Arch Resources (ARCH) 10-Q25 Jul 242024 Q2 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page - shares	6 Months Ended
Cover Page - shares	Jun. 30, 2024	Jul. 22, 2024
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Entity File Number	1-13105
Entity Registrant Name	Arch Resources, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	43-0921172
Entity Address, Address Line One	One CityPlace Drive
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	St. Louis
Entity Address, State or Province	MO
Entity Address, Postal Zip Code	63141
City Area Code	314
Local Phone Number	994-2700
Title of 12(b) Security	Common stock, $.01 par value
Trading Symbol	ARCH
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business Company	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		18,084,477
Entity Central Index Key	0001037676
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2
Amendment Flag	false

Condensed Consolidated Income S

Condensed Consolidated Income Statements - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Condensed Consolidated Income Statements
Revenues	$ 608,751	$ 757,294	$ 1,288,941	$ 1,627,225
Costs, expenses and other operating
Cost of sales (exclusive of items shown separately below)	528,684	606,127	1,096,407	1,177,864
Depreciation, depletion and amortization	38,439	36,077	77,259	71,556
Accretion on asset retirement obligations	5,870	5,293	11,739	10,585
Selling, general and administrative expenses	22,518	22,791	48,105	48,813
Other operating income, net	(2,410)	(2,010)	(18,393)	(7,179)
Costs, expenses and other operating	593,101	668,278	1,215,117	1,301,639
Income from operations	15,650	89,016	73,824	325,586
Interest expense, net
Interest expense	(3,933)	(3,537)	(8,249)	(7,663)
Interest and investment income	5,403	4,201	11,503	7,537
Interest expense, net	1,470	664	3,254	(126)
Income before nonoperating expenses	17,120	89,680	77,078	325,460
Nonoperating expense
Non-service related pension and postretirement benefit (costs) credits	(285)	593	(571)	1,185
Net loss resulting from early retirement of debt				(1,126)
Nonoperating expenses	(285)	593	(571)	59
Income before income taxes	16,835	90,273	76,507	325,519
Provision for income taxes	2,002	12,920	5,721	50,058
Net income	$ 14,833	$ 77,353	$ 70,786	$ 275,461
Net income per common share
Basic earnings per share (in dollars per share)	$ 0.82	$ 4.20	$ 3.88	$ 15.16
Diluted earnings per share (in dollars per share)	$ 0.81	$ 4.04	$ 3.82	$ 14.16
Weighted average shares outstanding
Basic weighted average shares outstanding (in shares)	18,097	18,406	18,222	18,165
Diluted weighted average shares outstanding (in shares)	18,295	19,135	18,535	19,459
Dividends declared per common share (in dollars per share)	$ 1.11	$ 2.45	$ 2.76	$ 5.56

Condensed Consolidated Statemen

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Condensed Consolidated Statements of Comprehensive Income
Net Income (Loss)	$ 14,833	$ 77,353	$ 70,786	$ 275,461
Pension, postretirement and other post-employment benefits
Comprehensive loss before tax	(2,006)	(2,895)	(4,012)	(5,790)
Provision for income taxes	427	636	854	1,272
Other comprehensive loss, pension, postretirement and other post-employment benefits, net of tax	(1,579)	(2,259)	(3,158)	(4,518)
Available-for-sale securities
Comprehensive income (loss) before tax	13	(24)	9	(39)
Provision for income taxes	(3)	5	(2)	8
Other comprehensive (loss) income, available-for-sale securities, net of tax	10	(19)	7	(31)
Total other comprehensive loss	(1,569)	(2,278)	(3,151)	(4,549)
Total comprehensive income	$ 13,264	$ 75,075	$ 67,635	$ 270,912

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets
Cash and cash equivalents	$ 243,707	$ 287,807
Short-term investments	35,583	32,724
Restricted cash	1,100	1,100
Trade accounts receivable (net of $0 allowance at June 30, 2024 and December 31, 2023)	241,910	273,522
Other receivables	6,005	13,700
Inventories	249,865	244,261
Other current assets	52,621	64,653
Total current assets	830,791	917,767
Property, plant and equipment, net	1,244,597	1,228,891
Other assets
Deferred income taxes	119,310	124,024
Equity investments	22,861	22,815
Fund for asset retirement obligations	146,010	142,266
Other noncurrent assets	46,999	48,410
Total other assets	335,180	337,515
Total assets	2,410,568	2,484,173
Current Liabilities
Accounts payable	186,549	205,001
Accrued expenses and other current liabilities	111,062	127,617
Current maturities of debt	29,721	35,343
Total current liabilities	327,332	367,961
Long-term debt	101,661	105,252
Asset retirement obligations	263,098	255,740
Accrued pension benefits	832	878
Accrued postretirement benefits other than pension	46,800	47,494
Accrued workers' compensation	157,663	154,650
Other noncurrent liabilities	62,617	72,742
Total liabilities	960,003	1,004,717
Stockholders' equity
Common stock, $0.01 par value, authorized 300,000 shares, issued 30,786 and 30,557 shares at June 30, 2024 and December 31, 2023, respectively	308	306
Paid-in capital	758,880	720,029
Retained earnings	1,849,622	1,830,018
Treasury stock, 12,701 and 12,197 shares at June 30, 2024 and December 31, 2023, respectively, at cost	(1,193,876)	(1,109,679)
Accumulated other comprehensive income	35,631	38,782
Total stockholders' equity	1,450,565	1,479,456
Total liabilities and stockholders' equity	$ 2,410,568	$ 2,484,173

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Condensed Consolidated Balance Sheets
Trade accounts receivable, allowance	$ 0	$ 0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	300,000	300,000
Common stock, shares issued (in shares)	30,786	30,557
Treasury stock, shares (in shares)	12,701	12,197

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating activities
Net income	$ 70,786	$ 275,461
Adjustments to reconcile to cash from operating activities:
Depreciation, depletion and amortization	77,259	71,556
Accretion on asset retirement obligations	11,739	10,585
Deferred income taxes	5,567	49,824
Employee stock-based compensation expense	10,445	13,206
Amortization relating to financing activities	1,441	884
Gain on disposals and divestitures, net	(150)	(393)
Reclamation work completed	(4,451)	(11,757)
Contribution to fund for asset retirement obligations	(3,745)	(2,664)
Changes in:
Receivables	39,306	(13,057)
Inventories	(5,604)	(40,295)
Accounts payable, accrued expenses and other current liabilities	(29,223)	(53,729)
Income taxes, net	(45)	(828)
Other	14,121	24,093
Cash provided by operating activities	187,446	322,886
Investing activities
Capital expenditures	(92,366)	(76,606)
Minimum royalty payments	(988)	(1,113)
Proceeds from disposals and divestitures	199	439
Purchases of short-term investments	(30,535)	(13,772)
Proceeds from sales of short-term investments	27,846	17,488
Investments in and advances to affiliates, net	(6,516)	(9,927)
Cash used in investing activities	(102,360)	(83,491)
Financing activities
Payments on convertible debt		(58,430)
Net payments on other debt	(21,992)	(24,849)
Debt financing costs	(1,516)
Purchases of treasury stock	(30,747)	(93,803)
Dividends paid	(63,757)	(111,913)
Payments for taxes related to net share settlement of equity awards	(24,339)	(27,217)
Proceeds from warrants exercised		43,750
Cash used in financing activities	(129,186)	(273,962)
Decrease in cash and cash equivalents, including restricted cash	(44,100)	(34,567)
Cash and cash equivalents, including restricted cash, beginning of period	288,907	237,159
Cash and cash equivalents, including restricted cash, end of period	244,807	202,592
SUPPLEMENTAL CASH FLOW INFORMATION
Cash and cash equivalents	243,707	201,492
Restricted Cash	1,100	1,100
Cash and cash equivalents, including restricted cash, end of period	244,807	202,592
Term loan due 2025
Financing activities
Proceeds from issuance of term loan due 2025	20,000
Payments on term loan	(3,333)
Term loan due 2024
Financing activities
Payments on term loan	$ (3,502)	$ (1,500)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Paid-in Capital	Treasury Stock, at cost	Retained Earnings	Accumulated Other Comprehensive Income	Total
Beginning Balance at Dec. 31, 2022	$ 288	$ 724,660	$ (986,171)	$ 1,565,374	$ 61,429	$ 1,365,580
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares				(55,140)		(55,140)
Dividend Equivalents earned on RSU grants		120		(2,354)		(2,234)
Purchase of common stock under share repurchase program		(13)	(18,994)			(19,007)
Employee stock-based compensation		6,767				6,767
Cash paid for convertible debt repurchased		(44,486)				(44,486)
Issuance of shares of common stock under long-term incentive plan	3					3
Common stock withheld related to net share settlement of equity awards		(27,055)				(27,055)
Issuance of shares of common stock for warrants exercised	10	43,719				43,729
Total comprehensive income (loss)				198,108	(2,271)	195,837
Ending Balance at Mar. 31, 2023	301	703,712	(1,005,165)	1,705,988	59,158	1,463,994
Beginning Balance at Dec. 31, 2022	288	724,660	(986,171)	1,565,374	61,429	1,365,580
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)						270,912
Ending Balance at Jun. 30, 2023	301	710,118	(1,079,396)	1,737,661	56,880	1,425,564
Beginning Balance at Mar. 31, 2023	301	703,712	(1,005,165)	1,705,988	59,158	1,463,994
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares				(45,011)		(45,011)
Dividend Equivalents earned on RSU grants		98		(669)		(571)
Purchase of common stock under share repurchase program			(74,231)			(74,231)
Employee stock-based compensation		6,439				6,439
Common stock withheld related to net share settlement of equity awards		(162)				(162)
Issuance of shares of common stock for warrants exercised		31				31
Total comprehensive income (loss)				77,353	(2,278)	75,075
Ending Balance at Jun. 30, 2023	301	710,118	(1,079,396)	1,737,661	56,880	1,425,564
Beginning Balance at Dec. 31, 2023	306	720,029	(1,109,679)	1,830,018	38,782	1,479,456
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares				(30,671)		(30,671)
Dividend Equivalents earned on RSU grants		72		(679)		(607)
Purchase of common stock under share repurchase program			(16,432)			(16,432)
Employee stock-based compensation		5,588				5,588
Receipt of shares from exercise of capped call, value		52,624	(52,624)
Issuance of shares of common stock under long-term incentive plan	2					2
Common stock withheld related to net share settlement of equity awards		(24,259)				(24,259)
Total comprehensive income (loss)				55,953	(1,582)	54,371
Ending Balance at Mar. 31, 2024	308	754,054	(1,178,735)	1,854,621	37,200	1,467,448
Beginning Balance at Dec. 31, 2023	306	720,029	(1,109,679)	1,830,018	38,782	1,479,456
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total comprehensive income (loss)						67,635
Ending Balance at Jun. 30, 2024	308	758,880	(1,193,876)	1,849,622	35,631	1,450,565
Beginning Balance at Mar. 31, 2024	308	754,054	(1,178,735)	1,854,621	37,200	1,467,448
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Dividends on common shares				(20,072)		(20,072)
Dividend Equivalents earned on RSU grants		49		240		289
Purchase of common stock under share repurchase program			(15,141)			(15,141)
Employee stock-based compensation		4,857				4,857
Common stock withheld related to net share settlement of equity awards		(80)				(80)
Total comprehensive income (loss)				14,833	(1,569)	13,264
Ending Balance at Jun. 30, 2024	$ 308	$ 758,880	$ (1,193,876)	$ 1,849,622	$ 35,631	$ 1,450,565

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) - shares	3 Months Ended
	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2023	Mar. 31, 2023
Condensed Consolidated Statements of Stockholders' Equity
Purchase of shares of common stock under share repurchase program	94,367	94,701	623,304	131,156
Issuance of shares of common stock under long-term incentive plan				275,053
Issuance of shares of common stock for warrants exercised		227,981	29,487	1,037,679
Receipt of shares from the exercise of capped call		315,721

Basis of Presentation

Basis of Presentation	6 Months Ended
Basis of Presentation	Jun. 30, 2024
Basis of Presentation
Basis of Presentation	1. The accompanying unaudited condensed consolidated financial statements include the accounts of Arch Resources, Inc. (“Arch Resources”) and its subsidiaries and controlled entities (“Arch” or the “Company”). Unless the context indicates otherwise, the terms “Arch” and the “Company” are used interchangeably in this Quarterly Report on Form 10-Q. The Company’s primary business is the production of metallurgical and thermal coal from underground and surface mines located throughout the United States, for sale to steel producers, utility companies, and industrial accounts both in the United States and around the world. The Company currently operates mining complexes in West Virginia, Wyoming and Colorado. All subsidiaries are wholly owned. Intercompany transactions and accounts have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial reporting and U.S. Securities and Exchange Commission regulations. In the opinion of management, all adjustments, consisting of normal, recurring accruals considered necessary for a fair presentation, have been included. Results of operations for the three and six months ended June 30, 2024 are not necessarily indicative of results to be expected for the year ending December 31, 2024. These financial statements should be read in conjunction with the audited financial statements and related notes as of and for the year ended December 31, 2023 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 filed with the U.S. Securities and Exchange Commission.

Accounting Policies

Accounting Policies	6 Months Ended
Accounting Policies	Jun. 30, 2024
Accounting Policies
Accounting Policies	2. Recently Adopted Accounting Guidance There is no recently issued accounting guidance effective that is expected to have a material impact on the Company’s financial position, results of operations, or liquidity. Recent Accounting Guidance Issued Not Yet Effective In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which includes amendments that further enhance income tax disclosures, primarily through standardization and disaggregation of rate reconciliation categories and income taxes paid by jurisdiction. The amendments are effective for the Company’s annual periods beginning June 1, 2025, with early adoption permitted, and should be applied either prospectively or retrospectively. The Company is currently evaluating the ASU to determine its impact on the Company’s disclosures.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	6 Months Ended
Accumulated Other Comprehensive Income (Loss)	Jun. 30, 2024
Accumulated Other Comprehensive Income (Loss).
Accumulated Other Comprehensive Income (Loss)	3. The following items are included in accumulated other comprehensive income (loss) (“AOCI”), net of tax: Pension, Postretirement Accumulated and Other Post- Other Employment Available-for- Comprehensive Benefits Sale Securities Income (loss) Balances at December 31, 2023 $ 38,783 $ (1) $ 38,782 Unrealized gains — 17 17 Amounts reclassified from accumulated other comprehensive income (4,012) (8) (4,020) Tax effect 854 (2) 852 Balances at June 30, 2024 $ 35,625 $ 6 $ 35,631 The following amounts were reclassified out of AOCI: Three Months Ended June 30, Six Months Ended June 30, Line Item in the Condensed Consolidated Details About AOCI Components 2024 2023 2024 2023 Income Statements (In thousands) Pension, postretirement and other post-employment benefits Amortization of actuarial gains, net 1 $ 2,006 $ 2,858 $ 4,012 $ 5,717 Non-service related pension and postretirement benefit credits Amortization of prior service credits — 37 — 73 Non-service related pension and postretirement benefit credits 2,006 2,895 4,012 5,790 Total before tax (427) (636) (854) (1,272) Provision for income taxes $ 1,579 $ 2,259 $ 3,158 $ 4,518 Net of tax Available-for-sale securities 2 $ (1) $ 1 $ 8 $ (21) Interest and investment income 3 3 2 8 Provision for income taxes $ 2 $ 4 $ 10 $ (13) Net of tax 1 2

Inventories

Inventories	6 Months Ended
Inventories	Jun. 30, 2024
Inventories
Inventories	4. Inventories consist of the following: June 30, December 31, 2024 2023 (In thousands) Coal $ 99,776 $ 99,174 Repair parts and supplies 150,089 145,087 $ 249,865 $ 244,261 The repair parts and supplies are stated net of an allowance for slow-moving and obsolete inventories of $1.6 million at June 30, 2024 and December 31, 2023, respectively.

Investments in Available-for-Sa

Investments in Available-for-Sale Securities	6 Months Ended
Investments in Available-for-Sale Securities	Jun. 30, 2024
Investments in Available-for-Sale Securities
Investments in Available-for-Sale Securities	5. The Company has invested in marketable debt securities, primarily highly liquid U.S. Treasury securities and investment grade corporate bonds. These investments are held in the custody of a major financial institution. These securities are classified as available-for-sale securities and, accordingly, the unrealized gains and losses are recorded through other comprehensive income. The Company’s investments in available-for-sale marketable securities are as follows: June 30, 2024 Gross Allowance Unrealized for - Credit Fair Cost Basis Gains Losses Losses Value (In thousands) Available-for-sale: U.S. government and agency securities $ 17,326 $ 10 $ (8) $ — $ 17,328 Corporate notes and bonds 18,240 22 (7) — 18,255 Total Investments $ 35,566 $ 32 $ (15) $ — $ 35,583 December 31, 2023 Gross Allowance Unrealized for - Credit Fair Cost Basis Gains Losses Losses Value (In thousands) Available-for-sale: U.S. government and agency securities $ 28,764 $ 14 $ (5) $ — $ 28,773 Corporate notes and bonds 3,951 1 (1) — 3,951 Total Investments $ 32,715 $ 15 $ (6) $ — $ 32,724 The aggregate fair value of investments with unrealized losses that had been owned for less than a year was $10.6 million and $2.2 million at June 30, 2024 and December 31, 2023, respectively. The aggregate fair value of investments with unrealized losses that were owned for over a year was million at June 30, 2024 and December 31, 2023, respectively. The unrealized losses in the Company’s portfolio at June 30, 2024 are the result of normal market fluctuations. The Company does not intend to sell these investments before recovery of their amortized cost base. The debt securities outstanding at June 30, 2024 have maturity dates ranging from the third quarter of 2024 through the fourth quarter of 2025. The Company classifies its investments as current based on the nature of the investments and their availability to provide cash for use in current operations, if needed.

Accrued Expenses and Other Curr

Accrued Expenses and Other Current Liabilities	6 Months Ended
Accrued Expenses and Other Current Liabilities	Jun. 30, 2024
Accrued Expenses and Other Current Liabilities.
Accrued Expenses and Other Current Liabilities	6. Accrued expenses and other current liabilities consist of the following: June 30, December 31, 2024 2023 (In thousands) Payroll and employee benefits $ 34,674 $ 37,259 Taxes other than income taxes 36,043 51,155 Interest 2,468 2,395 Workers’ compensation 17,070 18,724 Asset retirement obligations 6,018 6,089 Other 14,789 11,995 $ 111,062 $ 127,617

Debt and Financing Arrangements

Debt and Financing Arrangements	6 Months Ended
Debt and Financing Arrangements	Jun. 30, 2024
Debt and Financing Arrangements
Debt and Financing Arrangements	7. June 30, December 31, 2024 2023 (In thousands) Term loan due 2025 ($16.7 million face value) $ 16,667 $ — Term loan due 2024 — 3,502 Tax Exempt Bonds ($98.1 million face value) 98,075 98,075 Other 18,536 40,529 Debt issuance costs (1,896) (1,511) 131,382 140,595 Less: current maturities of debt 29,721 35,343 Long-term debt $ 101,661 $ 105,252 Term Loan Facility On February 8, 2024, the Company entered into a new senior secured term loan credit agreement in the principal amount of $20.0 million (the “Term Loan”) with PNC Bank, National Association, as administrative and collateral agent. The Term Loan requires quarterly principal amortization payments of $3.3 million and matures on June 30, 2025. The interest rate on the facility is, at the option of Arch Resources, either (i) Secured Overnight Financing Rate (“SOFR”) plus a SOFR adjustment of .10% plus an applicable margin of 3.00%, subject to a SOFR floor of 0.00%, or (ii) a base rate plus an applicable margin of 2.00%. The Term Loan is guaranteed by substantially all of the domestic subsidiaries of the Company. Additionally, the Term Loan is secured by substantially all the assets of the Company and the guarantors, subject to customary exceptions (including an exclusion for owned and leased real property). The Term Loan contains the following financial maintenance covenants: (i) total net leverage not to exceed 2.00 to 1.00 for the trailing four four The Term Loan is subject to certain usual and customary mandatory prepayment events, including 100% of net cash proceeds of debt issuances (other than debt permitted to be incurred under the terms of the Term Loan). The Term Loan contains customary affirmative and negative covenants and representations; and customary events of default, subject to customary thresholds and exceptions. As of June 30, 2024, the Company was in compliance with the Term Loan debt covenants. The proceeds from the Term Loan were used to pay off the $3.5 million balance of the term loan debt facility due 2024. Additionally, the Company incurred approximately $1.5 million in debt issuance costs related to the Term Loan. Accounts Receivable Securitization Facility On August 3, 2022, the Company amended and extended its existing trade accounts receivable securitization facility provided to Arch Receivable Company, LLC, a special-purpose entity that is a wholly owned subsidiary of Arch Resources (“Arch Receivable”) (the “Securitization Facility”), which supports the issuance of letters of credit and requests for cash advances. The amendment to the Securitization Facility increased the size of the facility from $110 million to $150 million of borrowing capacity and extended the maturity date to August 1, 2025. Under the Securitization Facility, Arch Receivable, Arch Resources and certain of Arch Resources’ subsidiaries party to the Securitization Facility have granted to the administrator of the Securitization Facility a first priority security interest in eligible trade accounts receivable generated by such parties from the sale of coal and all proceeds thereof. As of June 30, 2024, letters of credit totaling Inventory-Based Revolving Credit Facility On August 3, 2022, Arch Resources amended the senior secured inventory-based revolving credit facility in an aggregate principal amount of $50 million (the “Inventory Facility”). Availability under the Inventory Facility is subject to a borrowing base consisting of (i) 85% of the net orderly liquidation value of eligible coal inventory, plus (ii) the lesser of (x) 85% of the net orderly liquidation value of eligible parts and supplies inventory and (y) 35% of the amount determined pursuant to clause (i), plus (iii) 100% of Arch Resources’ Eligible Cash (defined in the Inventory Facility), subject to reduction for reserves imposed by Regions. The amendment of the Inventory Facility extended the maturity of the facility to August 3, 2025; maintained the minimum liquidity requirement of $100 million and included provisions that reduce the advance rates for coal inventory and parts and supplies, depending on liquidity, as defined in the agreement. The Inventory Facility contains certain customary affirmative and negative covenants; events of default, subject to customary thresholds and exceptions; and representations, including certain cash management and reporting requirements that are customary for asset-based credit facilities. The Inventory Facility also includes a requirement to maintain liquidity equal to or exceeding $100 million at all times. As of June 30, 2024, letters of credit totaling $26.2 million were outstanding under the facility with $23.8 million available for borrowings. Equipment Financing On July 29, 2021, the Company entered into an equipment financing arrangement accounted for as debt. The Company received maturing on February 1, 2025. Upon maturity, the Company will have the option to purchase the equipment. Tax Exempt Bonds On July 2, 2020, the West Virginia Economic Development Authority (the “Issuer”) issued $53.1 million aggregate principal amount of Solid Waste Disposal Facility Revenue Bonds (Arch Resources Project), Series 2020 (the “Tax Exempt Bonds”) pursuant to an Indenture of Trust dated as of June 1, 2020 (the “Indenture of Trust”) between the Issuer and Citibank, N.A., as trustee (the “Trustee”). On March 4, 2021, the Issuer issued an additional million of Series 2021 Tax Exempt Bonds. The proceeds of the Tax Exempt Bonds were loaned to the Company pursuant to a Loan Agreement dated as of June 1, as supplemented by a First Amendment to Loan Agreement dated as of March 1, 2021 (collectively, the “Loan Agreement”), each between the Issuer and the Company. The Tax Exempt Bonds are payable solely from payments to be made by the Company under the Loan Agreement as evidenced by a Note from the Company to the Trustee. The proceeds of the Tax Exempt Bonds have been used to finance certain costs of the acquisition, construction, reconstruction, and equipping of solid waste disposal facilities at the Company’s Leer South development, and for capitalized interest and certain costs related to issuance of the Tax Exempt Bonds. The Tax Exempt Bonds bear interest payable each January 1 and July 1, commencing January 1, 2021 for the Series 2020 and July 1, 2021 for the Series 2021, and have a final maturity of July 1, 2045; however, the Tax Exempt Bonds are subject to mandatory tender on July 1, 2025 at a purchase price equal to 100% of the principal amount of the Tax Exempt Bonds, plus accrued interest to July 1, 2025. The Series 2020 and Series 2021 Tax Exempt Bonds bear interest of Convertible Debt On November 3, 2020, the Company issued $155.3 million in aggregate principal amount of 5.25% convertible senior notes due 2025 (“Convertible Notes ” or “Convertible Debt”). The net proceeds from the issuance of the Convertible Notes, after deducting offering related costs of $5.1 million and cost of a “Capped Call Transaction” as defined below of $17.5 million, were approximately $132.7 million. During the six months ended June 30, 2023, the Company repurchased the remaining Convertible Notes with a principal amount of $13.2 million for aggregate consideration consisting of $58.4 million in cash. In connection with the repurchase, the Company recognized a loss of $1.1 million. This amount is included as “Net loss resulting from early retirement of debt” in the accompanying Condensed Consolidated Income Statements. Capped Call Transactions On February 16, 2024, Arch Resources, Inc. (the “Company”) agreed with each of Bank of Montreal, Goldman Sachs & Co. LLC and Jefferies International Limited (each a “Counterparty” and collectively, the “Counterparties”) to terminate and unwind certain capped call transactions by and between the Company and each Counterparty (such transactions, the “Capped Calls”). The Company entered into the Capped Calls in connection with the offering of its now-retired Convertible Notes, in order to reduce the potential dilution upon conversion of the notes. During the six months ended June 30, 2024, the Company retired

Income Taxes

Income Taxes	6 Months Ended
Income Taxes	Jun. 30, 2024
Income Taxes
Income Taxes	8. The Company's effective tax rate for six months ended June 30, 2024 is based on its estimated full year effective tax rate, adjusted for discrete items. The effective tax rate for the three and six months ended June 30, 2024 was For the three and six months ended June 30, 2023, the Company's effective tax rate was 14.3% and 15.4%, respectively. The effective tax rate for the three and six months ended June 30, 2023 differs from the U.S. federal statutory rate of 21%, primarily due to the income tax benefit for excess percentage depletion and discrete tax benefits related to equity compensation.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
Fair Value Measurements	Jun. 30, 2024
Fair Value Measurements
Fair Value Measurements	9. The hierarchy of fair value measurements assigns a level to fair value measurements based on the inputs used in the respective valuation techniques. The levels of the hierarchy, as defined below, give the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities and the lowest priority to unobservable inputs. ● Level 1 is defined as observable inputs such as quoted prices in active markets for identical assets. Level 1 assets include U.S. Treasury securities. ● Level 2 is defined as observable inputs other than Level 1 prices. These include quoted prices for similar assets or liabilities in an active market, quoted prices for identical assets and liabilities in markets that are not active, or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. The Company’s Level 2 assets and liabilities include U.S. government agency securities, with fair values derived from quoted prices in over-the-counter markets or from prices received from direct broker quotes. ● Level 3 is defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. The table below sets forth, by level, the Company’s financial assets and liabilities that are recorded at fair value in the accompanying Condensed Consolidated Balance Sheet: June 30, 2024 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 35,583 $ 17,328 $ 18,255 $ — Fund for asset retirement obligations 146,010 146,010 — — Total assets $ 181,593 $ 163,338 $ 18,255 $ — December 31, 2023 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 32,724 $ 28,773 $ 3,951 $ — Fund for asset retirement obligations 142,266 142,266 — — Total assets $ 174,990 $ 171,039 $ 3,951 $ — Fair Value of Long-Term Debt At June 30, 2024 and December 31, 2023, the fair value of the Company’s debt, including amounts classified as current, was $133.3 million and $142.1 million, respectively. Fair values are based upon observed prices in an active market, when available, or from valuation models using market information, which fall into Level 2 in the fair value hierarchy.

Earnings per Common Share

Earnings per Common Share	6 Months Ended
Earnings per Common Share	Jun. 30, 2024
Earnings per Common Share
Earnings per Common Share	10. The Company computes basic net income per share using the weighted average number of common shares outstanding during the period. Diluted net income per share is computed using the weighted average number of common shares and the effect of potentially dilutive securities outstanding during the period. Potentially dilutive securities may consist of warrants, restricted stock units, and convertible debt. The dilutive effect of outstanding warrants and restricted stock units is reflected in diluted earnings per share by application of the treasury stock method whereas the Convertible Debt uses the if converted method. The following table provides the basic and diluted earnings per share by reconciling the numerators and denominators of the computations: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In Thousands) Net income attributable to common shares $ 14,833 $ 77,353 $ 70,786 $ 275,461 Adjustment of interest expense attributable to Convertible Notes — — — 108 Diluted net income attributable to common stockholders 14,833 77,353 70,786 275,569 Basic weighted average shares outstanding 18,097 18,406 18,222 18,165 Effect of dilutive securities 198 729 313 1,126 Convertible Notes (a) — — — 168 Diluted weighted average shares outstanding 18,295 19,135 18,535 19,459 (a) Diluted weighted average common shares outstanding includes the dilutive effect had the Company's Convertible Notes been converted at the beginning of the year ended December 31, 2023. If converted by the holder, the Company may settle in cash, shares of the Company's common stock or a combination thereof, at the Company's election. The Capped Call Transaction is anti-dilutive and is excluded from the calculation of diluted earnings per share.

Workers Compensation Expense

Workers Compensation Expense	6 Months Ended
Workers Compensation Expense	Jun. 30, 2024
Workers Compensation Expense
Workers' Compensation Expense	11. The Company is liable under the Federal Mine Safety and Health Act of 1969, as subsequently amended, to provide for pneumoconiosis (occupational disease) benefits to eligible employees, former employees and dependents. The Company currently provides for federal claims principally through a self-insurance program. The Company is also liable under various state workers’ compensation statutes for occupational disease benefits. The occupational disease benefit obligation represents the present value of the actuarially computed present and future liabilities for such benefits over the employees’ applicable years of service. In October 2019, the Company filed an application with the Office of Workers’ Compensation Programs (“OWCP”) within the Department of Labor for reauthorization to self-insure federal black lung benefits. In February 2020, the Company received a reply from the OWCP confirming its status to remain self-insured contingent upon posting additional collateral of of receipt of the letter. The Company is currently appealing the ruling from the OWCP and has received an extension to self-insure during the appeal process. On January 18, 2023, the OWCP proposed revisions to regulations under the Black Lung Benefits Act governing authorization of self-insurers. The revisions seek to codify the practice of basing a self-insured operator’s security requirement on an actuarial assessment of its total present and future black lung liability. A material change to the regulations is the requirement that all self-insured operators must post security equal to 120% of their projected black lung liabilities. The proposed regulations were posted to the Federal Register on January 19, 2023 with written comments to be accepted within 60 days of this date. A subsequent extended comment period expired on April 19, 2023. On May 10, 2024, the OWCP forwarded its final rule establishing requirements for Black Lung Benefits Act self-insurance to the Office of Management and Budget (“OMB”) for review. OMB is charged by various executive orders to review significant regulations. OMB reviews are limited to 90 days and may be extended by an additional 30 days; however, OMB reviews often take longer. At this stage in the rulemaking process, no rule text is publicly available, and the final regulations have not yet been published. If the above regulation is codified into law, the Company will be required to post additional collateral to maintain its self-insured status. The Company is evaluating alternatives to self-insurance, including the purchase of commercial insurance to cover these claims. Additionally, the Company is assessing additional sources of liquidity, and other items to satisfy the proposed regulations. In addition, the Company is liable for workers’ compensation benefits for traumatic injuries which are calculated using actuarially-based loss rates, loss development factors and discounted based on a risk free rate. Traumatic workers’ compensation claims are insured with varying retentions/deductibles, or through state-sponsored workers’ compensation programs. Workers’ compensation expense consists of the following components: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Self-insured occupational disease benefits: Service cost $ 1,278 $ 994 $ 2,555 $ 1,987 Interest cost (1) 1,566 1,510 3,131 3,020 Net amortization (1) (3) (241) (6) (482) Total occupational disease $ 2,841 $ 2,263 $ 5,680 $ 4,525 Traumatic injury claims and assessments 2,592 2,741 5,076 4,431 Total workers’ compensation expense $ 5,433 $ 5,004 $ 10,756 $ 8,956 (1) In accordance with the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” these costs are recorded within Nonoperating expenses in the Condensed Consolidated Income Statements on the line item “Non-service related pension and postretirement benefit (costs) credits.”

Employee Benefit Plans

Employee Benefit Plans	6 Months Ended
Employee Benefit Plans	Jun. 30, 2024
Employee Benefit Plans
Employee Benefit Plans	12. Employee Benefit Plans The following table details the components of pension benefit credit: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Interest cost (1) $ 11 $ 1,533 $ 22 $ 3,067 Expected return on plan assets (1) — (1,518) — (3,036) Amortization of prior service credits (1) — (36) — (73) Amortization of other actuarial (gains) (1) (22) (195) (44) (390) Net benefit credit $ (11) $ (216) $ (22) $ (432) The following table details the components of other postretirement benefit credit: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Service cost $ 50 $ 57 $ 99 $ 115 Interest cost (1) 605 673 1,210 1,347 Amortization of other actuarial gains (1) (1,981) (2,423) (3,962) (4,845) Net benefit credit $ (1,326) $ (1,693) $ (2,653) $ (3,383) (1) In accordance with the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” these costs are recorded within Nonoperating expenses in the Condensed Consolidated Income Statements on the line item “Non-service related pension and postretirement benefit (costs) credits.” In February 2022, the Board of Directors approved the termination of the Company’s Cash Balance Pension Plan. The Company has executed plan amendments regarding the termination and filed an Application for Determination for Terminating Pension Plan with the Internal Revenue Service (“IRS”), which was approved by the IRS during the first quarter of 2023. The Company also prepared and filed appropriate notices and documents related to the Pension Plan's termination and wind-down with the Pension Benefit Guaranty Corporation (“PBGC”). The Company no longer administers or pays the retirement benefits of the Cash Balance Pension Plan.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
Commitments and Contingencies	Jun. 30, 2024
Commitments and Contingencies
Commitments and Contingencies	13. Commitments and Contingencies The Company accrues for costs related to contingencies when a loss is probable and the amount is reasonably determinable. Disclosure of contingencies is included in the financial statements when it is at least reasonably possible that a material loss or an additional material loss in excess of amounts already accrued may be incurred. The Company is a party to numerous claims and lawsuits with respect to various matters. The ultimate resolution of any such legal matter could result in outcomes that may be materially different from amounts the Company has accrued for such matters. The Company believes it has recorded adequate reserves for these matters. In the normal course of business, the Company is a party to certain 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 Condensed Consolidated Balance Sheets. However, the underlying liabilities that they secure, such as asset retirement obligations, workers’ compensation liabilities, and other obligations, are reflected in the Company’s Condensed Consolidated Balance Sheets. As of June 30, 2024, the Company had outstanding surety bonds with a face amount of $488.8 million to secure various obligations and commitments and $78.1 million of letters of credit under its Securitization and Inventory Facilities used to collateralize certain obligations. The Company posted million in cash collateral related to various obligations; this amount is recorded within “Other noncurrent assets” on the Condensed Consolidated Balance Sheets. As of June 30, 2024, the Company’s reclamation-related obligations of $269.1 million were supported by surety bonds of $402.7 million. The Company has posted million in cash collateral related to reclamation surety bonds. Additionally, in the first half of 2024, the Company contributed an additional million as of June 30, 2024. This amount is recorded as “Fund for asset retirement obligations” on the Condensed Consolidated Balance Sheets.

Segment Information

Segment Information	6 Months Ended
Segment Information	Jun. 30, 2024
Segment Information
Segment Information	14. The Company’s reportable business segments are based on two distinct lines of business, metallurgical and thermal, and may include a number of mine complexes. The Company manages its coal sales by market and coal quality, not by individual mining complex. Geology, coal transportation routes to customers, and regulatory environments also have a significant impact on the Company’s marketing and operations management. Mining operations are evaluated based on Adjusted EBITDA, per-ton cash operating costs (defined as including all mining costs except depreciation, depletion, amortization, accretion on asset retirement obligations, and pass-through transportation expenses, divided by segment tons sold), and on other non-financial measures, such as safety and environmental performance. Adjusted EBITDA is not a measure of financial performance in accordance with generally accepted accounting principles, and items excluded from Adjusted EBITDA are significant in understanding and assessing the Company’s financial condition. Therefore, Adjusted EBITDA should not be considered in isolation, nor as an alternative to net income, income from operations, cash flows from operations or as a measure of our profitability, liquidity or performance under generally accepted accounting principles. The Company uses Adjusted EBITDA to measure the operating performance of its segments and allocate resources to the segments. Furthermore, analogous measures are used by industry analysts and investors to evaluate the Company’s operating performance. Investors should be aware that the Company’s presentation of Adjusted EBITDA may not be comparable to similarly titled measures used by other companies. The Company reports its results of operations primarily through the following reportable segments: Metallurgical (MET) segment, containing the Company’s metallurgical operations in West Virginia, and the Thermal segment containing the Company’s thermal operations in Wyoming and Colorado. Reporting segment results for the three and six months ended June 30, 2024 and 2023 are presented below. The Corporate, Other, and Eliminations grouping includes these charges: idle operations; equity investments; change in fair value of coal derivatives, net; corporate overhead; land management activities; certain miscellaneous revenue; and the elimination of intercompany transactions. Corporate, Other and (In thousands) MET Thermal Eliminations Consolidated Three Months Ended June 30, 2024 Revenues $ 375,958 $ 232,793 $ — $ 608,751 Adjusted EBITDA 87,276 1,067 (28,384) 59,959 Depreciation, depletion and amortization 31,089 7,099 251 38,439 Accretion on asset retirement obligation 647 4,810 413 5,870 Capital expenditures 34,132 10,953 1,835 46,920 Three Months Ended June 30, 2023 Revenues $ 451,752 $ 305,542 $ — $ 757,294 Adjusted EBITDA 132,839 29,179 (31,632) 130,386 Depreciation, depletion and amortization 28,228 7,648 201 36,077 Accretion on asset retirement obligation 615 4,314 364 5,293 Capital expenditures 35,639 10,042 325 46,006 Six Months Ended June 30, 2024 Revenues $ 793,023 $ 495,918 $ — $ 1,288,941 Adjusted EBITDA 216,811 1,999 (55,988) 162,822 Depreciation, depletion and amortization 62,479 14,267 513 77,259 Accretion on asset retirement obligation 1,294 9,620 825 11,739 Capital expenditures 71,166 18,497 2,703 92,366 Six Months Ended June 30, 2023 Revenues $ 987,923 $ 639,302 $ — $ 1,627,225 Adjusted EBITDA 395,896 75,434 (63,603) 407,727 Depreciation, depletion and amortization 56,082 15,056 418 71,556 Accretion on asset retirement obligation 1,229 8,628 728 10,585 Capital expenditures 60,459 15,535 612 76,606 A reconciliation of net income to Adjusted EBITDA and segment Adjusted EBITDA from coal operations follows: Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2024 2023 2024 2023 Net income $ 14,833 $ 77,353 $ 70,786 $ 275,461 Provision for income taxes 2,002 12,920 5,721 50,058 Interest expense, net (1,470) (664) (3,254) 126 Depreciation, depletion and amortization 38,439 36,077 77,259 71,556 Accretion on asset retirement obligations 5,870 5,293 11,739 10,585 Non-service related pension and postretirement benefit costs (credits) 285 (593) 571 (1,185) Net loss resulting from early retirement of debt — — — 1,126 Adjusted EBITDA $ 59,959 $ 130,386 $ 162,822 $ 407,727 EBITDA from idled or otherwise disposed operations 3,695 4,664 7,392 8,696 Selling, general and administrative expenses 22,518 22,791 48,105 48,813 Other 2,172 4,177 491 6,094 Segment Adjusted EBITDA from coal operations $ 88,344 $ 162,018 $ 218,810 $ 471,330

Revenue Recognition

Revenue Recognition	6 Months Ended
Revenue Recognition	Jun. 30, 2024
Revenue Recognition
Revenue Recognition	15. ASC 606-10-50-5 requires that entities disclose disaggregated revenue information in categories (such as type of goods or services, 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 606-10-55-89 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. In general, the Company’s business segmentation is aligned according to the nature and economic characteristics of its coal and customer relationships and provides meaningful disaggregation of each segment’s results. The Company has further disaggregated revenue between North America and Seaborne revenues which depicts the pricing and contract differences between the two. North America revenue is characterized by contracts with a term of one year or longer and typically the pricing is fixed; whereas Seaborne revenue generally is derived from spot or short-term contracts with an index-based pricing mechanism. Corporate, Other and MET Thermal Eliminations Consolidated (in thousands) Three Months Ended June 30, 2024 North America revenues $ 67,213 $ 184,083 $ — $ 251,296 Seaborne revenues 308,745 48,710 — 357,455 Total revenues $ 375,958 $ 232,793 $ — $ 608,751 Three Months Ended June 30, 2023 North America revenues $ 93,715 $ 247,092 $ — $ 340,807 Seaborne revenues 358,037 58,450 — 416,487 Total revenues $ 451,752 $ 305,542 $ — $ 757,294 Six Months Ended June 30, 2024 North America revenues $ 102,797 $ 389,746 $ — $ 492,543 Seaborne revenues 690,226 106,172 — 796,398 Total revenues $ 793,023 $ 495,918 $ — $ 1,288,941 Six Months Ended June 30, 2023 North America revenues $ 165,122 $ 534,352 $ — $ 699,474 Seaborne revenues 822,801 104,950 — 927,751 Total revenues $ 987,923 $ 639,302 $ — $ 1,627,225 As of June 30, 2024, the Company has outstanding performance obligations for the remainder of 2024 of 29.1 million tons of fixed price contracts and 3.8 million tons of variable price contracts. Additionally, the Company has outstanding performance obligations beyond 2024 of approximately 78.6 million tons of fixed price contracts and 2.0 million tons of variable price contracts.

Leases

Leases	6 Months Ended
Leases	Jun. 30, 2024
Leases
Leases	16. The Company has operating and financing leases for mining equipment, office equipment, office space and transloading terminals with remaining lease terms ranging from less than one year to approximately three years. 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. As most of the leases do not provide an implicit rate, the Company calculated the “right-of-use” (“ROU”) assets and lease liabilities using its secured incremental borrowing rate at the lease commencement date. As of June 30, 2024 and December 31, 2023, the Company had the following ROU assets and lease liabilities within its Condensed Consolidated Balance Sheets: June 30, December 31, 2024 2023 Assets Balance Sheet Classification Operating lease right-of-use assets Other noncurrent assets $ 8,303 $ 9,626 Financing lease right-of-use assets Other noncurrent assets 973 1,621 Total Lease Assets $ 9,276 $ 11,247 Liabilities Balance Sheet Classification Financing lease liabilities - current Accrued expenses and other current liabilities $ 2,608 $ 1,041 Operating lease liabilities - current Accrued expenses and other current liabilities 2,843 2,789 Financing lease liabilities - long-term Other noncurrent liabilities - 2,079 Operating lease liabilities - long-term Other noncurrent liabilities 5,909 7,351 $ 11,360 $ 13,260 Weighted average remaining lease term in years Operating leases 2.82 3.32 Finance leases 0.75 1.25 Weighted average discount rate Operating leases 5.5% 5.5% Finance leases 6.4% 6.4% Information related to leases was as follows: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) (In thousands) Operating lease information: Operating lease cost $ 786 $ 831 $ 1,589 $ 1,661 Operating cash flows from operating leases 788 876 1,654 1,704 Financing lease information: Financing lease cost $ 393 $ 393 $ 786 $ 786 Operating cash flows from financing leases 303 303 605 605 Future minimum lease payments under non-cancellable leases as of June 30, 2024 were as follows: Operating Finance Year Leases Leases (In thousands) 2024 $ 1,627 $ 605 2025 3,266 2,111 2026 3,080 — 2027 1,533 — 2028 — — Thereafter — — Total minimum lease payments $ 9,506 $ 2,716 Less imputed interest (754) (108) Total lease liabilities $ 8,752 $ 2,608

Subsequent Event

Subsequent Event	6 Months Ended
Subsequent Event	Jun. 30, 2024
Subsequent Event.
Subsequent Event	17. Subsequent Event On July 25, 2024, the Company announced the board approval of a quarterly dividend of $0.25 per share for stockholders of record on August 30, 2024, with a payment date of September 13, 2024.

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ 14,833	$ 77,353	$ 70,786	$ 275,461

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
Insider Trading Arrangements	Jun. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Accounting Policies (Policies)

Accounting Policies (Policies)	6 Months Ended
Accounting Policies (Policies)	Jun. 30, 2024
Accounting Policies
Basis of Presentation	The accompanying unaudited condensed consolidated financial statements include the accounts of Arch Resources, Inc. (“Arch Resources”) and its subsidiaries and controlled entities (“Arch” or the “Company”). Unless the context indicates otherwise, the terms “Arch” and the “Company” are used interchangeably in this Quarterly Report on Form 10-Q. The Company’s primary business is the production of metallurgical and thermal coal from underground and surface mines located throughout the United States, for sale to steel producers, utility companies, and industrial accounts both in the United States and around the world. The Company currently operates mining complexes in West Virginia, Wyoming and Colorado. All subsidiaries are wholly owned. Intercompany transactions and accounts have been eliminated in consolidation. The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States for interim financial reporting and U.S. Securities and Exchange Commission regulations. In the opinion of management, all adjustments, consisting of normal, recurring accruals considered necessary for a fair presentation, have been included. Results of operations for the three and six months ended June 30, 2024 are not necessarily indicative of results to be expected for the year ending December 31, 2024. These financial statements should be read in conjunction with the audited financial statements and related notes as of and for the year ended December 31, 2023 included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2023 filed with the U.S. Securities and Exchange Commission.
Recently Adopted Accounting Guidance	Recently Adopted Accounting Guidance There is no recently issued accounting guidance effective that is expected to have a material impact on the Company’s financial position, results of operations, or liquidity. Recent Accounting Guidance Issued Not Yet Effective In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures, which includes amendments that further enhance income tax disclosures, primarily through standardization and disaggregation of rate reconciliation categories and income taxes paid by jurisdiction. The amendments are effective for the Company’s annual periods beginning June 1, 2025, with early adoption permitted, and should be applied either prospectively or retrospectively. The Company is currently evaluating the ASU to determine its impact on the Company’s disclosures.

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) (Tables)	6 Months Ended
Accumulated Other Comprehensive Income (Loss) (Tables)	Jun. 30, 2024
Accumulated Other Comprehensive Income (Loss).
Schedule of Accumulated Other Comprehensive Income (Loss)	Pension, Postretirement Accumulated and Other Post- Other Employment Available-for- Comprehensive Benefits Sale Securities Income (loss) Balances at December 31, 2023 $ 38,783 $ (1) $ 38,782 Unrealized gains — 17 17 Amounts reclassified from accumulated other comprehensive income (4,012) (8) (4,020) Tax effect 854 (2) 852 Balances at June 30, 2024 $ 35,625 $ 6 $ 35,631
Schedule of Comprehensive Income Reclassifications	Three Months Ended June 30, Six Months Ended June 30, Line Item in the Condensed Consolidated Details About AOCI Components 2024 2023 2024 2023 Income Statements (In thousands) Pension, postretirement and other post-employment benefits Amortization of actuarial gains, net 1 $ 2,006 $ 2,858 $ 4,012 $ 5,717 Non-service related pension and postretirement benefit credits Amortization of prior service credits — 37 — 73 Non-service related pension and postretirement benefit credits 2,006 2,895 4,012 5,790 Total before tax (427) (636) (854) (1,272) Provision for income taxes $ 1,579 $ 2,259 $ 3,158 $ 4,518 Net of tax Available-for-sale securities 2 $ (1) $ 1 $ 8 $ (21) Interest and investment income 3 3 2 8 Provision for income taxes $ 2 $ 4 $ 10 $ (13) Net of tax 1 2

Inventories (Tables)

Inventories (Tables)	6 Months Ended
Inventories (Tables)	Jun. 30, 2024
Inventories
Inventories	June 30, December 31, 2024 2023 (In thousands) Coal $ 99,776 $ 99,174 Repair parts and supplies 150,089 145,087 $ 249,865 $ 244,261

Investments in Available-for-_2

Investments in Available-for-Sale Securities (Tables)	6 Months Ended
Investments in Available-for-Sale Securities (Tables)	Jun. 30, 2024
Investments in Available-for-Sale Securities
Available-for-sale Securities	June 30, 2024 Gross Allowance Unrealized for - Credit Fair Cost Basis Gains Losses Losses Value (In thousands) Available-for-sale: U.S. government and agency securities $ 17,326 $ 10 $ (8) $ — $ 17,328 Corporate notes and bonds 18,240 22 (7) — 18,255 Total Investments $ 35,566 $ 32 $ (15) $ — $ 35,583 December 31, 2023 Gross Allowance Unrealized for - Credit Fair Cost Basis Gains Losses Losses Value (In thousands) Available-for-sale: U.S. government and agency securities $ 28,764 $ 14 $ (5) $ — $ 28,773 Corporate notes and bonds 3,951 1 (1) — 3,951 Total Investments $ 32,715 $ 15 $ (6) $ — $ 32,724

Accrued Expenses and Other Cu_2

Accrued Expenses and Other Current Liabilities (Tables)	6 Months Ended
Accrued Expenses and Other Current Liabilities (Tables)	Jun. 30, 2024
Accrued Expenses and Other Current Liabilities.
Schedule of Accrued Expenses and Other Current Liabilities	June 30, December 31, 2024 2023 (In thousands) Payroll and employee benefits $ 34,674 $ 37,259 Taxes other than income taxes 36,043 51,155 Interest 2,468 2,395 Workers’ compensation 17,070 18,724 Asset retirement obligations 6,018 6,089 Other 14,789 11,995 $ 111,062 $ 127,617

Debt and Financing Arrangemen_2

Debt and Financing Arrangements (Tables)	6 Months Ended
Debt and Financing Arrangements (Tables)	Jun. 30, 2024
Debt and Financing Arrangements
Schedule of Long-term debt	June 30, December 31, 2024 2023 (In thousands) Term loan due 2025 ($16.7 million face value) $ 16,667 $ — Term loan due 2024 — 3,502 Tax Exempt Bonds ($98.1 million face value) 98,075 98,075 Other 18,536 40,529 Debt issuance costs (1,896) (1,511) 131,382 140,595 Less: current maturities of debt 29,721 35,343 Long-term debt $ 101,661 $ 105,252

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
Fair Value Measurements (Tables)	Jun. 30, 2024
Fair Value Measurements
Summary of Financial Assets and Liabilities Accounted for at Fair Value	June 30, 2024 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 35,583 $ 17,328 $ 18,255 $ — Fund for asset retirement obligations 146,010 146,010 — — Total assets $ 181,593 $ 163,338 $ 18,255 $ — December 31, 2023 Total Level 1 Level 2 Level 3 (In thousands) Assets: Investments in marketable securities $ 32,724 $ 28,773 $ 3,951 $ — Fund for asset retirement obligations 142,266 142,266 — — Total assets $ 174,990 $ 171,039 $ 3,951 $ —

Earnings per Common Share (Tabl

Earnings per Common Share (Tables)	6 Months Ended
Earnings per Common Share (Tables)	Jun. 30, 2024
Earnings per Common Share
Schedule of Weighted Average Number of Shares	Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In Thousands) Net income attributable to common shares $ 14,833 $ 77,353 $ 70,786 $ 275,461 Adjustment of interest expense attributable to Convertible Notes — — — 108 Diluted net income attributable to common stockholders 14,833 77,353 70,786 275,569 Basic weighted average shares outstanding 18,097 18,406 18,222 18,165 Effect of dilutive securities 198 729 313 1,126 Convertible Notes (a) — — — 168 Diluted weighted average shares outstanding 18,295 19,135 18,535 19,459 (a) Diluted weighted average common shares outstanding includes the dilutive effect had the Company's Convertible Notes been converted at the beginning of the year ended December 31, 2023. If converted by the holder, the Company may settle in cash, shares of the Company's common stock or a combination thereof, at the Company's election. The Capped Call Transaction is anti-dilutive and is excluded from the calculation of diluted earnings per share.

Workers Compensation Expense (T

Workers Compensation Expense (Tables)	6 Months Ended
Workers Compensation Expense (Tables)	Jun. 30, 2024
Workers Compensation Expense
Workers' compensation expense	Workers’ compensation expense consists of the following components: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Self-insured occupational disease benefits: Service cost $ 1,278 $ 994 $ 2,555 $ 1,987 Interest cost (1) 1,566 1,510 3,131 3,020 Net amortization (1) (3) (241) (6) (482) Total occupational disease $ 2,841 $ 2,263 $ 5,680 $ 4,525 Traumatic injury claims and assessments 2,592 2,741 5,076 4,431 Total workers’ compensation expense $ 5,433 $ 5,004 $ 10,756 $ 8,956 (1) In accordance with the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” these costs are recorded within Nonoperating expenses in the Condensed Consolidated Income Statements on the line item “Non-service related pension and postretirement benefit (costs) credits.”

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	6 Months Ended
Employee Benefit Plans (Tables)	Jun. 30, 2024
Employee Benefit Plans
Schedule of Pension Benefit Costs (Credits)	The following table details the components of pension benefit credit: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Interest cost (1) $ 11 $ 1,533 $ 22 $ 3,067 Expected return on plan assets (1) — (1,518) — (3,036) Amortization of prior service credits (1) — (36) — (73) Amortization of other actuarial (gains) (1) (22) (195) (44) (390) Net benefit credit $ (11) $ (216) $ (22) $ (432) The following table details the components of other postretirement benefit credit: Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) Service cost $ 50 $ 57 $ 99 $ 115 Interest cost (1) 605 673 1,210 1,347 Amortization of other actuarial gains (1) (1,981) (2,423) (3,962) (4,845) Net benefit credit $ (1,326) $ (1,693) $ (2,653) $ (3,383) (1) In accordance with the adoption of ASU 2017-07, “Compensation-Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost,” these costs are recorded within Nonoperating expenses in the Condensed Consolidated Income Statements on the line item “Non-service related pension and postretirement benefit (costs) credits.”

Segment Information (Tables)

Segment Information (Tables)	6 Months Ended
Segment Information (Tables)	Jun. 30, 2024
Segment Information
Schedule of Operating Segment Results	Corporate, Other and (In thousands) MET Thermal Eliminations Consolidated Three Months Ended June 30, 2024 Revenues $ 375,958 $ 232,793 $ — $ 608,751 Adjusted EBITDA 87,276 1,067 (28,384) 59,959 Depreciation, depletion and amortization 31,089 7,099 251 38,439 Accretion on asset retirement obligation 647 4,810 413 5,870 Capital expenditures 34,132 10,953 1,835 46,920 Three Months Ended June 30, 2023 Revenues $ 451,752 $ 305,542 $ — $ 757,294 Adjusted EBITDA 132,839 29,179 (31,632) 130,386 Depreciation, depletion and amortization 28,228 7,648 201 36,077 Accretion on asset retirement obligation 615 4,314 364 5,293 Capital expenditures 35,639 10,042 325 46,006 Six Months Ended June 30, 2024 Revenues $ 793,023 $ 495,918 $ — $ 1,288,941 Adjusted EBITDA 216,811 1,999 (55,988) 162,822 Depreciation, depletion and amortization 62,479 14,267 513 77,259 Accretion on asset retirement obligation 1,294 9,620 825 11,739 Capital expenditures 71,166 18,497 2,703 92,366 Six Months Ended June 30, 2023 Revenues $ 987,923 $ 639,302 $ — $ 1,627,225 Adjusted EBITDA 395,896 75,434 (63,603) 407,727 Depreciation, depletion and amortization 56,082 15,056 418 71,556 Accretion on asset retirement obligation 1,229 8,628 728 10,585 Capital expenditures 60,459 15,535 612 76,606
Schedule of Reconciliation of Net Income to Adjusted EBITDA	Three Months Ended June 30, Six Months Ended June 30, (In thousands) 2024 2023 2024 2023 Net income $ 14,833 $ 77,353 $ 70,786 $ 275,461 Provision for income taxes 2,002 12,920 5,721 50,058 Interest expense, net (1,470) (664) (3,254) 126 Depreciation, depletion and amortization 38,439 36,077 77,259 71,556 Accretion on asset retirement obligations 5,870 5,293 11,739 10,585 Non-service related pension and postretirement benefit costs (credits) 285 (593) 571 (1,185) Net loss resulting from early retirement of debt — — — 1,126 Adjusted EBITDA $ 59,959 $ 130,386 $ 162,822 $ 407,727 EBITDA from idled or otherwise disposed operations 3,695 4,664 7,392 8,696 Selling, general and administrative expenses 22,518 22,791 48,105 48,813 Other 2,172 4,177 491 6,094 Segment Adjusted EBITDA from coal operations $ 88,344 $ 162,018 $ 218,810 $ 471,330

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
Revenue Recognition (Tables)	Jun. 30, 2024
Revenue Recognition
Schedule of effects of revenue recognition	Corporate, Other and MET Thermal Eliminations Consolidated (in thousands) Three Months Ended June 30, 2024 North America revenues $ 67,213 $ 184,083 $ — $ 251,296 Seaborne revenues 308,745 48,710 — 357,455 Total revenues $ 375,958 $ 232,793 $ — $ 608,751 Three Months Ended June 30, 2023 North America revenues $ 93,715 $ 247,092 $ — $ 340,807 Seaborne revenues 358,037 58,450 — 416,487 Total revenues $ 451,752 $ 305,542 $ — $ 757,294 Six Months Ended June 30, 2024 North America revenues $ 102,797 $ 389,746 $ — $ 492,543 Seaborne revenues 690,226 106,172 — 796,398 Total revenues $ 793,023 $ 495,918 $ — $ 1,288,941 Six Months Ended June 30, 2023 North America revenues $ 165,122 $ 534,352 $ — $ 699,474 Seaborne revenues 822,801 104,950 — 927,751 Total revenues $ 987,923 $ 639,302 $ — $ 1,627,225

Leases (Tables)

Leases (Tables)	6 Months Ended
Leases (Tables)	Jun. 30, 2024
Leases
Schedule of right-of-use assets and lease liabilities	June 30, December 31, 2024 2023 Assets Balance Sheet Classification Operating lease right-of-use assets Other noncurrent assets $ 8,303 $ 9,626 Financing lease right-of-use assets Other noncurrent assets 973 1,621 Total Lease Assets $ 9,276 $ 11,247 Liabilities Balance Sheet Classification Financing lease liabilities - current Accrued expenses and other current liabilities $ 2,608 $ 1,041 Operating lease liabilities - current Accrued expenses and other current liabilities 2,843 2,789 Financing lease liabilities - long-term Other noncurrent liabilities - 2,079 Operating lease liabilities - long-term Other noncurrent liabilities 5,909 7,351 $ 11,360 $ 13,260 Weighted average remaining lease term in years Operating leases 2.82 3.32 Finance leases 0.75 1.25 Weighted average discount rate Operating leases 5.5% 5.5% Finance leases 6.4% 6.4%
Schedule of Information Related to Leases	Three Months Ended June 30, Six Months Ended June 30, 2024 2023 2024 2023 (In thousands) (In thousands) Operating lease information: Operating lease cost $ 786 $ 831 $ 1,589 $ 1,661 Operating cash flows from operating leases 788 876 1,654 1,704 Financing lease information: Financing lease cost $ 393 $ 393 $ 786 $ 786 Operating cash flows from financing leases 303 303 605 605
Schedule of Future Minimum Lease Payments	Future minimum lease payments under non-cancellable leases as of June 30, 2024 were as follows: Operating Finance Year Leases Leases (In thousands) 2024 $ 1,627 $ 605 2025 3,266 2,111 2026 3,080 — 2027 1,533 — 2028 — — Thereafter — — Total minimum lease payments $ 9,506 $ 2,716 Less imputed interest (754) (108) Total lease liabilities $ 8,752 $ 2,608

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) - Schedule of accumulated other comprehensive income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss)
Beginning Balance	$ 1,467,448	$ 1,463,994	$ 1,479,456	$ 1,365,580
Tax effect	2,002	12,920	5,721	50,058
Ending Balance	1,450,565	1,425,564	1,450,565	1,425,564
Accumulated Other Comprehensive Income (loss)
Accumulated Other Comprehensive Income (Loss)
Beginning Balance	37,200	59,158	38,782	61,429
Unrealized gains			17
Amounts reclassified from accumulated other comprehensive income			(4,020)
Tax effect			852
Ending Balance	35,631	$ 56,880	35,631	$ 56,880
Pension, Postretirement and Other Post-Employment Benefits
Accumulated Other Comprehensive Income (Loss)
Beginning Balance			38,783
Amounts reclassified from accumulated other comprehensive income			(4,012)
Tax effect			854
Ending Balance	35,625		35,625
Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss)
Beginning Balance			(1)
Unrealized gains			17
Amounts reclassified from accumulated other comprehensive income			(8)
Tax effect			(2)
Ending Balance	$ 6		$ 6

Accumulated Other Comprehensi_4

Accumulated Other Comprehensive Income (Loss) - Schedule of reclassifications (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss)
Interest expense	$ (3,933)	$ (3,537)	$ (8,249)	$ (7,663)
Net loss resulting from early retirement of debt				1,126
Interest and investment income	5,403	4,201	11,503	7,537
Total before tax	16,835	90,273	76,507	325,519
Provision for income taxes	2,002	12,920	5,721	50,058
Net Income (Loss)	14,833	77,353	70,786	275,461
Pension, postretirement and other post-employment benefits
Accumulated Other Comprehensive Income (Loss)
Provision for income taxes			854
Available-for-sale securities
Accumulated Other Comprehensive Income (Loss)
Provision for income taxes			(2)
Reclassification out of Accumulated Other Comprehensive Income \| Pension, postretirement and other post-employment benefits
Accumulated Other Comprehensive Income (Loss)
Amortization of actuarial gains, net 1	2,006	2,858	4,012	5,717
Amortization of prior service credits		37		73
Total before tax	2,006	2,895	4,012	5,790
Provision for income taxes	427	636	854	1,272
Net Income (Loss)	1,579	2,259	3,158	4,518
Reclassification out of Accumulated Other Comprehensive Income \| Available-for-sale securities
Accumulated Other Comprehensive Income (Loss)
Interest and investment income	(1)	1	8	(21)
Provision for income taxes	(3)	(3)	(2)	(8)
Net Income (Loss)	$ 2	$ 4	$ 10	$ (13)

Inventories (Details)

Inventories (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Inventories
Coal	$ 99,776	$ 99,174
Repair parts and supplies	150,089	145,087
Inventories	249,865	244,261
Allowance for slow-moving and obsolete inventories	$ 1,600	$ 1,600

Investments in Available-for-_3

Investments in Available-for-Sale Securities - Schedule of investments (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	$ 35,566	$ 32,715
Available-for-sale, Gross Unrealized Gains	32	15
Available-for-sale, Gross Unrealized Losses	(15)	(6)
Available-for-sale, Fair Value	35,583	32,724
U.S. government and agency securities
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	17,326	28,764
Available-for-sale, Gross Unrealized Gains	10	14
Available-for-sale, Gross Unrealized Losses	(8)	(5)
Available-for-sale, Fair Value	17,328	28,773
Corporate notes and bonds
Debt Securities, Available-for-sale [Line Items]
Available-for-sale, Cost Basis	18,240	3,951
Available-for-sale, Gross Unrealized Gains	22	1
Available-for-sale, Gross Unrealized Losses	(7)	(1)
Available-for-sale, Fair Value	$ 18,255	$ 3,951

Investments in Available-for-_4

Investments in Available-for-Sale securities (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Investments in Available-for-Sale Securities
Unrealized losses owned for less than 12 months	$ 10.6	$ 2.2
Unrealized losses owed for over a year	$ 1.2	$ 2.3

Accrued Expenses and Other Cu_3

Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Accrued Expenses and Other Current Liabilities.
Payroll and employee benefits	$ 34,674	$ 37,259
Taxes other than income taxes	36,043	51,155
Interest	2,468	2,395
Workers' compensation	17,070	18,724
Asset retirement obligations	6,018	6,089
Other	14,789	11,995
Accrued expenses and other current liabilities	$ 111,062	$ 127,617

Debt and Financing Arrangemen_3

Debt and Financing Arrangements - Long term debt (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Debt issuance costs	$ (1,896)	$ (1,511)
Total	131,382	140,595
Less: current maturities of debt	29,721	35,343
Long-term debt	101,661	105,252
Term loan due 2025
Debt Instrument [Line Items]
Long-term debt	16,667
Debt instrument, face amount	16,700
Term loan due 2024
Debt Instrument [Line Items]
Long-term debt		3,502
Tax Exempt Bonds
Debt Instrument [Line Items]
Long-term debt	98,075	98,075
Debt instrument, face amount	98,100
Other Debt
Debt Instrument [Line Items]
Long-term debt	$ 18,536	$ 40,529

Debt and Financing Arrangemen_4

Debt and Financing Arrangements (Details) $ in Thousands						3 Months Ended	6 Months Ended
Debt and Financing Arrangements (Details) $ in Thousands	Feb. 08, 2024 USD ($)	Aug. 03, 2022 USD ($)	Jul. 29, 2021 USD ($) M	Nov. 03, 2020 USD ($)	Jul. 02, 2020 USD ($)	Mar. 31, 2024 shares	Jun. 30, 2024 USD ($) shares	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)	Aug. 02, 2022 USD ($)	Mar. 04, 2021 USD ($)
Debt Instrument [Line Items]
Receipt of shares from the exercise of capped call \| shares						315,721	315,721
Restricted cash							$ 1,100	$ 1,100	$ 1,100
Debt financing costs	$ 1,500						1,516
Outstanding debt							131,382		$ 140,595
New Term Loan Debt Facility \| Secured Debt
Debt Instrument [Line Items]
Term loan, face value	20,000
Amortization payments	$ 3,300
Term loan due 2025
Debt Instrument [Line Items]
Term loan, face value							16,700
Total net leverage	2
Term of financial maintenance covenants, maximum total net leverage ratio	12 months
Maximum consolidated EBITDA to consolidated interest expense ratio	3.50
Term of financial maintenance covenants on consolidated EBITDA	12 months
Customary mandatory prepayment events	100%
Payments on term loan							3,333
Proceeds from issuance of debt							20,000
Term loan due 2025 \| Minimum
Debt Instrument [Line Items]
Financial maintenance covenant for liquidity	$ 100,000
Term loan due 2025 \| SOFR
Debt Instrument [Line Items]
Applicable margin on interest rate	3%
Adjustment to basis spread on variable rate	10%
Floor, basis spread on variable rate	0%
Term loan due 2025 \| Base Rate
Debt Instrument [Line Items]
Applicable margin on interest rate	2%
Term loan due 2024
Debt Instrument [Line Items]
Payments on term loan	$ 3,500						3,502	1,500
Accounts Receivable Securitization Facility \| Line of Credit \| Secured Debt
Debt Instrument [Line Items]
Current borrowing capacity							62,800
Letters of credit outstanding							51,900
Accounts Receivable Securitization Facility \| Regions Bank \| Line of Credit \| Secured Debt
Debt Instrument [Line Items]
Current borrowing capacity		$ 150,000								$ 110,000
Inventory-Based Revolving Credit Facility
Debt Instrument [Line Items]
Covenant amount							23,800
Inventory-Based Revolving Credit Facility \| Regions Bank \| Line of Credit \| Secured Debt
Debt Instrument [Line Items]
Term loan, face value		$ 50,000
Letters of credit outstanding							26,200
Borrowing base percentage, coal inventory		85
Borrowing base percentage, parts and supplies inventory		85
Borrowing base, percentage of clause		35
Percent of eligible cash		100%
Covenant amount		$ 100,000
Equipment financing arrangement \| Secured Debt
Debt Instrument [Line Items]
Term loan, face value			$ 23,500
Number of monthly payments \| M			42
Interest rate			7.35%
Tax Exempt Bonds
Debt Instrument [Line Items]
Term loan, face value							$ 98,100
Series 2020 Tax Exempt Bonds
Debt Instrument [Line Items]
Term loan, face value					$ 53,100
Interest rate					5%
Mandatory tender percentage					100%
Series 2021 Tax Exempt Bonds
Debt Instrument [Line Items]
Term loan, face value											$ 45,000
Interest rate											4.125%
Convertible Notes
Debt Instrument [Line Items]
Term loan, face value				$ 155,300
Interest rate				5.25%
Net proceeds of convertible debt				$ 132,700
Principal amount of convertible notes								13,200
Cash on convertible notes								58,400
Deferred Offering Costs				5,100
Loss on debt conversion								$ 1,100
Capped Call Transactions
Debt Instrument [Line Items]
Capped call, transaction cost				$ 17,500

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended		6 Months Ended
Income Taxes (Details)	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Taxes
Effective income tax rate (as a percent)	12%	14.30%	7.50%	15.40%
U.S. federal statutory rate (as percent)	21%	21%	21%	21%

Fair Value Measurements - Finan

Fair Value Measurements - Financial assets and liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets:
Investments in marketable securities	$ 35,583	$ 32,724
Fund for asset retirement obligations	146,010	142,266
Total assets	181,593	174,990
Level 1
Assets:
Investments in marketable securities	17,328	28,773
Fund for asset retirement obligations	146,010	142,266
Total assets	163,338	171,039
Level 2
Assets:
Investments in marketable securities	18,255	3,951
Fund for asset retirement obligations	0
Total assets	18,255	$ 3,951
Level 3
Assets:
Investments in marketable securities	0
Fund for asset retirement obligations	0
Total assets	$ 0

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Fair Value Measurements
Fair value of debt, including amounts classified as current	$ 133.3	$ 142.1

Earnings per Common Share (Deta

Earnings per Common Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Earnings per Common Share
Net income attributable to common shares	$ 14,833	$ 77,353	$ 70,786	$ 275,461
Adjustment of interest expense attributable to Convertible Notes				108
Diluted net income attributable to common shareholders	$ 14,833	$ 77,353	$ 70,786	$ 275,569
Weighted average shares outstanding:
Basic weighted average shares outstanding (in shares)	18,097	18,406	18,222	18,165
Effect of dilutive securities (in shares)	198	729	313	1,126
Convertible Notes (in shares)				168
Diluted weighted average shares outstanding (in shares)	18,295	19,135	18,535	19,459

Workers Compensation Expense (D

Workers Compensation Expense (Details) - USD ($) $ in Millions		1 Months Ended
	Jan. 18, 2023	Feb. 29, 2020
Workers Compensation Expense
Self-insured operators must post security percent	120%
Additional collateral amount		$ 71.1
Number of days required to submit additional collateral to retain self-insurance status		30 days

Workers Compensation Expense -

Workers Compensation Expense - Worker's compensation expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Total workers' compensation expense
Accrued Workers' Compensation [Line Items]
Total workers' compensation expense	$ 5,433	$ 5,004	$ 10,756	$ 8,956
Occupational disease
Accrued Workers' Compensation [Line Items]
Service cost	1,278	994	2,555	1,987
Interest cost	1,566	1,510	3,131	3,020
Amortization of other actuarial (gains)	(3)	(241)	(6)	(482)
Net benefit credit	2,841	2,263	5,680	4,525
Traumatic injury claims and assessments
Accrued Workers' Compensation [Line Items]
Traumatic injury claims and assessments	$ 2,592	$ 2,741	$ 5,076	$ 4,431

Employee Benefit Plans - Schedu

Employee Benefit Plans - Schedule of net benefit credit (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 11	$ 1,533	$ 22	$ 3,067
Expected return on plan assets	0	(1,518)		(3,036)
Amortization of prior service credits	$ 0	$ (36)		$ (73)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Pension and Other Postretirement Benefits Cost (Reversal of Cost)	Pension and Other Postretirement Benefits Cost (Reversal of Cost)	Pension and Other Postretirement Benefits Cost (Reversal of Cost)	Pension and Other Postretirement Benefits Cost (Reversal of Cost)
Amortization of other actuarial (gains)	$ (22)	$ (195)	$ (44)	$ (390)
Net benefit credit	(11)	(216)	(22)	(432)
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	50	57	99	115
Interest cost	605	673	1,210	1,347
Amortization of other actuarial (gains)	$ (1,981)	$ (2,423)	$ (3,962)	$ (4,845)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Pension and Other Postretirement Benefits Cost (Reversal of Cost)	Pension and Other Postretirement Benefits Cost (Reversal of Cost)	Pension and Other Postretirement Benefits Cost (Reversal of Cost)	Pension and Other Postretirement Benefits Cost (Reversal of Cost)
Net benefit credit	$ (1,326)	$ (1,693)	$ (2,653)	$ (3,383)

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Loss Contingencies [Line Items]
Surety Bonds Outstanding	$ 488,800
Cash collateral for surety bond	5,600
Contribution to fund asset retirement obligations	3,745	$ 2,664
Fund for asset retirement obligations	146,010		$ 142,266
Securitization and Inventory Facilities
Loss Contingencies [Line Items]
Letters of credit outstanding	78,100
Asset retirement obligations
Loss Contingencies [Line Items]
Surety Bonds Outstanding	402,700
Cash collateral for surety bond	600
Reclamation-related obligations	269,100
Contribution to fund asset retirement obligations	3,700
Fund for asset retirement obligations	$ 146,000

Segment Information - Schedule

Segment Information - Schedule of operating segment results (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($)	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) item	Jun. 30, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of distinct lines of business \| item			2
Revenues	$ 608,751	$ 757,294	$ 1,288,941	$ 1,627,225
Adjusted EBITDA	59,959	130,386	162,822	407,727
Depreciation, depletion and amortization	38,439	36,077	77,259	71,556
Accretion on asset retirement obligation	5,870	5,293	11,739	10,585
Capital expenditures	46,920	46,006	92,366	76,606
Operating Segments \| MET
Segment Reporting Information [Line Items]
Revenues	375,958	451,752	793,023	987,923
Adjusted EBITDA	87,276	132,839	216,811	395,896
Depreciation, depletion and amortization	31,089	28,228	62,479	56,082
Accretion on asset retirement obligation	647	615	1,294	1,229
Capital expenditures	34,132	35,639	71,166	60,459
Operating Segments \| Thermal
Segment Reporting Information [Line Items]
Revenues	232,793	305,542	495,918	639,302
Adjusted EBITDA	1,067	29,179	1,999	75,434
Depreciation, depletion and amortization	7,099	7,648	14,267	15,056
Accretion on asset retirement obligation	4,810	4,314	9,620	8,628
Capital expenditures	10,953	10,042	18,497	15,535
Corporate, Other and Eliminations
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Adjusted EBITDA	(28,384)	(31,632)	(55,988)	(63,603)
Depreciation, depletion and amortization	251	201	513	418
Accretion on asset retirement obligation	413	364	825	728
Capital expenditures	$ 1,835	$ 325	$ 2,703	$ 612

Segment Information - Reconcili

Segment Information - Reconciliation segment income to net income (loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Information
Net Income (Loss)	$ 14,833	$ 77,353	$ 70,786	$ 275,461
Provision for income taxes	2,002	12,920	5,721	50,058
Interest expense, net	(1,470)	(664)	(3,254)	126
Depreciation, depletion and amortization	38,439	36,077	77,259	71,556
Accretion on asset retirement obligation	5,870	5,293	11,739	10,585
Non-service related pension and postretirement benefit costs (credits)	285	(593)	571	(1,185)
Net loss resulting from early retirement of debt				1,126
Adjusted EBITDA	59,959	130,386	162,822	407,727
EBITDA from idled or otherwise disposed operations	3,695	4,664	7,392	8,696
Selling, general and administrative expenses	22,518	22,791	48,105	48,813
Other	2,172	4,177	491	6,094
Segment Adjusted EBITDA from coal operations	$ 88,344	$ 162,018	$ 218,810	$ 471,330

Revenue Recognition - Schedule

Revenue Recognition - Schedule of revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Disaggregation of Revenue [Line Items]
Revenues	$ 608,751	$ 757,294	$ 1,288,941	$ 1,627,225
North America revenues
Disaggregation of Revenue [Line Items]
Revenues	251,296	340,807	492,543	699,474
Seaborne revenues
Disaggregation of Revenue [Line Items]
Revenues	357,455	416,487	796,398	927,751
Operating Segments \| MET
Disaggregation of Revenue [Line Items]
Revenues	375,958	451,752	793,023	987,923
Operating Segments \| MET \| North America revenues
Disaggregation of Revenue [Line Items]
Revenues	67,213	93,715	102,797	165,122
Operating Segments \| MET \| Seaborne revenues
Disaggregation of Revenue [Line Items]
Revenues	308,745	358,037	690,226	822,801
Operating Segments \| Thermal
Disaggregation of Revenue [Line Items]
Revenues	232,793	305,542	495,918	639,302
Operating Segments \| Thermal \| North America revenues
Disaggregation of Revenue [Line Items]
Revenues	184,083	247,092	389,746	534,352
Operating Segments \| Thermal \| Seaborne revenues
Disaggregation of Revenue [Line Items]
Revenues	48,710	58,450	106,172	104,950
Corporate, Other and Eliminations
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Corporate, Other and Eliminations \| North America revenues
Disaggregation of Revenue [Line Items]
Revenues	0	0	0	0
Corporate, Other and Eliminations \| Seaborne revenues
Disaggregation of Revenue [Line Items]
Revenues	$ 0	$ 0	$ 0	$ 0

Revenue Recognition (Details)

Revenue Recognition (Details) T in Millions	Jun. 30, 2024 T
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligation (in tons)	29.1
Remaining performance obligation, variable price contracts (in tons)	3.8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Remaining performance obligations, fixed price contracts (in tons)	78.6
Remaining performance obligation, variable price contracts (in tons)	2

Leases (Narrative) (Details)

Leases (Narrative) (Details)	Jun. 30, 2024
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, remaining lease terms	1 year
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, remaining lease terms	3 years

Leases - Lease assets and liabi

Leases - Lease assets and liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Assets
Operating lease right-of-use assets	$ 8,303	$ 9,626
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets, Noncurrent	Other Assets, Noncurrent
Financing lease right-of-use assets	$ 973	$ 1,621
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	Other Assets, Noncurrent	Other Assets, Noncurrent
Total Lease Assets	$ 9,276	$ 11,247
Liabilities
Financing lease liabilities - current	$ 2,608	$ 1,041
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued Liabilities, Current	Accrued Liabilities, Current
Operating lease liabilities - current	$ 2,843	$ 2,789
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued Liabilities, Current	Accrued Liabilities, Current
Financing lease liabilities - long-term		$ 2,079
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Operating lease liabilities - long-term	$ 5,909	$ 7,351
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Other Liabilities, Noncurrent	Other Liabilities, Noncurrent
Total Lease Liabilities	$ 11,360	$ 13,260

Leases - Weighted average lease

Leases - Weighted average lease term and discount rate (Details)	Jun. 30, 2024	Dec. 31, 2023
Leases
Weighted average remaining lease term in years - Operating leases	2 years 9 months 25 days	3 years 3 months 25 days
Weighted average remaining lease term in years - Finance leases	9 months	1 year 3 months
Weighted average discount rate - Operating leases	5.50%	5.50%
Weighted average discount rate - Finance leases	6.40%	6.40%

Leases - Other information rela

Leases - Other information related to leases (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Lease information:
Operating lease cost	$ 786	$ 831	$ 1,589	$ 1,661
Operating cash flows from operating leases	788	876	1,654	1,704
Financing lease cost	393	393	786	786
Operating cash flows from financing leases	$ 303	$ 303	$ 605	$ 605

Leases - Future minimum lease p

Leases - Future minimum lease payments (Details) $ in Thousands	Jun. 30, 2024 USD ($)
Operating Leases
2024	$ 1,627
2025	3,266
2026	3,080
2027	1,533
Total minimum lease payments	9,506
Less imputed interest	(754)
Total operating lease liabilities	8,752
Finance Leases
2024	605
2025	2,111
Total minimum lease payments	2,716
Less imputed interest	(108)
Total finance lease liabilities	$ 2,608

Subsequent Event (Details)

Subsequent Event (Details)	Jul. 25, 2024 $ / shares
Subsequent Event
Subsequent Event [Line Items]
Quarterly dividend	$ 0.25