09, 2018
Business Acquisition, Contingent Consideration [Line Items]
Liabilities held for sale			$ 28,254,000	$ 41,405,000
Acquisition related obligations, current			28,254,000	22,405,000
Discount			0	233,000
Contingent Revenue Obligation, Threshold One
Business Acquisition, Contingent Consideration [Line Items]
Percentage of revenue					1.50%
Revenue threshold					$ 500,000,000
Contingent Revenue Obligation, Threshold Two
Business Acquisition, Contingent Consideration [Line Items]
Percentage of revenue					1%
Revenue threshold					$ 500,000,000
Contingent Revenue Obligation
Business Acquisition, Contingent Consideration [Line Items]
Liabilities held for sale			27,719,000	35,005,000
Acquisition related obligations, current			27,719,000	16,005,000
Payment of contingent revenue obligation	$ 16,166,000	$ 11,396,000
Environmental Settlement Obligations
Business Acquisition, Contingent Consideration [Line Items]
Liabilities held for sale			535,000	6,400,000
Discount			$ 0	$ 233,000

Asset Retirement Obligations (D

Asset Retirement Obligations (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Asset Retirement Obligation Disclosure [Abstract]
Total asset retirement obligations, beginning balance	$ 164,172	$ 165,064
Accretion for the period	23,765	26,520	$ 26,504
Sites added during the period	9,602	2,125
Revisions in estimated cash flows	304	(12,744)
Expenditures for the period	(18,832)	(16,793)
Total asset retirement obligations at December 31, 2022	179,011	164,172	$ 165,064
Less current portion	(36,963)	(32,159)
Long-term portion	$ 142,048	$ 132,013

Fair Value of Financial Instr_3

Fair Value of Financial Instruments and Fair Value Measurements - Total Long-Term Debt (Details) - Term Loan - Term Loan Credit Facility - due June 2024 $ in Thousands	Dec. 31, 2021 USD ($)
Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Fair Value	$ 443,241
Fair Value, Measurements, Nonrecurring | Quoted Prices in Active Markets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Fair Value	0
Fair Value, Measurements, Nonrecurring | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Fair Value	447,561
Fair Value, Measurements, Nonrecurring | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Fair Value	0
Fair Value, Measurements, Nonrecurring | Total Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-Term Debt, Fair Value	$ 447,561

Fair Value of Financial Instr_4

Fair Value of Financial Instruments and Fair Value Measurements - Schedule of Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Short-term investments	$ 46,052	$ 0
Long-term restricted investments	105,735	30,949
Fair Value, Measurements, Recurring
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	27,719	35,005
Trading securities	151,787	30,949
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets (Level 1)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	0	0
Trading securities	0	27,075
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	0	0
Trading securities	151,787	3,874
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Contingent Revenue Obligation	27,719	35,005
Trading securities	$ 0	$ 0

Fair Value of Financial Instr_5

Fair Value of Financial Instruments and Fair Value Measurements - Level 3 of the Fair Value Hierarchy (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Acquisition-Related Obligations, Changes in Fair Value, Gain (Loss)	Acquisition-Related Obligations, Changes in Fair Value, Gain (Loss)
Significant Unobservable Inputs (Level 3)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 35,005	$ 28,967
Payments	(16,166)	(13,487)
Loss Recognized in Earnings	8,880	19,525
Transfer In (Out) of Level 3 Fair Value Hierarchy	0	0
Ending balance	$ 27,719	$ 35,005

Fair Value of Financial Instr_6

Fair Value of Financial Instruments and Fair Value Measurements - Unobservable Inputs (Details) - Black Scholes - Contingent Revenue Obligation $ in Billions	Dec. 31, 2021 USD ($)
Forecasted future revenue | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Forecasted future revenue	$ 1.5
Forecasted future revenue | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Forecasted future revenue	$ 2
Stated royalty rate | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Acquisition-related obligation, measurement input	1%
Stated royalty rate | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Acquisition-related obligation, measurement input	1.50%
Annualized volatility | Minimum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Acquisition-related obligation, measurement input	18.40%
Annualized volatility | Maximum
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Acquisition-related obligation, measurement input	39.30%
Annualized volatility | Weighted Average
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Acquisition-related obligation, measurement input	29.90%

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current tax expense (benefit):
Federal	$ 114,106	$ 2,422	$ (35,187)
State	6,620	1,149	(99)
Total current	120,726	3,571	(35,286)
Deferred tax (benefit) expense:
Federal	(1,726)	(3)	33,348
State	(12,795)	(160)	(226)
Total deferred	(14,521)	(163)	33,122
Total income tax expense (benefit):
Federal	112,380	2,419	(1,839)
State	(6,175)	989	(325)
Income tax expense (benefit)	$ 106,205	$ 3,408	$ (2,164)

Income Taxes - Effective Income

Income Taxes - Effective Income Tax Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Federal statutory income tax expense (benefit)	$ 326,497	$ 61,362	$ (51,163)
Increase (reductions) in taxes due to:
Percentage depletion allowance	(50,277)	(11,864)	(2,039)
Foreign-derived intangible income deduction	(69,917)	(1,453)	0
Change in valuation allowances	(119,082)	(78,043)	59,929
State taxes, net of federal tax impact	14,625	12,440	(9,640)
State apportioned tax rate change, net of federal tax impact	273	8,751	(1,235)
Capital loss carryforward expiration	140	10,552	0
Other, net	3,946	1,663	1,984
Income tax expense (benefit)	$ 106,205	$ 3,408	$ (2,164)

Income Taxes - Deferred Income

Income Taxes - Deferred Income Taxes (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Asset retirement obligations	$ 39,200	$ 36,252
Reserves and accruals not currently deductible	10,572	9,610
Workers’ compensation benefit obligations	38,099	47,105
Pension obligations	23,826	34,956
Equity method investments	1,555	1,846
Net operating loss carryforwards	43,716	137,865
Capital loss carryforwards	48,940	49,476
Acquisition-related obligations	6,194	9,156
Other	7,171	7,100
Gross deferred tax assets	219,273	333,366
Less valuation allowance	(53,801)	(172,883)	$ (263,387)	$ (133,020)
Deferred tax assets	165,472	160,483
Deferred tax liabilities:
Property, plant and mineral reserves	(148,189)	(134,075)
Acquired intangibles, net	(11,995)	(16,408)
Prepaid expenses	(4,215)	(4,955)
Restricted cash	(556)	(5,362)
Other	(13)	0
Total deferred tax liabilities	(164,968)	(160,800)
Net deferred tax assets	$ 504
Net deferred tax liabilities		$ (317)

Income Taxes - Valuation Allowa

Income Taxes - Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Valuation Allowance, Deferred Tax Asset, Increase (Decrease) [Roll Forward]
Valuation allowance beginning of period	$ 172,883	$ 263,387	$ 133,020
(Decrease) increase in valuation allowance recorded to income tax expense (benefit)	(119,082)	(78,043)	117,829
(Decrease) increase in valuation allowance not affecting income tax expense (benefit)	0	(12,461)	12,538
Valuation allowance end of period	$ 53,801	$ 172,883	$ 263,387

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Tax Credit Carryforward [Line Items]
Operating loss carryforwards	$ 1,139,000
Operating loss carryforwards available to offset regular federal taxable income	1,007,000
Operating loss carryforwards section 382 limitation one	1,000
Operating loss carryforwards subject to section 382 limitation two	132,000
Operating loss carryforwards section 382 limitation three	17,500
Reasonably possible decrease in unrecognized tax benefits			$ 20,788
Interest and penalties related to uncertain tax positions	0	$ 0
Tax Year 2016 | IRS
Tax Credit Carryforward [Line Items]
Carryback claim tax refund received		64,160
Accrued interest refunded		$ 5,425
Capital Loss Carryforward
Tax Credit Carryforward [Line Items]
Capital loss carryforwards	$ 223,000

Income Taxes - Reconciliation f

Income Taxes - Reconciliation for Uncertain Tax Position (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits - beginning of period	$ 0	$ 0	$ 20,788
Reductions for tax positions of prior years	0	0	(20,788)
Unrecognized tax benefits - end of period	$ 0	$ 0	$ 0

Employee Benefit Plans - Narrat

Employee Benefit Plans - Narrative (Details) $ in Thousands		3 Months Ended			12 Months Ended
	Nov. 09, 2018 plan	Sep. 30, 2022	Dec. 31, 2020 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2023	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of plans amended | plan									2
Contributions to defined contribution and profit sharing plans						$ 19,385	$ 10,275	$ 3,613
Annual salaries (as a percent)		2%
Self-insured medical expense						$ 68,706	$ 62,351	$ 52,517
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets (as a percent)						5.80%	5.80%	5.90%
Funded percentage						90%	90%
Employer contributions						$ 3,430	$ 6,571
Expected contributions in next fiscal year						25,011
Partial plan settlement						2,775	3,815
Accelerated recognition of portion of the accumulated other comprehensive loss						(244)	(412)	$ (1,636)
Benefit obligation						$ 110,836	$ 159,930
Pension Plan | Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation (as a percent)						50%
Pension Plan | Debt Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target allocation (as a percent)						50%
Pension Plan | Forecast
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets (as a percent)					6.20%
Target allocation (as a percent)					100%
Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets (as a percent)						2%	2%	2%
Employer contributions						$ 8,025	$ 6,040
High-deductible insurance premium expense for worker's compensation and black lung claims						9,274	8,630	$ 7,000
Workers' compensation (credit) expense for high-deductible insurance plans						(1,995)	664	1,275
Partial plan settlement			$ 8,290
Accelerated recognition of portion of the accumulated other comprehensive loss			$ 1,563			0	0	$ (1,563)
Increase in liability offset to accumulated other comprehensive loss				$ 7,400
Benefit obligation						90,883	114,478
Black Lung | Current liabilities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation						9,664	7,295
Life Insurance Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation						8,761	11,610
Life Insurance Benefits | Current liabilities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Benefit obligation						$ 648	$ 602
Alpha Companies
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Number of plans assumed | plan	3
Alpha Companies | Pension Plan | Qualified Plan | Frozen Defined Benefit Pension Plan, Pre 2004 Balance
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Guaranteed rates of interest on accumulated balances						6%
Alpha Companies | Pension Plan | Qualified Plan | Frozen Defined Benefit Pension Plan, Post 2004 Balance
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Guaranteed rates of interest on accumulated balances						4%

Employee Benefit Plans - Change

Employee Benefit Plans - Changes in Accumulated Benefits Obligations, Fair Value of Plan Assets and Funded Status of Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plan
Change in benefit obligation:
Accumulated benefit obligation at beginning of period	$ 668,055	$ 723,448
Interest cost	15,981	13,566	$ 18,730
Actuarial gain	(182,441)	(34,922)
Benefits paid	(30,378)	(30,222)
Accumulated benefit obligation at end of period	468,442	668,055	723,448
Change in fair value of plan assets:
Beginning balance	508,125	504,777
Actual return on plan assets	(120,796)	30,814
Employer contributions	3,430	6,571
Benefits paid	(30,378)	(30,222)
Settlement	(2,775)	(3,815)
Ending balance	357,606	508,125	504,777
Funded status	(110,836)	(159,930)
Accrued benefit cost at end of period	(110,836)	(159,930)
Black Lung
Change in benefit obligation:
Accumulated benefit obligation at beginning of period	117,142	127,506
Service cost	2,642	2,972	2,361
Interest cost	2,722	2,463	3,240
Actuarial gain	(21,060)	(9,759)
Benefits paid	(8,025)	(6,040)
Accumulated benefit obligation at end of period	93,421	117,142	127,506
Change in fair value of plan assets:
Beginning balance	2,664	2,720
Actual return on plan assets	(126)	(56)
Employer contributions	8,025	6,040
Benefits paid	(8,025)	(6,040)
Ending balance	2,538	2,664	$ 2,720
Funded status	(90,883)	(114,478)
Accrued benefit cost at end of period	$ (90,883)	$ (114,478)

Employee Benefit Plans - Gross

Employee Benefit Plans - Gross Amounts Recognized in Accumulated Other Comprehensive (Income) Loss (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial (gain) loss	$ 12,683	$ 47,950
Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net actuarial (gain) loss	$ (10,198)	$ 11,940

Employee Benefit Plans - Schedu

Employee Benefit Plans - Schedule of Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Interest cost	$ 15,981	$ 13,566	$ 18,730
Expected return on plan assets	(28,733)	(28,732)	(27,064)
Amortization of net actuarial loss (gain)	2,111	3,217	2,012
Settlement	244	412	1,636
Net periodic benefit (credit)	(10,397)	(11,537)	(4,686)
Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	2,642	2,972	2,361
Interest cost	2,722	2,463	3,240
Expected return on plan assets	(53)	(54)	(54)
Amortization of net actuarial loss (gain)	1,257	2,453	1,942
Settlement	0	0	1,563
Net periodic benefit (credit)	6,568	7,834	9,052
Continuing Operations | Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (credit)	6,568	7,834	7,670
Discontinued Operations | Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit (credit)	$ 0	$ 0	$ 1,382

Employee Benefit Plans - Chan_2

Employee Benefit Plans - Changes in Plan Assets and Benefit Obligations Recognized in Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial (gain) loss		$ (56,485)	$ (47,461)	$ 60,647
Amortization of net actuarial gain (loss)		(3,555)	(6,021)	(7,278)
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial (gain) loss		(32,912)	(37,004)	45,663
Amortization of net actuarial gain (loss)		(2,111)	(3,217)	(2,012)
Settlement		(244)	(412)	(1,636)
Total recognized in other comprehensive (loss) income		(35,267)	(40,633)	42,015
Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actuarial (gain) loss		(20,881)	(9,649)	14,567
Amortization of net actuarial gain (loss)		(1,257)	(2,453)	(1,942)
Settlement	$ 1,563	0	0	(1,563)
Total recognized in other comprehensive (loss) income		$ (22,138)	$ (12,102)	$ 11,062

Employee Benefit Plans - Sche_2

Employee Benefit Plans - Schedule of Plans with Benefit Obligations in Excess of Plan Assets (Details) - Pension Plan - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligation	$ 468,442	$ 668,055
Accumulated benefit obligation	468,442	668,055
Fair value of plan assets	$ 357,606	$ 508,125

Employee Benefit Plans - Assump

Employee Benefit Plans - Assumptions Used (Details)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Plan
Weighted-Average Assumptions to Determine Benefit Obligations
Discount rate	5.42%	2.92%
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost
Discount rate for benefit obligation	2.92%	2.62%	3.35%
Discount rate for interest cost	2.44%	1.96%	2.92%
Expected return on plan assets	5.80%	5.80%	5.90%
Black Lung
Weighted-Average Assumptions to Determine Benefit Obligations
Discount rate	5.42%	2.96%
Federal black lung income benefit trend rate	2.50%	2%
Federal black lung medical benefit trend rate	5%	5%
Weighted Average Assumptions Used in Calculating Net Periodic Benefit Cost
Discount rate for benefit obligation	2.96%	2.75%	3.47%
Discount rate for service cost	3.24%	3.15%	3.56%
Discount rate for interest cost	2.37%	1.96%	2.61%
Federal black lung income benefit trend rate	2.50%	2%	2.50%
Federal black lung medical benefit trend rate	5%	5%	5%
Black lung benefit expense inflation rate	0%	0%	2%
Expected return on plan assets	2%	2%	2%

Employee Benefit Plans - Alloca

Employee Benefit Plans - Allocation of Plan Assets (Details) - Pension Plan	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets		100%
Funded status level (less than)		90%	90%
Forecast
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	100%
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets		55%
Equity securities | Forecast
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	58%
Fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets		41%
Fixed income funds | Forecast
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	42%
Other
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets		4%
Other | Forecast
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Percentage	0%

Employee Benefit Plans - Estima

Employee Benefit Plans - Estimated Cash Payments (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2023	$ 31,084
2024	31,103
2025	31,136
2026	31,215
2027	31,264
2028-2032	153,885
Estimated future cash payments	309,687
Black Lung
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2023	9,664
2024	9,218
2025	9,009
2026	8,923
2027	8,828
2028-2032	20,454
Estimated future cash payments	$ 66,096

Employee Benefit Plans - Fair V

Employee Benefit Plans - Fair Value of Plan Assets (Details) - Pension Plan - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 357,606	$ 508,125	$ 504,777
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	11,912	11,652	$ 11,454
Defined Benefit Plan, Assets After Receivables For Investments Sold
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	356,855	506,946
Receivable
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,145	876
Defined Benefit Plan, Assets Before Receivables For Investments Sold | Total
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	355,710	506,070
Defined Benefit Plan, Assets Before Receivables For Investments Sold | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Defined Benefit Plan, Assets Before Receivables For Investments Sold | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	343,798	494,418
Defined Benefit Plan, Assets Before Receivables For Investments Sold | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	11,912	11,652
Equity securities | Total
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	198,262	284,568
Equity securities | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Equity securities | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	198,262	284,568
Equity securities | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fixed income funds | Total
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	144,197	208,466
Fixed income funds | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Fixed income funds | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	144,197	208,466
Fixed income funds | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Commingled short-term fund | Total
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,339	1,384
Commingled short-term fund | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Commingled short-term fund | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	1,339	1,384
Commingled short-term fund | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Guaranteed insurance contract | Total
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	11,912	11,652
Guaranteed insurance contract | Quoted Prices in Active Markets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Guaranteed insurance contract | Significant Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	0	0
Guaranteed insurance contract | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	11,912	11,652
Private equity funds
Defined Benefit Plan Disclosure [Line Items]
Total plan assets	$ 751	$ 1,179
Defined Benefit Plan, Plan Assets, Fair Value by Hierarchy and NAV [Extensible List]	Fair Value Measured at Net Asset Value Per Share [Member]	Fair Value Measured at Net Asset Value Per Share [Member]

Employee Benefit Plans - Sche_3

Employee Benefit Plans - Schedule of Changes in Level 3 Assets (Details) - Pension Plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Beginning balance	$ 508,125	$ 504,777
Ending balance	357,606	508,125
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan, Change in Fair Value of Plan Assets, Level 3 Reconciliation [Roll Forward]
Beginning balance	11,652	11,454
Relating to assets still held at the reporting date	562	528
Purchases, sales and settlements	(302)	(330)
Ending balance	$ 11,912	$ 11,652

Employee Benefit Plans - Worker

Employee Benefit Plans - Workers' Compensation (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Retirement Benefits [Abstract]
Current liabilities	$ 11,651	$ 13,312
Long-term liabilities	107,028	124,693
Total liabilities	118,679	138,005
Less expected insurance receivable	(46,866)	(53,664)
Workers’ compensation obligations, net of expected insurance receivables	$ 71,813	$ 84,341

Employee Benefit Plans - Amount

Employee Benefit Plans - Amounts Recognized in Balance Sheet (Details) - Black Lung - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued benefit cost at end of period	$ 90,883	$ 114,478
Current liabilities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued benefit cost at end of period	9,664	7,295
Long-term liabilities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accrued benefit cost at end of period	$ 81,219	$ 107,183

Stock-Based Compensation Awar_3

Stock-Based Compensation Awards - Narrative (Details)		3 Months Ended	12 Months Ended
	Nov. 09, 2018 shares	Mar. 31, 2021 shares	Dec. 31, 2022 USD ($) award_type $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of award types | award_type			4
Stock compensation expense | $			$ 9,841,000	$ 7,468,000	$ 5,540,000
Time-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			95,111
Grant date fair value (in dollars per share) | $ / shares			$ 96.60
Number of shares forfeited			1,374
Unrecognized compensation cost of non-vested shares | $			$ 4,672,000
Unrecognized compensation cost, period for recognition			1 year 10 days
Total fair value of vested shares | $			$ 20,275,000	$ 5,544,000	$ 809,000
Operational performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			36,515
Grant date fair value (in dollars per share) | $ / shares			$ 60.37
Number of shares forfeited			0
Unrecognized compensation cost of non-vested shares | $			$ 1,011,000
Unrecognized compensation cost, period for recognition			1 year 7 months 17 days
Relative performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			24,342
Grant date fair value (in dollars per share) | $ / shares			$ 97.33
Number of shares forfeited			46,551
Unrecognized compensation cost of non-vested shares | $			$ 2,025,000
Unrecognized compensation cost, period for recognition			1 year 10 months 17 days
Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target award amount for cash-based incentive plans | $			$ 1,105,000
Weighted average grant date fair value, percentage of target dollar value			61.97%
Unrecognized compensation cost of non-vested shares | $			$ 1,471,000
Unrecognized compensation cost, period for recognition			1 year 6 months 7 days
Absolute performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			0
Grant date fair value (in dollars per share) | $ / shares			$ 0
Number of shares forfeited			15,532
Unrecognized compensation cost of non-vested shares | $			$ 0
30-Day volume-weighted average price stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost | $			$ 0
CEO | Minimum | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential distribution of shares (as a percent)					0%
CEO | Maximum | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential distribution of shares (as a percent)					200%
Employee | Relative performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares forfeited			25,364
Employee | Absolute performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares forfeited			8,459
Employee | Minimum | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential distribution of shares (as a percent)			0%	0%
Employee | Maximum | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential distribution of shares (as a percent)			200%	200%
Selling, General and Administrative Expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense (as a percent)			92%	89%	83%
MIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance			1,201,202
Number of shares available for grant			64,296
LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance			1,500,000
Number of shares available for grant			845,961
LTIP | Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value, percentage of target dollar value			61.97%	51.73%
LTIP | CEO | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted					302,795
Vesting period					3 years
Number of shares forfeited		302,795
LTIP | CEO | Operational performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted					151,398
Closing price (in dollars per share) | $ / shares					$ 6.36
LTIP | CEO | Relative performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted					151,397
Grant date fair value (in dollars per share) | $ / shares					$ 8.53
LTIP | Employee | Performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			60,857	167,587
Vesting period			3 years	3 years
LTIP | Employee | Operational performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			36,515	100,552
Closing price (in dollars per share) | $ / shares			$ 60.37	$ 12
LTIP | Employee | Relative performance-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			24,342	67,035
Grant date fair value (in dollars per share) | $ / shares			$ 97.33	$ 16.18
LTIP | Employee | Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period			3 years	3 years	3 years
Target award amount for cash-based incentive plans | $			$ 1,105,000	$ 927,000	$ 2,755,000
Weighted average grant date fair value, percentage of target dollar value					82.45%
LTIP | Employee | Minimum | Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential distribution of cash-based payments (as a percent)			0%	0%	0%
LTIP | Employee | Maximum | Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential distribution of cash-based payments (as a percent)			200%	200%	200%
ANR EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized for issuance			0
Number of shares available for grant			0
Number of share awards granted	89,766
MIP and LTIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares repurchased			94,460	50,363
Common stock repurchases and related expenses | $			$ 7,867,000	$ 785,000
Share repurchase price (in dollars per share) | $ / shares			$ 83.28	$ 15.60
MIP and LTIP | Time-based restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share awards granted			95,111	223,496	402,620
Grant date fair value (in dollars per share) | $ / shares			$ 96.60	$ 12.03	$ 6.17
Vesting period			3 years	3 years	3 years
MIP, LTIP, and ANR EIP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares repurchased				43,559
Common stock repurchases and related expenses | $				$ 209,000
Share repurchase price (in dollars per share) | $ / shares				$ 4.79
2022 LTIP | Employee | Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liability for cash-based awards | $			$ 374,000
2021 LTIP | Employee | Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liability for cash-based awards | $			812,000	$ 255,000
2020 LTIP | Employee | Performance-based cash incentive awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Liability for cash-based awards | $			$ 3,968,000	$ 2,542,000

Stock-Based Compensation Awar_4

Stock-Based Compensation Awards - Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2022 d $ / shares	Dec. 31, 2021 d $ / shares	Dec. 31, 2020 d $ / shares	Dec. 31, 2019 d
Relative performance-based restricted stock units
Share-based Payment Award
Start price (in dollars per share)	$ 53.29	$ 11.81	$ 7.59
Valuation date stock price (in dollars per share)	$ 61.09	$ 11.34	$ 6.33
Expected volatility (as a percent)	106.48%	98.54%	55.27%
Risk-free interest rate (as a percent)	1.26%	0.18%	1.37%
Expected dividend yield (as a percent)	0%	0%	0%
Cash-based Payment Award
Average closing stock price, threshold trading days | d	20		20
Performance-based cash incentive awards
Cash-based Payment Award
Start price (in dollars per share)	$ 53.29	$ 11.81	$ 7.59
Valuation date stock price (in dollars per share)	$ 61.09	$ 11.34	$ 6.33
Expected volatility (as a percent)	106.48%	98.54%	55.27%
Risk-free interest rate (as a percent)	1.26%	0.18%	1.37%
Expected divided yield (as a percent)	0%	0%	0%
Average closing stock price, threshold trading days | d		20	20	20

Stock-Based Compensation Awar_5

Stock-Based Compensation Awards - Award Activity (Details)	12 Months Ended
	Dec. 31, 2022 $ / shares shares
Time-based restricted stock units
Number of Shares
Beginning balance (in shares)	392,275
Granted (in shares)	95,111
Vested (in shares)	(237,643)
Forfeited or Canceled (in shares)	(1,374)
Ending balance (in shares)	248,369
Weighted-Average Grant  Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 11.54
Granted (in dollars per share) | $ / shares	96.60
Vested (in dollars per share) | $ / shares	14.80
Forfeited or Cancelled (in dollars per share) | $ / shares	6.36
Ending balance (in dollars per share) | $ / shares	$ 41.02
Restricted stock units and deferred settlements
Number of Shares
Vested (in shares)	(4,254)
Relative performance-based restricted stock units
Number of Shares
Beginning balance (in shares)	113,586
Granted (in shares)	24,342
Vested (in shares)	0
Forfeited or Canceled (in shares)	(46,551)
Ending balance (in shares)	91,377
Weighted-Average Grant  Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 36.47
Granted (in dollars per share) | $ / shares	97.33
Vested (in dollars per share) | $ / shares	0
Forfeited or Cancelled (in dollars per share) | $ / shares	65.70
Ending balance (in dollars per share) | $ / shares	$ 37.80
Relative performance-based restricted stock units | Employee
Number of Shares
Forfeited or Canceled (in shares)	(25,364)
Absolute performance-based restricted stock units
Number of Shares
Beginning balance (in shares)	15,532
Granted (in shares)	0
Vested (in shares)	0
Forfeited or Canceled (in shares)	(15,532)
Ending balance (in shares)	0
Weighted-Average Grant  Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 50.60
Granted (in dollars per share) | $ / shares	0
Vested (in dollars per share) | $ / shares	0
Forfeited or Cancelled (in dollars per share) | $ / shares	50.60
Ending balance (in dollars per share) | $ / shares	$ 0
Absolute performance-based restricted stock units | Employee
Number of Shares
Forfeited or Canceled (in shares)	(8,459)
Operational performance-based restricted stock units
Number of Shares
Beginning balance (in shares)	100,552
Granted (in shares)	36,515
Vested (in shares)	0
Forfeited or Canceled (in shares)	0
Ending balance (in shares)	137,067
Weighted-Average Grant  Date Fair Value
Beginning balance (in dollars per share) | $ / shares	$ 12
Granted (in dollars per share) | $ / shares	60.37
Vested (in dollars per share) | $ / shares	0
Forfeited or Cancelled (in dollars per share) | $ / shares	0
Ending balance (in dollars per share) | $ / shares	$ 24.89

Stock-Based Compensation Awar_6

Stock-Based Compensation Awards - Option Activity (Details) - 30-Day volume-weighted average price stock options - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Number of Shares
Beginning balance, outstanding (in shares)	23,225
Beginning balance, exercisable (in shares)	23,225
Granted (in shares)	0
Exercised (in shares)	(19,818)
Forfeited or Expired (in shares)	0
Ending balance, outstanding (in shares)	3,407	23,225
Ending balance, exercisable (in shares)	3,407	23,225
Weighted-Average Exercise Price Per Share
Beginning balance, outstanding (in dollars per share)	$ 60.20
Beginning balance, exercisable (in dollars per share)	60.20
Granted (in dollars per share)	0
Exercised (in dollars per share)	59.18
Forfeited or Expired (in dollars per share)	0
Ending balance, outstanding (in dollars per share)	66.13	$ 60.20
Ending balance, exercisable (in dollars per share)	$ 66.13	$ 60.20
Weighted-Average Remaining Contractual Term (Years)
Outstanding	4 years 2 months 4 days	5 years 1 month 13 days
Exercisable	4 years 2 months 4 days	5 years 1 month 13 days
Aggregate Intrinsic Value
Beginning balance, outstanding	$ 20
Beginning balance, exercisable	20
Exercised	1,484
Ending balance, outstanding	273	$ 20
Ending balance, exercisable	$ 273	$ 20

Stock-Based Compensation Awar_7

Stock-Based Compensation Awards - Performance-Based Cash Incentive Awards (Details) - Performance-based cash incentive awards $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)
Target Dollar Value
Non-vested awards outstanding at December 31, 2021	$ 2,991
Granted	1,105
Vested	0
Forfeited	(138)
Non-vested awards outstanding at December 31, 2022	$ 3,958
Weighted-Average Fair Value as a % of Target Dollar Value
Non-vested awards outstanding at December 31, 2020 (as a percent)	162.03%
Granted (as a percent)	61.97%
Vested (as a percent)	0%
Forfeited (as a percent)	150.25%
Non-vested awards outstanding at December 31, 2021 (as a percent)	166.29%

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands		12 Months Ended
	Dec. 07, 2022	Dec. 31, 2021
Employment Agreement with Joseph Shannon Remines | Affiliated Entity | Maxxim Rebuild Co., LLC
Related Party Transaction [Line Items]
Employment agreement, initial term	3 years
Employment agreement, renewal term	1 year
Employment agreement, notice period to not automatically renew	90 days
Lease of Real Property for Bluefield Facility | Affiliated Entity | Maxxim Rebuild Co., LLC
Related Party Transaction [Line Items]
Initial lease term	5 years
Lease, renewal term	5 years
Renewal extension period	1 year
Base rent	$ 360,000
Privately Negotiated Transaction with a Contingent Revenue Obligation Creditor | Shareholder
Related Party Transaction [Line Items]
Percentage of contingent revenue obligation		7.75%
Aggregate purchase price of outstanding rights		$ 2,091

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Jan. 31, 2023	Feb. 10, 2022	Feb. 21, 2020	Feb. 20, 2020
Long-term Purchase Commitment [Line Items]
Coal royalty expense	$ 226,366	$ 113,685	$ 67,992
Black lung benefit expense inflation rate
Long-term Purchase Commitment [Line Items]
Collateral for black lung obligations					$ 10,000	$ 65,700	$ 2,600
Black lung benefit expense inflation rate | Subsequent Event | Minimum
Long-term Purchase Commitment [Line Items]
Collateral for black lung obligations				$ 80,000
Black lung benefit expense inflation rate | Subsequent Event | Maximum
Long-term Purchase Commitment [Line Items]
Collateral for black lung obligations				$ 100,000
New ABL Facility | Line of Credit
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding	61,877	$ 121,037
New ABL Facility | Line of Credit | Revolving Credit Facility
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding	61,877
Credit and Security Agreement | Line of Credit | Revolving Credit Facility
Long-term Purchase Commitment [Line Items]
Letters of credit outstanding	50
Surety bond
Long-term Purchase Commitment [Line Items]
Outstanding surety bonds	165,575
Reclamation-related obligations | Collateral Pledged
Long-term Purchase Commitment [Line Items]
Restricted cash, restricted investments and deposits	35,040
Coal purchase agreements
Long-term Purchase Commitment [Line Items]
Purchase commitment	149,763
Royalty obligations | Coal
Long-term Purchase Commitment [Line Items]
Minimum obligation, 2023	15,556
Minimum obligation, 2024	14,688
Minimum obligation, 2025	13,608
Minimum obligation, 2026	13,489
Minimum obligation, 2027	12,916
Minimum obligation, after 2027	62,118
Coal transportation agreements
Long-term Purchase Commitment [Line Items]
Minimum obligation, 2023	109,358
Minimum obligation, 2024	98,602
Minimum obligation, 2025	$ 4,887

Commitments and Contingencies_2

Commitments and Contingencies - Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Long-term Purchase Commitment [Line Items]
Total restricted cash	$ 53,488	$ 101,403
Less current portion	(24,547)	(11,977)	$ (9,311)
Restricted cash, net of current portion	28,941	89,426	$ 96,033
Workers’ compensation and black lung obligations
Long-term Purchase Commitment [Line Items]
Total restricted cash	15,334	70,637
Reclamation-related obligations
Long-term Purchase Commitment [Line Items]
Total restricted cash	3,220	10,449
Financial payments and other performance obligations
Long-term Purchase Commitment [Line Items]
Total restricted cash	10,387	8,340
Contingent Revenue Obligation escrow
Long-term Purchase Commitment [Line Items]
Total restricted cash	$ 24,547	$ 11,977

Commitments and Contingencies_3

Commitments and Contingencies - Restricted Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Long-term Purchase Commitment [Line Items]
Total restricted investments	$ 105,735	$ 30,949
Workers’ compensation and black lung obligations
Long-term Purchase Commitment [Line Items]
Total restricted investments	72,136	2,716
Reclamation-related obligations
Long-term Purchase Commitment [Line Items]
Total restricted investments	31,718	26,225
Financial payments and other performance obligations
Long-term Purchase Commitment [Line Items]
Total restricted investments	$ 1,881	$ 2,008

Commitments and Contingencies_4

Commitments and Contingencies - Cash Deposits Held by Third Parties (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Long-term Purchase Commitment [Line Items]
Total deposits	$ 86,111	$ 1,796
Deposit for dividend payment	84,748
Reclamation-related obligations
Long-term Purchase Commitment [Line Items]
Total deposits	102	118
Financial payments and other performance obligations
Long-term Purchase Commitment [Line Items]
Total deposits	391	403
Other operating agreements
Long-term Purchase Commitment [Line Items]
Total deposits	$ 85,618	$ 1,275

Concentration of Credit Risk _3

Concentration of Credit Risk and Major Customer (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($) customer	Dec. 31, 2021 USD ($) customer	Dec. 31, 2020 USD ($) customer
Concentration Risk [Line Items]
Coal revenues	$ 4,092,987	$ 2,252,624	$ 1,413,124
Revenues	4,101,592	2,258,686	1,416,187
Met coal
Concentration Risk [Line Items]
Coal revenues	3,883,311	2,071,307	1,232,775
Thermal Coal
Concentration Risk [Line Items]
Coal revenues	$ 209,676	$ 181,317	$ 180,349
Revenues | Customer Concentration Risk
Concentration Risk [Line Items]
Number of customers | customer	1	2	2
Revenues | Customer Concentration Risk | Top Customer
Concentration Risk [Line Items]
Concentration risk (as a percent)	25%	13%	16%
Revenues | Customer Concentration Risk | Top 10 Customers
Concentration Risk [Line Items]
Concentration risk (as a percent)	70%	64%	63%
Revenues | Geographic Concentration Risk | Domestic Coal Revenue
Concentration Risk [Line Items]
Concentration risk (as a percent)	19%	24%	36%
Revenues | Geographic Concentration Risk | Export Coal Revenue
Concentration Risk [Line Items]
Concentration risk (as a percent)	81%	76%	64%
Accounts Receivable | Customer Concentration Risk
Concentration Risk [Line Items]
Number of customers | customer	2	3	3
Coal Sales Volume | Product Concentration Risk | Met coal
Concentration Risk [Line Items]
Concentration risk (as a percent)	87%	83%	80%
Coal Sales Volume | Product Concentration Risk | Thermal Coal
Concentration Risk [Line Items]
Concentration risk (as a percent)	13%	17%	20%

Segment Information - Narrative

Segment Information - Narrative (Details)	12 Months Ended
	Dec. 31, 2022 segment plant mine
Segment Reporting Information [Line Items]
Number of reportable segments | segment	1
West Virgina | All Other
Segment Reporting Information [Line Items]
Number of active mines | mine	1
Number of preparation plants | plant	1
Met | Virgina
Segment Reporting Information [Line Items]
Number of active mines | mine	6
Number of preparation plants | plant	2
Met | West Virgina
Segment Reporting Information [Line Items]
Number of active mines | mine	17
Number of preparation plants | plant	5

Segment Information - Schedule

Segment Information - Schedule of Operating Results and Capital Expenditures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Revenues	$ 4,101,592	$ 2,258,686	$ 1,416,187
Depreciation, depletion and amortization	107,620	110,047	139,885
Amortization of acquired intangibles, net	19,498	13,244	9,214
Adjusted EBITDA	1,740,612	534,481	83,401
Capital expenditures	164,309	83,300	119,579
Operating segments | Met
Segment Reporting Information [Line Items]
Revenues	4,023,688	2,176,080	1,264,496
Depreciation, depletion and amortization	100,584	99,963	124,060
Amortization of acquired intangibles, net	15,699	13,671	12,889
Adjusted EBITDA	1,776,642	567,270	120,281
Capital expenditures	160,679	79,185	111,745
All Other
Segment Reporting Information [Line Items]
Revenues	77,904	82,606	151,691
Depreciation, depletion and amortization	7,036	10,084	15,825
Amortization of acquired intangibles, net	3,799	(427)	(3,675)
Adjusted EBITDA	(36,030)	(32,789)	(36,880)
Capital expenditures	$ 3,630	$ 4,115	$ 7,834

Segment Information - Reconcili

Segment Information - Reconciliation of Net Income (Loss) to Adjusted EBITDA (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net income (loss) from continuing operations	$ 1,448,545	$ 288,790	$ (241,470)
Interest expense	21,802	69,654	74,528
Interest income	(3,187)	(336)	(7,027)
Income tax expense	106,205	3,408	(2,164)
Depreciation, depletion and amortization	107,620	110,047	139,885
Non-cash stock compensation expense	7,484	5,315	4,896
Mark-to-market adjustment for acquisition-related obligations	8,880	19,525	(8,750)
Gain on settlement of acquisition-related obligations		(1,125)
Accretion on asset retirement obligations	23,765	26,520	26,504
Asset impairment and restructuring	0	(561)	83,878
Loss on partial settlement of benefit obligations			2,966
Amortization of acquired intangibles, net	19,498	13,244	9,214
Adjusted EBITDA	1,740,612	534,481	83,401
Senior Management Changes
Segment Reporting, Other Significant Reconciling Item [Line Items]
Management restructuring costs			941
Operating segments | Met
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net income (loss) from continuing operations	1,647,104	439,859	(77,519)
Interest expense	202	184	(2,014)
Interest income	(541)	(6)	(63)
Income tax expense	0	0	0
Depreciation, depletion and amortization	100,584	99,963	124,060
Non-cash stock compensation expense	4	28	289
Mark-to-market adjustment for acquisition-related obligations	0	0	0
Gain on settlement of acquisition-related obligations		0
Accretion on asset retirement obligations	13,590	13,571	14,214
Asset impairment and restructuring		0	46,317
Loss on partial settlement of benefit obligations			1,607
Amortization of acquired intangibles, net	15,699	13,671	12,889
Adjusted EBITDA	1,776,642	567,270	120,281
Operating segments | Met | Senior Management Changes
Segment Reporting, Other Significant Reconciling Item [Line Items]
Management restructuring costs			501
All Other
Segment Reporting, Other Significant Reconciling Item [Line Items]
Net income (loss) from continuing operations	(198,559)	(151,069)	(163,951)
Interest expense	21,600	69,470	76,542
Interest income	(2,646)	(330)	(6,964)
Income tax expense	106,205	3,408	(2,164)
Depreciation, depletion and amortization	7,036	10,084	15,825
Non-cash stock compensation expense	7,480	5,287	4,607
Mark-to-market adjustment for acquisition-related obligations	8,880	19,525	(8,750)
Gain on settlement of acquisition-related obligations		(1,125)
Accretion on asset retirement obligations	10,175	12,949	12,290
Asset impairment and restructuring		(561)	37,561
Loss on partial settlement of benefit obligations			1,359
Amortization of acquired intangibles, net	3,799	(427)	(3,675)
Adjusted EBITDA	$ (36,030)	$ (32,789)	(36,880)
All Other | Senior Management Changes
Segment Reporting, Other Significant Reconciling Item [Line Items]
Management restructuring costs			$ 440

Subsequent Events (Details)

Subsequent Events (Details) - USD ($)					3 Months Ended	6 Months Ended	12 Months Ended
	Feb. 21, 2023	Nov. 04, 2022	Aug. 04, 2022	May 03, 2022	Dec. 31, 2022	Jan. 03, 2023	Dec. 31, 2022	Mar. 04, 2022
Subsequent Event [Line Items]
Dividends declared per share (in dollars per share)		$ 5.418	$ 0.392	$ 0.375	$ 0.418		$ 6.185
Authorized share repurchases		$ 1,000,000,000		$ 600,000,000				$ 150,000,000
Subsequent Event
Subsequent Event [Line Items]
Dividends declared per share (in dollars per share)	$ 0.44					$ 6.185
Additional authorized amount	$ 200,000
Authorized share repurchases	$ 1,200,000

Uncategorized Items - amr-20221

Label	Element	Value
Accounting Standards Update [Extensible Enumeration]	us-gaap_AccountingStandardsUpdateExtensibleList	Accounting Standards Update 2016-13 [Member]