Alliance Resource Partners (ARLP) 10-Q 8 Aug 22 2022 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 08, 2022
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2022
Entity File Number	0-26823
Entity Registrant Name	ALLIANCE RESOURCE PARTNERS LP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	73-1564280
Entity Address, Address Line One	1717 South Boulder Avenue, Suite 400
Entity Address, City or Town	Tulsa
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	74119
City Area Code	918
Local Phone Number	295-7600
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
Entity Shell Company	false
Title of 12(b) Security	Common units
Trading Symbol	ARLP
Security Exchange Name	NASDAQ
Entity Common Units Outstanding		127,195,219
Entity Central Index Key	0001086600
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash and cash equivalents	$ 106,089	$ 122,403
Trade receivables	230,577	129,531
Other receivables	431	680
Inventories, net	109,676	60,302
Advance royalties	3,458	4,958
Prepaid expenses and other assets	15,853	21,354
Total current assets	466,084	339,228
PROPERTY, PLANT AND EQUIPMENT:
Property, plant and equipment, at cost	3,656,835	3,608,347
Less accumulated depreciation, depletion and amortization	(1,970,964)	(1,909,669)
Total property, plant and equipment, net	1,685,871	1,698,678
OTHER ASSETS:
Advance royalties	70,800	63,524
Equity method investments	46,388	26,325
Equity securities	32,639
Goodwill	4,373	4,373
Operating lease right-of-use assets	14,731	14,158
Other long-term assets	12,305	13,120
Total other assets	181,236	121,500
TOTAL ASSETS	2,333,191	2,159,406
CURRENT LIABILITIES:
Accounts payable	90,408	69,586
Accrued taxes other than income taxes	13,972	17,787
Accrued payroll and related expenses	38,796	36,805
Accrued interest	5,000	5,000
Workers' compensation and pneumoconiosis benefits	12,276	12,293
Current finance lease obligations	486	840
Current operating lease obligations	2,157	1,820
Other current liabilities	18,511	17,375
Current maturities, long-term debt, net	14,942	16,071
Total current liabilities	196,548	177,577
LONG-TERM LIABILITIES:
Long-term debt, excluding current maturities, net	412,991	418,942
Pneumoconiosis benefits	108,819	107,560
Accrued pension benefit	24,130	25,590
Workers' compensation	38,701	44,911
Asset retirement obligations	124,180	123,517
Long-term finance lease obligations	562	618
Long-term operating lease obligations	12,657	12,366
Deferred income tax liabilities	37,331	391
Other liabilities	25,079	21,865
Total long-term liabilities	784,450	755,760
Total liabilities	980,998	933,337
COMMITMENTS AND CONTINGENCIES - (Note 3)
ARLP Partners' Capital:
Limited Partners - Common Unitholders 127,195,219 units outstanding	1,403,733	1,279,183
Accumulated other comprehensive loss	(62,645)	(64,229)
Total ARLP Partners' Capital	1,341,088	1,214,954
Noncontrolling interest	11,105	11,115
Total Partners' Capital	1,352,193	1,226,069
TOTAL LIABILITIES AND PARTNERS' CAPITAL	$ 2,333,191	$ 2,159,406

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Jun. 30, 2022	Dec. 31, 2021
CONDENSED CONSOLIDATED BALANCE SHEETS
Common units outstanding	127,195,219	127,195,219

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
SALES AND OPERATING REVENUES:
Revenues	$ 616,501	$ 362,443	$ 1,077,364	$ 681,065
EXPENSES:
Outside coal purchases	151	114	151	114
General and administrative	22,457	17,492	41,053	32,996
Depreciation, depletion and amortization	66,734	64,733	130,048	123,935
Total operating expenses	441,229	307,436	814,257	589,730
INCOME FROM OPERATIONS	175,272	55,007	263,107	91,335
Interest expense (net of interest capitalized for the three and six months ended June 30, 2022 and 2021 of $171, $105, $241 and $191, respectively)	(9,397)	(9,842)	(19,059)	(20,238)
Interest income	93	15	128	32
Equity method investment income	1,585	341	2,468	403
Other income (expense)	579	(1,351)	1,145	(2,548)
INCOME BEFORE INCOME TAXES	168,132	44,170	247,789	68,984
INCOME TAX EXPENSE (BENEFIT)	6,331	5	49,046	(7)
NET INCOME	161,801	44,165	198,743	68,991
LESS: NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST	(323)	(130)	(613)	(208)
NET INCOME ATTRIBUTABLE TO ARLP	$ 161,478	$ 44,035	$ 198,130	$ 68,783
EARNINGS PER LIMITED PARTNER UNIT - BASIC (in dollars per unit)	$ 1.23	$ 0.34	$ 1.51	$ 0.53
EARNINGS PER LIMITED PARTNER UNIT - DILUTED (in dollars per unit)	$ 1.23	$ 0.34	$ 1.51	$ 0.53
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - BASIC (in units)	127,195,219	127,195,219	127,195,219	127,195,219
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - DILUTED (in units)	127,195,000	127,195,000	127,195,000	127,195,000
Product
EXPENSES:
Operating expenses (excluding depreciation, depletion and amortization)	$ 316,502	$ 213,039	$ 578,248	$ 409,559
Coal sales
SALES AND OPERATING REVENUES:
Revenues	531,807	325,974	920,167	613,461
Oil & gas royalties
SALES AND OPERATING REVENUES:
Revenues	35,927	17,114	66,854	31,113
Transportation
SALES AND OPERATING REVENUES:
Revenues	35,385	12,058	64,757	23,126
EXPENSES:
Operating expenses (excluding depreciation, depletion and amortization)	35,385	12,058	64,757	23,126
Other revenues
SALES AND OPERATING REVENUES:
Revenues	$ 13,382	$ 7,297	$ 25,586	$ 13,365

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
CONDENSED CONSOLIDATED STATEMENTS OF INCOME
Interest expense, interest capitalized	$ 171	$ 105	$ 241	$ 191

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
NET INCOME	$ 161,801	$ 44,165	$ 198,743	$ 68,991
OTHER COMPREHENSIVE INCOME:
OTHER COMPREHENSIVE INCOME	794	2,231	1,584	4,462
COMPREHENSIVE INCOME	162,595	46,396	200,327	73,453
Less: Comprehensive income attributable to noncontrolling interest	(323)	(130)	(613)	(208)
COMPREHENSIVE INCOME ATTRIBUTABLE TO ARLP	162,272	46,266	199,714	73,245
Defined benefit pension plan
OTHER COMPREHENSIVE INCOME:
Amortization of prior service cost	46	46	93	93
Amortization of net actuarial loss	489	1,142	972	2,283
Total recognized in accumulated other comprehensive loss	535	1,188	1,065	2,376
Pneumoconiosis benefits
OTHER COMPREHENSIVE INCOME:
Amortization of net actuarial loss	259	1,043	519	2,086
Total recognized in accumulated other comprehensive loss	$ 259	$ 1,043	$ 519	$ 2,086

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS
CASH FLOWS FROM OPERATING ACTIVITIES	$ 235,317	$ 158,216
Property, plant and equipment:
Capital expenditures	(121,982)	(55,626)
Increase in accounts payable and accrued liabilities	8,951	1,547
Proceeds from sale of property, plant and equipment	3,373	2,838
Contributions to equity method investments	(20,110)
Purchase of equity security	(32,639)
Distributions received from investments in excess of cumulative earnings	47	994
Other	(982)
Net cash used in investing activities	(163,342)	(50,247)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under securitization facility	27,500	35,000
Payments under securitization facility	(27,500)	(52,800)
Payments on equipment financings	(8,696)	(8,535)
Borrowings under revolving credit facilities		15,000
Payments under revolving credit facilities		(102,500)
Borrowings from line of credit		1,830
Payments on finance lease obligations	(410)	(375)
Payment of debt issuance costs		(6)
Distributions paid to Partners	(78,560)	(13,045)	$ (52,158)
Other	(623)	(363)
Net cash used in financing activities	(88,289)	(125,794)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(16,314)	(17,825)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	122,403	55,574	55,574
CASH AND CASH EQUIVALENTS AT END OF PERIOD	106,089	37,749	$ 122,403
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest	17,506	18,817
Cash paid for income taxes	10,964	11
SUPPLEMENTAL NON-CASH ACTIVITY:
Accounts payable for purchase of property, plant and equipment	17,276	$ 7,278
Right-of-use assets acquired by operating lease	$ 99

ORGANIZATION AND PRESENTATION

ORGANIZATION AND PRESENTATION	6 Months Ended
	Jun. 30, 2022
ORGANIZATION AND PRESENTATION
ORGANIZATION AND PRESENTATION	1. ORGANIZATION AND PRESENTATION ​ Significant Relationships Referenced in Notes to Condensed Consolidated Financial Statements ​ ● References to "we," "us," "our" or "ARLP Partnership" mean the business and operations of Alliance Resource Partners, L.P., the parent company, as well as its consolidated subsidiaries. ● References to "ARLP" mean Alliance Resource Partners, L.P., individually as the parent company, and not on a consolidated basis. ● References to "MGP" mean Alliance Resource Management GP, LLC, ARLP's general partner. ● References to "Mr. Craft" mean Joseph W. Craft III, the Chairman, President and Chief Executive Officer of MGP. ● References to "Intermediate Partnership" mean Alliance Resource Operating Partners, L.P., the intermediate partnership of Alliance Resource Partners, L.P. ● References to "Alliance Coal" mean Alliance Coal, LLC, the holding company for our coal mining operations. ● References to "Alliance Minerals" mean Alliance Minerals, LLC, the holding company for our oil and gas mineral interests. ● References to "Alliance Resource Properties" mean Alliance Resource Properties, LLC, the land holding company for certain of our coal mineral interests, including the subsidiaries of Alliance Resource Properties, LLC. ​ Organization ​ ARLP is a Delaware limited partnership listed on the NASDAQ Global Select Market under the ticker symbol "ARLP." ARLP was formed in May 1999 and completed its initial public offering on August 19, 1999 when it acquired substantially all of the coal production and marketing assets of Alliance Resource Holdings, Inc., a Delaware corporation, and its subsidiaries. We are managed by our general partner, MGP, a Delaware limited liability company which holds a non-economic general partner interest in ARLP. ​ Change in Tax Status ​ On March 15, 2022, Alliance Minerals changed its federal income tax status from a pass-through entity to a taxable entity via a "check the box" election (the "Tax Election"), which became effective January 1, 2022. This election for Alliance Minerals is anticipated to reduce the total income tax burden on our oil & gas royalties, as Alliance Minerals will pay entity-level taxes at corporate tax rates that are well below individual tax rates that would otherwise be paid by our unitholders. For more information on the Tax Election please see Note 7 – Income Taxes. ​ Francis Investment ​ On April 5, 2022, we committed to invest up to $50 million in Francis Renewable Energy, LLC ("Francis") through the purchase of preferred equity interests. Francis currently is active in the installation, management and operation of metered-for-fee, public-access electric vehicle ("EV") charging stations. Francis also develops and constructs EV charging stations for third-party customers. Our investment in Francis furthers our business strategy to develop strategic relationships and invest in attractive opportunities in the fast-growing energy infrastructure transition. For more information on this investment please see Note 8 – Variable Interest Entities. ​ Infinitum Investment ​ On April 29, 2022, we purchased $32.6 million of Series D Preferred Stock from Infinitum Electric, Inc. ("Infinitum"), a Texas-based startup developer and manufacturer of electric motors featuring printed circuit board stators which have the potential to result in motors that are smaller, lighter, quieter, more efficient and capable of operating at a fraction of the carbon footprint of conventional electric motors. The preferred stock provides for non-cumulative dividends when and if declared by Infinitum’s board of directors. Each share is convertible, at any time, at our option, into shares of common stock of Infinitum. Our investment in Infinitum furthers our business strategy to develop strategic relationships and invest in attractive opportunities in the fast-growing energy infrastructure transition. For more information on this investment please see Note 9 – Investments. ​ NGP ETP IV Investment ​ On June 2, 2022, we committed to purchase $25.0 million of limited partner interests in NGP ETP IV, L.P. ("NGP ETP IV"), a ​ Basis of Presentation ​ The accompanying condensed consolidated financial statements include the accounts and operations of the ARLP Partnership and present our financial position as of June 30, 2022 and December 31, 2021, the results of our operations and comprehensive income for the three and six months ended June 30, 2022 and 2021, and cash flows for the six months ended June 30, 2022 and 2021. All intercompany transactions and accounts have been eliminated. ​ These condensed consolidated financial statements and notes are prepared pursuant to the rules and regulations of the Securities and Exchange Commission for interim reporting and do not include all the information normally included with financial statements prepared in accordance with generally accepted accounting principles ("GAAP") of the United States. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2021. ​ These condensed consolidated financial statements and notes are unaudited. However, in the opinion of management, these condensed consolidated financial statements reflect all normal recurring adjustments necessary for a fair presentation of the results for the periods presented. Results for interim periods are not necessarily indicative of results to be expected for the full year ending December 31, 2022. ​ Use of Estimates ​ The preparation of the ARLP Partnership's condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosures in our condensed consolidated financial statements. Actual results could differ from those estimates. ​ Income Taxes ​ We are not a taxable entity for federal or state income tax purposes; the tax effect of our activities accrues to our unitholders. Although publicly traded partnerships as a general rule are taxed as corporations, we qualify for an exemption because at least 90% of our income consists of qualifying income, as defined in Section 7704(c) of the Internal Revenue Code. Net income for financial statement purposes may differ significantly from taxable income reportable to unitholders as a result of differences between the tax basis and financial reporting basis of assets and liabilities and the taxable income allocation requirements under our partnership agreement. Individual unitholders have different investment bases depending upon the timing and price of acquisition of their partnership units. Furthermore, each unitholder's tax accounting, which is partially dependent upon the unitholder's tax position, differs from the accounting followed in our consolidated financial statements. Accordingly, the aggregate difference in the basis of our net assets for financial and tax reporting purposes cannot be readily determined because information regarding each unitholder's tax attributes in our partnership is not available to us. ​ Our subsidiary Alliance Minerals within our Oil & Gas Royalties segment and certain other subsidiaries within our Other, Corporate and Elimination category are subject to federal and state income taxes. We use the liability method of accounting for income taxes, under which deferred tax assets and liabilities are recognized for the future tax consequences of (i) temporary differences between the financial statement carrying amounts and the tax basis of existing assets and liabilities and (ii) operating losses and tax credit carryforwards. Deferred income tax assets and liabilities are based on enacted rates applicable to the future period when those temporary differences are expected to be recovered or settled. The effect of a change in tax status or a change in tax rates on deferred tax assets and liabilities is recognized in the period the change in status is elected or rate change is enacted. A valuation allowance is provided for deferred tax assets when it is more likely than not the deferred tax assets will not be realized.

NEW ACCOUNTING STANDARDS

NEW ACCOUNTING STANDARDS	6 Months Ended
	Jun. 30, 2022
NEW ACCOUNTING STANDARDS
NEW ACCOUNTING STANDARDS	2. NEW ACCOUNTING STANDARDS ​ New Accounting Standards Issued and Adopted ​ In November 2021, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance ("ASU 2021-10"). ASU 2021-10 increases the transparency of government assistance including the disclosure of (1) the types of assistance, (2) an entity’s accounting for the assistance, and (3) the effect of the assistance on an entity’s financial statements. We adopted ASU 2021-10 on January 1, 2022. The adoption of ASU 2021-10 did not have a material impact on our condensed consolidated financial statements.

CONTINGENCIES

CONTINGENCIES	6 Months Ended
	Jun. 30, 2022
CONTINGENCIES
CONTINGENCIES	3. CONTINGENCIES ​ We are party to litigation that has been initiated against certain of our subsidiaries in which the plaintiffs allege violations of the Fair Labor Standards Act and Kentucky Wage and Hour Act due to an alleged failure to compensate for time "donning" and "doffing" equipment and to account for certain bonuses in the calculation of overtime rates and pay. The plaintiffs seek class or collective action certification. Because the litigation of these matters is in the early stages, we cannot reasonably estimate a range of potential exposure at this time. We believe the plaintiffs’ claims are without merit and our ultimate exposure, if any, will not be material to our results of operations or financial position and we intend to defend the litigation vigorously. However, if our current belief that the claims are without merit is not upheld, it is reasonably possible that the ultimate resolution of these matters could result in a potential loss that may be material to our results of operations. ​ We also have various other lawsuits, claims and regulatory proceedings incidental to our business that are pending against the ARLP Partnership. We record an accrual for a potential loss related to these matters when, in management's opinion, such loss is probable and reasonably estimable. Based on known facts and circumstances, we believe the ultimate outcome of these outstanding lawsuits, claims and regulatory proceedings will not have a material adverse effect on our financial condition, results of operations or liquidity. However, if the results of these matters are different from management's current expectations and in amounts greater than our accruals, such matters could have a material adverse effect on our business and operations.

INVENTORIES

INVENTORIES	6 Months Ended
	Jun. 30, 2022
INVENTORIES
INVENTORIES	4. INVENTORIES ​ Inventories consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ ​ ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal ​ $ 63,933 ​ $ 24,845 ​ Supplies (net of reserve for obsolescence of $5,620 and $5,554, respectively) ​ 45,743 ​ 35,457 ​ Total inventories, net ​ $ 109,676 ​ $ 60,302 ​ ​

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	6 Months Ended
	Jun. 30, 2022
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS	5. FAIR VALUE MEASUREMENTS ​ The following table summarizes our fair value measurements within the hierarchy not included elsewhere in these notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2022 ​ December 31, 2021 ​ ​ Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 ​ ​ (in thousands) ​ Long-term debt ​ $ — ​ $ 428,645 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​ Total ​ $ — ​ $ 428,645 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​ ​ The carrying amounts for cash equivalents, accounts receivable, accounts payable, accrued and other liabilities approximate fair value due to the short maturity of those instruments. ​ The estimated fair value of our long-term debt, including current maturities, is based on interest rates that we believe are currently available to us in active markets for issuance of debt with similar terms and remaining maturities (See Note 6 – Long-Term Debt). The fair value of debt, which is based upon these interest rates, is classified as a Level 2 measurement under the fair value hierarchy.

LONG-TERM DEBT

LONG-TERM DEBT	6 Months Ended
	Jun. 30, 2022
LONG-TERM DEBT
LONG-TERM DEBT	6. LONG-TERM DEBT ​ Long-term debt consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unamortized Discount and ​ ​ ​ Principal ​ Debt Issuance Costs ​ ​ ​ June 30, ​ December 31, ​ June 30, ​ December 31, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Revolving credit facility ​ $ — ​ $ — ​ $ (3,861) ​ $ (5,019) ​ Senior notes ​ 400,000 ​ 400,000 ​ (2,592) ​ (3,048) ​ Securitization facility ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ May 2019 equipment financing ​ ​ — ​ ​ 1,503 ​ ​ — ​ ​ — ​ November 2019 equipment financing ​ ​ 26,587 ​ ​ 31,972 ​ ​ — ​ ​ — ​ June 2020 equipment financing ​ ​ 7,799 ​ ​ 9,605 ​ ​ — ​ ​ — ​ ​ ​ 434,386 ​ 443,080 ​ (6,453) ​ (8,067) ​ Less current maturities ​ (14,942) ​ (16,071) ​ — ​ — ​ Total long-term debt ​ $ 419,444 ​ $ 427,009 ​ $ (6,453) ​ $ (8,067) ​ ​ Credit Facility. ​ The Credit Agreement is guaranteed by certain of our Intermediate Partnership's material direct and indirect subsidiaries (the "Restricted Subsidiaries") and is secured by substantially all the assets of the Restricted Subsidiaries. The Credit Agreement is also guaranteed by Alliance Minerals but the oil and gas mineral assets of Alliance Minerals and its direct and indirect subsidiaries (collectively with Alliance Minerals, the "Unrestricted Subsidiaries") are not collateral under the Credit Agreement. Borrowings under the Revolving Credit Facility bear interest, at our option, at either (i) the Base Rate at the greater of three benchmarks or (ii) a Eurodollar Rate, plus margins for (i) or (ii), as applicable, that fluctuate depending upon the ratio of Consolidated Debt to Consolidated Cash Flow (each as defined in the Credit Agreement). The Eurodollar Rate, with applicable margin, under the Revolving Credit Facility was 4.14% as of June 30, 2022. On June 30, 2022, we had $44.1 million of letters of credit outstanding with $415.4 million available for borrowing under the Revolving Credit Facility. We incur an annual commitment fee of 0.35% on the undrawn portion of the Revolving Credit Facility. We utilize the Revolving Credit Facility, as appropriate, for working capital requirements, capital expenditures and investments, scheduled debt payments and distribution payments. ​ The Credit Agreement contains various restrictions affecting the Intermediate Partnership and its Restricted Subsidiaries including, among other things, restrictions on incurrence of additional indebtedness and liens, sale of assets, investments, mergers and consolidations and transactions with affiliates, including transactions with Unrestricted Subsidiaries. In each case, these restrictions are subject to various exceptions. In addition, the payment of cash distributions is restricted if such payment would result in a fixed charge coverage ratio of less than 1.0 to 1.0 (as defined in the Credit Agreement) for the four most recently ended fiscal quarters. The Credit Agreement requires the Intermediate Partnership to maintain (a) a debt to cash flow ratio of not more than 2.5 to 1.0, (b) a cash flow to interest expense ratio of not less than 3.0 to 1.0 and (c) a first lien debt to cash flow ratio of not more than 1.5 to 1.0, in each case, during the four most recently ended fiscal quarters. The debt to cash flow ratio, cash flow to interest expense ratio and first lien debt to cash flow ratio were 0.74 to 1.0, 15.52 to 1.0 and 0.07 to 1.0, respectively, for the trailing twelve months ended June 30, 2022. We remained in compliance with the covenants of the Credit Agreement as of June 30, 2022 and anticipate remaining in compliance with the covenants. ​ Senior Notes. On April 24, 2017, the Intermediate Partnership and Alliance Resource Finance Corporation (as co-issuer), a wholly owned subsidiary of the Intermediate Partnership ("Alliance Finance"), issued an aggregate principal amount of $400.0 million of senior unsecured notes due 2025 ("Senior Notes") in a private placement to qualified institutional buyers. The Senior Notes have a term of eight years , maturing on May 1, 2025 (the "Term") and accrue interest at an annual rate of 7.5% . Interest is payable semi-annually in arrears on each May 1 and November 1. The indenture governing the Senior Notes contains customary terms, events of default and covenants relating to, among other things, the incurrence of debt, the payment of distributions or similar restricted payments, undertaking transactions with affiliates and limitations on asset sales. The issuers of the Senior Notes may redeem all or a part of the notes at any time at redemption prices set forth in the indenture governing the Senior Notes. ​ Accounts Receivable Securitization. ​ May 2019 Equipment Financing . On May 17, 2019, the Intermediate Partnership entered into an equipment financing arrangement accounted for as debt, wherein the Intermediate Partnership received $10.0 million in exchange for conveying its interest in certain equipment owned indirectly by the Intermediate Partnership and entering into a master lease agreement for that equipment (the "May 2019 Equipment Financing"). The May 2019 Equipment Financing contained customary terms and events of default and provided for thirty-six monthly payments with an implicit interest rate of 6.25% . The May 2019 Equipment Financing matured on May 1, 2022 and the equipment reverted to the Intermediate Partnership. ​ November 2019 Equipment Financing. On November 6, 2019, the Intermediate Partnership entered into an equipment financing arrangement accounted for as debt, wherein the Intermediate Partnership received $53.1 million in exchange for conveying its interest in certain equipment owned indirectly by the Intermediate Partnership and entering into a master lease agreement for that equipment (the "November 2019 Equipment Financing"). The November 2019 Equipment Financing contains customary terms and events of default and an implicit interest rate of 4.75% , providing for a four-year term with forty-seven monthly payments of $1.0 million and a balloon payment of $11.6 million upon maturity on November 6, 2023. Upon maturity, the equipment will revert to the Intermediate Partnership. ​ June 2020 Equipment Financing. customary terms and events of default and provides for forty-eight monthly payments with an implicit interest rate of 6.1% , maturing on June 5, 2024. Upon maturity, the equipment will revert to the Intermediate Partnership.

INCOME TAXES

INCOME TAXES	6 Months Ended
	Jun. 30, 2022
INCOME TAXES
INCOME TAXES	7. INCOME TAXES ​ Components of income tax expense (benefit) are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Current: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 6,175 ​ $ — ​ $ 11,209 ​ $ (1) ​ State ​ 445 ​ — ​ 831 ​ — ​ ​ ​ 6,620 ​ — ​ 12,040 ​ (1) ​ Deferred: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ (255) ​ 5 ​ 34,665 ​ (6) ​ State ​ (34) ​ — ​ 2,341 ​ — ​ ​ ​ (289) ​ 5 ​ 37,006 ​ (6) ​ Income tax expense (benefit) ​ $ 6,331 ​ $ 5 ​ $ 49,046 ​ $ (7) ​ ​ Alliance Minerals' Tax Election resulted in the recognition of an initial deferred tax liability of $37.3 million and a corresponding increase to income tax expense for the six months ended June 30, 2022. This increase in income tax expense reduced net income by $37.3 million, or approximately $0.29 per basic and diluted limited partner unit, for the six months ended June 30, 2022. Recognition of the initial deferred tax liability and expense is primarily the result of the $177.0 million non-cash acquisition gain recognized in 2019 related to the acquisition of the remaining interests in AllDale Minerals LP ("AllDale I") and AllDale Minerals II, LP ("AllDale II", and collectively with AllDale I, "AllDale I & II") (the “Acquisition Gain”). The Acquisition Gain was recognized to step up to fair value the financial reporting basis of the interests we already owned at the time of acquisition. The tax basis of the underlying properties of AllDale I & II did not include the Acquisition Gain. ​ Reconciliations of income taxes at the U.S. federal statutory tax rate to income taxes at our effective tax rate are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Income taxes at statutory rate ​ $ 30,738 ​ $ 9,276 ​ $ 47,466 ​ $ 14,487 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: Income taxes at statutory rate on Partnership income not subject to income taxes ​ (25,018) ​ (9,141) ​ (37,105) ​ (14,174) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase (decrease) resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ State taxes, net of federal income tax ​ 457 ​ 34 ​ 818 ​ 72 ​ Change in valuation allowance of deferred tax assets ​ 11 ​ (142) ​ 1 ​ (305) ​ Deferred taxes related to tax election ​ ​ — ​ ​ — ​ ​ 37,253 ​ ​ — ​ Other ​ 143 ​ (22) ​ 613 ​ (87) ​ Income tax expense (benefit) ​ $ 6,331 ​ $ 5 ​ $ 49,046 ​ $ (7) ​ ​ The effective income tax rate for our income tax expense for the three months ended June 30, 2022 is less than the federal statutory rate, primarily due to the portion of income not subject to income taxes, partially offset by the effect of the Tax Election previously discussed. The effective income tax rate for our income tax expense for the six months ended June 30, 2022 is greater than the federal statutory rate, primarily due to the effect of the Tax Election, partially offset by the portion of income not subject to income taxes. The effective income tax rate for our income tax expense (benefit) for the three and six months ended June 30, 2021 is less than the federal statutory rate, primarily due to the portion of income not subject to income taxes. ​ Significant components of deferred tax liabilities and deferred tax assets are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ 2022 2021 ​ ​ (in thousands) ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ $ (38,710) ​ $ (2,169) ​ Total deferred tax liabilities ​ ​ (38,710) ​ ​ (2,169) ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ Federal loss carryovers and credits ​ ​ 933 ​ ​ 1,328 ​ Other ​ 764 ​ 808 ​ Total deferred tax assets ​ ​ 1,697 ​ ​ 2,136 ​ Less valuation allowance ​ ​ (318) ​ ​ (317) ​ Net deferred tax assets ​ ​ 1,379 ​ ​ 1,819 ​ ​ ​ ​ ​ ​ ​ ​ ​ Overall net deferred tax liabilities ​ $ (37,331) ​ $ (350) ​ ​ The change in deferred tax liabilities for property, plant and equipment is primarily as a result of the Alliance Minerals’ Tax Election and associated impact of the Acquisition Gain discussed above. ​ Federal loss carryovers and credits are primarily due to net operating losses and research and development credits associated with the operations of other subsidiaries that are taxable for federal income tax purposes. ​ The valuation allowance as of June 30, 2022 and 2021 serves to reduce the available deferred tax assets to amounts that will, more likely than not, be realized. We considered all available positive and negative evidence, which incorporates available tax planning strategies and our estimate of future reversals of existing temporary differences, and have determined that a portion of our deferred tax assets relating to state losses and credits may not be realized. ​ Our 2018 through 2021 tax years remain open to examination by tax authorities.

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES	6 Months Ended
	Jun. 30, 2022
VARIABLE INTEREST ENTITIES
VARIABLE INTEREST ENTITIES	8. VARIABLE INTEREST ENTITIES ​ Cavalier Minerals ​ On November 10, 2014, our subsidiary, Alliance Minerals, and Bluegrass Minerals Management, LLC ("Bluegrass Minerals") entered into a limited liability company agreement (the "Cavalier Agreement") to create Cavalier Minerals JV, LLC ("Cavalier Minerals"), which was formed to indirectly acquire oil & gas mineral interests through its ownership in AllDale I & II. Alliance Minerals owns a 96% member interest in Cavalier Minerals, and Bluegrass Minerals owns a 4% member interest in Cavalier Minerals and a profits interest which entitles it to receive distributions equal to 25% of all distributions (including in liquidation) after all members have recovered their investment. Distributions with respect to Bluegrass Minerals' profits interest will be offset by all distributions received by Bluegrass Minerals from the former general partners of AllDale I & II. To date, there has been no profits interest distribution. We hold the managing member interest in Cavalier Minerals. Total contributions to and cumulative distributions from Cavalier Minerals are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Alliance ​ Bluegrass ​ ​ ​ Minerals ​ Minerals ​ ​ ​ (in thousands) ​ Contributions ​ $ 143,112 ​ $ 5,963 ​ Distributions ​ ​ 124,945 ​ ​ 5,205 ​ ​ We have concluded that Cavalier Minerals is a variable interest entity ("VIE") which we consolidate as the primary beneficiary because we are the managing member and a substantial equity owner in Cavalier Minerals. Bluegrass Minerals' equity ownership of Cavalier Minerals is accounted for as noncontrolling ownership interest in our condensed consolidated balance sheets. In addition, earnings attributable to Bluegrass Minerals are recognized as noncontrolling interest in our condensed consolidated statements of income. ​ AllDale III ​ In February 2017, Alliance Minerals committed to directly invest $30.0 million in AllDale Minerals III, LP ("AllDale III") which was created for similar investment purposes as AllDale I & II. Alliance Minerals completed funding of this commitment in 2018. ​ The AllDale III Partnership Agreement includes a 25% profits interest for the general partner, subject to a return hurdle equal to the greater of 125% of cumulative capital contributions and a 10% internal rate of return, and following an 80/20 "catch-up" provision for the general partner. ​ Since AllDale III is structured as a limited partnership with the limited partners (i) not having the ability to remove the general partner and (ii) not participating significantly in the operational decisions, we concluded that AllDale III is a VIE. ​ Francis ​ On April 5, 2022, we committed to invest up to $50 million in Francis through the purchase of preferred equity interests. We funded the first $20 million on April 5, 2022, in the form of a convertible note with a maturity date of April 1, 2023. Our convertible note represents a 15.4% ownership interest in Francis. The note converts into preferred equity interests in Francis at maturity, or any time prior at our option. We have determined the note more closely represents equity as opposed to debt. Therefore, we will account for the convertible note as an equity contribution even though we will not participate in Francis’ earnings or losses and will not be eligible to receive distributions until the note converts. We have options to acquire the remaining preferred equity interests as part of our investment. ​ We have concluded that Francis is a VIE as the management structure is similar to a limited partnership with the non-managing members (i) not having the ability to remove the managing member and (ii) not participating significantly in the operational decisions. We are not the primary beneficiary of Francis as we do not have the power to direct the activities that most significantly impact Francis's economic performance. We account for our ownership interest in the income or loss of Francis as an equity method investment. We record equity income or loss based on Francis’ distribution structure. See Note 9 – Investments for more information. ​ NGP ETP IV ​ On June 2, 2022, we committed to purchase $25.0 million of limited partner interests in NGP ETP IV, a private equity fund sponsored by NGP and focused on investments that are part of the global transition toward a lower carbon economy. We funded $0.1 million on June 21, 2022. Our final ownership percentage in NGP ETP IV is not yet known. ​

INVESTMENTS

INVESTMENTS	6 Months Ended
	Jun. 30, 2022
INVESTMENTS
INVESTMENTS	9. INVESTMENT S ​ AllDale III ​ As discussed in Note 8 – Variable Interest Entities, we account for our ownership interest in the income or loss of AllDale III as an equity method investment. The changes in our equity method investment in AllDale III for each of the periods presented were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2022 2021 2022 2021 ​ ​ ​ (in thousands) ​ Beginning balance ​ $ 26,194 ​ $ 26,907 ​ $ 26,325 ​ $ 27,268 ​ Equity method investment income ​ ​ 1,585 ​ ​ 341 ​ ​ 2,468 ​ ​ 403 ​ Distributions received ​ ​ (1,501) ​ ​ (974) ​ ​ (2,515) ​ ​ (1,397) ​ Ending balance ​ $ 26,278 ​ $ 26,274 ​ $ 26,278 ​ $ 26,274 ​ ​ Francis ​ As discussed in Note 8 – Variable Interest Entities, we accounted for our ownership interest in the income or loss of Francis as an equity method investment. The changes in our equity method investment in Francis for three months ended June 30, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ June 30, ​ ​ 2022 ​ ​ (in thousands) ​ Beginning balance ​ $ — ​ Contributions ​ ​ 20,000 ​ Ending balance ​ $ 20,000 ​ ​ NGP ETP IV ​ As discussed in Note 8 – Variable Interest Entities, we account for our ownership interest in the income or loss of NGP ETP IV as an equity method investment. The changes in our equity method investment in NGP ETP IV for three months ended June 30, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ June 30, ​ ​ 2022 ​ ​ ​ (in thousands) ​ Beginning balance ​ $ — ​ Contributions ​ ​ 110 ​ Ending balance ​ $ 110 ​ ​ Infinitum ​ On April 29, 2022, we purchased $32.6 million of Series D Preferred Stock from Infinitum, a Texas-based startup developer and manufacturer of electric motors featuring printed circuit board stators. The preferred stock provides for non-cumulative dividends when and if declared by Infinitum’s board of directors. Each share is convertible, at any time, at our option, into shares of common stock of Infinitum. We account for our ownership interest in Infinitum as an equity investment without a readily determinable fair value. It is not practicable to estimate the fair value of our investment in Infinitum because of the lack of a quoted market price for our ownership interests. Therefore, we use a measurement alternative other than fair value to account for our investment. There were no changes in our investment in Infinitum for three months ended June 30, 2022.

PARTNERS' CAPITAL

PARTNERS' CAPITAL	6 Months Ended
	Jun. 30, 2022
PARTNERS' CAPITAL
PARTNERS' CAPITAL	10. PARTNERS' CAPITAL ​ Distributions ​ Distributions paid or declared during 2021 and 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Payment Date Per Unit Cash Distribution Total Cash Distribution ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ May 14, 2021 ​ $ 0.1000 ​ $ 13,045 ​ August 13, 2021 ​ ​ 0.1000 ​ ​ 13,041 ​ November 12, 2021 ​ ​ 0.2000 ​ ​ 26,072 ​ Total ​ $ 0.4000 ​ $ 52,158 ​ ​ ​ ​ ​ ​ ​ ​ ​ February 14, 2022 ​ $ 0.2500 ​ $ 32,750 ​ May 13, 2022 ​ ​ 0.3500 ​ ​ 45,810 ​ August 12, 2022 (1) ​ ​ 0.4000 ​ ​ — ​ Total ​ $ 1.0000 ​ $ 78,560 ​ (1) On July 26, 2022, we declared this quarterly distribution payable on August 12, 2022 to all unitholders of record as of August 5, 2022. ​ Unit Repurchase Program ​ In May 2018, the MGP board of directors approved the establishment of a unit repurchase program authorizing us to repurchase and retire up to $100 million of ARLP common units. The program has no time limit and we may repurchase units from time to time in the open market or in other privately negotiated transactions. The unit repurchase program authorization does not obligate us to repurchase any dollar amount or number of units. No unit repurchases were made during the six months ended June 30, 2022. Since inception of the unit repurchase program, we have repurchased and retired 5,460,639 units at an average unit price of $17.12 for an aggregate purchase price of $93.5 million. ​ Change in Partners' Capital ​ The following tables present the quarterly change in Partners' Capital for the six months ended June 30, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Limited ​ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ Limited Partner ​ Partners' ​ Comprehensive ​ Noncontrolling ​ Total Partners' ​ ​ Units Capital Income (Loss) Interest Capital ​ ​ (in thousands, except unit data) ​ Balance at January 1, 2022 127,195,219 ​ $ 1,279,183 ​ $ (64,229) ​ $ 11,115 ​ $ 1,226,069 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 36,652 ​ — ​ ​ 290 36,942 ​ Actuarially determined long-term liability adjustments — ​ — ​ 790 ​ — 790 ​ Total comprehensive income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 37,732 ​ Common unit-based compensation — ​ 2,640 ​ ​ — ​ ​ — ​ ​ 2,640 ​ Distributions on deferred common unit-based compensation — ​ (950) ​ ​ — ​ ​ — ​ ​ (950) ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (298) ​ ​ (298) ​ Distributions to Partners — ​ ​ (31,800) ​ ​ — ​ ​ — ​ ​ (31,800) ​ Balance at March 31, 2022 ​ 127,195,219 ​ ​ 1,285,725 ​ ​ (63,439) ​ ​ 11,107 ​ ​ 1,233,393 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 161,478 ​ — ​ ​ 323 161,801 ​ Actuarially determined long-term liability adjustments — ​ — ​ 794 ​ — 794 ​ Total comprehensive income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 162,595 ​ Common unit-based compensation — ​ 2,340 ​ ​ — ​ ​ — ​ ​ 2,340 ​ Distributions on deferred common unit-based compensation — ​ (1,292) ​ ​ — ​ ​ — ​ ​ (1,292) ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (325) ​ ​ (325) ​ Distributions to Partners — ​ ​ (44,518) ​ ​ — ​ ​ — ​ ​ (44,518) ​ Balance at June 30, 2022 ​ 127,195,219 ​ $ 1,403,733 ​ $ (62,645) ​ $ 11,105 ​ $ 1,352,193 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Limited ​ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ Limited Partner ​ Partners' ​ Comprehensive ​ Noncontrolling ​ Total Partners' ​ ​ Units Capital Income (Loss) Interest Capital ​ ​ (in thousands, except unit data) ​ Balance at January 1, 2021 127,195,219 ​ $ 1,148,565 ​ $ (87,674) ​ $ 11,376 ​ $ 1,072,267 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 24,748 ​ — ​ ​ 78 24,826 ​ Actuarially determined long-term liability adjustments — ​ — ​ 2,231 ​ — 2,231 ​ Total comprehensive income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 27,057 ​ Common unit-based compensation — ​ 723 ​ ​ — ​ ​ — ​ ​ 723 ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (141) ​ ​ (141) ​ Balance at March 31, 2021 127,195,219 ​ ​ 1,174,036 ​ ​ (85,443) ​ ​ 11,313 ​ ​ 1,099,906 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 44,035 ​ — ​ ​ 130 44,165 ​ Actuarially determined long-term liability adjustments — ​ — ​ 2,231 ​ — 2,231 ​ Total comprehensive loss ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 46,396 ​ Common unit-based compensation — ​ 1,485 ​ ​ — ​ ​ — ​ ​ 1,485 ​ Distributions on deferred common unit-based compensation — ​ (324) ​ ​ — ​ ​ — ​ ​ (324) ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (222) ​ ​ (222) ​ Distributions to Partners — ​ ​ (12,721) ​ ​ — ​ ​ — ​ ​ (12,721) ​ Balance at June 30, 2021 127,195,219 ​ $ 1,206,511 ​ $ (83,212) ​ $ 11,221 ​ $ 1,134,520 ​ ​

REVENUE FROM CONTRACTS WITH CUS

REVENUE FROM CONTRACTS WITH CUSTOMERS	6 Months Ended
	Jun. 30, 2022
REVENUE FROM CONTRACTS WITH CUSTOMERS
REVENUE FROM CONTRACTS WITH CUSTOMERS	11. REVENUE FROM CONTRACTS WITH CUSTOMERS ​ The following table illustrates the disaggregation of our revenues by type, including a reconciliation to our segment presentation as presented in Note 16 – Segment Information. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal Operations ​ Royalties ​ Other, ​ ​ ​ ​ ​ ​ Illinois ​ ​ ​ ​ Corporate and ​ ​ ​ ​ Basin Appalachia Oil & Gas Coal Elimination Consolidated ​ ​ ​ (in thousands) ​ Three Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 290,389 ​ $ 241,418 ​ $ — ​ $ — ​ $ — ​ $ 531,807 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 35,927 ​ ​ — ​ ​ — ​ ​ 35,927 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 14,525 ​ ​ (14,525) ​ ​ — ​ Transportation revenues ​ ​ 21,449 ​ ​ 13,936 ​ ​ — ​ ​ — ​ ​ — ​ ​ 35,385 ​ Other revenues ​ ​ 1,659 ​ ​ 328 ​ ​ 652 ​ ​ — ​ ​ 10,743 ​ ​ 13,382 ​ Total revenues ​ $ 313,497 ​ $ 255,682 ​ $ 36,579 ​ $ 14,525 ​ $ (3,782) ​ $ 616,501 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 210,157 ​ $ 115,817 ​ $ — ​ $ — ​ $ — ​ $ 325,974 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 17,114 ​ ​ — ​ ​ — ​ ​ 17,114 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 11,653 ​ ​ (11,653) ​ ​ — ​ Transportation revenues ​ ​ 7,434 ​ ​ 4,624 ​ ​ — ​ ​ — ​ ​ — ​ ​ 12,058 ​ Other revenues ​ ​ 642 ​ ​ 282 ​ ​ 473 ​ ​ — ​ ​ 5,900 ​ ​ 7,297 ​ Total revenues ​ $ 218,233 ​ $ 120,723 ​ $ 17,587 ​ $ 11,653 ​ $ (5,753) ​ $ 362,443 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 544,294 ​ $ 375,873 ​ $ — ​ $ — ​ $ — ​ $ 920,167 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 66,854 ​ ​ — ​ ​ — ​ ​ 66,854 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 29,692 ​ ​ (29,692) ​ ​ — ​ Transportation revenues ​ ​ 40,340 ​ ​ 24,417 ​ ​ — ​ ​ — ​ ​ — ​ ​ 64,757 ​ Other revenues ​ ​ 3,559 ​ ​ 691 ​ ​ 686 ​ ​ — ​ ​ 20,650 ​ ​ 25,586 ​ Total revenues ​ $ 588,193 ​ $ 400,981 ​ $ 67,540 ​ $ 29,692 ​ $ (9,042) ​ $ 1,077,364 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 392,798 ​ $ 220,663 ​ $ — ​ $ — ​ $ — ​ $ 613,461 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 31,113 ​ ​ — ​ ​ — ​ ​ 31,113 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 22,954 ​ ​ (22,954) ​ ​ — ​ Transportation revenues ​ ​ 15,114 ​ ​ 8,012 ​ ​ — ​ ​ — ​ ​ — ​ ​ 23,126 ​ Other revenues ​ ​ 1,255 ​ ​ 667 ​ ​ 494 ​ ​ — ​ ​ 10,949 ​ ​ 13,365 ​ Total revenues ​ $ 409,167 ​ $ 229,342 ​ $ 31,607 ​ $ 22,954 ​ $ (12,005) ​ $ 681,065 ​ ​ The following table illustrates the amount of our transaction price for all current coal supply contracts allocated to performance obligations that are unsatisfied or partially unsatisfied as of June 30, 2022 and disaggregated by segment and contract duration. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2025 and ​ ​ ​ 2022 2023 2024 Thereafter Total ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations coal revenues ​ $ 650,837 ​ $ 729,307 ​ $ 361,381 ​ $ 290,746 ​ $ 2,032,271 Appalachia Coal Operations coal revenues ​ ​ 381,828 ​ ​ 335,595 ​ ​ 236,536 ​ ​ 40,701 ​ ​ 994,660 Total coal revenues (1) ​ $ 1,032,665 ​ $ 1,064,902 ​ $ 597,917 ​ $ 331,447 ​ $ 3,026,931 (1) Coal revenues generally consists of consolidated revenues excluding our Oil & Gas Royalties segment as well as intercompany revenues from our Coal Royalties segment .

EARNINGS PER LIMITED PARTNER UN

EARNINGS PER LIMITED PARTNER UNIT	6 Months Ended
	Jun. 30, 2022
EARNINGS PER LIMITED PARTNER UNIT
EARNINGS PER LIMITED PARTNER UNIT	12. EARNINGS PER LIMITED PARTNER UNIT ​ We utilize the two-class method in calculating basic and diluted earnings per limited partner unit ("EPU"). Net income attributable to ARLP is allocated to limited partners and participating securities under deferred compensation plans, which include rights to nonforfeitable distributions or distribution equivalents. Net losses attributable to ARLP are allocated to limited partners but not to participating securities. Our participating securities are outstanding restricted unit awards under our Long-Term Incentive Plan ("LTIP") and phantom units in notional accounts under our Supplemental Executive Retirement Plan ("SERP") and the MGP Amended and Restated Deferred Compensation Plan for Directors ("Directors' Deferred Compensation Plan"). ​ The following is a reconciliation of net income attributable to ARLP used for calculating basic and diluted earnings per unit and the weighted-average units used in computing EPU for the three and six months ended June 30, 2022 and 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands, except per unit data) ​ Net income attributable to ARLP ​ $ 161,478 ​ $ 44,035 ​ $ 198,130 ​ $ 68,783 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Distributions to participating securities ​ (1,720) ​ (401) ​ (3,272) ​ (619) ​ Undistributed earnings attributable to participating securities ​ (3,645) ​ (825) ​ (3,245) ​ (934) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income attributable to ARLP available to limited partners ​ $ 156,113 ​ $ 42,809 ​ $ 191,613 ​ $ 67,230 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average limited partner units outstanding – basic and diluted ​ 127,195 ​ 127,195 ​ 127,195 ​ 127,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Earnings per limited partner unit - basic and diluted (1) ​ $ 1.23 ​ $ 0.34 ​ $ 1.51 ​ $ 0.53 ​ (1) Diluted EPU gives effect to all potentially dilutive common units outstanding during the period using the treasury stock method. Diluted EPU excludes all potentially dilutive units calculated under the treasury stock method if their effect is anti-dilutive. The combined total of LTIP, SERP and Directors' Deferred Compensation Plan units of 3,529 and 3,289 for the three and six months ended June 30, 2022, respectively, and 1,525 and 1,397 for the three and six months ended June 30, 2021 , respectively, were considered anti-dilutive under the treasury stock method .

WORKERS' COMPENSATION AND PNEUM

WORKERS' COMPENSATION AND PNEUMOCONIOSIS	6 Months Ended
	Jun. 30, 2022
WORKERS' COMPENSATION AND PNEUMOCONIOSIS
WORKERS' COMPENSATION AND PNEUMOCONIOSIS	13. WORKERS' COMPENSATION AND PNEUMOCONIOSIS ​ The changes in the workers' compensation liability, including current and long-term liability balances, for each of the periods presented were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ ​ (in thousands) ​ Beginning balance ​ $ 53,206 ​ $ 54,233 ​ $ 53,448 ​ $ 54,739 ​ Accruals increase ​ 2,271 ​ 1,565 ​ 4,546 ​ 3,237 ​ Payments ​ (3,278) ​ (2,565) ​ (6,082) ​ (4,975) ​ Interest accretion ​ 287 ​ 231 ​ 574 ​ 463 ​ Valuation gain (1) ​ (5,265) ​ (1,405) ​ (5,265) ​ (1,405) ​ Ending balance ​ $ 47,221 ​ $ 52,059 ​ $ 47,221 ​ $ 52,059 ​ (1) Our estimate of the liability for the present value of current workers′ compensation benefits is based on our actuarial calculations. Our actuarial calculations are based on a blend of actuarial projection methods and numerous assumptions including claims development patterns, mortality, medical costs and interest rates. The valuation gain in 2022 is due to an increase in the discount rate from 2.41% on December 31, 2021 to 4.22% on June 30, 202 2 . The valuation gain in 2021 is due to an increase in the discount rate from 1.95% on December 31, 2020 to 2.34% on June 30, 202 1 . ​ We limit our exposure to traumatic injury claims by purchasing a high deductible insurance policy that starts paying benefits after deductibles for a claim have been met. The deductible level may vary by claim year. Our workers' compensation liability above is presented on a gross basis and does not include our expected receivables on our insurance policy. Our receivables for traumatic injury claims under this policy as of June 30, 2022 are $5.7 million and are included in Other long-term assets ​ Certain of our mine operating entities are liable under state statutes and the Federal Coal Mine Health and Safety Act of 1969, as amended, to pay pneumoconiosis, or black lung, benefits to eligible employees and former employees and their dependents. Components of the net periodic benefit cost for each of the periods presented are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Service cost ​ $ 954 ​ $ 989 ​ $ 1,901 ​ $ 2,020 Interest cost (1) ​ 749 ​ 637 ​ 1,496 ​ 1,273 ​ Net amortization (1) ​ 259 ​ 1,043 ​ 519 ​ 2,086 ​ Net periodic benefit cost ​ $ 1,962 ​ $ 2,669 ​ $ 3,916 ​ $ 5,379 ​ (1) Interest cost and net amortization are included in the Other income (expense) line item within our condensed consolidated statements of income.

COMMON UNIT-BASED COMPENSATION

COMMON UNIT-BASED COMPENSATION PLANS	6 Months Ended
	Jun. 30, 2022
COMMON UNIT-BASED COMPENSATION PLANS
COMMON UNIT-BASED COMPENSATION PLANS	14. COMMON UNIT-BASED COMPENSATION PLANS ​ Long-Term Incentive Plan ​ We maintain the LTIP for certain employees and officers of MGP and its affiliates who perform services for us. As part of our LTIP, unit awards of non-vested "phantom" or notional units, also referred to as "restricted units", may be granted which upon satisfaction of time and performance-based vesting requirements, entitle the LTIP participant to receive ARLP common units. Certain awards may also contain a minimum-value guarantee payable in ARLP common units or cash that would be paid regardless of whether or not the awards vest, as long as service requirements are met. Annual grant levels, vesting provisions and minimum-value guarantees of restricted units for designated participants are recommended by Mr. Craft, subject to review and approval of the compensation committee of the MGP board of directors (the "Compensation Committee"). Vesting of all restricted units outstanding is subject to the satisfaction of certain financial tests. If it is not probable the financial tests for a particular grant of restricted units will be met, any previously expensed amounts for that grant are reversed and no future expense will be recognized for that grant. Assuming the financial tests are met, grants of restricted units issued to LTIP participants are generally expected to cliff vest on January 1st of the third year following issuance of the grants. We expect to settle restricted unit grants by delivery of newly-issued ARLP common units, except for the portion of the grants that will satisfy employee tax withholding obligations of LTIP participants. We account for forfeitures of non-vested LTIP restricted unit grants as they occur. As provided under the distribution equivalent rights ("DERs") provisions of the LTIP and the terms of the LTIP restricted unit awards, all non-vested restricted units include contingent rights to receive quarterly distributions in cash or, at the discretion of the Compensation Committee, phantom units in lieu of cash credited to a bookkeeping account with value equal to the cash distributions we make to unitholders during the vesting period. If it is not probable the financial tests for a particular grant of restricted units will be met, any previously paid DER amounts for that grant are reversed from Partners’ Capital and recorded as compensation expense and future DERs for that grant, if any, will be recognized as compensation expense when paid. ​ A summary of non-vested LTIP grants as of and for the six months ended June 30, 2022 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of units Weighted average grant date fair value per unit Intrinsic value ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-vested grants at January 1, 2022 ​ 3,130,475 ​ $ 5.59 ​ $ 39,569 ​ Granted (1) 687,719 ​ ​ 13.34 ​ ​ ​ ​ Forfeited (165,224) ​ 6.72 ​ ​ ​ ​ Non-vested grants at June 30, 2022 3,652,970 ​ 7.00 ​ ​ 66,594 ​ (1) The restricted units granted during 2022 have minimum-value guarantees of either $9.62 or $6.41 per unit, regardless of whether or not the awards vest. ​ LTIP expense for grants of restricted units was $2.1 million and $ 1.4 million for the three months ended June 30, 2022 and 2021, respectively, and $4.4 million and $2.1 million for the six months ended June 30, 2022 and 2021, respectively. The total obligation associated with LTIP grants of restricted units as of June 30, 2022 was $ 11.0 million and is included in the partners' capital Limited partners-common unitholders line item in our condensed consolidated balance sheets. As of June 30, 2022, there was $14.5 million in total unrecognized compensation expense related to the non-vested LTIP restricted unit grants that are expected to vest. That expense is expected to be recognized over a weighted-average period of 1.3 years. ​ Supplemental Executive Retirement Plan and Directors' Deferred Compensation Plan ​ We utilize the SERP to provide deferred compensation benefits for certain officers and key employees. All allocations made to participants under the SERP are made in the form of "phantom" ARLP units and SERP distributions will be settled in the form of ARLP common units. The SERP is administered by the Compensation Committee. ​ Our directors participate in the Directors' Deferred Compensation Plan. Pursuant to the Directors' Deferred Compensation Plan, for amounts deferred either automatically or at the election of the director, a notional account is established and credited with notional common units of ARLP, described in the Directors' Deferred Compensation Plan as "phantom" units. Distributions from the Directors' Deferred Compensation Plan will be settled in the form of ARLP common units. ​ For both the SERP and Directors' Deferred Compensation Plan, when quarterly cash distributions are made with respect to ARLP common units, an amount equal to such quarterly distribution is credited to each participant's notional account as additional phantom units. All grants of phantom units under the SERP and Directors' Deferred Compensation Plan vest immediately. ​ A summary of SERP and Directors' Deferred Compensation Plan activity as of and for the six months ended June 30, 2022 is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of units Weighted average grant date fair value per unit Intrinsic value ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Phantom units outstanding as of January 1, 2022 ​ 668,698 ​ $ 20.37 ​ $ 8,452 ​ Granted ​ 25,359 ​ ​ 15.80 ​ ​ ​ ​ Phantom units outstanding as of June 30, 2022 694,057 ​ 20.20 ​ ​ 12,653 ​ ​ Total SERP and Directors' Deferred Compensation Plan expense was $0.3 million and $0.1 million for the three months ended June 30, 2022 and 2021, respectively, and $0.6 million and $0.2 million for the six months ended June 30, 2022 and 2021, respectively. As of June 30, 2022, the total obligation associated with the SERP and Directors' Deferred Compensation Plan was $14.0 million and is included in the partners' capital Limited partners-common unitholders

COMPONENTS OF PENSION PLAN NET

COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS	6 Months Ended
	Jun. 30, 2022
COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS
COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS	15. COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS ​ Eligible employees at certain of our mining operations participate in a defined benefit plan (the "Pension Plan") that we sponsor. The Pension Plan is currently closed to new applicants and participants in the Pension Plan are no longer receiving benefit accruals for service. The benefit formula for the Pension Plan is a fixed dollar unit based on years of service. Components of the net periodic benefit cost for each of the periods presented are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Interest cost ​ $ 936 ​ $ 860 ​ $ 1,868 ​ $ 1,720 ​ Expected return on plan assets ​ (1,664) ​ (1,671) ​ (3,329) ​ (3,342) ​ Amortization of prior service cost ​ ​ 46 ​ ​ 46 ​ ​ 93 ​ ​ 93 ​ Amortization of net loss ​ 489 ​ 1,142 ​ 972 ​ 2,283 ​ Net periodic benefit cost (1) ​ $ (193) ​ $ 377 ​ $ (396) ​ $ 754 ​ (1) Net periodic benefit cost for the Pension Plan is included in the Other income (expense) line item within our condensed consolidated statements of income. ​ As a result of certain pension plan contribution relief provided by the American Rescue Plan Act enacted in March 2021, we do not expect to make contributions to the Pension Plan during 2022.

SEGMENT INFORMATION

SEGMENT INFORMATION	6 Months Ended
	Jun. 30, 2022
SEGMENT INFORMATION
SEGMENT INFORMATION	16. SEGMENT INFORMATION ​ We operate in the United States as a diversified natural resource company that generates operating and royalty income from the production and marketing of coal to major domestic and international utilities and industrial users as well as royalty income from oil & gas mineral interests. We aggregate multiple operating segments into four reportable segments, Illinois Basin Coal Operations, Appalachia Coal Operations, Oil & Gas Royalties and Coal Royalties. We also have an "all other" category referred to as Other, Corporate and Elimination. Our two coal operations reportable segments correspond to major coal producing regions in the eastern United States with similar economic characteristics including coal quality, geology, coal marketing opportunities, mining and transportation methods and regulatory issues. The two coal operations reportable segments include seven mining complexes operating in Illinois, Indiana, Kentucky, Maryland, Pennsylvania and West Virginia and a coal-loading terminal in Indiana on the Ohio River. Our Oil & Gas Royalties reportable segment includes our oil & gas mineral interests which are located primarily in the Permian (Delaware and Midland), Anadarko (SCOOP/STACK) and Williston (Bakken) basins. The operations within our Oil & Gas Royalties reportable segment primarily include receiving royalties and lease bonuses for our oil & gas mineral interests. Our Coal Royalties reportable segment includes coal mineral reserves and resources owned or leased by Alliance Resource Properties, which are either (a) leased to our mining complexes or (b) near our coal mining operations but not yet leased. ​ The Illinois Basin Coal Operations reportable segment includes operating mining complexes (a) the Gibson County Coal, LLC mining complex, (b) the Warrior Coal, LLC mining complex, (c) the River View Coal, LLC mining complex and (d) the Hamilton County Coal, LLC mining complex. The segment also includes our Mt. Vernon Transfer Terminal, LLC coal-loading terminal in Indiana which operates on the Ohio River, Mid-America Carbonates, LLC and other support services, and our non-operating Illinois Basin mining complexes. ​ The Appalachia Coal Operations reportable segment includes operating mining complexes (a) the Mettiki mining complex, (b) the Tunnel Ridge, LLC mining complex and (c) the MC Mining, LLC mining complex. The Mettiki mining complex includes Mettiki Coal (WV), LLC's Mountain View mine and Mettiki Coal, LLC's preparation plant. ​ The Oil & Gas Royalties reportable segment includes oil & gas mineral interests held by AR Midland, LP ("AR Midland") and AllDale I & II and includes Alliance Minerals' equity interests in both AllDale III (Note 9 – Investments) and Cavalier Minerals. ​ The Coal Royalties reportable segment includes coal mineral reserves and resources owned or leased by Alliance Resource Properties that are (a) leased to certain of our mining complexes in both the Illinois Basin Coal Operations and Appalachia Coal Operations reportable segments or (b) located near our operations and external mining operations. Approximately two thirds of the coal sold by our Coal Operations' mines is leased from our Coal Royalties entities. ​ Other, Corporate and Elimination includes marketing and administrative activities, Matrix Design Group, LLC, its subsidiaries, and Alliance Design Group, LLC (collectively referred to as the "Matrix Group"), our investments in Francis, Infinitum and NGP ETP IV (see Note 9 – Investments), Wildcat Insurance, LLC, which assists the ARLP Partnership with its insurance requirements, AROP Funding and Alliance Finance (both discussed in Note 6 – Long-Term Debt), Pontiki Coal, LLC's workers' compensation and pneumoconiosis liabilities and other miscellaneous activities. The eliminations included in Other, Corporate and Elimination primarily represent the intercompany coal royalty transactions described above between our Coal Royalties reportable segment and our coal operations' mines. ​ Reportable segment results are presented below. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal Operations ​ Royalties ​ Other, ​ ​ ​ ​ ​ Illinois ​ ​ ​ ​ ​ Corporate and ​ ​ ​ ​ Basin Appalachia Oil & Gas Coal ​ Elimination Consolidated ​ ​ (in thousands) Three Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 313,497 ​ $ 255,682 ​ $ 36,579 ​ $ — ​ $ 10,743 ​ $ 616,501 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 14,525 ​ ​ (14,525) ​ ​ — ​ Total revenues (1) ​ ​ 313,497 ​ ​ 255,682 ​ ​ 36,579 ​ ​ 14,525 ​ ​ (3,782) ​ ​ 616,501 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 194,697 ​ 117,369 ​ 3,234 ​ 5,398 ​ (4,624) ​ 316,074 ​ Segment Adjusted EBITDA (3) ​ 97,352 ​ 124,377 ​ 34,609 ​ 9,127 ​ 839 ​ 266,304 ​ Capital expenditures ​ 35,343 ​ 22,491 ​ — ​ — ​ 4,995 ​ 62,829 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 218,233 ​ $ 120,723 ​ $ 17,587 ​ $ — ​ $ 5,900 ​ $ 362,443 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 11,653 ​ ​ (11,653) ​ ​ — ​ Total revenues (1) ​ ​ 218,233 ​ ​ 120,723 ​ ​ 17,587 ​ ​ 11,653 ​ ​ (5,753) ​ ​ 362,443 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 140,176 ​ 74,456 ​ 2,419 ​ 4,871 ​ (7,418) ​ 214,504 ​ Segment Adjusted EBITDA (3) ​ 70,623 ​ 41,641 ​ 15,379 ​ 6,782 ​ 1,667 ​ 136,092 ​ Capital expenditures ​ 12,515 ​ 10,382 ​ — ​ — ​ 1,292 ​ 24,189 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 588,193 ​ $ 400,981 ​ $ 67,540 ​ $ — ​ $ 20,650 ​ $ 1,077,364 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 29,692 ​ ​ (29,692) ​ ​ — ​ Total revenues (1) ​ ​ 588,193 ​ ​ 400,981 ​ ​ 67,540 ​ ​ 29,692 ​ ​ (9,042) ​ ​ 1,077,364 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 372,286 ​ ​ 201,084 ​ ​ 6,235 ​ ​ 10,217 ​ ​ (12,568) ​ 577,254 ​ Segment Adjusted EBITDA (3) ​ 175,567 ​ ​ 175,480 ​ ​ 63,161 ​ ​ 19,475 ​ ​ 3,525 ​ 437,208 ​ Total assets ​ 748,291 ​ ​ 457,724 ​ ​ 667,278 ​ ​ 288,509 ​ ​ 171,389 ​ 2,333,191 ​ Capital expenditures ​ 71,890 ​ ​ 40,836 ​ ​ — ​ ​ — ​ ​ 9,256 ​ 121,982 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 409,167 ​ $ 229,342 ​ $ 31,607 ​ $ — ​ $ 10,949 ​ $ 681,065 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 22,954 ​ ​ (22,954) ​ ​ — ​ Total revenues (1) ​ ​ 409,167 ​ ​ 229,342 ​ ​ 31,607 ​ ​ 22,954 ​ ​ (12,005) ​ ​ 681,065 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 265,757 ​ ​ 148,182 ​ ​ 4,477 ​ ​ 8,899 ​ ​ (15,094) ​ 412,221 ​ Segment Adjusted EBITDA (3) ​ 128,296 ​ ​ 73,147 ​ ​ 27,325 ​ ​ 14,055 ​ ​ 3,090 ​ 245,913 ​ Total assets ​ 726,555 ​ ​ 425,574 ​ ​ 604,355 ​ ​ 292,134 ​ ​ 66,895 ​ 2,115,513 ​ Capital expenditures ​ 28,916 ​ ​ 22,048 ​ ​ — ​ ​ — ​ ​ 4,662 ​ 55,626 ​ (1) Revenues included in the Other, Corporate and Elimination column are attributable to intercompany eliminations, which are primarily intercompany coal royalty eliminations, outside revenues at the Matrix Group and other outside miscellaneous sales and revenue activities. ​ (2) Segment Adjusted EBITDA Expense includes operating expenses, coal purchases and other income. Transportation expenses are excluded as transportation revenues are recognized in an amount equal to transportation expenses when title passes to the customer. ​ ​ The following is a reconciliation of consolidated Segment Adjusted EBITDA Expense to Operating expenses (excluding depreciation, depletion and amortization) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Segment Adjusted EBITDA Expense ​ $ 316,074 ​ $ 214,504 ​ $ 577,254 ​ $ 412,221 ​ Outside coal purchases ​ (151) ​ (114) ​ (151) ​ (114) ​ Other income (expense) ​ 579 ​ (1,351) ​ 1,145 ​ (2,548) ​ Operating expenses (excluding depreciation, depletion and amortization) ​ $ 316,502 ​ $ 213,039 ​ $ 578,248 ​ $ 409,559 ​ ​ (3) Segment Adjusted EBITDA is defined as net income attributable to ARLP before net interest expense, income taxes, depreciation, depletion and amortization, and general and administrative expenses. Management therefore is able to focus solely on the evaluation of segment operating profitability as it relates to our revenues and operating expenses, which are primarily controlled by our segments. Consolidated Segment Adjusted EBITDA is reconciled to net income as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Consolidated Segment Adjusted EBITDA ​ $ 266,304 ​ $ 136,092 ​ $ 437,208 ​ $ 245,913 ​ General and administrative ​ (22,457) ​ (17,492) ​ (41,053) ​ (32,996) ​ Depreciation, depletion and amortization ​ (66,734) ​ (64,733) ​ (130,048) ​ (123,935) ​ Interest expense, net ​ (9,304) ​ (9,827) ​ (18,931) ​ (20,206) ​ Income tax (expense) benefit ​ (6,331) ​ (5) ​ (49,046) ​ 7 ​ Net income attributable to ARLP ​ $ 161,478 ​ $ 44,035 ​ $ 198,130 ​ $ 68,783 ​ Noncontrolling interest ​ ​ 323 ​ ​ 130 ​ ​ 613 ​ ​ 208 ​ Net income ​ $ 161,801 ​ $ 44,165 ​ $ 198,743 ​ $ 68,991 ​ ​

ORGANIZATION AND PRESENTATION (

ORGANIZATION AND PRESENTATION (Policies)	6 Months Ended
	Jun. 30, 2022
ORGANIZATION AND PRESENTATION
Consolidation	Significant Relationships Referenced in Notes to Condensed Consolidated Financial Statements ​ ● References to "we," "us," "our" or "ARLP Partnership" mean the business and operations of Alliance Resource Partners, L.P., the parent company, as well as its consolidated subsidiaries. ● References to "ARLP" mean Alliance Resource Partners, L.P., individually as the parent company, and not on a consolidated basis. ● References to "MGP" mean Alliance Resource Management GP, LLC, ARLP's general partner. ● References to "Mr. Craft" mean Joseph W. Craft III, the Chairman, President and Chief Executive Officer of MGP. ● References to "Intermediate Partnership" mean Alliance Resource Operating Partners, L.P., the intermediate partnership of Alliance Resource Partners, L.P. ● References to "Alliance Coal" mean Alliance Coal, LLC, the holding company for our coal mining operations. ● References to "Alliance Minerals" mean Alliance Minerals, LLC, the holding company for our oil and gas mineral interests. ● References to "Alliance Resource Properties" mean Alliance Resource Properties, LLC, the land holding company for certain of our coal mineral interests, including the subsidiaries of Alliance Resource Properties, LLC. ​ Organization ​ ARLP is a Delaware limited partnership listed on the NASDAQ Global Select Market under the ticker symbol "ARLP." ARLP was formed in May 1999 and completed its initial public offering on August 19, 1999 when it acquired substantially all of the coal production and marketing assets of Alliance Resource Holdings, Inc., a Delaware corporation, and its subsidiaries. We are managed by our general partner, MGP, a Delaware limited liability company which holds a non-economic general partner interest in ARLP.
Change in Tax Status	Change in Tax Status ​ On March 15, 2022, Alliance Minerals changed its federal income tax status from a pass-through entity to a taxable entity via a "check the box" election (the "Tax Election"), which became effective January 1, 2022. This election for Alliance Minerals is anticipated to reduce the total income tax burden on our oil & gas royalties, as Alliance Minerals will pay entity-level taxes at corporate tax rates that are well below individual tax rates that would otherwise be paid by our unitholders. For more information on the Tax Election please see Note 7 – Income Taxes.
Investment	Francis Investment ​ On April 5, 2022, we committed to invest up to $50 million in Francis Renewable Energy, LLC ("Francis") through the purchase of preferred equity interests. Francis currently is active in the installation, management and operation of metered-for-fee, public-access electric vehicle ("EV") charging stations. Francis also develops and constructs EV charging stations for third-party customers. Our investment in Francis furthers our business strategy to develop strategic relationships and invest in attractive opportunities in the fast-growing energy infrastructure transition. For more information on this investment please see Note 8 – Variable Interest Entities. ​ Infinitum Investment ​ On April 29, 2022, we purchased $32.6 million of Series D Preferred Stock from Infinitum Electric, Inc. ("Infinitum"), a Texas-based startup developer and manufacturer of electric motors featuring printed circuit board stators which have the potential to result in motors that are smaller, lighter, quieter, more efficient and capable of operating at a fraction of the carbon footprint of conventional electric motors. The preferred stock provides for non-cumulative dividends when and if declared by Infinitum’s board of directors. Each share is convertible, at any time, at our option, into shares of common stock of Infinitum. Our investment in Infinitum furthers our business strategy to develop strategic relationships and invest in attractive opportunities in the fast-growing energy infrastructure transition. For more information on this investment please see Note 9 – Investments. ​ NGP ETP IV Investment ​ On June 2, 2022, we committed to purchase $25.0 million of limited partner interests in NGP ETP IV, L.P. ("NGP ETP IV"), a
Basis of Presentation	Basis of Presentation ​ The accompanying condensed consolidated financial statements include the accounts and operations of the ARLP Partnership and present our financial position as of June 30, 2022 and December 31, 2021, the results of our operations and comprehensive income for the three and six months ended June 30, 2022 and 2021, and cash flows for the six months ended June 30, 2022 and 2021. All intercompany transactions and accounts have been eliminated. ​ These condensed consolidated financial statements and notes are prepared pursuant to the rules and regulations of the Securities and Exchange Commission for interim reporting and do not include all the information normally included with financial statements prepared in accordance with generally accepted accounting principles ("GAAP") of the United States. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2021. ​ These condensed consolidated financial statements and notes are unaudited. However, in the opinion of management, these condensed consolidated financial statements reflect all normal recurring adjustments necessary for a fair presentation of the results for the periods presented. Results for interim periods are not necessarily indicative of results to be expected for the full year ending December 31, 2022.
Use of Estimates	Use of Estimates ​ The preparation of the ARLP Partnership's condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosures in our condensed consolidated financial statements. Actual results could differ from those estimates.
Income Taxes	Income Taxes ​ We are not a taxable entity for federal or state income tax purposes; the tax effect of our activities accrues to our unitholders. Although publicly traded partnerships as a general rule are taxed as corporations, we qualify for an exemption because at least 90% of our income consists of qualifying income, as defined in Section 7704(c) of the Internal Revenue Code. Net income for financial statement purposes may differ significantly from taxable income reportable to unitholders as a result of differences between the tax basis and financial reporting basis of assets and liabilities and the taxable income allocation requirements under our partnership agreement. Individual unitholders have different investment bases depending upon the timing and price of acquisition of their partnership units. Furthermore, each unitholder's tax accounting, which is partially dependent upon the unitholder's tax position, differs from the accounting followed in our consolidated financial statements. Accordingly, the aggregate difference in the basis of our net assets for financial and tax reporting purposes cannot be readily determined because information regarding each unitholder's tax attributes in our partnership is not available to us. ​ Our subsidiary Alliance Minerals within our Oil & Gas Royalties segment and certain other subsidiaries within our Other, Corporate and Elimination category are subject to federal and state income taxes. We use the liability method of accounting for income taxes, under which deferred tax assets and liabilities are recognized for the future tax consequences of (i) temporary differences between the financial statement carrying amounts and the tax basis of existing assets and liabilities and (ii) operating losses and tax credit carryforwards. Deferred income tax assets and liabilities are based on enacted rates applicable to the future period when those temporary differences are expected to be recovered or settled. The effect of a change in tax status or a change in tax rates on deferred tax assets and liabilities is recognized in the period the change in status is elected or rate change is enacted. A valuation allowance is provided for deferred tax assets when it is more likely than not the deferred tax assets will not be realized.
New Accounting Standards Issued and Adopted	New Accounting Standards Issued and Adopted ​ In November 2021, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance ("ASU 2021-10"). ASU 2021-10 increases the transparency of government assistance including the disclosure of (1) the types of assistance, (2) an entity’s accounting for the assistance, and (3) the effect of the assistance on an entity’s financial statements. We adopted ASU 2021-10 on January 1, 2022. The adoption of ASU 2021-10 did not have a material impact on our condensed consolidated financial statements.

INVENTORIES (Tables)

INVENTORIES (Tables)	6 Months Ended
	Jun. 30, 2022
INVENTORIES
Schedule of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ ​ ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal ​ $ 63,933 ​ $ 24,845 ​ Supplies (net of reserve for obsolescence of $5,620 and $5,554, respectively) ​ 45,743 ​ 35,457 ​ Total inventories, net ​ $ 109,676 ​ $ 60,302 ​

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	6 Months Ended
	Jun. 30, 2022
FAIR VALUE MEASUREMENTS
Summary of fair value measurements within the hierarchy	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, 2022 ​ December 31, 2021 ​ ​ Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 ​ ​ (in thousands) ​ Long-term debt ​ $ — ​ $ 428,645 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​ Total ​ $ — ​ $ 428,645 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	6 Months Ended
	Jun. 30, 2022
LONG-TERM DEBT
Schedule of long-term debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unamortized Discount and ​ ​ ​ Principal ​ Debt Issuance Costs ​ ​ ​ June 30, ​ December 31, ​ June 30, ​ December 31, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Revolving credit facility ​ $ — ​ $ — ​ $ (3,861) ​ $ (5,019) ​ Senior notes ​ 400,000 ​ 400,000 ​ (2,592) ​ (3,048) ​ Securitization facility ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ May 2019 equipment financing ​ ​ — ​ ​ 1,503 ​ ​ — ​ ​ — ​ November 2019 equipment financing ​ ​ 26,587 ​ ​ 31,972 ​ ​ — ​ ​ — ​ June 2020 equipment financing ​ ​ 7,799 ​ ​ 9,605 ​ ​ — ​ ​ — ​ ​ ​ 434,386 ​ 443,080 ​ (6,453) ​ (8,067) ​ Less current maturities ​ (14,942) ​ (16,071) ​ — ​ — ​ Total long-term debt ​ $ 419,444 ​ $ 427,009 ​ $ (6,453) ​ $ (8,067) ​

INCOME TAXES (Tables)

INCOME TAXES (Tables)	6 Months Ended
	Jun. 30, 2022
INCOME TAXES
Components of income tax expense (benefit)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Current: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 6,175 ​ $ — ​ $ 11,209 ​ $ (1) ​ State ​ 445 ​ — ​ 831 ​ — ​ ​ ​ 6,620 ​ — ​ 12,040 ​ (1) ​ Deferred: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ (255) ​ 5 ​ 34,665 ​ (6) ​ State ​ (34) ​ — ​ 2,341 ​ — ​ ​ ​ (289) ​ 5 ​ 37,006 ​ (6) ​ Income tax expense (benefit) ​ $ 6,331 ​ $ 5 ​ $ 49,046 ​ $ (7) ​
Reconciliation from provision for income taxes at U.S. federal statutory rate to effective tax rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, Six Months Ended June 30, ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Income taxes at statutory rate ​ $ 30,738 ​ $ 9,276 ​ $ 47,466 ​ $ 14,487 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: Income taxes at statutory rate on Partnership income not subject to income taxes ​ (25,018) ​ (9,141) ​ (37,105) ​ (14,174) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase (decrease) resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ State taxes, net of federal income tax ​ 457 ​ 34 ​ 818 ​ 72 ​ Change in valuation allowance of deferred tax assets ​ 11 ​ (142) ​ 1 ​ (305) ​ Deferred taxes related to tax election ​ ​ — ​ ​ — ​ ​ 37,253 ​ ​ — ​ Other ​ 143 ​ (22) ​ 613 ​ (87) ​ Income tax expense (benefit) ​ $ 6,331 ​ $ 5 ​ $ 49,046 ​ $ (7) ​
Components of deferred tax liabilities and deferred tax assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ June 30, ​ December 31, ​ 2022 2021 ​ ​ (in thousands) ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ $ (38,710) ​ $ (2,169) ​ Total deferred tax liabilities ​ ​ (38,710) ​ ​ (2,169) ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ Federal loss carryovers and credits ​ ​ 933 ​ ​ 1,328 ​ Other ​ 764 ​ 808 ​ Total deferred tax assets ​ ​ 1,697 ​ ​ 2,136 ​ Less valuation allowance ​ ​ (318) ​ ​ (317) ​ Net deferred tax assets ​ ​ 1,379 ​ ​ 1,819 ​ ​ ​ ​ ​ ​ ​ ​ ​ Overall net deferred tax liabilities ​ $ (37,331) ​ $ (350) ​

VARIABLE INTEREST ENTITIES (Tab

VARIABLE INTEREST ENTITIES (Tables)	6 Months Ended
	Jun. 30, 2022
VARIABLE INTEREST ENTITIES
Schedule of distributions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Alliance ​ Bluegrass ​ ​ ​ Minerals ​ Minerals ​ ​ ​ (in thousands) ​ Contributions ​ $ 143,112 ​ $ 5,963 ​ Distributions ​ ​ 124,945 ​ ​ 5,205 ​

INVESTMENTS (Tables)

INVESTMENTS (Tables)	6 Months Ended
	Jun. 30, 2022
All Dale Minerals III
INVESTMENTS
Schedule of changes in equity method investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2022 2021 2022 2021 ​ ​ ​ (in thousands) ​ Beginning balance ​ $ 26,194 ​ $ 26,907 ​ $ 26,325 ​ $ 27,268 ​ Equity method investment income ​ ​ 1,585 ​ ​ 341 ​ ​ 2,468 ​ ​ 403 ​ Distributions received ​ ​ (1,501) ​ ​ (974) ​ ​ (2,515) ​ ​ (1,397) ​ Ending balance ​ $ 26,278 ​ $ 26,274 ​ $ 26,278 ​ $ 26,274 ​
Francis Renewable Energy
INVESTMENTS
Schedule of changes in equity method investments	​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ June 30, ​ ​ 2022 ​ ​ (in thousands) ​ Beginning balance ​ $ — ​ Contributions ​ ​ 20,000 ​ Ending balance ​ $ 20,000 ​
NGP ETP
INVESTMENTS
Schedule of changes in equity method investments	​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ ​ ​ June 30, ​ ​ 2022 ​ ​ ​ (in thousands) ​ Beginning balance ​ $ — ​ Contributions ​ ​ 110 ​ Ending balance ​ $ 110 ​

PARTNERS' CAPITAL (Tables)

PARTNERS' CAPITAL (Tables)	6 Months Ended
	Jun. 30, 2022
PARTNERS' CAPITAL
Summary of quarterly per unit distribution paid	​ ​ ​ ​ ​ ​ ​ ​ Payment Date Per Unit Cash Distribution Total Cash Distribution ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ May 14, 2021 ​ $ 0.1000 ​ $ 13,045 ​ August 13, 2021 ​ ​ 0.1000 ​ ​ 13,041 ​ November 12, 2021 ​ ​ 0.2000 ​ ​ 26,072 ​ Total ​ $ 0.4000 ​ $ 52,158 ​ ​ ​ ​ ​ ​ ​ ​ ​ February 14, 2022 ​ $ 0.2500 ​ $ 32,750 ​ May 13, 2022 ​ ​ 0.3500 ​ ​ 45,810 ​ August 12, 2022 (1) ​ ​ 0.4000 ​ ​ — ​ Total ​ $ 1.0000 ​ $ 78,560 ​ (1) On July 26, 2022, we declared this quarterly distribution payable on August 12, 2022 to all unitholders of record as of August 5, 2022.
Summary of changes to Partners' Capital	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Limited ​ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ Limited Partner ​ Partners' ​ Comprehensive ​ Noncontrolling ​ Total Partners' ​ ​ Units Capital Income (Loss) Interest Capital ​ ​ (in thousands, except unit data) ​ Balance at January 1, 2022 127,195,219 ​ $ 1,279,183 ​ $ (64,229) ​ $ 11,115 ​ $ 1,226,069 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 36,652 ​ — ​ ​ 290 36,942 ​ Actuarially determined long-term liability adjustments — ​ — ​ 790 ​ — 790 ​ Total comprehensive income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 37,732 ​ Common unit-based compensation — ​ 2,640 ​ ​ — ​ ​ — ​ ​ 2,640 ​ Distributions on deferred common unit-based compensation — ​ (950) ​ ​ — ​ ​ — ​ ​ (950) ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (298) ​ ​ (298) ​ Distributions to Partners — ​ ​ (31,800) ​ ​ — ​ ​ — ​ ​ (31,800) ​ Balance at March 31, 2022 ​ 127,195,219 ​ ​ 1,285,725 ​ ​ (63,439) ​ ​ 11,107 ​ ​ 1,233,393 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 161,478 ​ — ​ ​ 323 161,801 ​ Actuarially determined long-term liability adjustments — ​ — ​ 794 ​ — 794 ​ Total comprehensive income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 162,595 ​ Common unit-based compensation — ​ 2,340 ​ ​ — ​ ​ — ​ ​ 2,340 ​ Distributions on deferred common unit-based compensation — ​ (1,292) ​ ​ — ​ ​ — ​ ​ (1,292) ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (325) ​ ​ (325) ​ Distributions to Partners — ​ ​ (44,518) ​ ​ — ​ ​ — ​ ​ (44,518) ​ Balance at June 30, 2022 ​ 127,195,219 ​ $ 1,403,733 ​ $ (62,645) ​ $ 11,105 ​ $ 1,352,193 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accumulated ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Limited ​ Other ​ ​ ​ ​ ​ ​ ​ ​ ​ Limited Partner ​ Partners' ​ Comprehensive ​ Noncontrolling ​ Total Partners' ​ ​ Units Capital Income (Loss) Interest Capital ​ ​ (in thousands, except unit data) ​ Balance at January 1, 2021 127,195,219 ​ $ 1,148,565 ​ $ (87,674) ​ $ 11,376 ​ $ 1,072,267 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 24,748 ​ — ​ ​ 78 24,826 ​ Actuarially determined long-term liability adjustments — ​ — ​ 2,231 ​ — 2,231 ​ Total comprehensive income ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 27,057 ​ Common unit-based compensation — ​ 723 ​ ​ — ​ ​ — ​ ​ 723 ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (141) ​ ​ (141) ​ Balance at March 31, 2021 127,195,219 ​ ​ 1,174,036 ​ ​ (85,443) ​ ​ 11,313 ​ ​ 1,099,906 ​ Comprehensive income: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income — ​ 44,035 ​ — ​ ​ 130 44,165 ​ Actuarially determined long-term liability adjustments — ​ — ​ 2,231 ​ — 2,231 ​ Total comprehensive loss ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 46,396 ​ Common unit-based compensation — ​ 1,485 ​ ​ — ​ ​ — ​ ​ 1,485 ​ Distributions on deferred common unit-based compensation — ​ (324) ​ ​ — ​ ​ — ​ ​ (324) ​ Distributions from consolidated company to noncontrolling interest ​ — ​ ​ — ​ ​ — ​ ​ (222) ​ ​ (222) ​ Distributions to Partners — ​ ​ (12,721) ​ ​ — ​ ​ — ​ ​ (12,721) ​ Balance at June 30, 2021 127,195,219 ​ $ 1,206,511 ​ $ (83,212) ​ $ 11,221 ​ $ 1,134,520 ​

REVENUE FROM CONTRACTS WITH C_2

REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	6 Months Ended
	Jun. 30, 2022
REVENUE FROM CONTRACTS WITH CUSTOMERS
Schedule of disaggregation of revenues by type	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal Operations ​ Royalties ​ Other, ​ ​ ​ ​ ​ ​ Illinois ​ ​ ​ ​ Corporate and ​ ​ ​ ​ Basin Appalachia Oil & Gas Coal Elimination Consolidated ​ ​ ​ (in thousands) ​ Three Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 290,389 ​ $ 241,418 ​ $ — ​ $ — ​ $ — ​ $ 531,807 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 35,927 ​ ​ — ​ ​ — ​ ​ 35,927 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 14,525 ​ ​ (14,525) ​ ​ — ​ Transportation revenues ​ ​ 21,449 ​ ​ 13,936 ​ ​ — ​ ​ — ​ ​ — ​ ​ 35,385 ​ Other revenues ​ ​ 1,659 ​ ​ 328 ​ ​ 652 ​ ​ — ​ ​ 10,743 ​ ​ 13,382 ​ Total revenues ​ $ 313,497 ​ $ 255,682 ​ $ 36,579 ​ $ 14,525 ​ $ (3,782) ​ $ 616,501 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 210,157 ​ $ 115,817 ​ $ — ​ $ — ​ $ — ​ $ 325,974 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 17,114 ​ ​ — ​ ​ — ​ ​ 17,114 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 11,653 ​ ​ (11,653) ​ ​ — ​ Transportation revenues ​ ​ 7,434 ​ ​ 4,624 ​ ​ — ​ ​ — ​ ​ — ​ ​ 12,058 ​ Other revenues ​ ​ 642 ​ ​ 282 ​ ​ 473 ​ ​ — ​ ​ 5,900 ​ ​ 7,297 ​ Total revenues ​ $ 218,233 ​ $ 120,723 ​ $ 17,587 ​ $ 11,653 ​ $ (5,753) ​ $ 362,443 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 544,294 ​ $ 375,873 ​ $ — ​ $ — ​ $ — ​ $ 920,167 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 66,854 ​ ​ — ​ ​ — ​ ​ 66,854 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 29,692 ​ ​ (29,692) ​ ​ — ​ Transportation revenues ​ ​ 40,340 ​ ​ 24,417 ​ ​ — ​ ​ — ​ ​ — ​ ​ 64,757 ​ Other revenues ​ ​ 3,559 ​ ​ 691 ​ ​ 686 ​ ​ — ​ ​ 20,650 ​ ​ 25,586 ​ Total revenues ​ $ 588,193 ​ $ 400,981 ​ $ 67,540 ​ $ 29,692 ​ $ (9,042) ​ $ 1,077,364 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 392,798 ​ $ 220,663 ​ $ — ​ $ — ​ $ — ​ $ 613,461 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 31,113 ​ ​ — ​ ​ — ​ ​ 31,113 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 22,954 ​ ​ (22,954) ​ ​ — ​ Transportation revenues ​ ​ 15,114 ​ ​ 8,012 ​ ​ — ​ ​ — ​ ​ — ​ ​ 23,126 ​ Other revenues ​ ​ 1,255 ​ ​ 667 ​ ​ 494 ​ ​ — ​ ​ 10,949 ​ ​ 13,365 ​ Total revenues ​ $ 409,167 ​ $ 229,342 ​ $ 31,607 ​ $ 22,954 ​ $ (12,005) ​ $ 681,065 ​
Schedule of current coal supply contracts allocated to performance obligations that are unsatisfied or partially unsatisfied	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2025 and ​ ​ ​ 2022 2023 2024 Thereafter Total ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations coal revenues ​ $ 650,837 ​ $ 729,307 ​ $ 361,381 ​ $ 290,746 ​ $ 2,032,271 Appalachia Coal Operations coal revenues ​ ​ 381,828 ​ ​ 335,595 ​ ​ 236,536 ​ ​ 40,701 ​ ​ 994,660 Total coal revenues (1) ​ $ 1,032,665 ​ $ 1,064,902 ​ $ 597,917 ​ $ 331,447 ​ $ 3,026,931 (1) Coal revenues generally consists of consolidated revenues excluding our Oil & Gas Royalties segment as well as intercompany revenues from our Coal Royalties segment .

EARNINGS PER LIMITED PARTNER _2

EARNINGS PER LIMITED PARTNER UNIT (Tables)	6 Months Ended
	Jun. 30, 2022
EARNINGS PER LIMITED PARTNER UNIT
Reconciliation of net income and EPU calculations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands, except per unit data) ​ Net income attributable to ARLP ​ $ 161,478 ​ $ 44,035 ​ $ 198,130 ​ $ 68,783 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Distributions to participating securities ​ (1,720) ​ (401) ​ (3,272) ​ (619) ​ Undistributed earnings attributable to participating securities ​ (3,645) ​ (825) ​ (3,245) ​ (934) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income attributable to ARLP available to limited partners ​ $ 156,113 ​ $ 42,809 ​ $ 191,613 ​ $ 67,230 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average limited partner units outstanding – basic and diluted ​ 127,195 ​ 127,195 ​ 127,195 ​ 127,195 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Earnings per limited partner unit - basic and diluted (1) ​ $ 1.23 ​ $ 0.34 ​ $ 1.51 ​ $ 0.53 ​ (1) Diluted EPU gives effect to all potentially dilutive common units outstanding during the period using the treasury stock method. Diluted EPU excludes all potentially dilutive units calculated under the treasury stock method if their effect is anti-dilutive. The combined total of LTIP, SERP and Directors' Deferred Compensation Plan units of 3,529 and 3,289 for the three and six months ended June 30, 2022, respectively, and 1,525 and 1,397 for the three and six months ended June 30, 2021 , respectively, were considered anti-dilutive under the treasury stock method .

WORKERS' COMPENSATION AND PNE_2

WORKERS' COMPENSATION AND PNEUMOCONIOSIS (Tables)	6 Months Ended
	Jun. 30, 2022
Black lung benefits:
Reconciliation of changes in workers' compensation liability	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ ​ (in thousands) ​ Beginning balance ​ $ 53,206 ​ $ 54,233 ​ $ 53,448 ​ $ 54,739 ​ Accruals increase ​ 2,271 ​ 1,565 ​ 4,546 ​ 3,237 ​ Payments ​ (3,278) ​ (2,565) ​ (6,082) ​ (4,975) ​ Interest accretion ​ 287 ​ 231 ​ 574 ​ 463 ​ Valuation gain (1) ​ (5,265) ​ (1,405) ​ (5,265) ​ (1,405) ​ Ending balance ​ $ 47,221 ​ $ 52,059 ​ $ 47,221 ​ $ 52,059 ​ (1) Our estimate of the liability for the present value of current workers′ compensation benefits is based on our actuarial calculations. Our actuarial calculations are based on a blend of actuarial projection methods and numerous assumptions including claims development patterns, mortality, medical costs and interest rates. The valuation gain in 2022 is due to an increase in the discount rate from 2.41% on December 31, 2021 to 4.22% on June 30, 202 2 . The valuation gain in 2021 is due to an increase in the discount rate from 1.95% on December 31, 2020 to 2.34% on June 30, 202 1 .
Pneumoconiosis benefits
Black lung benefits:
Components of net periodic benefit cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Service cost ​ $ 954 ​ $ 989 ​ $ 1,901 ​ $ 2,020 Interest cost (1) ​ 749 ​ 637 ​ 1,496 ​ 1,273 ​ Net amortization (1) ​ 259 ​ 1,043 ​ 519 ​ 2,086 ​ Net periodic benefit cost ​ $ 1,962 ​ $ 2,669 ​ $ 3,916 ​ $ 5,379 ​ (1) Interest cost and net amortization are included in the Other income (expense) line item within our condensed consolidated statements of income.

COMMON UNIT-BASED COMPENSATIO_2

COMMON UNIT-BASED COMPENSATION PLANS (Tables)	6 Months Ended
	Jun. 30, 2022
COMMON UNIT-BASED COMPENSATION PLANS
Summary of non-vested share activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of units Weighted average grant date fair value per unit Intrinsic value ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-vested grants at January 1, 2022 ​ 3,130,475 ​ $ 5.59 ​ $ 39,569 ​ Granted (1) 687,719 ​ ​ 13.34 ​ ​ ​ ​ Forfeited (165,224) ​ 6.72 ​ ​ ​ ​ Non-vested grants at June 30, 2022 3,652,970 ​ 7.00 ​ ​ 66,594 ​ (1) The restricted units granted during 2022 have minimum-value guarantees of either $9.62 or $6.41 per unit, regardless of whether or not the awards vest.
SERP and Deferred Compensation Plans
COMMON UNIT-BASED COMPENSATION PLANS
Summary of activity in share-based plans	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of units Weighted average grant date fair value per unit Intrinsic value ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Phantom units outstanding as of January 1, 2022 ​ 668,698 ​ $ 20.37 ​ $ 8,452 ​ Granted ​ 25,359 ​ ​ 15.80 ​ ​ ​ ​ Phantom units outstanding as of June 30, 2022 694,057 ​ 20.20 ​ ​ 12,653 ​

COMPONENTS OF PENSION PLAN NE_2

COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS (Tables)	6 Months Ended
	Jun. 30, 2022
Defined benefit pension plan
Employee Benefit Plans
Components of net periodic benefit cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Interest cost ​ $ 936 ​ $ 860 ​ $ 1,868 ​ $ 1,720 ​ Expected return on plan assets ​ (1,664) ​ (1,671) ​ (3,329) ​ (3,342) ​ Amortization of prior service cost ​ ​ 46 ​ ​ 46 ​ ​ 93 ​ ​ 93 ​ Amortization of net loss ​ 489 ​ 1,142 ​ 972 ​ 2,283 ​ Net periodic benefit cost (1) ​ $ (193) ​ $ 377 ​ $ (396) ​ $ 754 ​ (1) Net periodic benefit cost for the Pension Plan is included in the Other income (expense) line item within our condensed consolidated statements of income.

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2022
SEGMENT INFORMATION
Schedule of reportable segment results	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal Operations ​ Royalties ​ Other, ​ ​ ​ ​ ​ Illinois ​ ​ ​ ​ ​ Corporate and ​ ​ ​ ​ Basin Appalachia Oil & Gas Coal ​ Elimination Consolidated ​ ​ (in thousands) Three Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 313,497 ​ $ 255,682 ​ $ 36,579 ​ $ — ​ $ 10,743 ​ $ 616,501 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 14,525 ​ ​ (14,525) ​ ​ — ​ Total revenues (1) ​ ​ 313,497 ​ ​ 255,682 ​ ​ 36,579 ​ ​ 14,525 ​ ​ (3,782) ​ ​ 616,501 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 194,697 ​ 117,369 ​ 3,234 ​ 5,398 ​ (4,624) ​ 316,074 ​ Segment Adjusted EBITDA (3) ​ 97,352 ​ 124,377 ​ 34,609 ​ 9,127 ​ 839 ​ 266,304 ​ Capital expenditures ​ 35,343 ​ 22,491 ​ — ​ — ​ 4,995 ​ 62,829 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 218,233 ​ $ 120,723 ​ $ 17,587 ​ $ — ​ $ 5,900 ​ $ 362,443 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 11,653 ​ ​ (11,653) ​ ​ — ​ Total revenues (1) ​ ​ 218,233 ​ ​ 120,723 ​ ​ 17,587 ​ ​ 11,653 ​ ​ (5,753) ​ ​ 362,443 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 140,176 ​ 74,456 ​ 2,419 ​ 4,871 ​ (7,418) ​ 214,504 ​ Segment Adjusted EBITDA (3) ​ 70,623 ​ 41,641 ​ 15,379 ​ 6,782 ​ 1,667 ​ 136,092 ​ Capital expenditures ​ 12,515 ​ 10,382 ​ — ​ — ​ 1,292 ​ 24,189 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 588,193 ​ $ 400,981 ​ $ 67,540 ​ $ — ​ $ 20,650 ​ $ 1,077,364 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 29,692 ​ ​ (29,692) ​ ​ — ​ Total revenues (1) ​ ​ 588,193 ​ ​ 400,981 ​ ​ 67,540 ​ ​ 29,692 ​ ​ (9,042) ​ ​ 1,077,364 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 372,286 ​ ​ 201,084 ​ ​ 6,235 ​ ​ 10,217 ​ ​ (12,568) ​ 577,254 ​ Segment Adjusted EBITDA (3) ​ 175,567 ​ ​ 175,480 ​ ​ 63,161 ​ ​ 19,475 ​ ​ 3,525 ​ 437,208 ​ Total assets ​ 748,291 ​ ​ 457,724 ​ ​ 667,278 ​ ​ 288,509 ​ ​ 171,389 ​ 2,333,191 ​ Capital expenditures ​ 71,890 ​ ​ 40,836 ​ ​ — ​ ​ — ​ ​ 9,256 ​ 121,982 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Six Months Ended June 30, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 409,167 ​ $ 229,342 ​ $ 31,607 ​ $ — ​ $ 10,949 ​ $ 681,065 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 22,954 ​ ​ (22,954) ​ ​ — ​ Total revenues (1) ​ ​ 409,167 ​ ​ 229,342 ​ ​ 31,607 ​ ​ 22,954 ​ ​ (12,005) ​ ​ 681,065 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 265,757 ​ ​ 148,182 ​ ​ 4,477 ​ ​ 8,899 ​ ​ (15,094) ​ 412,221 ​ Segment Adjusted EBITDA (3) ​ 128,296 ​ ​ 73,147 ​ ​ 27,325 ​ ​ 14,055 ​ ​ 3,090 ​ 245,913 ​ Total assets ​ 726,555 ​ ​ 425,574 ​ ​ 604,355 ​ ​ 292,134 ​ ​ 66,895 ​ 2,115,513 ​ Capital expenditures ​ 28,916 ​ ​ 22,048 ​ ​ — ​ ​ — ​ ​ 4,662 ​ 55,626 ​ (1) Revenues included in the Other, Corporate and Elimination column are attributable to intercompany eliminations, which are primarily intercompany coal royalty eliminations, outside revenues at the Matrix Group and other outside miscellaneous sales and revenue activities. ​ (2) Segment Adjusted EBITDA Expense includes operating expenses, coal purchases and other income. Transportation expenses are excluded as transportation revenues are recognized in an amount equal to transportation expenses when title passes to the customer.
Reconciliation of consolidated Segment Adjusted EBITDA Expense to operating expenses (excluding depreciation, depletion and amortization)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Segment Adjusted EBITDA Expense ​ $ 316,074 ​ $ 214,504 ​ $ 577,254 ​ $ 412,221 ​ Outside coal purchases ​ (151) ​ (114) ​ (151) ​ (114) ​ Other income (expense) ​ 579 ​ (1,351) ​ 1,145 ​ (2,548) ​ Operating expenses (excluding depreciation, depletion and amortization) ​ $ 316,502 ​ $ 213,039 ​ $ 578,248 ​ $ 409,559 ​
Reconciliation of consolidated Segment Adjusted EBITDA to net income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Six Months Ended ​ ​ ​ June 30, ​ June 30, ​ ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Consolidated Segment Adjusted EBITDA ​ $ 266,304 ​ $ 136,092 ​ $ 437,208 ​ $ 245,913 ​ General and administrative ​ (22,457) ​ (17,492) ​ (41,053) ​ (32,996) ​ Depreciation, depletion and amortization ​ (66,734) ​ (64,733) ​ (130,048) ​ (123,935) ​ Interest expense, net ​ (9,304) ​ (9,827) ​ (18,931) ​ (20,206) ​ Income tax (expense) benefit ​ (6,331) ​ (5) ​ (49,046) ​ 7 ​ Net income attributable to ARLP ​ $ 161,478 ​ $ 44,035 ​ $ 198,130 ​ $ 68,783 ​ Noncontrolling interest ​ ​ 323 ​ ​ 130 ​ ​ 613 ​ ​ 208 ​ Net income ​ $ 161,801 ​ $ 44,165 ​ $ 198,743 ​ $ 68,991 ​

ORGANIZATION AND PRESENTATION_2

ORGANIZATION AND PRESENTATION (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Jun. 02, 2022	Apr. 29, 2022	Apr. 05, 2022
Ownership interests
Equity investment without readily determinable fair value	$ 32,639
Francis Renewable Energy
Ownership interests
Funding commitment				$ 50,000
Infinitum Electric
Ownership interests
Equity investment without readily determinable fair value			$ 32,600
NGP ETP
Ownership interests
Funding commitment		$ 25,000

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
INVENTORIES
Coal	$ 63,933	$ 24,845
Supplies (net of reserve for obsolescence of $5,571 and $5,554, respectively)	45,743	35,457
Total inventories, net	109,676	60,302
Reserve for obsolescence	$ 5,620	$ 5,554

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - Estimated fair value - Significant Observable Inputs (Level 2) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
FAIR VALUE MEASUREMENTS
Long-term debt	$ 428,645	$ 457,758
Total	$ 428,645	$ 457,758

LONG-TERM DEBT - Components (De

LONG-TERM DEBT - Components (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Principal
Aggregate maturities of long-term debt	$ 434,386	$ 443,080
Less current maturities	(14,942)	(16,071)
Total long-term debt	419,444	427,009
Unamortized Discount and Debt Issuance Costs
Unamortized debt issuance costs including current and non-current	(6,453)	(8,067)
Total unamortized debt issuance costs	(6,453)	(8,067)
Revolving credit facility
Unamortized Discount and Debt Issuance Costs
Unamortized debt issuance costs including current and non-current	(3,861)	(5,019)
Senior notes due 2025
Principal
Aggregate maturities of long-term debt	400,000	400,000
Unamortized Discount and Debt Issuance Costs
Unamortized debt issuance costs including current and non-current	(2,592)	(3,048)
May 2019 equipment financing
Principal
Aggregate maturities of long-term debt		1,503
November 2019 equipment financing
Principal
Aggregate maturities of long-term debt	26,587	31,972
June 2020 equipment financing
Principal
Aggregate maturities of long-term debt	$ 7,799	$ 9,605

LONG-TERM DEBT - Credit Facilit

LONG-TERM DEBT - Credit Facility (Details) $ in Millions		6 Months Ended
	Mar. 09, 2020 USD ($)	Jun. 30, 2022 USD ($)
Credit Agreement
Long-Term Debt
Maximum borrowing capacity	$ 459.5
ARLP debt arrangements requirements, fixed charge coverage ratio	1
ARLP debt arrangements requirements, debt to cash flow ratio	2.5
ARLP debt arrangements requirements, cash flow to interest expense ratio	3
Actual debt to cash flow ratio for trailing twelve months		0.74
Actual cash flow to interest expense ratio for trailing twelve months		15.52
ARLP debt arrangements requirements, period over which the ratios are required to be maintained	12 months
Credit Agreement | Credit Agreement, first lien
Long-Term Debt
ARLP debt arrangements requirements, debt to cash flow ratio	1.5
Actual debt to cash flow ratio for trailing twelve months		0.07
Revolving credit facility
Long-Term Debt
Debt available for borrowing		$ 415.4
Annual commitment fee percentage, undrawn portion		0.35%
Revolving credit facility | Eurodollar Rate
Long-Term Debt
Effective interest rate (as a percent)		4.14%
Letters of credit subfacility
Long-Term Debt
Maximum borrowing capacity	$ 125
Letters of credit outstanding		$ 44.1
Swingline subfacility
Long-Term Debt
Maximum borrowing capacity	$ 15

LONG-TERM DEBT - 2025 Senior No

LONG-TERM DEBT - 2025 Senior Notes (Details) - Senior notes due 2025 $ in Millions	Apr. 24, 2017 USD ($)
Issuance of Senior Notes
Principal amount	$ 400
Term	8 years
Interest rate (as a percent)	7.50%

LONG-TERM DEBT - Securitization

LONG-TERM DEBT - Securitization Facility (Details) - Securitization Facility - USD ($) $ in Millions	Jun. 30, 2022	Jan. 31, 2021	Dec. 05, 2014
Long-Term Debt
Maximum borrowing capacity		$ 60	$ 100
Letters of credit outstanding	$ 9.2
Debt available for borrowing	50.8
Facility outstanding amount	$ 0

LONG-TERM DEBT - Equipment fina

LONG-TERM DEBT - Equipment financing and other (Details) $ in Millions	Jun. 05, 2020 USD ($)	Nov. 06, 2019 USD ($) payment	May 17, 2019 USD ($)
May 2019 Equipment Financing
Long-Term Debt
Principal amount			$ 10
Term			36 months
Effective interest rate (as a percent)			6.25%
November 2019 Equipment Financing
Long-Term Debt
Principal amount		$ 53.1
Term		4 years
Effective interest rate (as a percent)		4.75%
Number of monthly payments | payment		47
Periodic Payment		$ 1
Balloon payment on maturity		$ 11.6
June 2020 equipment financing
Long-Term Debt
Principal amount	$ 14.7
Term	48 months
Effective interest rate (as a percent)	6.10%

INCOME TAXES - Components (Deta

INCOME TAXES - Components (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Current:
Federal	$ 6,175		$ 11,209	$ (1)
State	445		831
Total current income tax expense (benefit)	6,620		12,040	(1)
Deferred:
Federal	(255)	$ 5	34,665	(6)
State	(34)		2,341
Total deferred income tax expense (benefit)	(289)	5	37,006	(6)
Income tax expense (benefit)	$ 6,331	$ 5	$ 49,046	$ (7)

INCOME TAXES - Tax election (De

INCOME TAXES - Tax election (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2019	Dec. 31, 2021
Taxes
Deferred tax liability	$ 37,331		$ 37,331			$ 350
Income tax expense	$ 6,331	$ 5	$ 49,046	$ (7)
Earnings per limited partner unit - basic (in dollars per unit)	$ 1.23	$ 0.34	$ 1.51	$ 0.53
Earnings per limited partner unit - diluted (in dollars per unit)	$ 1.23	$ 0.34	$ 1.51	$ 0.53
AllDale I and II
Taxes
Non - cash acquisition gain recognized					$ 177,000
Change in tax accounting
Taxes
Deferred tax liability	$ 37,300		$ 37,300
Income tax expense			$ 37,300
Earnings per limited partner unit - basic (in dollars per unit)			$ (0.29)
Earnings per limited partner unit - diluted (in dollars per unit)			$ (0.29)

INCOME TAXES - Reconciliation (

INCOME TAXES - Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Taxes
Income taxes at statutory rate	$ 30,738	$ 9,276	$ 47,466	$ 14,487
Less: Income taxes at statutory rate on Partnership income not subject to income taxes	(25,018)	(9,141)	(37,105)	(14,174)
Increase/(decrease) resulting from:
State taxes, net of federal income tax	457	34	818	72
Change in valuation allowance of deferred tax assets	11	(142)	1	(305)
Other	143	(22)	613	(87)
Income tax expense (benefit)	$ 6,331	$ 5	49,046	$ (7)
Change in tax accounting
Increase/(decrease) resulting from:
Deferred taxes related to tax election			37,253
Income tax expense (benefit)			$ 37,300

INCOME TAXES - Deferred tax (De

INCOME TAXES - Deferred tax (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Deferred tax liabilities:
Property, plant and equipment	$ (38,710)	$ (2,169)
Deferred tax liabilities	(38,710)	(2,169)
Deferred tax assets:
Federal loss carryovers and credits	933	1,328
Other	764	808
Total deferred tax assets	1,697	2,136
Less valuation allowance	(318)	(317)
Net deferred tax assets	1,379	1,819
Overall net deferred tax liabilities	$ (37,331)	$ (350)

VARIABLE INTEREST ENTITIES - Ca

VARIABLE INTEREST ENTITIES - Cavalier (Details) - USD ($) $ in Thousands						6 Months Ended		12 Months Ended
	May 13, 2022	Feb. 14, 2022	Nov. 12, 2021	Aug. 13, 2021	May 14, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Variable Interest Entities
Distributions paid to Partners	$ 45,810	$ 32,750	$ 26,072	$ 13,041	$ 13,045	$ 78,560	$ 13,045	$ 52,158
Cavalier Minerals | Alliance Minerals
Variable Interest Entities
Contributions						143,112
Distributions paid to Partners						124,945
Cavalier Minerals | Bluegrass Minerals
Variable Interest Entities
Contributions						5,963
Distributions paid to Partners						$ 5,205
Cavalier Minerals | Bluegrass Minerals
Variable Interest Entities
Incentive distribution of available cash (as a percent)						25%
Cavalier Minerals
Variable Interest Entities
Ownership interest in VIE (as a percent)						96%
Cavalier Minerals | Bluegrass Minerals
Variable Interest Entities
Noncontrolling ownership interest (as a percent)						4%

VARIABLE INTEREST ENTITIES - Al

VARIABLE INTEREST ENTITIES - All Dale III (Detail) - All Dale Minerals III - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2022	Feb. 28, 2017
Investments
Other Commitment		$ 30
Distribution after hurdles (as a percent)	25%
Specified internal rate of return (as a percent)	10%
Percentage of available cash distributed	125%
All Dale Minerals III
Investments
Ownership percentage by limited partners	13.90%

VARIABLE INTEREST ENTITIES - In

VARIABLE INTEREST ENTITIES - Investments (Detail) - USD ($) $ in Thousands			3 Months Ended	6 Months Ended
	Jun. 21, 2022	Apr. 05, 2022	Jun. 30, 2022	Jun. 30, 2022	Jun. 02, 2022
Investments
Purchase of equity method investment				$ 20,110
Francis Renewable Energy
Investments
Funding commitment		$ 50,000
Purchase of equity method investment		$ 20,000	$ 20,000
Francis Renewable Energy | Francis Renewable Energy
Investments
Ownership interest in VIE (as a percent)		15.40%
NGP ETP
Investments
Funding commitment					$ 25,000
Purchase of equity method investment	$ 100		$ 110

INVESTMENTS (Details)

INVESTMENTS (Details) - USD ($) $ in Thousands				3 Months Ended		6 Months Ended
	Jun. 21, 2022	Apr. 29, 2022	Apr. 05, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Investments
Beginning balance						$ 26,325
Contributions						20,110
Equity method investment income				$ 1,585	$ 341	2,468	$ 403
Ending balance				46,388		46,388
Payment to acquire investment						32,639
All Dale Minerals III
Investments
Beginning balance				26,194	26,907	26,325	27,268
Equity method investment income				1,585	341	2,468	403
Distributions received				(1,501)	(974)	(2,515)	(1,397)
Ending balance				26,278	$ 26,274	26,278	$ 26,274
Francis Renewable Energy
Investments
Contributions			$ 20,000	20,000
Ending balance				20,000		20,000
NGP ETP
Investments
Contributions	$ 100			110
Ending balance				$ 110		$ 110
Infinitum Electric
Investments
Payment to acquire investment		$ 32,600

PARTNERS' CAPITAL - Distributio

PARTNERS' CAPITAL - Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands							6 Months Ended		12 Months Ended
	Aug. 12, 2022	May 13, 2022	Feb. 14, 2022	Nov. 12, 2021	Aug. 13, 2021	May 14, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
PARTNERS' CAPITAL
Quarterly distribution paid (in dollars per unit)	$ 0.4000	$ 0.3500	$ 0.2500	$ 0.2000	$ 0.1000	$ 0.1000	$ 1		$ 0.4000
Total Cash Distribution		$ 45,810	$ 32,750	$ 26,072	$ 13,041	$ 13,045	$ 78,560	$ 13,045	$ 52,158

PARTNERS' CAPITAL - Narrative (

PARTNERS' CAPITAL - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended	50 Months Ended
	Jun. 30, 2022	Jun. 30, 2022	May 31, 2018
Partners' capital
Treasury units retired	$ 0
Limited Partners' Capital
Partners' capital
Repurchase and retire authorization			$ 100
Treasury units retired		$ 93.5
Number of units retired		5,460,639
Repurchase price (in dollars per unit)		$ 17.12
Remaining authorized amount	$ 6.5	$ 6.5

PARTNERS' CAPITAL - Change (Det

PARTNERS' CAPITAL - Change (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Increase (decrease) in Partners' Capital
Balance at beginning of period	$ 1,233,393	$ 1,226,069	$ 1,099,906	$ 1,072,267	$ 1,226,069	$ 1,072,267
Balance at beginning of period (in units)		127,195,219			127,195,219
Comprehensive income (loss):
Net income	161,801	$ 36,942	44,165	24,826	$ 198,743	68,991
Actuarially determined long-term liability adjustments	794	790	2,231	2,231	1,584	4,462
COMPREHENSIVE INCOME	162,595	37,732	46,396	27,057	200,327	73,453
Common unit-based compensation	2,340	2,640	1,485	723
Distributions on deferred common unit-based compensation	(1,292)	(950)	(324)
Distributions from consolidated company to noncontrolling interest	(325)	(298)	(222)	(141)
Distributions to Partners	(44,518)	(31,800)	(12,721)
Balance at end of period	$ 1,352,193	1,233,393	1,134,520	1,099,906	$ 1,352,193	1,134,520
Balance at end of period (in units)	127,195,219				127,195,219
Accumulated Other Comprehensive Income (Loss)
Increase (decrease) in Partners' Capital
Balance at beginning of period	$ (63,439)	(64,229)	(85,443)	(87,674)	$ (64,229)	(87,674)
Comprehensive income (loss):
Actuarially determined long-term liability adjustments	794	790	2,231	2,231
Balance at end of period	(62,645)	(63,439)	(83,212)	(85,443)	(62,645)	(83,212)
Noncontrolling Interest
Increase (decrease) in Partners' Capital
Balance at beginning of period	11,107	11,115	11,313	11,376	11,115	11,376
Comprehensive income (loss):
Net income	323	290	130	78
Distributions from consolidated company to noncontrolling interest	(325)	(298)	(222)	(141)
Balance at end of period	11,105	11,107	11,221	11,313	11,105	11,221
Limited Partners' Capital
Increase (decrease) in Partners' Capital
Balance at beginning of period	$ 1,285,725	$ 1,279,183	$ 1,174,036	$ 1,148,565	$ 1,279,183	$ 1,148,565
Balance at beginning of period (in units)	127,195,219	127,195,219	127,195,219	127,195,219	127,195,219	127,195,219
Comprehensive income (loss):
Net income	$ 161,478	$ 36,652	$ 44,035	$ 24,748
Common unit-based compensation	2,340	2,640	1,485	723
Distributions on deferred common unit-based compensation	(1,292)	(950)	(324)
Distributions to Partners	(44,518)	(31,800)	(12,721)
Balance at end of period	$ 1,403,733	$ 1,285,725	$ 1,206,511	$ 1,174,036	$ 1,403,733	$ 1,206,511
Balance at end of period (in units)	127,195,219	127,195,219	127,195,219	127,195,219	127,195,219	127,195,219

REVENUE FROM CONTRACTS WITH C_3

REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of revenues
Revenues	$ 616,501	$ 362,443	$ 1,077,364	$ 681,065
Illinois Basin
Disaggregation of revenues
Revenues	313,497	218,233	588,193	409,167
Appalachia
Disaggregation of revenues
Revenues	255,682	120,723	400,981	229,342
Oil & Gas Royalties
Disaggregation of revenues
Revenues	36,579	17,587	67,540	31,607
Coal Royalties
Disaggregation of revenues
Revenues	14,525	11,653	29,692	22,954
Other, Corporate and Elimination
Disaggregation of revenues
Revenues	(3,782)	(5,753)	(9,042)	(12,005)
Coal sales
Disaggregation of revenues
Revenues	531,807	325,974	920,167	613,461
Coal sales | Illinois Basin
Disaggregation of revenues
Revenues	290,389	210,157	544,294	392,798
Coal sales | Appalachia
Disaggregation of revenues
Revenues	241,418	115,817	375,873	220,663
Oil & gas royalties
Disaggregation of revenues
Revenues	35,927	17,114	66,854	31,113
Oil & gas royalties | Oil & Gas Royalties
Disaggregation of revenues
Revenues	35,927	17,114	66,854	31,113
Coal royalties | Coal Royalties
Disaggregation of revenues
Revenues	14,525	11,653	29,692	22,954
Coal royalties | Other, Corporate and Elimination
Disaggregation of revenues
Revenues	(14,525)	(11,653)	(29,692)	(22,954)
Transportation
Disaggregation of revenues
Revenues	35,385	12,058	64,757	23,126
Transportation | Illinois Basin
Disaggregation of revenues
Revenues	21,449	7,434	40,340	15,114
Transportation | Appalachia
Disaggregation of revenues
Revenues	13,936	4,624	24,417	8,012
Other revenues
Disaggregation of revenues
Revenues	13,382	7,297	25,586	13,365
Other revenues | Illinois Basin
Disaggregation of revenues
Revenues	1,659	642	3,559	1,255
Other revenues | Appalachia
Disaggregation of revenues
Revenues	328	282	691	667
Other revenues | Oil & Gas Royalties
Disaggregation of revenues
Revenues	652	473	686	494
Other revenues | Other, Corporate and Elimination
Disaggregation of revenues
Revenues	$ 10,743	$ 5,900	$ 20,650	$ 10,949

REVENUE FROM CONTRACTS WITH C_4

REVENUE FROM CONTRACTS WITH CUSTOMERS - Supply contracts (Details) $ in Thousands	Jun. 30, 2022 USD ($)
Performance obligations unsatisfied or partially unsatisfied
Total	$ 3,026,931
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 1,032,665
Expected timing of satisfaction period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 1,064,902
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 597,917
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 331,447
Expected timing of satisfaction period	1 year
Illinois Basin
Performance obligations unsatisfied or partially unsatisfied
Total	$ 2,032,271
Illinois Basin | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 650,837
Expected timing of satisfaction period	6 months
Illinois Basin | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 729,307
Expected timing of satisfaction period	1 year
Illinois Basin | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 361,381
Expected timing of satisfaction period	1 year
Illinois Basin | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 290,746
Expected timing of satisfaction period	1 year
Appalachia
Performance obligations unsatisfied or partially unsatisfied
Total	$ 994,660
Appalachia | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-07-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 381,828
Expected timing of satisfaction period	6 months
Appalachia | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 335,595
Expected timing of satisfaction period	1 year
Appalachia | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 236,536
Expected timing of satisfaction period	1 year
Appalachia | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 40,701
Expected timing of satisfaction period	1 year

EARNINGS PER LIMITED PARTNER _3

EARNINGS PER LIMITED PARTNER UNIT - Reconciliation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
EARNINGS PER LIMITED PARTNER UNIT
Net income attributable to ARLP	$ 161,478	$ 44,035	$ 198,130	$ 68,783
Distributions to participating securities	(1,720)	(401)	(3,272)	(619)
Undistributed earnings attributable to participating securities	(3,645)	(825)	(3,245)	(934)
Net income attributable to ARLP available to limited partners	$ 156,113	$ 42,809	$ 191,613	$ 67,230
Weighted-average limited partner units outstanding - basic (in units)	127,195,219	127,195,219	127,195,219	127,195,219
Weighted-average limited partner units outstanding - diluted (in units)	127,195,000	127,195,000	127,195,000	127,195,000
Earnings per limited partner unit - basic (in dollars per unit)	$ 1.23	$ 0.34	$ 1.51	$ 0.53
Earnings per limited partner unit - diluted (in dollars per unit)	$ 1.23	$ 0.34	$ 1.51	$ 0.53
Anti-dilutive under the treasury stock method (in units)	3,529,000	1,525,000	3,289,000	1,397,000

WORKERS' COMPENSATION AND PNE_3

WORKERS' COMPENSATION AND PNEUMOCONIOSIS - Liability (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of changes in the workers' compensation liability
Beginning balance	$ 53,206	$ 54,233	$ 53,448	$ 54,739	$ 54,739
Accruals increase	2,271	1,565	4,546	3,237
Payments	(3,278)	(2,565)	(6,082)	(4,975)
Interest accretion	287	231	574	463
Valuation gain	(5,265)	(1,405)	(5,265)	(1,405)
Ending balance	47,221	$ 52,059	$ 47,221	$ 52,059	$ 53,448	$ 54,739
Estimated present value of future obligations and other information
Workers' compensation discount rate			4.22%	2.34%	2.41%	1.95%
Other long-term assets
Estimated present value of future obligations and other information
Receivables for traumatic injury claims	$ 5,700		$ 5,700

WORKERS' COMPENSATION AND PNE_4

WORKERS' COMPENSATION AND PNEUMOCONIOSIS - Periodic Benefit Cost (Details) - Pneumoconiosis benefits - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Black lung benefits:
Service cost	$ 954	$ 989	$ 1,901	$ 2,020
Interest cost	$ 749	$ 637	$ 1,496	$ 1,273
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Net amortization	$ 259	$ 1,043	$ 519	$ 2,086
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Net periodic benefit cost	$ 1,962	$ 2,669	$ 3,916	$ 5,379

COMMON UNIT-BASED COMPENSATIO_3

COMMON UNIT-BASED COMPENSATION PLANS - LTIP Grants (Details) - ARLP LTIP - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Number of units
Balance at the beginning of the period (in units)	3,130,475
Granted (in units)	687,719
Forfeited (in units)	(165,224)
Balance at the end of the period (in units)	3,652,970
Weighted average grant date fair value per unit
Balance at the beginning of the period (in dollars per unit)	$ 5.59
Granted (in dollars per unit)	13.34
Forfeited (in dollars per unit)	6.72
Balance at the end of the period (in dollars per unit)	$ 7
Intrinsic value (in dollars)
Intrinsic value of outstanding grants (in dollars)	$ 66,594	$ 39,569
$9.62 minimum-value guarantee
Other information
Guaranteed minimum (in dollars per unit)	$ 9.62
$6.41 minimum-value guarantee
Other information
Guaranteed minimum (in dollars per unit)	$ 6.41

COMMON UNIT-BASED COMPENSATIO_4

COMMON UNIT-BASED COMPENSATION PLANS - LTIP Other (Details) - ARLP LTIP - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Other information
Unit-based compensation expense	$ 2.1	$ 1.4	$ 4.4	$ 2.1
Total unit-based obligation recorded	11		11
Unrecognized compensation expense (in dollars)	$ 14.5		$ 14.5
Weighted-average period for recognition of expense			1 year 3 months 18 days

COMMON UNIT-BASED COMPENSATIO_5

COMMON UNIT-BASED COMPENSATION PLANS - SERP and Directors Comp (Details) - SERP and Deferred Compensation Plans - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Other information
Unit-based compensation expense	$ 300	$ 100	$ 600	$ 200
Total unit-based obligation recorded	$ 14,000		$ 14,000
Phantom Share Units (PSUs)
Number of units
Balance at the beginning of the period (in units)			668,698
Granted (in units)			25,359
Balance at the end of the period (in units)	694,057		694,057
Weighted average grant date fair value per unit
Balance at the beginning of the period (in dollars per unit)			$ 20.37
Granted (in dollars per unit)			15.80
Balance at the end of the period (in dollars per unit)	$ 20.20		$ 20.20
Intrinsic value of outstanding grants (in dollars)	$ 12,653		$ 12,653		$ 8,452

COMPONENTS OF PENSION PLAN NE_3

COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS (Details) - Defined benefit pension plan - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Components of net periodic benefit cost:
Interest cost	$ 936	$ 860	$ 1,868	$ 1,720
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Interest Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Expected return on plan assets	$ (1,664)	$ (1,671)	$ (3,329)	$ (3,342)
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Expected Return (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Amortization of prior service cost	$ 46	$ 46	$ 93	$ 93
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Amortization of Prior Service Cost (Credit), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Amortization of net loss	$ 489	$ 1,142	$ 972	$ 2,283
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Amortization of Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)	Other Nonoperating Income (Expense)
Net periodic benefit cost	$ (193)	$ 377	$ (396)	$ 754

SEGMENT INFORMATION - General (

SEGMENT INFORMATION - General (Details)	6 Months Ended
	Jun. 30, 2022 segment
SEGMENT INFORMATION
Number of reportable segments	4
Number Of Coal Reportable Segments	2
Number Of Mining Complex	7

SEGMENT INFORMATION - Segment R

SEGMENT INFORMATION - Segment Results (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Reportable segment results
Revenues	$ 616,501	$ 362,443	$ 1,077,364	$ 681,065
Segment Adjusted EBITDA Expense	316,074	214,504	577,254	412,221
Segment Adjusted EBITDA	266,304	136,092	437,208	245,913
Total assets	2,333,191	2,115,513	2,333,191	2,115,513	$ 2,159,406
Capital expenditures	62,829	24,189	121,982	55,626
Illinois Basin
Reportable segment results
Revenues	313,497	218,233	588,193	409,167
Segment Adjusted EBITDA Expense	194,697	140,176	372,286	265,757
Segment Adjusted EBITDA	97,352	70,623	175,567	128,296
Total assets	748,291	726,555	748,291	726,555
Capital expenditures	35,343	12,515	71,890	28,916
Appalachia
Reportable segment results
Revenues	255,682	120,723	400,981	229,342
Segment Adjusted EBITDA Expense	117,369	74,456	201,084	148,182
Segment Adjusted EBITDA	124,377	41,641	175,480	73,147
Total assets	457,724	425,574	457,724	425,574
Capital expenditures	22,491	10,382	40,836	22,048
Oil & Gas Royalties
Reportable segment results
Revenues	36,579	17,587	67,540	31,607
Segment Adjusted EBITDA Expense	3,234	2,419	6,235	4,477
Segment Adjusted EBITDA	34,609	15,379	63,161	27,325
Total assets	667,278	604,355	667,278	604,355
Coal Royalties
Reportable segment results
Revenues	14,525	11,653	29,692	22,954
Segment Adjusted EBITDA Expense	5,398	4,871	10,217	8,899
Segment Adjusted EBITDA	9,127	6,782	19,475	14,055
Total assets	288,509	292,134	288,509	292,134
Other, Corporate and Elimination
Reportable segment results
Revenues	(3,782)	(5,753)	(9,042)	(12,005)
Segment Adjusted EBITDA Expense	(4,624)	(7,418)	(12,568)	(15,094)
Segment Adjusted EBITDA	839	1,667	3,525	3,090
Total assets	171,389	66,895	171,389	66,895
Capital expenditures	4,995	1,292	9,256	4,662
Operating segments
Reportable segment results
Revenues	616,501	362,443	1,077,364	681,065
Operating segments | Illinois Basin
Reportable segment results
Revenues	313,497	218,233	588,193	409,167
Operating segments | Appalachia
Reportable segment results
Revenues	255,682	120,723	400,981	229,342
Operating segments | Oil & Gas Royalties
Reportable segment results
Revenues	36,579	17,587	67,540	31,607
Operating segments | Other, Corporate and Elimination
Reportable segment results
Revenues	10,743	5,900	20,650	10,949
Elimination | Coal Royalties
Reportable segment results
Revenues	14,525	11,653	29,692	22,954
Elimination | Other, Corporate and Elimination
Reportable segment results
Revenues	$ (14,525)	$ (11,653)	$ (29,692)	$ (22,954)

SEGMENT INFORMATION - EBITDA Ex

SEGMENT INFORMATION - EBITDA Expense Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Reconciliation of consolidated Segment Adjusted EBITDA Expense
Segment Adjusted EBITDA Expense	$ 316,074	$ 214,504	$ 577,254	$ 412,221
Outside coal purchases	(151)	(114)	(151)	(114)
Other income (expense)	579	(1,351)	1,145	(2,548)
Product
Reconciliation of consolidated Segment Adjusted EBITDA Expense
Operating expenses (excluding depreciation, depletion and amortization)	$ 316,502	$ 213,039	$ 578,248	$ 409,559

SEGMENT INFORMATION - EBITDA Re

SEGMENT INFORMATION - EBITDA Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Reconciliation of consolidated Segment Adjusted EBITDA to net income
Consolidated Segment Adjusted EBITDA	$ 266,304		$ 136,092		$ 437,208	$ 245,913
General and administrative	(22,457)		(17,492)		(41,053)	(32,996)
Depreciation, depletion and amortization	(66,734)		(64,733)		(130,048)	(123,935)
Interest expense, net	(9,304)		(9,827)		(18,931)	(20,206)
Income tax (expense) benefit	(6,331)		(5)		(49,046)	7
NET INCOME ATTRIBUTABLE TO ARLP	161,478		44,035		198,130	68,783
Noncontrolling interest	323		130		613	208
NET INCOME	$ 161,801	$ 36,942	$ 44,165	$ 24,826	$ 198,743	$ 68,991