Alliance Resource Partners (ARLP) 10-K 24 Feb 23 2022 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Feb. 24, 2023	Jun. 30, 2022
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 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
Title of 12(b) Security	Common Units
Trading Symbol	ARLP
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Common Units Outstanding				127,198,650
Entity Public Float					$ 1,929,455,252
Auditor Name	GRANT THORNTON LLP	GRANT THORNTON LLP	Ernst & Young LLP
Auditor Firm ID	248	248	42
Auditor Location	Tulsa, Oklahoma	Tulsa, Oklahoma	Tulsa, Oklahoma
Entity Central Index Key	0001086600
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
CURRENT ASSETS:
Cash and cash equivalents	$ 296,023	$ 122,403
Trade receivables	238,610	129,531
Other receivables	8,601	680
Inventories, net	77,326	60,302
Advance royalties	7,556	4,958
Prepaid expenses and other assets	26,675	21,354
Total current assets	654,791	339,228
PROPERTY, PLANT AND EQUIPMENT:
Property, plant and equipment, at cost	3,857,390	3,608,347
Less accumulated depreciation, depletion and amortization	(2,040,468)	(1,909,669)
Total property, plant and equipment, net	1,816,922	1,698,678
OTHER ASSETS:
Advance royalties	67,713	63,524
Equity method investments	49,371	26,325
Equity securities	42,000
Operating lease right-of-use assets	14,950	14,158
Other long-term assets	15,726	17,493
Total other assets	189,760	121,500
TOTAL ASSETS	2,661,473	2,159,406
CURRENT LIABILITIES:
Accounts payable	95,122	69,586
Accrued taxes other than income taxes	22,967	17,787
Accrued payroll and related expenses	39,623	36,805
Accrued interest	5,000	5,000
Workers' compensation and pneumoconiosis benefits	14,099	12,293
Other current liabilities	53,790	20,035
Current maturities, long-term debt, net	24,970	16,071
Total current liabilities	255,571	177,577
LONG-TERM LIABILITIES:
Long-term debt, excluding current maturities, net	397,203	418,942
Pneumoconiosis benefits	100,089	107,560
Accrued pension benefit	12,553	25,590
Workers' compensation	39,551	44,911
Asset retirement obligations	142,254	123,517
Long-term operating lease obligations	12,132	12,366
Deferred income tax liabilities	35,814	391
Other liabilities	24,828	22,483
Total long-term liabilities	764,424	755,760
Total liabilities	1,019,995	933,337
COMMITMENTS AND CONTINGENCIES - (Note 23)
ARLP Partners' Capital:
Limited Partners - Common Unitholders 127,195,219 units outstanding	1,656,025	1,279,183
Accumulated other comprehensive loss	(41,054)	(64,229)
Total ARLP Partners' Capital	1,614,971	1,214,954
Noncontrolling interest	26,507	11,115
Total Partners' Capital	1,641,478	1,226,069
TOTAL LIABILITIES AND PARTNERS' CAPITAL	$ 2,661,473	$ 2,159,406

CONSOLIDATED BALANCE SHEETS (Pa

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

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
SALES AND OPERATING REVENUES:
Revenues	$ 2,406,511	$ 1,569,976	$ 1,328,129
EXPENSES:
Outside coal purchases	151	6,372
General and administrative	80,334	70,160	59,806
Depreciation, depletion and amortization	273,759	261,377	313,387
Settlement gain	(6,664)
Asset impairments			24,977
Goodwill impairment	0	0	132,026
Total operating expenses	1,748,075	1,350,773	1,410,981
INCOME (LOSS) FROM OPERATIONS	658,436	219,203	(82,852)
Interest expense (net of interest capitalized of $922, $396 and $1,325, respectively)	(37,332)	(39,229)	(45,613)
Interest income	2,035	88	135
Equity method investment income	5,634	2,130	907
Other income (expense)	4,353	(3,020)	(1,593)
INCOME (LOSS) BEFORE INCOME TAXES	633,126	179,172	(129,016)
INCOME TAX EXPENSE	53,978	417	35
NET INCOME (LOSS)	579,148	178,755	(129,051)
LESS: NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST	(1,958)	(598)	(169)
NET INCOME (LOSS) ATTRIBUTABLE TO ARLP	$ 577,190	$ 178,157	$ (129,220)
EARNINGS PER LIMITED PARTNER UNIT - BASIC (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
EARNINGS PER LIMITED PARTNER UNIT - DILUTED (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - BASIC (in units)	127,195,219	127,195,219	127,164,659
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - DILUTED (in units)	127,195,000	127,195,000	127,165,000
Product
EXPENSES:
Operating expenses (excluding depreciation, depletion and amortization)	$ 1,286,635	$ 943,257	$ 859,656
Coal sales
SALES AND OPERATING REVENUES:
Revenues	2,102,229	1,386,923	1,232,272
Oil & gas royalties
SALES AND OPERATING REVENUES:
Revenues	138,402	74,988	42,912
Transportation
SALES AND OPERATING REVENUES:
Revenues	113,860	69,607	21,129
EXPENSES:
Operating expenses (excluding depreciation, depletion and amortization)	113,860	69,607	21,129
Other revenues
SALES AND OPERATING REVENUES:
Revenues	$ 52,020	$ 38,458	$ 31,816

CONSOLIDATED STATEMENTS OF OP_2

CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CONSOLIDATED STATEMENTS OF INCOME
Interest expense, interest capitalized	$ 922	$ 396	$ 1,325

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
NET INCOME (LOSS)	$ 579,148	$ 178,755	$ (129,051)
OTHER COMPREHENSIVE INCOME (LOSS):
Total recognized in accumulated other comprehensive loss	23,175	23,445	(9,681)
OTHER COMPREHENSIVE INCOME (LOSS)	23,175	23,445	(9,681)
COMPREHENSIVE INCOME (LOSS)	602,323	202,200	(138,732)
Less: Comprehensive income attributable to noncontrolling interest	(1,958)	(598)	(169)
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO ARLP	600,365	201,602	(138,901)
Defined benefit pension plan
OTHER COMPREHENSIVE INCOME (LOSS):
Amortization of prior service cost (1)	186	186	186
Net actuarial gain	10,148	14,921	(5,522)
Amortization of net actuarial loss (gain) (1)	1,963	4,327	4,128
Total recognized in accumulated other comprehensive loss	12,297	19,434	(1,208)
Pneumoconiosis benefits
OTHER COMPREHENSIVE INCOME (LOSS):
Net actuarial gain	9,840	(161)	(7,787)
Amortization of net actuarial loss (gain) (1)	1,038	4,172	(686)
Total recognized in accumulated other comprehensive loss	$ 10,878	$ 4,011	$ (8,473)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income (loss)	$ 579,148	$ 178,755	$ (129,051)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, depletion and amortization	273,759	261,377	313,387
Non-cash compensation expense	11,029	5,709	3,345
Equity investment income	(5,634)	(2,130)	(907)
Distributions from equity method investments	5,634	2,130	907
Net gain on sale of property, plant and equipment	(3,665)	(6,592)	(5,850)
Asset impairment			24,977
Goodwill impairment	0	0	132,026
Change in deferred income tax	34,775	349	112
Other	5,677	3,970	13,909
Changes in operating assets and liabilities:
Trade receivables	(107,510)	(24,952)	56,172
Other receivables	(7,921)	3,109	(3,225)
Inventories, net	(20,138)	(4,673)	30,522
Prepaid expenses and other assets	(9,179)	211	(2,514)
Advance royalties	(6,787)	(7,523)	(7,690)
Accounts payable	14,580	19,481	(24,282)
Accrued taxes other than income taxes	5,180	(7,267)	9,286
Accrued payroll and related benefits	2,818	8,281	(8,051)
Pneumoconiosis benefits	3,849	6,832	2,340
Workers' compensation	(3,996)	(1,292)	1,355
Other	20,193	(10,573)	(6,123)
Total net adjustments	212,664	246,447	529,696
Net cash provided by operating activities	791,812	425,202	400,645
Property, plant and equipment:
Capital expenditures	(286,394)	(122,984)	(121,101)
Change in accounts payable and accrued liabilities	35,956	2,594	(8,773)
Proceeds from sale of property, plant and equipment	7,468	7,719	3,762
Contributions to equity method investments	24,087
Purchase of equity securities	(42,000)
Payments for acquisitions of businesses	(92,618)
Oil & gas reserve acquisition		(30,960)
Other	(1,663)	943	988
Net cash used in investing activities	(403,338)	(142,688)	(125,124)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under securitization facility	27,500	35,000	46,100
Payments under securitization facility	(27,500)	(90,900)	(64,000)
Proceeds from equipment financings			14,705
Payments on equipment financings	(16,071)	(17,299)	(14,805)
Borrowings under revolving credit facilities		15,000	70,000
Payments under revolving credit facilities		(102,500)	(237,500)
Borrowings from line of credit		5,340
Payment on line of credit		(5,340)
Payments on finance lease obligations	(840)	(766)	(8,368)
Cash settlement of grants under deferred compensation plan			(2,490)
Distributions paid to Partners	(196,347)	(52,158)	(51,753)
Other	(1,596)	(2,062)	(8,318)
Net cash used in financing activities	(214,854)	(215,685)	(256,429)
NET CHANGE IN CASH AND CASH EQUIVALENTS	173,620	66,829	19,092
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	122,403	55,574	36,482
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 296,023	$ 122,403	$ 55,574

CONSOLIDATED STATEMENT OF PARTN

CONSOLIDATED STATEMENT OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Limited Partners' Capital	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest	Total
Balance at beginning of period at Dec. 31, 2019	$ 1,331,482	$ (77,993)	$ 11,935	$ 1,265,424
Balance at beginning of period (in units) at Dec. 31, 2019	126,915,597
Comprehensive income (loss):
Net income (loss)	$ (129,220)		169	(129,051)
Actuarially determined long-term liability adjustments		(9,681)		(9,681)
COMPREHENSIVE INCOME (LOSS)				(138,732)
Settlement of deferred compensation plans	$ (3,800)			(3,800)
Settlement of deferred compensation plans (in units)	279,622
Common unit-based compensation	$ 3,345			3,345
Distributions on deferred common unit-based compensation	(986)			(986)
Distributions from consolidated company to noncontrolling interest			(728)	(728)
Distributions to Partners	(50,767)			(50,767)
Other	(1,489)			(1,489)
Balance at end of period at Dec. 31, 2020	$ 1,148,565	(87,674)	11,376	1,072,267
Balance at end of period (in units) at Dec. 31, 2020	127,195,219
Comprehensive income (loss):
Net income (loss)	$ 178,157		598	178,755
Actuarially determined long-term liability adjustments		23,445		23,445
COMPREHENSIVE INCOME (LOSS)				202,200
Settlement of deferred compensation plans	(1,090)			(1,090)
Common unit-based compensation	5,709			5,709
Distributions on deferred common unit-based compensation	(1,280)			(1,280)
Distributions from consolidated company to noncontrolling interest			(859)	(859)
Distributions to Partners	(50,878)			(50,878)
Balance at end of period at Dec. 31, 2021	$ 1,279,183	(64,229)	11,115	$ 1,226,069
Balance at end of period (in units) at Dec. 31, 2021	127,195,219			127,195,219
Comprehensive income (loss):
Net income (loss)	$ 577,190		1,958	$ 579,148
Actuarially determined long-term liability adjustments		23,175		23,175
COMPREHENSIVE INCOME (LOSS)				602,323
Common unit-based compensation	11,029			11,029
Distributions on deferred common unit-based compensation	(5,553)			(5,553)
Distributions from consolidated company to noncontrolling interest			(1,596)	(1,596)
Profits interest adjustment for noncontrolling interest	(15,030)		15,030
Distributions to Partners	(190,794)			(190,794)
Balance at end of period at Dec. 31, 2022	$ 1,656,025	$ (41,054)	$ 26,507	$ 1,641,478
Balance at end of period (in units) at Dec. 31, 2022	127,195,219			127,195,219

ORGANIZATION AND PRESENTATION

ORGANIZATION AND PRESENTATION	12 Months Ended
	Dec. 31, 2022
ORGANIZATION AND PRESENTATION
ORGANIZATION AND PRESENTATION	1. ORGANIZATION AND PRESENTATION ​ Significant Relationships Referenced in Notes to 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, an indirect wholly owned subsidiary. ● References to "Alliance Minerals" mean Alliance Minerals, LLC, an indirect wholly owned subsidiary. ● References to "Alliance Resource Properties" mean Alliance Resource Properties, LLC, an indirect wholly owned subsidiary . ​ 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 ("ARH"), 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. Alliance GP, LLC ("AGP"), which is indirectly wholly owned by Mr. Craft, is the direct owner of MGP. ​ Oil & Gas Acquisitions ​ Boulders ​ On October 13, 2021, we acquired approximately 1,480 oil & gas net royalty acres in the Delaware Basin from Boulders Royalty Corp. ("Boulders") for a purchase price of $31.0 million (the "Boulders Acquisition"). ​ Belvedere ​ On September 9, 2022, we acquired approximately 394 oil & gas net royalty acres in the Delaware Basin from Belvedere Operating, LLC ("Belvedere") for a purchase price of $11.4 million (the "Belvedere Acquisition"). ​ Jase ​ On October 26, 2022, we acquired approximately 3,928 oil & gas net royalty acres in the Midland and Delaware Basins from Jase Minerals, LP ("Jase") for a purchase price of $81.2 million (the "Jase Acquisition"). ​ The Boulders, Belvedere and Jase Acquisitions enhanced our ownership position in the Permian Basin and furthered our business strategy to grow our Oil & Gas Royalties segment through accretive acquisitions. See Note 3 – Acquisitions for more information. We now hold approximately 61,400 net royalty acres in premier oil & gas resource plays including previous acquisitions and our investment in AllDale Minerals III, LP ("AllDale III"). ​ 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 which are anticipated to be favorable to our unitholders. For more information on the Tax Election please see Note 9 – Income Taxes. ​ New Venture Investments ​ Francis ​ On April 5, 2022, we made a $20 million convertible note investment in Francis Renewable Energy, LLC ("Francis"). 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. For more information on this investment, please see Note 13 – Variable Interest Entities. ​ Infinitum ​ On April 29, 2022, we purchased $32.6 million of Series D Preferred Stock in 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. On November 2, 2022, we purchased an additional $9.4 million of Series D Preferred Stock in Infinitum. 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. For more information on this investment, please see Note 14 – Investments. ​ NGP ETP IV ​ 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 private equity fund sponsored by NGP Energy Capital Management, LLC ("NGP"). NGP ETP IV focuses on investments that are part of the global transition toward a lower carbon economy by partnering with top-tier management teams and investing growth equity in companies that drive or enable the growth of renewable energy, the electrification of our economy or the efficient use of energy. For more information on this investment, please see Note 13 – Variable Interest Entities. ​ Presentation ​ The consolidated financial statements include the accounts and operations of the ARLP Partnership and present our financial position as of December 31, 2022 and 2021, and results of our operations, comprehensive income, cash flows and changes in partners' capital for each of the three years in the period ended December 31, 2022. All of our intercompany transactions and accounts have been eliminated. Certain immaterial amounts in the prior year have been reclassified to conform to the current year presentation.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2022
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	2. SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES ​ Consolidation ​ Variable Interest Entity ("VIE") impact the VIE's economic performance and (b) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. The primary beneficiary is required to consolidate the VIE for financial reporting purposes. ​ To determine a VIE's primary beneficiary, we perform a qualitative assessment to determine which party, if any, has the power to direct activities of the VIE and the obligation to absorb losses and/or receive its benefits. This assessment involves identifying the activities that most significantly impact the VIE's economic performance and determine whether it, or another party, has the power to direct those activities. When evaluating whether we are the primary beneficiary of a VIE, we perform a qualitative analysis that considers the design of the VIE, the nature of our involvement and the variable interests held by other parties. See Note 13 – Variable Interest Entities for further information. ​ Estimates ​ ● Impairment assessments of investments, property, plant and equipment, and goodwill; ● Asset retirement obligations; ● Pension valuation variables; ● Workers' compensation and pneumoconiosis valuation variables; ● Acquisition related purchase price allocations; ● Life of mine assumptions; ● Oil & gas reserve quantities and carrying amounts; and ● Determination of oil & gas revenue accruals ​ These significant estimates and assumptions are discussed throughout these notes to the consolidated financial statements. ​ Fair Value Measurements ​ We use the following fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels: ​ ● Level 1 – Quoted prices for identical assets and liabilities in active markets that we have the ability to access at the measurement date. ​ ● Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model derived valuations whose inputs are observable or whose significant value drivers are observable. ​ ● Level 3 – Unobservable inputs for the asset or liability including situations where there is little, if any, market activity for the asset or liability. ​ The fair value hierarchy gives the highest priority to quoted prices in active markets (Level 1) and the lowest priority to unobservable data (Level 3). In some cases, the inputs used to measure fair value might fall into different levels of the fair value hierarchy. The lowest level input that is significant to a fair value measurement determines the applicable level in the fair value hierarchy. Assessing the significance of a particular input to the fair value measurement requires judgment, considering factors specific to the asset or liability. Significant fair value measurements are used in our significant estimates and are discussed throughout these notes. ​ Cash and Cash Equivalents ​ Cash Management ​ Inventories ​ Business Combinations ​ Goodwill ​ Property, Plant and Equipment ​ Mine Development Costs ​ Leases ​ We review each agreement to determine if an arrangement within the agreement contains a lease at the inception of an arrangement. Once an arrangement is determined to contain an operating or finance lease with a term greater than 12 months, we recognize a lease liability for the obligation to make lease payments and a right-of-use asset for the right to use the underlying asset for the lease term based on the present value of lease payments over the lease term. The lease term includes all noncancelable periods defined in the lease as well as periods covered by options to extend the lease that we are reasonably certain to exercise. As an implicit borrowing rate cannot be determined under most of our leases, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. ​ Expenses related to leases determined to be operating leases will be recognized on a straight-line basis over the lease term including any reasonably assured renewal periods, while those determined to be finance leases will be recognized following a front-loaded expense profile in which interest and amortization are presented separately in the income statement. The determination of whether a lease is accounted for as a finance lease or an operating lease requires management to make estimates primarily about the fair value of the asset and its estimated economic useful life. ​ Long-Lived Asset Impairment ​ Oil & Gas Reserve Quantities and Carrying Amounts ​ Mineral interests in oil & gas properties are grouped using a reasonable aggregation of properties with a common geological structural feature or stratigraphic condition, which we may also refer to as a depletable group. Mineral interests in proved oil & gas properties are depleted based on the units-of-production method. Proved reserves are quantities of oil & gas that can be estimated with reasonable certainty to be recoverable in the future from a given date forward, from known reservoirs, under existing economic conditions, operating methods, and government regulations. Proved developed resources are the quantities expected to be recovered through our operators' existing wells with existing equipment, infrastructure and operating methods. ​ We evaluate impairment of our oil & gas mineral interests in proved properties whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. This evaluation is performed on a depletable group basis. We compare the undiscounted projected future cash flows expected in connection with a depletable group to its unamortized carrying amount to determine recoverability. When the carrying amount of a depletable group exceeds its estimated undiscounted future cash flows, the carrying amount is written down to its fair value, which is measured as the present value of the projected future cash flows of such properties. The factors used to determine fair value include estimates of proved reserves, future commodity prices, timing of future production, future expenditures, and a risk-adjusted discount rate. ​ Our oil & gas mineral interests in unproved properties are also assessed for impairment periodically but at least annually when facts and circumstances indicate that the unproved property will not be transferred to proved properties. Impairment of individual unproved properties whose acquisition costs are relatively significant are assessed on a property-by-property basis, and an impairment loss is recognized if we determine that the unproved property will not be transferred to proved properties. Impairment of unproved properties whose acquisition costs are not individually significant are assessed on a group basis. Any amount of loss to be recognized and the amount of a valuation allowance needed to provide for impairment of those properties is determined by amortizing those properties in the aggregate on the basis of historical experience and other relevant information, such as the relative proportion of such properties on which proved reserves have been found in the past. ​ Upon the sale of a complete depletable group, the book value thereof, less proceeds or salvage value, are charged to income. Upon the sale or retirement of an aggregation of interests which make up less than a complete depletable group, the proceeds are credited to accumulated depreciation, depletion and amortization, unless doing so would significantly alter the depreciation, depletion and amortization rate of the depletable group, in which case a gain or loss would be recorded. ​ Intangibles Prepaid expenses and other assets Other long-term assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ December 31, 2021 ​ ​ ​ ​ Accumulated Intangibles, ​ ​ Accumulated Intangibles, ​ Original Cost Amortization Net Original Cost Amortization Net ​ ​ (in thousands) ​ Customer contracts and other ​ 10,623 ​ (10,623) ​ — ​ 10,623 ​ (9,504) ​ 1,119 ​ Mining permits ​ 1,500 ​ (472) ​ 1,028 ​ 1,500 ​ (418) ​ 1,082 ​ Total ​ $ 12,123 ​ $ (11,095) ​ $ 1,028 ​ $ 12,123 ​ $ (9,922) ​ $ 2,201 ​ ​ Amortization expense attributable to intangible assets is estimated as follows: ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ (in thousands) 2023 ​ $ 54 ​ 2024 ​ 54 ​ 2025 ​ 54 ​ 2026 ​ 54 ​ 2027 ​ 54 ​ Thereafter ​ 758 ​ ​ Investments ​ Our investments and ownership interests in entities in which we do not have a controlling financial interest are accounted for under the equity method of accounting if we have the ability to exercise significant influence over the entity. Investments accounted for under the equity method are initially recorded at cost, and the difference between the basis of our investment and the underlying equity in the net assets of the joint venture at the investment date, if any, is amortized over the lives of the related assets that gave rise to the difference. ​ In the event our ownership requires a disproportionate sharing of income or loss, we use the hypothetical liquidation at book value ("HLBV") method to determine the appropriate allocation of income or loss. Under the HLBV method, income or loss of the investee is allocated based on hypothetical amounts that each investor would be entitled to receive if the net assets held were liquidated at book value at the end of each period, adjusted for any contributions made and distributions received during the period. ​ We hold equity method investments in AllDale III, Francis and NGP ETP IV. See Note 13 – Variable Interest Entities and Note 14 – Investments for further discussion of our equity method investments. ​ We review our investments for impairment whenever events or changes in circumstances indicate a loss in the value of the investment may be other-than-temporary. ​ Advance Royalties Advance royalties ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Advance royalties, affiliates (see Note 22 – Related-Party Transactions) ​ $ 60,608 ​ $ 55,613 ​ Advance royalties, third-parties ​ 14,661 ​ 12,869 ​ Total advance royalties ​ $ 75,269 ​ $ 68,482 ​ ​ Asset Retirement Obligations ​ Pension Benefits ​ The discount rate is determined for our pension benefit plan based on an approach specific to our plan. The year end discount rate is determined considering a yield curve comprised of high-quality corporate bonds and the timing of the expected benefit cash flows. ​ The expected long-term rate of return on plan assets is determined based on broad equity and bond indices, the investment goals and objectives, the target investment allocation and on the average annual total return for each asset class. ​ Unrecognized actuarial gains and losses and unrecognized prior service costs and credits are deferred and recorded in accumulated other comprehensive loss until amortized as a component of net periodic benefit cost. Unrecognized actuarial gains and losses in excess of 10% of the greater of the benefit obligation or the market-related value of plan assets are amortized over the participants' average remaining future years of service. ​ Workers Compensation and Pneumoconiosis (Black Lung) Benefits ​ We provide income replacement and medical treatment for work-related traumatic injury claims as required by applicable state laws. Workers' compensation laws also compensate survivors of workers who suffer employment related deaths. Our liability for traumatic injury claims is the estimated present value of current workers' compensation benefits, based on our actuarial estimates. Our actuarial calculations are based on a blend of actuarial projection methods and numerous assumptions including claim development patterns, mortality, medical costs and interest rates. ​ Our pneumoconiosis benefits liability is calculated using the service cost method based on the actuarial present value of the estimated pneumoconiosis obligation. Our actuarial calculations are based on numerous assumptions including claim development patterns, medical costs and mortality. Actuarial gains or losses are amortized over the remaining service period of active miners. See Note 21 – Accrued Workers' Compensation and Pneumoconiosis Benefits for more information on Workers' Compensation and Pneumoconiosis Benefits. ​ Coal Revenue Recognition ​ The estimated transaction price from each of our contracts is based on the total amount of consideration we expect to be entitled to under the contract. Included in the transaction price for certain coal supply contracts is the impact of variable consideration, including quality price adjustments, handling services, government imposition claims, per ton price fluctuations based on certain coal sales price indices and anticipated payments in lieu of shipments. We have constrained the expected value of variable consideration in our estimation of transaction price and only included this consideration to the extent that it is probable that a significant revenue reversal will not occur. The estimated transaction price for each contract is allocated to our performance obligations based on relative standalone selling prices determined at contract inception. Variable consideration is allocated to a specific part of the contract in many instances, such as if the variable consideration is based on production activities for coal delivered during a certain period or the outcome of a customer's ability to accept coal shipments over a certain period. ​ Contract assets are recorded as trade receivables and reported separately in our consolidated balance sheet from other contract assets as title passes to the customer and our right to consideration becomes unconditional. Payments for coal shipments are typically due within two four weeks ​ Oil & Gas Revenue Recognition ​ We also periodically earn revenue from lease bonuses. We recognize lease bonus revenue when we execute a lease of our mineral interests to exploration and production companies. A lease agreement represents our contract with an operator, which is generally an exploration and production company. The contract will (a) generally transfer the rights to any oil or gas discovered, (b) grant us a right to a specified royalty interest from the operator, and (c) require the operator to commence drilling and complete operations within a specified time period. Control of the minerals transfers to the operator when the lease agreement is executed. At the time we execute the lease agreement, we expect to receive the lease bonus payment within a reasonable time, though in no case more than one year, such that we do not adjust the expected amount of consideration for the effects of any significant financing component. ​ As a non-operator, we have limited visibility into the timing of when new wells start producing. In addition, production statements may not be received for 30 to 90 days or more after the date production is delivered. As a result, we are required to estimate the amount of production delivered to the purchaser and the price that will be received for the sale of the product. The expected sales volumes and prices from our properties are estimated and recorded within the Trade receivables ​ Common Unit-Based Compensation ​ We utilize the Supplemental Executive Retirement Plan ("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 MGP Amended and Restated Deferred Compensation Plan for Directors ("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. ​ The fair value of restricted common unit grants under the LTIP, SERP and the Directors' Deferred Compensation Plan are determined on the grant date of the award and recognized as compensation expense on a pro rata basis for LTIP and SERP awards, as appropriate, over the requisite service period. Compensation expense is fully recognized on the grant date for quarterly distributions credited to SERP accounts and Directors' Deferred Compensation Plan awards. The corresponding liability is classified as equity and included in limited partners' capital in the consolidated financial statements (See Note 18 – Common Unit-Based Compensation Plans). ​ Income Taxes ​ 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

ACQUISITIONS

ACQUISITIONS	12 Months Ended
	Dec. 31, 2022
ACQUISITION
ACQUISITION	3. ACQUISITION S ​ Boulders ​ On October 13, 2021, we acquired approximately 1,480 oil & gas net royalty acres in the Delaware Basin from Boulders for a purchase price of $31.0 million, which was funded with cash on hand. This acquisition gives us increased exposure to a prolific area of the Delaware Basin and is within close proximity to reserves acquired in previous acquisitions. The acreage acquired in the Boulders Acquisition was mostly undeveloped. Because more than 90% of the mineral interests acquired in the acquisition represent undeveloped properties, including proved undeveloped, we have determined that the Boulders Acquisition should be accounted for as an asset acquisition. We have allocated the purchase price to the acquired reserves as follows: ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ Mineral interests in proved properties ​ $ 12,542 ​ Mineral interests in unproved properties ​ ​ 18,418 ​ ​ ​ $ 30,960 ​ ​ Belvedere ​ On September 9, 2022 (the "Belvedere Acquisition Date"), we acquired approximately 394 oil & gas net royalty acres in the Delaware Basin from Belvedere for a cash purchase price of $11.4 million, which was funded with cash on hand. This acquisition gives us additional exposure to a productive area of the Delaware Basin and is within close proximity to reserves that we currently own. Because the mineral interests acquired in the Belvedere Acquisition include royalty interests in both developed properties and undeveloped properties, we have determined that the acquisition should be accounted for as a business combination and the underlying assets should be recorded at fair value as of the Belvedere Acquisition Date on our consolidated balance sheet. ​ The following table summarizes the fair value allocation of assets acquired as of the Belvedere Acquisition Date: ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ Mineral interests in proved properties ​ $ 7,724 ​ Mineral interests in unproved properties ​ ​ 3,667 ​ ​ ​ $ 11,391 ​ ​ The fair value of the mineral interests was determined using an income approach consisting of a discounted cash flow model. The assumptions used in the discounted cash flow model included estimated production, projected cash flows, forward oil & gas prices and risk adjusted discount rates. Certain assumptions used are not observable in active markets; therefore, the fair value measurements represent Level 3 fair value measurements. ​ The amounts of revenue and earnings from the mineral interests acquired in the Belvedere Acquisition included in our consolidated statements of operations since the Belvedere Acquisition Date are as follows: ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 ​ (in thousands) ​ ​ ​ ​ Revenue $ 722 ​ Net income 488 ​ ​ The following represents our supplemental pro forma consolidated revenues and net income for the years ended December 31, 2022 and 2021 as if the mineral interests acquired in the Belvedere Acquisition had been included in our consolidated results since January 1, 2021. These amounts have been calculated after applying our accounting policies. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ (unaudited) ​ Revenues ​ $ 2,407,368 ​ $ 1,571,119 ​ Net income ​ ​ 579,906 ​ ​ 179,747 ​ ​ Jase ​ On October 26, 2022 (the "Jase Acquisition Date"), we acquired approximately 3,928 oil & gas net royalty acres in the Midland and Delaware Basins from Jase for a cash purchase price of $81.2 million which was funded with cash on hand. This acquisition further enhanced our ownership position in the Permian Basin. Because the mineral interests acquired in the Jase Acquisition include royalty interests in both developed properties and undeveloped properties, we have determined that the acquisition should be accounted for as a business combination and the underlying assets should be recorded at fair value as of the Jase Acquisition Date on our consolidated balance sheet. ​ The following table summarizes the fair value allocation of assets acquired as of the Jase Acquisition Date: ​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ Mineral interests in proved properties ​ $ 35,918 ​ Mineral interests in unproved properties ​ ​ 43,740 ​ Receivables ​ ​ 1,569 ​ Net assets acquired ​ $ 81,227 ​ ​ The fair value of the mineral interests was determined using an income approach consisting of a discounted cash flow model. The assumptions used in the discounted cash flow model included estimated production, projected cash flows, forward oil & gas prices and risk adjusted discount rates. The fair value of the receivables was determined using estimated production during the period between the Jase Acquisition Date and the effective date of the agreement and observable sales prices during the period. Certain assumptions used are not observable in active markets; therefore, the fair value measurements represent Level 3 fair value measurements. ​ The amounts of revenue and earnings from the mineral interests acquired in the Jase Acquisition included in our consolidated statements of operations since the Jase Acquisition Date are as follows: ​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 ​ (in thousands) ​ ​ ​ ​ Revenue $ 1,689 ​ Net income 854 ​ ​ The following represents our supplemental pro forma consolidated revenues and net income for the years ended December 31, 2022 and 2021 as if the mineral interests acquired in the Jase Acquisition had been included in our consolidated results since January 1, 2021. These amounts have been calculated after applying our accounting policies. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ (unaudited) ​ Revenues ​ $ 2,417,278 ​ $ 1,579,660 ​ Net income ​ ​ 587,749 ​ ​ 186,151 ​ ​

LONG-LIVED ASSET IMPAIRMENTS

LONG-LIVED ASSET IMPAIRMENTS	12 Months Ended
	Dec. 31, 2022
LONG-LIVED ASSET IMPAIRMENTS
LONG-LIVED ASSET IMPAIRMENTS	4. LONG-LIVED ASSET IMPAIRMENT S ​ During the year ended December 31, 2020, we recorded $23.5 million of non-cash asset impairment charges in our Illinois Basin Coal Operations segment due to sealing our idled Gibson North mine, resulting in its permanent closure, and a decrease in the fair value of certain mining equipment at our idled operations and greenfield coal mineral resources as a result of weakened coal market conditions including the impact of the COVID-19 pandemic. During the same period, we also recorded an asset impairment charge of $1.5 million in our Coal Royalties segment due to a decrease in the fair value of greenfield coal mineral resources held by Alliance Resource Properties near our coal mining operations in the Illinois Basin. See Note 25 – Segment Information for more information about our segments. ​ The fair values of the impaired assets were determined using a market approach, which represents Level 3 fair value measurements under the fair value hierarchy. The fair value analysis used assumptions regarding the marketability of certain mining and coal mineral reserve and resource assets near our Illinois Basin coal mining operations. ​ See Note 2 – Summary of Significant Accounting Policies – Long-Lived Asset Impairment for more information on our accounting policy for asset impairments.

GOODWILL IMPAIRMENT

GOODWILL IMPAIRMENT	12 Months Ended
	Dec. 31, 2022
GOODWILL IMPAIRMENT
GOODWILL IMPAIRMENT	5. GOODWILL IMPAIRMENT ​ During the first quarter of 2020, we considered whether an interim test of our consolidated goodwill of $136.4 million was necessary. Our consolidated goodwill included $132.0 million recorded in our Illinois Basin Coal Operations segment in conjunction with our acquisition of the Hamilton mine on July 31, 2015. We assessed certain events and changes in circumstances, including (a) adverse industry and market developments, including the impact of the COVID-19 pandemic, (b) our response to these developments, including temporarily ceasing production at several mines, including our Hamilton mine and (c) our actual performance during the quarter. After consideration of these events and changes in circumstances, we performed an interim test of the goodwill associated with Hamilton comparing Hamilton's carrying amount to its fair value. ​ We estimated the fair value of Hamilton using an income approach utilizing a discounted cash flow model. The assumptions used in the discounted cash flow model included estimated production, forward coal prices, operating expenses, capital expenditures and a weighted average cost of capital. Our forecasts of future cash flows considered market conditions at the time of the assessment and our estimate of the mine's performance in future years based on the information available to us. Key assumptions used in our valuation were not observable in active markets; therefore, the fair value measurements represent Level 3 fair value measurements. The fair value of Hamilton was determined to be below its carrying amount (including goodwill) by more than the recorded balance of goodwill associated with the mine. Accordingly, we recognized an impairment charge of $132.0 million consisting of the total carrying amount of goodwill associated with Hamilton.

INVENTORIES

INVENTORIES	12 Months Ended
	Dec. 31, 2022
INVENTORIES
INVENTORIES	6. INVENTORIES ​ Inventories consist of the following : ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal ​ $ 23,553 ​ $ 24,845 ​ Supplies (net of reserve for obsolescence of $6,601 and $5,554, respectively) ​ 53,773 ​ 35,457 ​ Total inventories, net ​ $ 77,326 ​ $ 60,302 ​ ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for inventories.

PROPERTY, PLANT AND EQUIPMENT

PROPERTY, PLANT AND EQUIPMENT	12 Months Ended
	Dec. 31, 2022
PROPERTY, PLANT AND EQUIPMENT
PROPERTY, PLANT AND EQUIPMENT	7. PROPERTY, PLANT AND EQUIPMENT ​ Property, plant and equipment consist of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Mining equipment and processing facilities ​ $ 1,927,603 ​ $ 1,896,470 ​ Land and coal mineral rights ​ 499,950 ​ 458,440 ​ Oil & gas mineral interests ​ ​ 740,635 ​ ​ 647,864 ​ Buildings, office equipment, improvements and other miscellaneous equipment ​ 300,436 ​ 282,902 ​ Construction, mine development and other projects in progress ​ 99,042 ​ 44,217 ​ Mine development costs ​ 289,724 ​ 278,454 ​ Property, plant and equipment, at cost ​ 3,857,390 ​ 3,608,347 ​ Less accumulated depreciation, depletion and amortization ​ (2,040,468) ​ (1,909,669) ​ Total property, plant and equipment, net ​ $ 1,816,922 ​ $ 1,698,678 ​ ​ Depreciation, depletion and amortization expense related to property, plant and equipment was $270.9 million, $256.9 million and $297.0 million for the years ended December 31, 2022, 2021 and 2020, respectively. ​ At December 31, 2022 and 2021, land and coal mineral rights above include $29.9 million and $37.4 million, respectively, of carrying value associated with coal mineral reserves and resources attributable to properties where we or a third party to which we lease coal mineral reserves and resources are not currently engaged in mining operations or leasing to third parties, and therefore, the coal mineral reserves are not currently being depleted. We believe that the carrying value of these coal mineral reserves will be recovered. ​ At December 31, 2022 and 2021, our oil & gas mineral interests noted in the table above includes the carrying value of our unproved oil & gas mineral interests totaling $383.6 million and $355.1 million, respectively. As discussed in Note 2 – Summary of Significant Accounting Policies, we generally do not record depletion expense for our unproved oil & gas mineral interests; however, we do review for impairment as needed throughout the year. ​ During 2022, we incurred $11.3 million in mine development costs, primarily related to Hamilton and River View Coal, LLC ("River View") mine. During 2021, we did not incur material mine development costs. All past capitalized mine development costs are associated with other mines that shifted to the production phase in past years and we are amortizing these costs accordingly. We believe that the carrying value of the past development costs will be recovered. ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for property, plant and equipment.

LONG-TERM DEBT

LONG-TERM DEBT	12 Months Ended
	Dec. 31, 2022
LONG-TERM DEBT
LONG-TERM DEBT	8. LONG-TERM DEBT ​ Long-term debt consists of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unamortized Discount and ​ ​ ​ Principal ​ Debt Issuance Costs ​ ​ ​ December 31, ​ December 31, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Replaced credit facility ​ $ — ​ $ — ​ $ (2,702) ​ $ (5,019) ​ Senior notes ​ 400,000 ​ 400,000 ​ (2,134) ​ (3,048) ​ Securitization facility ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ May 2019 equipment financing ​ ​ — ​ ​ 1,503 ​ ​ — ​ ​ — ​ November 2019 equipment financing ​ ​ 21,072 ​ ​ 31,972 ​ ​ — ​ ​ — ​ June 2020 equipment financing ​ ​ 5,937 ​ ​ 9,605 ​ ​ — ​ ​ — ​ ​ ​ 427,009 ​ 443,080 ​ (4,836) ​ (8,067) ​ Less current maturities ​ (24,970) ​ (16,071) ​ — ​ — ​ Total long-term debt ​ $ 402,039 ​ $ 427,009 ​ $ (4,836) ​ $ (8,067) ​ ​ Credit Facility. ​ The Credit Agreement is guaranteed by ARLP and certain of its subsidiaries, including the Intermediate Partnership and most of the direct and indirect subsidiaries of Alliance Coal (the "Subsidiary Guarantors"). The Credit Agreement also is secured by substantially all of the assets of the Subsidiary Guarantors and Alliance Coal. Borrowings under the Credit Agreement bear interest, at our option, at either (i) an adjusted term rate plus the applicable margin or (ii) the base rate plus the applicable margin. The base rate is the highest of (i) the Overnight Bank Funding Rate plus 0.50%, (ii) the Administrative Agent's prime rate, and (iii) the Daily Simple Secured Overnight Financing Rate plus 100 basis points. The applicable margin for borrowings under the Credit Agreement are determined by reference to the Consolidated Debt to Consolidated Cash Flow Ratio. Borrowings under the Replaced Credit Facility bore interest, at our option, at either (i) the base rate at the greater of three benchmarks or (ii) a Eurodollar Rate, plus margins. The Eurodollar Rate, with applicable margin, under the Replaced Credit Facility was 6.74% as of December 31, 2022. At December 31, 2022, we had $41.1 million of letters of credit outstanding with $418.4 million available for borrowing under the Replaced Credit Facility. We incurred an annual commitment fee of 0.35% on the undrawn portion of the Replaced Credit Facility. ​ The Credit Agreement contains various restrictions affecting Alliance Coal and its subsidiaries, including, among other things, restrictions on incurrence of additional indebtedness and liens, sale of assets, investments, mergers and consolidations and transactions with affiliates. In each case, these restrictions are subject to various exceptions. In addition, the restrictions apply to the payment of cash distributions if such payment would result in a certain fixed charge coverage ratio (as determined in the Credit Agreement) or in Alliance Coal having liquidity of less than $200 million. The Credit Agreement requires us to maintain (a) debt of Alliance Coal to cash flow ratio of not more than 1.5 to 1.0, (b) a consolidated debt of Alliance Coal and the Intermediate Partnership to cash flow ratio of not more than 2.5 to 1.0 and (c) an interest coverage ratio of not less than 3.0 to 1.0, in each case, during the four most recently ended fiscal quarters. The Replaced Credit Facility was subject to similar restrictions on the Intermediate Partnership. The Replaced Credit Facility required 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 0.52 to 1.0, 21.76 to 1.0 and 0.03 to 1.0, respectively, for the trailing twelve months ended December 31, 2022. We remained in compliance with the covenants of the Replaced Credit Facility as of December 31, 2022 and anticipate remaining in compliance with the covenants of the new Credit Agreement. We utilize the Credit Agreement, as appropriate, for working capital requirements, capital expenditures and investments, scheduled debt payments and distribution payments. ​ Net restricted assets, as defined by the Securities and Exchange Commission, refers to the amount of our consolidated subsidiaries' net assets for which the ability to transfer funds to ARLP in the form of cash dividends, loans, advances, or transfers is restricted. As a result of the restrictions contained in the Replaced Credit Facility and its associated compliance ratios, the amount of our net restricted assets at December 31, 2022 was $537.3 million. ​ Senior Notes. ​ Accounts Receivable Securitization ​ May 2019 Equipment Financing. ​ November 2019 Equipment Financing. ​ June 2020 Equipment Financing. ​ Other. ​ Aggregate maturities of long-term debt are payable as follows: ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ ​ December 31, (in thousands) 2023 ​ $ 24,970 ​ 2024 ​ 2,039 ​ 2025 ​ 400,000 ​ ​ ​ $ 427,009 ​ ​

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2022
INCOME TAXES
INCOME TAXES	9. INCOME TAXES ​ Components of income tax expense are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Current: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 17,572 ​ $ (1) ​ $ (78) ​ State ​ 1,605 ​ 70 ​ 1 ​ ​ ​ 19,177 ​ 69 ​ (77) ​ Deferred: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ 33,038 ​ 356 ​ (178) ​ State ​ 1,763 ​ (8) ​ 290 ​ ​ ​ 34,801 ​ 348 ​ 112 ​ Income tax expense ​ $ 53,978 ​ $ 417 ​ $ 35 ​ ​ 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 year ended December 31, 2022. This increase in income tax expense reduced net income by $37.3 million, or approximately $0.29 per basic and diluted ​ Reconciliations of income taxes at the U.S. federal statutory tax rate to income taxes at our effective tax rate are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ ​ (in thousands) ​ Income taxes at statutory rate ​ $ 132,956 ​ $ 37,626 ​ $ (27,093) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: Income taxes at statutory rate on Partnership income not subject to income taxes ​ (112,032) ​ (36,577) ​ 26,293 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase (decrease) resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ State taxes, net of federal income tax ​ 1,492 ​ 275 ​ (192) ​ Change in valuation allowance of deferred tax assets ​ (317) ​ (834) ​ 1,151 ​ Deferred taxes related to tax election ​ ​ 37,253 ​ ​ — ​ ​ — ​ Tax effect of noncontrolling interest income not subject to income taxes ​ ​ (5,399) ​ ​ — ​ ​ — ​ Other ​ 25 ​ (73) ​ (124) ​ Income tax expense ​ $ 53,978 ​ $ 417 ​ $ 35 ​ ​ The effective income tax rate for our income tax expense for the year ended December 31, 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 rates for our income tax expense for the years ended December 31, 2021 and 2020 are 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: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2022 2021 ​ ​ (in thousands) ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ $ (38,349) ​ $ (2,169) ​ Total deferred tax liabilities ​ ​ (38,349) ​ ​ (2,169) ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ Federal loss carryovers and credits ​ ​ 2,139 ​ ​ 1,328 ​ Other ​ 1,084 ​ 808 ​ Total deferred tax assets ​ ​ 3,223 ​ ​ 2,136 ​ Less valuation allowance ​ ​ — ​ ​ (317) ​ Net deferred tax assets ​ ​ 3,223 ​ ​ 1,819 ​ ​ ​ ​ ​ ​ ​ ​ ​ Overall net deferred tax liabilities ​ $ (35,126) ​ $ (350) ​ ​ ​ 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. ​ Our 2019 through 2022 tax years remain open to examination by tax authorities. We have been notified by the Internal Revenue Service that lower-tier partnership income tax returns for the tax year ended December 31, 2020 have been selected for audit.

LEASES

LEASES	12 Months Ended
	Dec. 31, 2022
LEASES
LEASES	10. LEASES ​ The components of lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 ​ 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ $ 597 ​ $ 597 ​ $ 704 ​ Interest on lease liabilities ​ 73 ​ 147 ​ 377 ​ Operating lease cost ​ 274 ​ 2,404 ​ 3,873 ​ Short-term lease cost ​ ​ — ​ ​ 200 ​ ​ 84 ​ Variable lease cost ​ 1,665 ​ 1,306 ​ 1,375 ​ Total lease cost ​ $ 2,609 ​ $ 4,654 ​ $ 6,413 ​ ​ Rental expense was $5.1 million, $3.3 million and $5.2 million for the years ended December 31, 2022, 2021 and 2020 respectively. ​ Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 ​ 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating cash flows for operating leases ​ $ 2,880 ​ $ 2,367 ​ $ 3,870 ​ Operating cash flows for finance leases ​ $ 73 ​ $ 147 ​ $ 377 ​ Financing cash flows for finance leases ​ $ 840 ​ $ 766 ​ $ 8,368 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for lease obligations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases ​ $ 1,315 ​ $ 189 ​ $ 278 ​ ​ Supplemental balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ Finance leases: ​ ​ ​ ​ ​ ​ ​ Property and equipment finance lease assets, gross ​ $ 5,485 ​ $ 5,485 ​ Accumulated depreciation ​ (5,061) ​ (4,464) ​ Property and equipment finance lease assets, net ​ $ 424 ​ $ 1,021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ Weighted average remaining lease term ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 13.4 years ​ ​ 15.5 years ​ Finance leases ​ ​ 5.0 years ​ ​ 3.5 years ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average discount rate ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 6.0 % ​ ​ 6.0 % ​ Finance leases ​ 4.8 % ​ ​ 7.4 % ​ ​ Maturities of lease liabilities as of December 31, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases Finance leases ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ $ 3,253 ​ $ 140 ​ 2024 ​ ​ 2,918 ​ ​ 140 ​ 2025 ​ ​ 1,734 ​ ​ 140 ​ 2026 ​ ​ 1,106 ​ ​ 140 ​ 2027 ​ ​ 1,112 ​ ​ 140 ​ Thereafter ​ ​ 11,901 ​ ​ — ​ Total lease payments ​ ​ 22,024 ​ ​ 700 ​ Less imputed interest ​ ​ (7,100) ​ ​ (82) ​ Total ​ $ 14,924 ​ $ 618 ​ ​ The current portion of our operating and finance lease obligations are included in Other current liabilities Other liabilities ​

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS	12 Months Ended
	Dec. 31, 2022
FAIR VALUE MEASUREMENTS
FAIR VALUE MEASUREMENTS	11. FAIR VALUE MEASUREMENTS ​ The following table summarizes our fair value measurements within the hierarchy not included elsewhere in these notes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ December 31, 2021 ​ ​ Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 ​ ​ (in thousands) ​ Long-term debt ​ $ — ​ $ 424,420 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​ Total ​ $ — ​ $ 424,420 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​ ​ See Note 2 – Summary of Significant Accounting Policies – Fair Value Measurements for more information regarding fair value hierarchy levels. ​ 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 8 – Long-Term Debt). The fair value of debt, which is based on these interest rates, is classified as a Level 2 measurement under the fair value hierarchy.

PARTNERS' CAPITAL

PARTNERS' CAPITAL	12 Months Ended
	Dec. 31, 2022
PARTNERS' CAPITAL
PARTNERS' CAPITAL	12. PARTNERS' CAPITAL ​ Distributions ​ Our available cash that is not used for unit repurchases may, at the discretion of our general partner, be distributed within 45 days after the end of each quarter to unitholders of record. Available cash is generally defined in the partnership agreement as all cash and cash equivalents on hand at the end of each quarter less reserves established by MGP in its reasonable discretion for future cash requirements. These reserves are retained to provide for the conduct of our business, the payment of debt principal and interest and to provide funds for future distributions. The following table summarizes the quarterly per unit distribution paid during each quarter of 2020 through 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 First Quarter ​ $ 0.250 ​ $ — ​ $ 0.400 ​ Second Quarter ​ $ 0.350 ​ $ 0.100 ​ $ — ​ Third Quarter ​ $ 0.400 ​ $ 0.100 ​ $ — ​ Fourth Quarter ​ $ 0.500 ​ $ 0.200 ​ $ — ​ ​ On January 27, 2023, we declared a quarterly distribution of $0.70 per unit, totaling approximately $89.0 million, on all our common units outstanding, which was paid on February 14, 2023, to all unitholders of record on February 7, 2023. ​ Unit Repurchase Program ​ In May 2018, the board of directors of our general partner ("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 year ended December 31, 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. ​ In January 2023, the Board of Directors authorized a $93.5 million increase to the unit repurchase program, which had $6.5 million of available capacity as of December 31, 2022. As a result, we are authorized to repurchase up to a total of $100.0 million of ARLP common units. As of February 24, 2023, we have repurchased and retired 856,629 units at an average unit price of $21.15 for an aggregate purchase price of $18.1 million since we increased the amount authorized under the unit repurchase program. ​ Other ​ The noncontrolling interest in our consolidated balance sheets represents Bluegrass Minerals Management, LLC's ("Bluegrass Minerals") ownership interest in Cavalier Minerals JV, LLC ("Cavalier Minerals"). Our accumulated other comprehensive loss consists of unrecognized actuarial gains and losses as well as unrecognized prior service costs related to our pension and pneumoconiosis benefits. See Note 13 – Variable Interest Entities, Note 17 –Employee Benefit Plans and Note 21 – Accrued Workers' Compensation and Pneumoconiosis Benefits for further information.

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES	12 Months Ended
	Dec. 31, 2022
VARIABLE INTEREST ENTITIES
VARIABLE INTEREST ENTITIES	13. VARIABLE INTEREST ENTITIES ​ Cavalier Minerals ​ On November 10, 2014, our subsidiary, Alliance Minerals, and Bluegrass Minerals entered into a limited liability company agreement (the "Cavalier Agreement") to create 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 recovered their investment. Distributions with respect to Bluegrass Minerals' profits interest are offset by all distributions received by Bluegrass Minerals from the former general partners of AllDale I & II. Bluegrass Minerals' profits interest distributions began in late 2022. 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 ​ ​ ​ ​ ​ 146,484 ​ ​ 6,179 ​ We have concluded that Cavalier Minerals is a 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 consolidated balance sheets. In addition, earnings attributable to Bluegrass Minerals are recognized as noncontrolling interest in our consolidated statements of operations. ​ AllDale III ​ In February 2017, Alliance Minerals committed to directly invest $30.0 million in AllDale III, which was created for similar investment purposes as AllDale I & II. Alliance Minerals completed funding of this commitment in 2018. Alliance Minerals' limited partner interest in AllDale III is 13.9%. ​ 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 1) not having the ability to remove the general partner and 2) not participating significantly in the operational decisions, we concluded that AllDale III is a VIE. We are not the primary beneficiary of AllDale III as we do not have the power to direct the activities that most significantly impact AllDale III's economic performance. We account for our ownership interest in the income or loss of AllDale III as an equity method investment. We record equity income or loss based on AllDale III's distribution structure. See Note 14 – Investments for more information. ​ Francis ​ On April 5, 2022, we invested $20 million in Francis, in the form of a convertible note with a maturity date of April 1, 2023. Our convertible note represents an ownership interest in Francis upon conversion. 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 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 14 – 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 $4.1 million during the year ended December 31, 2022. Our final ownership percentage in NGP ETP IV is not yet known. ​ We have concluded that NGP ETP IV is a VIE as it is structured as a limited partnership with limited partners (i) not having the ability to remove the general partner and (ii) not participating significantly in the operational decisions. We are not the primary beneficiary of NGP ETP IV as we do not have the power to direct the activities that most significantly impact NGP ETP IV's economic performance. We account for our ownership interest in the income or loss of NGP ETP IV as an equity method investment. See Note 14 – Investments for more information. ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for variable interest entities.

INVESTMENTS

INVESTMENTS	12 Months Ended
	Dec. 31, 2022
INVESTMENTS
INVESTMENTS	14. INVESTMENTS ​ AllDale III ​ As discussed in Note 13 – Variable Interest Entities, we account for our ownership interest in the income or loss of AllDale III as an equity method investment. We record equity income or loss based on AllDale III's distribution structure. The changes in our equity method investment in AllDale III for each of the periods presented were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ (in thousands) Beginning balance ​ $ 26,325 ​ $ 27,268 ​ $ 28,529 Equity method investment income ​ ​ 5,634 ​ ​ 2,130 ​ ​ 907 Distributions received ​ ​ (6,675) ​ ​ (3,073) ​ ​ (1,895) Other ​ ​ — ​ ​ — ​ ​ (273) Ending balance ​ $ 25,284 ​ $ 26,325 ​ $ 27,268 ​ Francis ​ As discussed in Note 13 – Variable Interest Entities, we account 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 the year ended December 31, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2022 ​ ​ ​ (in thousands) ​ Beginning balance ​ ​ $ — ​ Contributions ​ ​ ​ 20,000 ​ Ending balance ​ ​ $ 20,000 ​ ​ NGP ETP IV ​ As discussed in Note 13 – 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 the year ended December 31, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2022 ​ ​ ​ ​ (in thousands) ​ Beginning balance ​ ​ $ — ​ Contributions ​ ​ ​ 4,087 ​ Ending balance ​ ​ $ 4,087 ​ ​ Infinitum ​ On April 29, 2022, we purchased $32.6 million of Series D Preferred Stock in Infinitum, a Texas-based startup developer and manufacturer of electric motors featuring printed circuit board stators. On November 2, 2022, we purchased an additional $9.4 million of Series D Preferred Stock in Infinitum at the same price per share as those shares of Series D Preferred Stock that we acquired on April 29, 2022. Our 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 have been no fair value adjustments in our investment in Infinitum subsequent to our purchases. During the period we have not observed any price changes that have occurred to identical or similar securities sold by Infinitum that would indicate an adjustment to the fair value of our investment is warranted. The changes in our investment in Infinitum for the year ended December 31, 2022 were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2022 ​ ​ ​ ​ (in thousands) ​ Beginning balance ​ ​ $ — ​ Contributions ​ ​ ​ 42,000 ​ Ending balance ​ ​ $ 42,000 ​ ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for investments.

REVENUE FROM CONTRACTS WITH CUS

REVENUE FROM CONTRACTS WITH CUSTOMERS	12 Months Ended
	Dec. 31, 2022
REVENUE FROM CONTRACTS WITH CUSTOMERS
REVENUE FROM CONTRACTS WITH CUSTOMERS	15. 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 25 – Segment Information. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal Operations ​ Royalties ​ Other, ​ ​ ​ ​ ​ ​ Illinois ​ ​ ​ ​ Corporate and ​ ​ ​ ​ Basin Appalachia Oil & Gas Coal Elimination Consolidated ​ ​ ​ (in thousands) ​ Year Ended December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 1,219,943 ​ $ 882,286 ​ $ — ​ $ — ​ $ — ​ $ 2,102,229 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 138,402 ​ ​ — ​ ​ — ​ ​ 138,402 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 60,624 ​ ​ (60,624) ​ ​ — ​ Transportation revenues ​ ​ 69,540 ​ ​ 44,320 ​ ​ — ​ ​ — ​ ​ — ​ ​ 113,860 ​ Other revenues ​ ​ 6,822 ​ ​ 1,481 ​ ​ 3,039 ​ ​ 56 ​ ​ 40,622 ​ ​ 52,020 ​ Total revenues ​ $ 1,296,305 ​ $ 928,087 ​ $ 141,441 ​ $ 60,680 ​ $ (20,002) ​ $ 2,406,511 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 873,930 ​ $ 512,993 ​ $ — ​ $ — ​ $ — ​ $ 1,386,923 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 74,988 ​ ​ — ​ ​ — ​ ​ 74,988 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 51,402 ​ ​ (51,402) ​ ​ — ​ Transportation revenues ​ ​ 41,001 ​ ​ 28,606 ​ ​ — ​ ​ — ​ ​ — ​ ​ 69,607 ​ Other revenues ​ ​ 4,666 ​ ​ 3,940 ​ ​ 2,197 ​ ​ 69 ​ ​ 27,586 ​ ​ 38,458 ​ Total revenues ​ $ 919,597 ​ $ 545,539 ​ $ 77,185 ​ $ 51,471 ​ $ (23,816) ​ $ 1,569,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 755,208 ​ $ 477,064 ​ $ — ​ $ — ​ $ — ​ $ 1,232,272 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 42,912 ​ ​ — ​ ​ — ​ ​ 42,912 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 42,112 ​ ​ (42,112) ​ ​ — ​ Transportation revenues ​ ​ 12,817 ​ ​ 8,312 ​ ​ — ​ ​ — ​ ​ — ​ ​ 21,129 ​ Other revenues ​ ​ 1,932 ​ ​ 14,954 ​ ​ 229 ​ ​ 105 ​ ​ 14,596 ​ ​ 31,816 ​ Total revenues ​ $ 769,957 ​ $ 500,330 ​ $ 43,141 ​ $ 42,217 ​ $ (27,516) ​ $ 1,328,129 ​ ​ The following table illustrates the projected revenue for all current coal supply contracts allocated to performance obligations that are unsatisfied or partially unsatisfied as of December 31, 2022 and disaggregated by segment and contract duration. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2026 and ​ ​ ​ ​ 2023 2024 2025 Thereafter Total ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations coal revenues ​ $ 1,230,551 ​ $ 730,825 ​ $ 344,601 ​ $ 243,600 ​ $ 2,549,577 ​ Appalachia Coal Operations coal revenues ​ ​ 721,143 ​ ​ 532,647 ​ ​ 308,925 ​ ​ 1,600 ​ ​ 1,564,315 ​ Total coal revenues (1) ​ $ 1,951,694 ​ $ 1,263,472 ​ $ 653,526 ​ $ 245,200 ​ $ 4,113,892 ​ (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	12 Months Ended
	Dec. 31, 2022
EARNINGS PER LIMITED PARTNER UNIT
EARNINGS PER LIMITED PARTNER UNIT	16. 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 LTIP and phantom units in notional accounts under our SERP and the Directors' Deferred Compensation Plan. ​ The following is a reconciliation of net income (loss) attributable to ARLP used for calculating basic and diluted earnings per unit and the weighted-average units used in computing EPU. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ ​ (in thousands, except per unit data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to ARLP ​ $ 577,190 ​ $ 178,157 ​ $ (129,220) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Distributions to participating securities ​ (8,527) ​ (2,334) ​ — ​ Undistributed earnings attributable to participating securities ​ (10,576) ​ (2,403) ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to ARLP available to limited partners ​ $ 558,087 ​ $ 173,420 ​ $ (129,220) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average limited partner units outstanding – basic and diluted ​ 127,195 ​ 127,195 ​ 127,165 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Earnings per limited partner unit - basic and diluted (1) ​ $ 4.39 ​ $ 1.36 ​ $ (1.02) ​ (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. For the years ended December 31, 2022, 2021 and 2020, the combined total of LTIP, SERP and Directors' Deferred Compensation Plan units of 3,540,385 , 1,967,672 and 773,664 , respectively, were considered anti-dilutive under the treasury stock method.

EMPLOYEE BENEFIT PLANS

EMPLOYEE BENEFIT PLANS	12 Months Ended
	Dec. 31, 2022
EMPLOYEE BENEFIT PLANS
EMPLOYEE BENEFIT PLANS	17. EMPLOYEE BENEFIT PLANS ​ Defined Contribution Plans ​ Defined Benefit Plan ​ The following sets forth changes in benefit obligations and plan assets for the years ended December 31, 2022 and 2021 and the funded status of the Pension Plan reconciled with the amounts reported in our consolidated financial statements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ (dollars in thousands) ​ Change in benefit obligations: ​ ​ ​ ​ ​ ​ ​ Benefit obligations at beginning of year ​ $ 139,566 ​ $ 147,934 ​ Interest cost ​ 3,749 ​ 3,438 ​ Actuarial gain ​ (32,996) ​ (6,406) ​ Benefits paid ​ (5,637) ​ (5,400) ​ Benefit obligations at end of year ​ 104,682 ​ 139,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in plan assets: ​ ​ ​ ​ ​ ​ ​ Fair value of plan assets at beginning of year ​ 113,976 ​ 100,969 ​ Employer contribution ​ — ​ 3,312 ​ Actual return on plan assets ​ (16,210) ​ 15,095 ​ Benefits paid ​ (5,637) ​ (5,400) ​ Fair value of plan assets at end of year ​ 92,129 ​ 113,976 ​ Funded status at the end of year ​ $ (12,553) ​ $ (25,590) ​ ​ ​ ​ ​ ​ ​ ​ ​ Amounts recognized in balance sheet: ​ ​ ​ ​ ​ ​ ​ Non-current liability ​ $ (12,553) ​ $ (25,590) ​ ​ ​ ​ ​ ​ ​ ​ ​ Amounts recognized in accumulated other comprehensive income consists of: ​ ​ ​ ​ ​ ​ ​ Prior service cost ​ $ (382) ​ $ (568) ​ Net actuarial loss ​ ​ (15,160) ​ ​ (27,271) ​ ​ ​ $ (15,542) ​ $ (27,839) ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average assumption to determine benefit obligations as of December 31, ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 5.10% ​ 2.73% ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average assumptions used to determine net periodic benefit cost for the year ended December 31, ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 2.73% ​ 2.37% ​ Expected return on plan assets ​ 6.00% ​ 6.50% ​ ​ The actuarial gain components of the change in benefit obligations in 2022 and 2021 were primarily attributable to an increase in the discount rate compared to the prior year end. ​ The expected long-term rate of return used to determine our pension liability is based on a 1.5% active management premium in addition to an asset allocation assumption of: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset allocation ​ As of December 31, 2022 assumption Equity securities ​ 60% ​ Fixed income securities 35% ​ Real estate 5% ​ ​ 100% ​ ​ The actual return on plan assets was (14.6)% and 15.1% for the years ended December 31, 2022 and 2021, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ ​ (in thousands) Components of net periodic benefit cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest cost ​ $ 3,749 ​ $ 3,438 ​ $ 4,185 ​ Expected return on plan assets ​ (6,638) ​ (6,580) ​ (5,861) ​ Amortization of prior service cost ​ ​ 186 ​ ​ 186 ​ ​ 186 ​ Amortization of net loss ​ 1,963 ​ 4,327 ​ 4,128 ​ Net periodic benefit cost (1) ​ $ (740) ​ $ 1,371 ​ $ 2,638 ​ (1) Nonservice components of net periodic benefit cost are included in the Other income (expense) line item within our consolidated statements of operations. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ Other changes in plan assets and benefit obligation recognized in accumulated other comprehensive loss: ​ ​ ​ ​ ​ ​ ​ Net actuarial gain ​ $ 10,148 ​ $ 14,921 ​ Reversal of amortization item: ​ ​ ​ ​ ​ ​ ​ Prior service cost ​ ​ 186 ​ ​ 186 ​ Net actuarial loss ​ 1,963 ​ 4,327 ​ Total recognized in accumulated other comprehensive loss ​ 12,297 ​ 19,434 ​ Net periodic benefit cost (credit) ​ 740 ​ (1,371) ​ Total recognized in net periodic benefit cost and accumulated other comprehensive loss ​ $ 13,037 ​ $ 18,063 ​ ​ Estimated future benefit payments as of December 31, 2022 are as follows: ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ ​ December 31, (in thousands) ​ ​ ​ ​ ​ 2023 ​ $ 6,239 ​ 2024 ​ 6,416 ​ 2025 ​ 6,605 ​ 2026 ​ 6,816 ​ 2027 ​ 6,907 ​ 2028-2032 ​ 35,293 ​ ​ ​ $ 68,276 ​ ​ 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 2023. ​ The Compensation Committee has appointed an investment manager with full investment authority with respect to Pension Plan investments subject to investment guidelines and compliance with Employee Retirement Income Security Act of 1974 or other applicable laws. The investment manager employs a series of asset allocation strategy phases to glide the portfolio risk commensurate with both plan characteristics and market conditions. The objective of the allocation policy is to reach and maintain fully funded status. The total portfolio allocation will be adjusted as the funded ratio of the Pension Plan changes and market conditions warrant. Total account performance is reviewed at least annually, using a dynamic benchmark approach to track investment performance. General asset allocation guidelines at December 31, 2022 are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ Percentage of Total Portfolio ​ Minimum Maximum ​ ​ ​ ​ ​ ​ Equity securities ​ 35% ​ 80% ​ Fixed income securities ​ 15% ​ 65% ​ Convertible securities ​ 0% ​ 10% ​ Alternatives ​ 0% ​ 20% ​ ​ Equity securities include domestic equity securities, developed international equity securities, emerging markets equity securities and real estate investment trust. Fixed income securities include domestic and international investment grade fixed income securities, high yield securities and emerging markets fixed income securities. Futures may also be utilized within the equity securities and fixed income securities asset allocation. Alternatives may include individual securities, exchange traded notes, exchange traded commodities and underlying funds providing exposure to market neutral strategies, long/short strategies, direct real estate and commodities. ​ The following information discloses the fair values of our Pension Plan assets by asset category: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 ​ 2021 ​ ​ ​ (in thousands) Cash and cash equivalents (a) ​ $ 5,422 ​ $ 4,426 ​ ​ ​ ​ ​ ​ ​ ​ ​ Commingled investment funds measured at net asset value (b): ​ ​ ​ ​ ​ ​ ​ Equities - Global ​ ​ — ​ ​ 24,868 ​ Equities - United States ​ ​ 36,259 ​ ​ 41,140 ​ Equities - United States futures ​ ​ (697) ​ ​ (2,055) ​ Equities - International developed markets ​ ​ 14,214 ​ ​ 16,382 ​ Equities - International developed markets futures ​ ​ (1,693) ​ ​ (16,260) ​ Equities - International emerging markets ​ ​ 782 ​ ​ (3,363) ​ Equities - International emerging markets futures ​ ​ 3,289 ​ ​ 7,024 ​ Fixed income - Investment grade ​ ​ 13,856 ​ ​ 27,095 ​ Fixed income - High yield ​ ​ 156 ​ ​ 177 ​ Fixed income - Futures ​ ​ 8,590 ​ ​ (689) ​ Alternatives ​ ​ 11,951 ​ ​ 15,231 ​ Total ​ $ 92,129 ​ $ 113,976 ​ (a) Cash and cash equivalents represents a Level 1 fair value measurement. See Note 2 – Summary of Significant Accounting Policies – Fair Value Measurements for more information regarding the definitions of fair value hierarchy levels. (b) Investments measured at fair value using the net asset value per share (or its equivalent) have not been classified within the fair value hierarchy. The fair values of all commingled investment funds are determined based on the net asset values per unit of each of the funds. The net asset values per unit represent the aggregate value of the fund's assets at fair value less liabilities, divided by the number of units outstanding. ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for pension benefits.

COMMON UNIT-BASED COMPENSATION

COMMON UNIT-BASED COMPENSATION PLANS	12 Months Ended
	Dec. 31, 2022
COMMON UNIT-BASED COMPENSATION PLANS
COMMON UNIT-BASED COMPENSATION PLANS	18. COMMON UNIT-BASED COMPENSATION PLANS ​ Long-Term Incentive Plan ​ A summary of non-vested LTIP grants of restricted units is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of units Weighted average grant date fair value per unit Intrinsic value ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-vested grants at January 1, 2020 ​ 1,603,378 ​ $ 20.39 ​ $ 17,349 ​ Granted (1) ​ 1,430,489 ​ ​ 5.02 ​ ​ ​ ​ Vested (2) ​ (919,524) ​ ​ 21.70 ​ ​ ​ ​ Grants canceled (3) ​ (675,302) ​ 18.62 ​ ​ ​ ​ Forfeited ​ (8,552) ​ 20.16 ​ ​ ​ ​ Non-vested grants at December 31, 2020 ​ 1,430,489 ​ ​ 5.02 ​ ​ 6,409 ​ Granted (4) ​ 1,818,190 ​ ​ 6.03 ​ ​ ​ ​ Forfeited ​ (118,204) ​ 5.48 ​ ​ ​ ​ Non-vested grants at December 31, 2021 ​ 3,130,475 ​ ​ 5.59 ​ ​ 39,569 ​ Granted (4) 769,907 ​ ​ 14.65 ​ ​ ​ ​ Forfeited (203,249) ​ 6.93 ​ ​ ​ ​ Non-vested grants at December 31, 2022 3,697,133 ​ 7.40 ​ ​ 75,126 ​ (1) In December 2020, we modified the vesting requirements for certain restricted units that we granted in February 2020 which were determined to be improbable of vesting under the original vesting requirements (the "2020 Grants"). The new vesting requirements make it probable the modified restricted units will vest. Also in December 2020, an additional 578,114 restricted units under these modified vesting requirements were granted. The grant date fair value reflects the modification date fair value for those awards that were modified. (2) In February 2020, we issued 279,622 unrestricted common units to LTIP participants as a result of satisfying the vesting requirements for 424,486 restricted units that were granted in 2017. The remaining vested units were settled in cash to satisfy tax withholding obligations of the LTIP participants. In December 2020, we accelerated the vesting requirements for 495,038 restricted units that were granted in 2018 (the "2018 Grants") and settled these restricted units in cash. (3) In December 2020, 675,302 restricted units that were granted in 2019 (the "2019 Grants") were canceled since it was determined that the vesting requirements for these restricted units were not probable of being satisfied. (4) The restricted units granted during 2021 and 2022 have certain minimum-value guarantees per unit, regardless of whether or not the awards vest . ​ For the years ended December 31, 2022, 2021 and 2020, our LTIP expense for grants of restricted units was $9.4 million, $5.4 million and $8.1 million, respectively. LTIP expense for grants of restricted units for the year ended December 31, 2020 includes the impact of the reversal of the 2019 Grants, the modification of the 2020 Grants and incremental compensation cost associated with the cash settlement of the 2018 Grants. The cash settlement of the 2018 Grants was the first time we have settled restricted units in cash and we currently do not expect to do so again in the future. The cash settlement of the 2018 Grants resulted in $5.4 million in incremental compensation cost. The 2019 Grants were determined to be not probable of vesting therefore $4.8 million of cumulative previously recognized expense was reversed in 2020, offset in part by related DERs for the 2019 Grants previously recorded to equity and then expensed in 2020. The 2020 Grants were determined to be improbable of vesting therefore the Compensation Committee modified the awards to change the vesting requirement, which made the grants probable of vesting, and granted additional restricted units under these modified vesting requirements as previously discussed. As a result, the grant date fair value of the modified awards was changed to reflect the modification date fair value of the awards resulting in a net reduction in LTIP expense of $1.0 million for the year ended December 31, 2020. ​ The total obligation associated with LTIP grants of restricted units as of December 31, 2022 and 2021 was $16.0 million and $6.7 million, respectively, and is included in the partners' capital Limited partners-common unitholders 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 0.8 years. ​ On January 27, 2023, the Compensation Committee authorized additional grants of 462,225 restricted units, of which 447,225 units were granted. These restricted units have certain minimum-value guarantees, regardless of whether or not the awards vest. ​ Supplemental Executive Retirement Plan and Directors' Deferred Compensation Plan ​ A summary of SERP and Directors' Deferred Compensation Plan activity 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, 2020 ​ 631,365 ​ $ 25.48 ​ $ 6,831 ​ Granted ​ 129,265 ​ ​ 5.25 ​ ​ ​ ​ Phantom units outstanding as of December 31, 2020 ​ 760,630 ​ ​ 22.04 ​ ​ 3,408 ​ Granted ​ 46,638 ​ ​ 9.45 ​ ​ ​ ​ Issued (1) ​ (138,570) ​ ​ 25.86 ​ ​ ​ ​ Phantom units outstanding as of December 31, 2021 ​ 668,698 ​ ​ 20.37 ​ ​ 8,452 ​ Granted ​ 73,842 ​ ​ 19.44 ​ ​ ​ ​ Phantom units outstanding as of December 31, 2022 742,540 ​ 20.28 ​ ​ 15,088 ​ (1) During the year ended December 31, 2021, we purchased 102,962 ARLP common units on the open market to settle the account of a participant under the SERP. Units purchased were net of units settled in cash to satisfy tax-withholding obligations. ​ Total SERP and Directors' Deferred Compensation Plan expense was $1.4 million, $0.4 million and $0.7 million for the years ended December 31, 2022, 2021 and 2020, respectively. As of December 31, 2022 and 2021, the total obligation associated with the SERP and Directors' Deferred Compensation Plan was $15.1 million and $13.5 million, respectively, and is included in the partners' capital Limited partners-common unitholders ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for unit-based compensation.

SUPPLEMENTAL CASH FLOW INFORMAT

SUPPLEMENTAL CASH FLOW INFORMATION	12 Months Ended
	Dec. 31, 2022
SUPPLEMENTAL CASH FLOW INFORMATION
SUPPLEMENTAL CASH FLOW INFORMATION	19. SUPPLEMENTAL CASH FLOW INFORMATION ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Cash Paid For: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest ​ $ 34,844 ​ $ 36,402 ​ $ 44,226 ​ Income taxes ​ $ 23,794 ​ $ 11 ​ $ 12 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-Cash Activity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable for purchase of property, plant and equipment ​ $ 44,281 ​ $ 8,325 ​ $ 5,731 ​ Right-of-use assets acquired by operating lease ​ $ 1,315 ​ $ 189 ​ $ 278 ​ Market value of common units issued under deferred compensation plans before tax withholding requirements ​ $ — ​ $ 1,082 ​ $ 3,837 ​ ​

ASSET RETIREMENT OBLIGATIONS

ASSET RETIREMENT OBLIGATIONS	12 Months Ended
	Dec. 31, 2022
ASSET RETIREMENT OBLIGATIONS
ASSET RETIREMENT OBLIGATIONS	20. ASSET RETIREMENT OBLIGATIONS ​ The following table presents the activity affecting the asset retirement and mine closing liability: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 131,099 ​ $ 127,898 ​ Accretion expense ​ 3,731 ​ 3,688 ​ Payments ​ (2,445) ​ (1,383) ​ Allocation of liability associated with mine development and change in assumptions ​ 17,428 ​ 896 ​ Ending balance ​ $ 149,813 ​ $ 131,099 ​ ​ For the year ended December 31, 2022, the allocation of liability associated with mine development and change in assumptions increased by $17.4 million. The increase was largely attributable to higher cost assumptions as well as the expansion of refuse disposal facilities at certain mines. ​ For the year ended December 31, 2021, the allocation of liability associated with mine development and change in assumptions was immaterial. ​ The impact of discounting our estimated cash flows resulted in reducing the accrual for asset retirement obligations by $110.4 million and $98.3 million at December 31, 2022 and 2021, respectively. Estimated payments of asset retirement obligations as of December 31, 2022 are as follows: ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ ​ December 31, (in thousands) ​ ​ ​ ​ ​ 2023 ​ $ 7,559 ​ 2024 ​ 4,936 ​ 2025 ​ 1,935 ​ 2026 ​ 1,569 ​ 2027 ​ 3,182 ​ Thereafter ​ 241,065 ​ Aggregate undiscounted asset retirement obligations ​ 260,246 ​ Effect of discounting ​ (110,433) ​ Total asset retirement obligations ​ 149,813 ​ Less: current portion ​ (7,559) ​ Non-current asset retirement obligations ​ $ 142,254 ​ ​ As of December 31, 2022 and 2021, we had approximately $174.3 million and $173.9 million, respectively, in surety bonds outstanding to secure the performance of our reclamation obligations. ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for asset retirement obligations.

ACCRUED WORKERS' COMPENSATION A

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS	12 Months Ended
	Dec. 31, 2022
WORKERS' COMPENSATION AND PNEUMOCONIOSIS
WORKERS' COMPENSATION AND PNEUMOCONIOSIS	21. ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS ​ The following is a reconciliation of the changes in workers' compensation liability (including current and long-term liability balances): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 53,448 ​ $ 54,739 ​ Changes in accruals ​ 7,384 ​ 5,168 ​ Payments ​ (12,708) ​ (10,725) ​ Interest accretion ​ 1,147 ​ 926 ​ Valuation loss ​ 181 ​ 3,340 ​ Ending balance ​ $ 49,452 ​ $ 53,448 ​ ​ The discount rate used to calculate the estimated present value of future obligations for workers' compensation was 4.87% and 2.41% at December 31, 2022 and 2021, respectively. ​ The valuation loss in 2022 was primarily attributable to an increase in the discount rate used to calculate the estimated present value of the future obligations being partially offset by unfavorable changes in claims development. The 2021valuation loss was primarily attributable to unfavorable changes in claims development partially offset by an increase in the discount rate used to calculate the estimated present value of future obligations. ​ As of December 31, 2022 and 2021, we had $99.8 million and $100.4 million, respectively, in surety bonds and letters of credit outstanding to secure workers' compensation obligations. ​ We limit our exposure to traumatic injury claims by purchasing a high deductible insurance policy that starts paying benefits after deductibles for the particular claim year have been met. 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 December 31, 2022 and 2021 are $4.1 million and $5.7 million, respectively. Our receivables are included in Other long-term assets ​ The following is a reconciliation of the changes in pneumoconiosis benefit obligations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Benefit obligations at beginning of year ​ $ 111,316 ​ $ 108,496 ​ Service cost ​ 3,798 ​ 4,021 ​ Interest cost ​ 2,991 ​ 2,545 ​ Actuarial loss (gain) ​ (9,840) ​ 161 ​ Benefits and expenses paid ​ (3,978) ​ (3,907) ​ Benefit obligations at end of year ​ $ 104,287 ​ $ 111,316 ​ ​ The following is a reconciliation of the changes in the pneumoconiosis benefit obligation recognized in accumulated other comprehensive loss: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net actuarial gain (loss) ​ $ 9,840 ​ $ (161) ​ $ (7,787) ​ Reversal of amortization item: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net actuarial loss (gain) ​ 1,038 ​ 4,172 ​ (686) ​ Total recognized in accumulated other comprehensive loss ​ $ 10,878 ​ $ 4,011 ​ $ (8,473) ​ ​ The discount rate used to calculate the estimated present value of future obligations for pneumoconiosis benefits was 5.0%, 2.73% and 2.38% at December 31, 2022, 2021 and 2020, respectively. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ (in thousands) ​ Amount recognized in accumulated other comprehensive loss consists of: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net actuarial loss ​ $ 25,510 ​ $ 36,388 ​ $ 40,399 ​ ​ The actuarial gain component of the change in benefit obligations in 2022 was primarily attributable to favorable assumption changes in the discount rate and demographics in the at-risk population. These components were offset in part by a) unfavorable black lung claims experience, b) unfavorable assumption changes regarding future average medical benefits and legal expense levels, and c) unfavorable assumption changes related to Federal and State benefit levels. The actuarial loss component of the change in benefit obligations in 2021 was primarily attributable to unfavorable assumption changes regarding future medical and legal expense levels. These components were offset in part by a) an increase in the discount rate used to calculate the estimated present value of the future obligations and b) favorable black lung claims experience and other demographic changes in the at-risk population. ​ Summarized below is information about the amounts recognized in the accompanying consolidated balance sheets for pneumoconiosis and workers' compensation benefits: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Workers' compensation claims ​ $ 49,452 ​ $ 53,448 ​ Pneumoconiosis benefit claims ​ ​ 104,287 ​ ​ 111,316 ​ Total obligations ​ 153,739 ​ 164,764 ​ Less current portion ​ (14,099) ​ (12,293) ​ Non-current obligations ​ $ 139,640 ​ $ 152,471 ​ ​ Both the pneumoconiosis benefit and workers' compensation obligations were unfunded at December 31, 2022 and 2021. ​ The pneumoconiosis benefit and workers' compensation expense consists of the following components: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ ​ (in thousands) ​ Black lung benefits: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost $ 3,798 ​ $ 4,021 ​ $ 3,526 ​ Interest cost (1) ​ 2,991 ​ 2,545 ​ 2,998 ​ Net amortization (1) ​ 1,038 ​ 4,172 ​ (686) ​ Total pneumoconiosis expense ​ 7,827 ​ 10,738 ​ 5,838 ​ Workers' compensation expense ​ 11,675 ​ 8,339 ​ 12,305 ​ Net periodic benefit cost ​ $ 19,502 ​ $ 19,077 ​ $ 18,143 ​ ________________________________________ (1) Interest cost and net amortization is included in the Other income (expense) line item within our consolidated statements of income ( see Note 2 – Summary of Significant Accounting Policies). ​ See Note 2 – Summary of Significant Accounting Policies for more information on our accounting policy for workers' compensation and pneumoconiosis benefits.

RELATED-PARTY TRANSACTIONS

RELATED-PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2022
RELATED-PARTY TRANSACTIONS
RELATED-PARTY TRANSACTIONS	22. RELATED-PARTY TRANSACTIONS ​ We have continuing related-party transactions with MGP and its affiliates. The Board of Directors and its conflicts committee ("Conflicts Committee") review our related-party transactions that involve a potential conflict of interest between our general partner or its affiliates and ARLP or its subsidiaries or any other partner of ARLP to determine that such transactions are fair and reasonable to ARLP. As a result of these reviews, the Board of Directors and the Conflicts Committee approved each of the transactions described below that had such potential conflict of interest as fair and reasonable to ARLP. ​ Line of Credit ​ On February 19, 2021, we entered into a line of credit arrangement (the "Line of Credit") with a related party for $5.0 million. This Line of Credit was amended on November 4, 2021 to increase the total available under the Line of Credit to $5.5 million. The Line of Credit had a maturity date of February 28, 2023 and accrued interest at an annual rate of 3.5% payable quarterly. During the year ended December 31, 2021 we received proceeds and made payments ​ Affiliate Coal Lease Agreements ​ The following table summarizes advanced royalties outstanding and related payments and recoupments under our affiliate coal lease agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ WKY CoalPlay ​ ​ ​ ​ ​ ​ ​ Towhead ​ Webster ​ Henderson ​ WKY ​ ​ ​ ​ ​ Craft Foundations ​ Coal ​ Coal ​ Coal ​ CoalPlay ​ ​ ​ ​ ​ ​ ​ Henderson ​ ​ ​ ​ ​ Henderson ​ ​ ​ ​ ​ ​ Tunnel ​ & Union ​ Webster ​ Henderson ​ & Union ​ ​ ​ ​ ​ ​ Ridge ​ Counties, KY ​ County, KY ​ County, KY ​ Counties, KY ​ Total ​ ​ ​ Acquired ​ Acquired ​ Acquired ​ Acquired ​ Acquired ​ ​ ​ ​ ​ ​ 2005 ​ December 2014 ​ December 2014 ​ December 2014 ​ February 2015 ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of January 1, 2020 ​ $ 1,500 ​ $ 16,603 ​ $ — ​ $ 12,607 ​ $ 10,506 ​ $ 41,216 ​ Payments ​ ​ 3,000 ​ ​ 3,597 ​ ​ 2,568 ​ ​ 2,522 ​ ​ 2,132 ​ ​ 13,819 ​ Recoupment ​ ​ (3,000) ​ ​ (1,022) ​ ​ — ​ ​ — ​ ​ (56) ​ ​ (4,078) ​ Unrecoupable ​ ​ — ​ ​ — ​ ​ (2,568) ​ ​ — ​ ​ — ​ ​ (2,568) ​ As of December 31, 2020 ​ ​ 1,500 ​ ​ 19,178 ​ ​ — ​ ​ 15,129 ​ ​ 12,582 ​ ​ 48,389 ​ Payments ​ ​ 3,000 ​ ​ 3,597 ​ ​ 2,568 ​ ​ 2,521 ​ ​ 2,131 ​ ​ 13,817 ​ Recoupment ​ ​ (3,000) ​ ​ (1,025) ​ ​ — ​ ​ — ​ ​ — ​ ​ (4,025) ​ Unrecoupable ​ ​ — ​ ​ — ​ ​ (2,568) ​ ​ — ​ ​ — ​ ​ (2,568) ​ As of December 31, 2021 ​ ​ 1,500 ​ ​ 21,750 ​ ​ — ​ ​ 17,650 ​ ​ 14,713 ​ ​ 55,613 ​ Payments ​ ​ 3,000 ​ ​ 3,597 ​ ​ — ​ ​ 2,522 ​ ​ 2,131 ​ ​ 11,250 ​ Recoupment ​ ​ (3,000) ​ ​ (3,255) ​ ​ — ​ ​ — ​ ​ — ​ ​ (6,255) ​ Unrecoupable ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ As of December 31, 2022 ​ $ 1,500 ​ $ 22,092 ​ $ — ​ $ 20,172 ​ $ 16,844 ​ $ 60,608 ​ ​ Craft Foundations — one half ​ Tunnel Ridge has a surface land lease with an annual payment of $0.2 million, payable in January of each year with the Craft Foundations. ​ WKY CoalPlay — ​ In December 2014, WKY CoalPlay's subsidiaries, Towhead Coal Reserves, LLC and Henderson Coal Reserves, LLC entered into coal lease agreements with Alliance Resource Properties. The leases have initial terms of 20 years and provide for earned royalty payments of 4.0% of the coal sales price and annual minimum royalty payments of $3.6 million and $2.5 million, respectively. All annual minimum royalty payments under each agreement are recoupable from future earned royalties payable under that agreement. ​ In December 2014, WKY CoalPlay's subsidiary, Webster Coal Reserves, LLC entered into a coal lease agreement with Alliance Resource Properties. The lease had a term of 7 years and provided for earned royalty payments of 4.0% of the coal sales price and annual minimum royalty payments of $2.6 million. This lease expired in December 2021. ​ Cavalier Minerals

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2022
COMMITMENTS AND CONTINGENCIES.
COMMITMENTS AND CONTINGENCIES	23. COMMITMENTS AND CONTINGENCIES ​ Commitments — ​ Contractual Commitments — ​ General Litigation — ​ 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. ​ Other

CONCENTRATION OF CREDIT RISK AN

CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS	12 Months Ended
	Dec. 31, 2022
CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS
CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS	24. CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS ​ The international coal market has been a part of our business with indirect sales to end-users in Europe, Africa, Asia, North America and South America. Our sales into the international coal market are considered exports and are made through brokered transactions. During the years ended December 31, 2022, 2021 and 2020, export tons represented approximately 12.5%, 12.5% and 3.3% of tons sold, respectively. ​ Because title to our export shipments typically transfers to our brokerage customers at a point that does not necessarily reflect the end-usage point, we attribute export tons to the country with the end-usage point, if known. No individual country was attributed greater than 10% of total domestic and export tons sold during the years ended December 31, 2022, 2021 and 2020. ​ We have significant long-term coal supply agreements, some of which contain prospective price adjustment provisions designed to reflect changes in market conditions, labor and other production costs and, in the infrequent circumstance when the coal is sold other than free on board the mine, changes in transportation rates. A major customer is defined as a customer from which we derive at least ten percent of our total revenues, including transportation revenues. Total revenues from major customers are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ Segment 2022 ​ 2021 ​ 2020 ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer A Illinois Basin ​ $ 328,406 ​ $ 239,482 ​ $ 197,379 ​ Customer B ​ Illinois Basin ​ ​ 260,146 ​ ​ — ​ ​ 157,271 ​ Customer C ​ Illinois Basin/Appalachia ​ ​ 228,480 ​ ​ — ​ ​ — ​ Customer D Illinois Basin/Appalachia ​ — ​ ​ — ​ 137,785 ​ ​ Trade accounts receivable from major customers totaled approximately $63.6 million and $10.8 million at December 31, 2022 and 2021, respectively. Our credit loss experience has historically been insignificant. Financial conditions of our customers could result in a material change to our credit loss expense in future periods. The coal supply agreements with Customers A, B and C expire in 2026, 2029 and 2024 respectively.

SEGMENT INFORMATION

SEGMENT INFORMATION	12 Months Ended
	Dec. 31, 2022
SEGMENT INFORMATION
SEGMENT INFORMATION	25. 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 (a) the Gibson County Coal, LLC's ("Gibson County Coal") mining complex, (b) the Warrior Coal, LLC ("Warrior") mining complex, (c) the River View mining complex and (d) the Hamilton mining complex. The segment also includes our Mt. Vernon Transfer Terminal, LLC ("Mt. Vernon") coal loading terminal in Indiana which operates on the Ohio River, Mid-America Carbonates, LLC ("MAC") and other support services, and our non-operating mining complexes. ​ The Appalachia Coal Operations reportable segment includes (a) the Mettiki mining complex, (b) the Tunnel Ridge mining complex and (c) the MC Mining, LLC ("MC Mining") mining complex. ​ 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 14 – Investments) and Cavalier Minerals. ​ 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 14 – Investments), Wildcat Insurance, which assists the ARLP Partnership with its insurance requirements, AROP Funding and Alliance Finance (both discussed in Note 8 – Long-Term Debt) 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) Year Ended December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 1,296,305 ​ $ 928,087 ​ $ 141,441 ​ $ 56 ​ $ 40,622 ​ $ 2,406,511 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 60,624 ​ ​ (60,624) ​ ​ — ​ Total revenues (1) ​ ​ 1,296,305 ​ ​ 928,087 ​ ​ 141,441 ​ ​ 60,680 ​ ​ (20,002) ​ ​ 2,406,511 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 806,080 ​ ​ 464,029 ​ ​ 13,950 ​ ​ 21,871 ​ ​ (23,497) ​ 1,282,433 ​ Segment Adjusted EBITDA (3) ​ 420,684 ​ ​ 426,402 ​ ​ 131,168 ​ ​ 38,809 ​ ​ 3,495 ​ 1,020,558 ​ Total assets ​ 779,018 ​ ​ 431,913 ​ ​ 711,917 ​ ​ 321,587 ​ ​ 417,038 ​ 2,661,473 ​ Capital expenditures (4) ​ 158,624 ​ ​ 76,603 ​ ​ — ​ ​ 38,276 ​ ​ 12,891 ​ 286,394 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 919,597 ​ $ 545,539 ​ $ 77,185 ​ $ 69 ​ $ 27,586 ​ $ 1,569,976 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 51,402 ​ ​ (51,402) ​ ​ — ​ Total revenues (1) ​ ​ 919,597 ​ ​ 545,539 ​ ​ 77,185 ​ ​ 51,471 ​ ​ (23,816) ​ ​ 1,569,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 613,303 ​ ​ 344,332 ​ ​ 9,943 ​ ​ 18,269 ​ ​ (33,198) ​ 952,649 ​ Segment Adjusted EBITDA (3) ​ 265,292 ​ ​ 172,601 ​ ​ 68,774 ​ ​ 33,202 ​ ​ 9,383 ​ 549,252 ​ Total assets ​ 676,091 ​ ​ 420,144 ​ ​ 630,627 ​ ​ 285,943 ​ ​ 146,601 ​ 2,159,406 ​ Capital expenditures (4) ​ 60,166 ​ ​ 47,577 ​ ​ — ​ ​ 45 ​ ​ 15,196 ​ 122,984 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 769,957 ​ $ 500,330 ​ $ 43,141 ​ $ 105 ​ $ 14,596 ​ $ 1,328,129 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 42,112 ​ ​ (42,112) ​ ​ — ​ Total revenues (1) ​ ​ 769,957 ​ ​ 500,330 ​ ​ 43,141 ​ ​ 42,217 ​ ​ (27,516) ​ ​ 1,328,129 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 543,264 ​ 320,656 ​ 4,106 ​ 18,249 ​ ​ (25,026) ​ 861,249 ​ Segment Adjusted EBITDA (3) ​ 213,876 ​ 171,362 ​ 39,773 ​ 23,968 ​ ​ (2,490) ​ 446,489 ​ Total assets ​ 738,315 ​ 440,815 ​ 613,916 ​ 288,525 ​ ​ 84,445 ​ 2,166,016 ​ Capital expenditures ​ 48,636 ​ 70,960 ​ — ​ 12 ​ ​ 1,493 ​ 121,101 ​ (1) Revenues included in the Other, Corporate and Elimination column are attributable to intercompany eliminations, which are primarily intercompany coal royalties 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 Operating expenses (excluding depreciation, depletion and amortization) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Operating expenses (excluding depreciation, depletion and amortization) ​ $ 1,286,635 ​ $ 943,257 ​ $ 859,656 ​ Outside coal purchases ​ 151 ​ 6,372 ​ — ​ Other expense (income) ​ (4,353) ​ 3,020 ​ 1,593 ​ Segment Adjusted EBITDA Expense ​ $ 1,282,433 ​ $ 952,649 ​ $ 861,249 ​ ​ (3) Segment Adjusted EBITDA is defined as net income (loss) attributable to ARLP before net interest expense, income taxes, depreciation, depletion and amortization, general and administrative expense, asset and goodwill impairments and acquisition gain. 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. Net income (loss) , the most comparable GAAP financial measure, is reconciled to consolidated Segment Adjusted EBITDA: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Net income (loss) ​ $ 579,148 ​ $ 178,755 ​ $ (129,051) ​ Noncontrolling interest ​ ​ (1,958) ​ ​ (598) ​ ​ (169) ​ Net income (loss) attributable to ARLP ​ $ 577,190 ​ $ 178,157 ​ $ (129,220) ​ General and administrative ​ 80,334 ​ 70,160 ​ 59,806 ​ Depreciation, depletion and amortization ​ 273,759 ​ 261,377 ​ 313,387 ​ Asset impairments ​ — ​ — ​ 24,977 ​ Goodwill impairment ​ ​ — ​ ​ — ​ ​ 132,026 ​ Interest expense, net ​ 35,297 ​ 39,141 ​ 45,478 ​ Income tax expense ​ 53,978 ​ 417 ​ 35 ​ Consolidated Segment Adjusted EBITDA ​ $ 1,020,558 ​ $ 549,252 $ 446,489 ​ ​ . (4) Capital Expenditures shown exclude the Belvedere Acquisition on September 9, 2022, Jase Acquisition on October 26, 2022 and the Boulders Acquisition on October 13, 2021. (Note 3 – Acquisitions).

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2022
SUBSEQUENT EVENTS
SUBSEQUENT EVENTS	26. SUBSEQUENT EVENT S ​ Acquisition Agreement ​ On January 27, 2023, we entered into a one-year collaborative agreement with a third party, effective January 1, 2023, committing up to $35.0 million for the acquisition of oil & gas mineral interests in the Midland and Delaware basins. Under the agreement, the third party will assist us in the identification, evaluation, and acquisition of target oil & gas mineral interests. In exchange for these services, the third party will receive a participation share, partially funded by the third party, and will be paid a periodic management fee. ​ JC Resources ​ On February 22, 2023, we acquired approximately 2,682 oil & gas net royalty acres in the Delaware Basin from JC Resources LP ("JC Resources"), a related-party entity owned by Mr. Craft, for $72.3 million, which was funded with cash on hand. ​

SCHEDULE I CONDENSED FINANCIAL

SCHEDULE I CONDENSED FINANCIAL INFORMATION OF REGISTRANT	12 Months Ended
	Dec. 31, 2022
CONDENSED FINANCIAL INFORMATION OF REGISTRANT
CONDENSED FINANCIAL INFORMATION OF REGISTRANT	SCHEDULE I – CONDENSED FINANCIAL INFORMATION OF REGISTRANT ALLIANCE RESOURCE PARTNERS, L.P. ​ CONDENSED BALANCE SHEETS (PARENT) DECEMBER 31, 2022 AND 2021 (In thousands, except unit data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ASSETS ​ ​ ​ ​ ​ CURRENT ASSETS: ​ ​ ​ ​ ​ ​ ​ Cash and cash equivalents ​ $ 2,174 ​ $ 2,173 ​ Total current assets ​ 2,174 ​ 2,173 ​ OTHER ASSETS: ​ ​ ​ ​ ​ ​ ​ Investments in consolidated subsidiaries ​ 1,653,951 ​ 1,277,110 ​ Total other assets ​ 1,653,951 ​ 1,277,110 ​ TOTAL ASSETS ​ $ 1,656,125 ​ $ 1,279,283 ​ ​ ​ ​ ​ ​ ​ ​ ​ LIABILITIES AND PARTNERS' CAPITAL ​ ​ ​ ​ ​ ​ ​ CURRENT LIABILITIES: ​ ​ ​ ​ ​ ​ ​ Accrued taxes other than income taxes ​ $ 100 ​ $ 100 ​ Total current liabilities ​ 100 ​ 100 ​ Total liabilities ​ 100 ​ 100 ​ ​ ​ ​ ​ ​ ​ ​ ​ PARTNERS' CAPITAL: ​ ​ ​ ​ ​ ​ ​ Limited Partners - Common Unitholders 127,195,219 units outstanding ​ 1,656,025 ​ 1,279,183 ​ TOTAL LIABILITIES AND PARTNERS' CAPITAL ​ $ 1,656,125 ​ $ 1,279,283 ​ See accompanying notes. ​ CONDENSED STATEMENTS OF OPERATIONS (PARENT) FOR THE YEARS ENDED DECEMBER 31, 2022, 2021 AND 2020 (In thousands, except unit and per unit data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest income ​ $ — ​ $ — ​ $ 24 ​ Equity in earnings of consolidated subsidiaries ​ 577,190 ​ 178,157 ​ (129,244) ​ NET INCOME (LOSS) ATTRIBUTABLE TO ARLP ​ $ 577,190 ​ $ 178,157 ​ $ (129,220) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ EARNINGS PER LIMITED PARTNER UNIT - BASIC AND DILUTED ​ $ 4.39 ​ $ 1.36 ​ $ (1.02) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING – BASIC AND DILUTED ​ 127,195,219 ​ 127,195,219 ​ 127,164,659 ​ See accompanying notes. ​ CONDENSED STATEMENTS OF CASH FLOWS (PARENT) FOR THE YEARS ENDED DECEMBER 31, 2022, 2021 AND 2020 (In thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CASH FLOWS FROM OPERATING ACTIVITIES: ​ $ 196,348 ​ $ 52,157 ​ $ 51,751 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ CASH FLOWS FROM FINANCING ACTIVITIES: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Distributions paid to Partners ​ ​ (196,347) ​ (52,158) ​ (51,753) ​ Net cash used in financing activities ​ (196,347) ​ (52,158) ​ (51,753) ​ NET CHANGE IN CASH AND CASH EQUIVALENTS ​ 1 ​ (1) ​ (2) ​ CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD ​ 2,173 ​ 2,174 ​ 2,176 ​ CASH AND CASH EQUIVALENTS AT END OF PERIOD ​ $ 2,174 ​ $ 2,173 ​ $ 2,174 ​ See accompanying notes. ​ ​ NOTES TO FINANCIAL INFORMATION (PARENT) ​ 1. BASIS OF PRESENTATION ​ In these parent-company-only financial statements, our investment in consolidated subsidiaries is stated at cost plus equity in undistributed earnings of subsidiaries and reduced by distributions received from subsidiaries since the date of acquisition. These parent-company-only financial statements should be read in conjunction with our consolidated financial statements in "Item 8. Financial Statements and Supplementary Data" of this Annual Report on Form 10-K. ​ 2. GUARANTEES ​ As the parent of the Intermediate Partnership, ARLP was a guarantor of the Replaced Credit Facility and is a guarantor of the Senior Notes discussed in "Item 8. Financial Statements and Supplementary Data—Note 8 – Long-Term Debt" of this Annual Report on Form 10-K. In addition to these guarantees, ARLP has provided guarantees on surety indemnity agreements and financially guaranteed certain coal supply agreements. The duration of these guarantees varies. The maximum undiscounted potential future payment obligation for our guarantees of certain coal supply agreements as of December 31, 2022 is approximately $425.6 million as a result of elevated market prices. These guarantees provide for compensation to customers based on additional cost to the customer to replace any contracted tons that our subsidiaries fail to deliver. We do not expect to make any payments under these guarantees. ​ 3. CASH DISTRIBUTIONS RECEIVED ​ We received distributions of $196.3 million, $52.2 million and $51.8 million from our consolidated subsidiaries during the years ended December 31, 2022, 2021, and 2020, respectively.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2022
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Consolidation	Consolidation ​
Variable Interest Entity ("VIE")	Variable Interest Entity ("VIE") impact the VIE's economic performance and (b) the obligation to absorb losses of the VIE that could potentially be significant to the VIE or the right to receive benefits from the VIE that could potentially be significant to the VIE. The primary beneficiary is required to consolidate the VIE for financial reporting purposes. ​ To determine a VIE's primary beneficiary, we perform a qualitative assessment to determine which party, if any, has the power to direct activities of the VIE and the obligation to absorb losses and/or receive its benefits. This assessment involves identifying the activities that most significantly impact the VIE's economic performance and determine whether it, or another party, has the power to direct those activities. When evaluating whether we are the primary beneficiary of a VIE, we perform a qualitative analysis that considers the design of the VIE, the nature of our involvement and the variable interests held by other parties. See Note 13 – Variable Interest Entities for further information. ​
Estimates	Estimates ​ ● Impairment assessments of investments, property, plant and equipment, and goodwill; ● Asset retirement obligations; ● Pension valuation variables; ● Workers' compensation and pneumoconiosis valuation variables; ● Acquisition related purchase price allocations; ● Life of mine assumptions; ● Oil & gas reserve quantities and carrying amounts; and ● Determination of oil & gas revenue accruals ​ These significant estimates and assumptions are discussed throughout these notes to the consolidated financial statements. ​
Fair Value Measurements	Fair Value Measurements ​ We use the following fair value hierarchy, which prioritizes the inputs to valuation techniques used to measure fair value into three broad levels: ​ ● Level 1 – Quoted prices for identical assets and liabilities in active markets that we have the ability to access at the measurement date. ​ ● Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model derived valuations whose inputs are observable or whose significant value drivers are observable. ​ ● Level 3 – Unobservable inputs for the asset or liability including situations where there is little, if any, market activity for the asset or liability. ​ The fair value hierarchy gives the highest priority to quoted prices in active markets (Level 1) and the lowest priority to unobservable data (Level 3). In some cases, the inputs used to measure fair value might fall into different levels of the fair value hierarchy. The lowest level input that is significant to a fair value measurement determines the applicable level in the fair value hierarchy. Assessing the significance of a particular input to the fair value measurement requires judgment, considering factors specific to the asset or liability. Significant fair value measurements are used in our significant estimates and are discussed throughout these notes. ​
Cash and Cash Equivalents	Cash and Cash Equivalents ​
Cash Management	Cash Management ​
Inventories	Inventories ​
Business Combinations	Business Combinations ​
Goodwill	Goodwill ​
Property, Plant and Equipment	Property, Plant and Equipment ​
Mine Development Costs	Mine Development Costs
Leases	Leases ​ We review each agreement to determine if an arrangement within the agreement contains a lease at the inception of an arrangement. Once an arrangement is determined to contain an operating or finance lease with a term greater than 12 months, we recognize a lease liability for the obligation to make lease payments and a right-of-use asset for the right to use the underlying asset for the lease term based on the present value of lease payments over the lease term. The lease term includes all noncancelable periods defined in the lease as well as periods covered by options to extend the lease that we are reasonably certain to exercise. As an implicit borrowing rate cannot be determined under most of our leases, we use our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. ​ Expenses related to leases determined to be operating leases will be recognized on a straight-line basis over the lease term including any reasonably assured renewal periods, while those determined to be finance leases will be recognized following a front-loaded expense profile in which interest and amortization are presented separately in the income statement. The determination of whether a lease is accounted for as a finance lease or an operating lease requires management to make estimates primarily about the fair value of the asset and its estimated economic useful life.
Long-Lived Asset Impairment	Long-Lived Asset Impairment ​
Oil & Gas Reserve Quantities and Carrying Amounts	Oil & Gas Reserve Quantities and Carrying Amounts ​ Mineral interests in oil & gas properties are grouped using a reasonable aggregation of properties with a common geological structural feature or stratigraphic condition, which we may also refer to as a depletable group. Mineral interests in proved oil & gas properties are depleted based on the units-of-production method. Proved reserves are quantities of oil & gas that can be estimated with reasonable certainty to be recoverable in the future from a given date forward, from known reservoirs, under existing economic conditions, operating methods, and government regulations. Proved developed resources are the quantities expected to be recovered through our operators' existing wells with existing equipment, infrastructure and operating methods. ​ We evaluate impairment of our oil & gas mineral interests in proved properties whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. This evaluation is performed on a depletable group basis. We compare the undiscounted projected future cash flows expected in connection with a depletable group to its unamortized carrying amount to determine recoverability. When the carrying amount of a depletable group exceeds its estimated undiscounted future cash flows, the carrying amount is written down to its fair value, which is measured as the present value of the projected future cash flows of such properties. The factors used to determine fair value include estimates of proved reserves, future commodity prices, timing of future production, future expenditures, and a risk-adjusted discount rate. ​ Our oil & gas mineral interests in unproved properties are also assessed for impairment periodically but at least annually when facts and circumstances indicate that the unproved property will not be transferred to proved properties. Impairment of individual unproved properties whose acquisition costs are relatively significant are assessed on a property-by-property basis, and an impairment loss is recognized if we determine that the unproved property will not be transferred to proved properties. Impairment of unproved properties whose acquisition costs are not individually significant are assessed on a group basis. Any amount of loss to be recognized and the amount of a valuation allowance needed to provide for impairment of those properties is determined by amortizing those properties in the aggregate on the basis of historical experience and other relevant information, such as the relative proportion of such properties on which proved reserves have been found in the past. ​ Upon the sale of a complete depletable group, the book value thereof, less proceeds or salvage value, are charged to income. Upon the sale or retirement of an aggregation of interests which make up less than a complete depletable group, the proceeds are credited to accumulated depreciation, depletion and amortization, unless doing so would significantly alter the depreciation, depletion and amortization rate of the depletable group, in which case a gain or loss would be recorded.
Intangibles	Intangibles Prepaid expenses and other assets Other long-term assets ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ December 31, 2021 ​ ​ ​ ​ Accumulated Intangibles, ​ ​ Accumulated Intangibles, ​ Original Cost Amortization Net Original Cost Amortization Net ​ ​ (in thousands) ​ Customer contracts and other ​ 10,623 ​ (10,623) ​ — ​ 10,623 ​ (9,504) ​ 1,119 ​ Mining permits ​ 1,500 ​ (472) ​ 1,028 ​ 1,500 ​ (418) ​ 1,082 ​ Total ​ $ 12,123 ​ $ (11,095) ​ $ 1,028 ​ $ 12,123 ​ $ (9,922) ​ $ 2,201 ​ ​ Amortization expense attributable to intangible assets is estimated as follows: ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ (in thousands) 2023 ​ $ 54 ​ 2024 ​ 54 ​ 2025 ​ 54 ​ 2026 ​ 54 ​ 2027 ​ 54 ​ Thereafter ​ 758 ​ ​
Investment	Investments ​ Our investments and ownership interests in entities in which we do not have a controlling financial interest are accounted for under the equity method of accounting if we have the ability to exercise significant influence over the entity. Investments accounted for under the equity method are initially recorded at cost, and the difference between the basis of our investment and the underlying equity in the net assets of the joint venture at the investment date, if any, is amortized over the lives of the related assets that gave rise to the difference. ​ In the event our ownership requires a disproportionate sharing of income or loss, we use the hypothetical liquidation at book value ("HLBV") method to determine the appropriate allocation of income or loss. Under the HLBV method, income or loss of the investee is allocated based on hypothetical amounts that each investor would be entitled to receive if the net assets held were liquidated at book value at the end of each period, adjusted for any contributions made and distributions received during the period. ​ We hold equity method investments in AllDale III, Francis and NGP ETP IV. See Note 13 – Variable Interest Entities and Note 14 – Investments for further discussion of our equity method investments. ​ We review our investments for impairment whenever events or changes in circumstances indicate a loss in the value of the investment may be other-than-temporary. ​
Advance Royalties	Advance Royalties Advance royalties ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Advance royalties, affiliates (see Note 22 – Related-Party Transactions) ​ $ 60,608 ​ $ 55,613 ​ Advance royalties, third-parties ​ 14,661 ​ 12,869 ​ Total advance royalties ​ $ 75,269 ​ $ 68,482 ​ ​
Asset Retirement Obligations	Asset Retirement Obligations ​
Pension Benefits	Pension Benefits ​ The discount rate is determined for our pension benefit plan based on an approach specific to our plan. The year end discount rate is determined considering a yield curve comprised of high-quality corporate bonds and the timing of the expected benefit cash flows. ​ The expected long-term rate of return on plan assets is determined based on broad equity and bond indices, the investment goals and objectives, the target investment allocation and on the average annual total return for each asset class. ​ Unrecognized actuarial gains and losses and unrecognized prior service costs and credits are deferred and recorded in accumulated other comprehensive loss until amortized as a component of net periodic benefit cost. Unrecognized actuarial gains and losses in excess of 10% of the greater of the benefit obligation or the market-related value of plan assets are amortized over the participants' average remaining future years of service. ​
Workers' Compensation and Pneumoconiosis (Black Lung) Benefits	Workers Compensation and Pneumoconiosis (Black Lung) Benefits ​ We provide income replacement and medical treatment for work-related traumatic injury claims as required by applicable state laws. Workers' compensation laws also compensate survivors of workers who suffer employment related deaths. Our liability for traumatic injury claims is the estimated present value of current workers' compensation benefits, based on our actuarial estimates. Our actuarial calculations are based on a blend of actuarial projection methods and numerous assumptions including claim development patterns, mortality, medical costs and interest rates. ​ Our pneumoconiosis benefits liability is calculated using the service cost method based on the actuarial present value of the estimated pneumoconiosis obligation. Our actuarial calculations are based on numerous assumptions including claim development patterns, medical costs and mortality. Actuarial gains or losses are amortized over the remaining service period of active miners. See Note 21 – Accrued Workers' Compensation and Pneumoconiosis Benefits for more information on Workers' Compensation and Pneumoconiosis Benefits. ​
Coal Revenue Recognition	Coal Revenue Recognition ​ The estimated transaction price from each of our contracts is based on the total amount of consideration we expect to be entitled to under the contract. Included in the transaction price for certain coal supply contracts is the impact of variable consideration, including quality price adjustments, handling services, government imposition claims, per ton price fluctuations based on certain coal sales price indices and anticipated payments in lieu of shipments. We have constrained the expected value of variable consideration in our estimation of transaction price and only included this consideration to the extent that it is probable that a significant revenue reversal will not occur. The estimated transaction price for each contract is allocated to our performance obligations based on relative standalone selling prices determined at contract inception. Variable consideration is allocated to a specific part of the contract in many instances, such as if the variable consideration is based on production activities for coal delivered during a certain period or the outcome of a customer's ability to accept coal shipments over a certain period. ​ Contract assets are recorded as trade receivables and reported separately in our consolidated balance sheet from other contract assets as title passes to the customer and our right to consideration becomes unconditional. Payments for coal shipments are typically due within two four weeks ​ Oil & Gas Revenue Recognition ​ We also periodically earn revenue from lease bonuses. We recognize lease bonus revenue when we execute a lease of our mineral interests to exploration and production companies. A lease agreement represents our contract with an operator, which is generally an exploration and production company. The contract will (a) generally transfer the rights to any oil or gas discovered, (b) grant us a right to a specified royalty interest from the operator, and (c) require the operator to commence drilling and complete operations within a specified time period. Control of the minerals transfers to the operator when the lease agreement is executed. At the time we execute the lease agreement, we expect to receive the lease bonus payment within a reasonable time, though in no case more than one year, such that we do not adjust the expected amount of consideration for the effects of any significant financing component. ​ As a non-operator, we have limited visibility into the timing of when new wells start producing. In addition, production statements may not be received for 30 to 90 days or more after the date production is delivered. As a result, we are required to estimate the amount of production delivered to the purchaser and the price that will be received for the sale of the product. The expected sales volumes and prices from our properties are estimated and recorded within the Trade receivables ​
Common Unit-Based Compensation	Common Unit-Based Compensation ​ We utilize the Supplemental Executive Retirement Plan ("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 MGP Amended and Restated Deferred Compensation Plan for Directors ("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. ​ The fair value of restricted common unit grants under the LTIP, SERP and the Directors' Deferred Compensation Plan are determined on the grant date of the award and recognized as compensation expense on a pro rata basis for LTIP and SERP awards, as appropriate, over the requisite service period. Compensation expense is fully recognized on the grant date for quarterly distributions credited to SERP accounts and Directors' Deferred Compensation Plan awards. The corresponding liability is classified as equity and included in limited partners' capital in the consolidated financial statements (See Note 18 – Common Unit-Based Compensation Plans). ​
Income Taxes	Income Taxes ​ 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

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)	12 Months Ended
	Dec. 31, 2022
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES
Summary of intangible assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ December 31, 2021 ​ ​ ​ ​ Accumulated Intangibles, ​ ​ Accumulated Intangibles, ​ Original Cost Amortization Net Original Cost Amortization Net ​ ​ (in thousands) ​ Customer contracts and other ​ 10,623 ​ (10,623) ​ — ​ 10,623 ​ (9,504) ​ 1,119 ​ Mining permits ​ 1,500 ​ (472) ​ 1,028 ​ 1,500 ​ (418) ​ 1,082 ​ Total ​ $ 12,123 ​ $ (11,095) ​ $ 1,028 ​ $ 12,123 ​ $ (9,922) ​ $ 2,201 ​ ​
Schedule of estimated amortization expense attributable to intangible assets	​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ (in thousands) 2023 ​ $ 54 ​ 2024 ​ 54 ​ 2025 ​ 54 ​ 2026 ​ 54 ​ 2027 ​ 54 ​ Thereafter ​ 758 ​ ​
Summary of advance royalties	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Advance royalties, affiliates (see Note 22 – Related-Party Transactions) ​ $ 60,608 ​ $ 55,613 ​ Advance royalties, third-parties ​ 14,661 ​ 12,869 ​ Total advance royalties ​ $ 75,269 ​ $ 68,482 ​ ​

ACQUISITIONS (Tables)

ACQUISITIONS (Tables)	12 Months Ended
	Dec. 31, 2022
Acquisition
Schedule of asset acquisition	​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ Mineral interests in proved properties ​ $ 12,542 ​ Mineral interests in unproved properties ​ ​ 18,418 ​ ​ ​ $ 30,960 ​ ​
Belvedere
Acquisition
Summary of assets acquired and liabilities assumed	​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ Mineral interests in proved properties ​ $ 7,724 ​ Mineral interests in unproved properties ​ ​ 3,667 ​ ​ ​ $ 11,391 ​ ​
Schedule of pro forma income statement	​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 ​ (in thousands) ​ ​ ​ ​ Revenue $ 722 ​ Net income 488 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ (unaudited) ​ Revenues ​ $ 2,407,368 ​ $ 1,571,119 ​ Net income ​ ​ 579,906 ​ ​ 179,747 ​ ​
Jase
Acquisition
Summary of assets acquired and liabilities assumed	​ ​ ​ ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ Mineral interests in proved properties ​ $ 35,918 ​ Mineral interests in unproved properties ​ ​ 43,740 ​ Receivables ​ ​ 1,569 ​ Net assets acquired ​ $ 81,227 ​ ​
Schedule of pro forma income statement	​ ​ ​ ​ ​ ​ Year Ended ​ ​ December 31, ​ ​ 2022 ​ (in thousands) ​ ​ ​ ​ Revenue $ 1,689 ​ Net income 854 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ (unaudited) ​ Revenues ​ $ 2,417,278 ​ $ 1,579,660 ​ Net income ​ ​ 587,749 ​ ​ 186,151 ​

INVENTORIES (Tables)

INVENTORIES (Tables)	12 Months Ended
	Dec. 31, 2022
INVENTORIES
Schedule of inventories	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal ​ $ 23,553 ​ $ 24,845 ​ Supplies (net of reserve for obsolescence of $6,601 and $5,554, respectively) ​ 53,773 ​ 35,457 ​ Total inventories, net ​ $ 77,326 ​ $ 60,302 ​ ​

PROPERTY, PLANT AND EQUIPMENT (

PROPERTY, PLANT AND EQUIPMENT (Tables)	12 Months Ended
	Dec. 31, 2022
PROPERTY, PLANT AND EQUIPMENT
Schedule of property, plant and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Mining equipment and processing facilities ​ $ 1,927,603 ​ $ 1,896,470 ​ Land and coal mineral rights ​ 499,950 ​ 458,440 ​ Oil & gas mineral interests ​ ​ 740,635 ​ ​ 647,864 ​ Buildings, office equipment, improvements and other miscellaneous equipment ​ 300,436 ​ 282,902 ​ Construction, mine development and other projects in progress ​ 99,042 ​ 44,217 ​ Mine development costs ​ 289,724 ​ 278,454 ​ Property, plant and equipment, at cost ​ 3,857,390 ​ 3,608,347 ​ Less accumulated depreciation, depletion and amortization ​ (2,040,468) ​ (1,909,669) ​ Total property, plant and equipment, net ​ $ 1,816,922 ​ $ 1,698,678 ​ ​

LONG-TERM DEBT (Tables)

LONG-TERM DEBT (Tables)	12 Months Ended
	Dec. 31, 2022
LONG-TERM DEBT
Schedule of long-term debt	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Unamortized Discount and ​ ​ ​ Principal ​ Debt Issuance Costs ​ ​ ​ December 31, ​ December 31, ​ ​ 2022 2021 2022 2021 ​ ​ (in thousands) ​ Replaced credit facility ​ $ — ​ $ — ​ $ (2,702) ​ $ (5,019) ​ Senior notes ​ 400,000 ​ 400,000 ​ (2,134) ​ (3,048) ​ Securitization facility ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ May 2019 equipment financing ​ ​ — ​ ​ 1,503 ​ ​ — ​ ​ — ​ November 2019 equipment financing ​ ​ 21,072 ​ ​ 31,972 ​ ​ — ​ ​ — ​ June 2020 equipment financing ​ ​ 5,937 ​ ​ 9,605 ​ ​ — ​ ​ — ​ ​ ​ 427,009 ​ 443,080 ​ (4,836) ​ (8,067) ​ Less current maturities ​ (24,970) ​ (16,071) ​ — ​ — ​ Total long-term debt ​ $ 402,039 ​ $ 427,009 ​ $ (4,836) ​ $ (8,067) ​ ​
Schedule of aggregate maturities of long-term debt	​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ ​ December 31, (in thousands) 2023 ​ $ 24,970 ​ 2024 ​ 2,039 ​ 2025 ​ 400,000 ​ ​ ​ $ 427,009 ​

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2022
INCOME TAXES
Components of income tax expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Current: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ $ 17,572 ​ $ (1) ​ $ (78) ​ State ​ 1,605 ​ 70 ​ 1 ​ ​ ​ 19,177 ​ 69 ​ (77) ​ Deferred: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Federal ​ 33,038 ​ 356 ​ (178) ​ State ​ 1,763 ​ (8) ​ 290 ​ ​ ​ 34,801 ​ 348 ​ 112 ​ Income tax expense ​ $ 53,978 ​ $ 417 ​ $ 35 ​ ​
Reconciliation from provision for income taxes at U.S. federal statutory rate to effective tax rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ ​ (in thousands) ​ Income taxes at statutory rate ​ $ 132,956 ​ $ 37,626 ​ $ (27,093) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: Income taxes at statutory rate on Partnership income not subject to income taxes ​ (112,032) ​ (36,577) ​ 26,293 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Increase (decrease) resulting from: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ State taxes, net of federal income tax ​ 1,492 ​ 275 ​ (192) ​ Change in valuation allowance of deferred tax assets ​ (317) ​ (834) ​ 1,151 ​ Deferred taxes related to tax election ​ ​ 37,253 ​ ​ — ​ ​ — ​ Tax effect of noncontrolling interest income not subject to income taxes ​ ​ (5,399) ​ ​ — ​ ​ — ​ Other ​ 25 ​ (73) ​ (124) ​ Income tax expense ​ $ 53,978 ​ $ 417 ​ $ 35 ​ ​
Components of deferred tax liabilities and deferred tax assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2022 2021 ​ ​ (in thousands) ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ Property, plant and equipment ​ $ (38,349) ​ $ (2,169) ​ Total deferred tax liabilities ​ ​ (38,349) ​ ​ (2,169) ​ ​ ​ ​ ​ ​ ​ ​ ​ Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ Federal loss carryovers and credits ​ ​ 2,139 ​ ​ 1,328 ​ Other ​ 1,084 ​ 808 ​ Total deferred tax assets ​ ​ 3,223 ​ ​ 2,136 ​ Less valuation allowance ​ ​ — ​ ​ (317) ​ Net deferred tax assets ​ ​ 3,223 ​ ​ 1,819 ​ ​ ​ ​ ​ ​ ​ ​ ​ Overall net deferred tax liabilities ​ $ (35,126) ​ $ (350) ​ ​

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2022
LEASES
Schedule of lease cost and other information	The components of lease expense were as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 ​ 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Finance lease cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Amortization of right-of-use assets ​ $ 597 ​ $ 597 ​ $ 704 ​ Interest on lease liabilities ​ 73 ​ 147 ​ 377 ​ Operating lease cost ​ 274 ​ 2,404 ​ 3,873 ​ Short-term lease cost ​ ​ — ​ ​ 200 ​ ​ 84 ​ Variable lease cost ​ 1,665 ​ 1,306 ​ 1,375 ​ Total lease cost ​ $ 2,609 ​ $ 4,654 ​ $ 6,413 ​ ​ Supplemental cash flow information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 ​ 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash paid for amounts included in the measurement of lease liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating cash flows for operating leases ​ $ 2,880 ​ $ 2,367 ​ $ 3,870 ​ Operating cash flows for finance leases ​ $ 73 ​ $ 147 ​ $ 377 ​ Financing cash flows for finance leases ​ $ 840 ​ $ 766 ​ $ 8,368 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Right-of-use assets obtained in exchange for lease obligations: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases ​ $ 1,315 ​ $ 189 ​ $ 278 ​ ​ Supplemental balance sheet information related to leases was as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ Finance leases: ​ ​ ​ ​ ​ ​ ​ Property and equipment finance lease assets, gross ​ $ 5,485 ​ $ 5,485 ​ Accumulated depreciation ​ (5,061) ​ (4,464) ​ Property and equipment finance lease assets, net ​ $ 424 ​ $ 1,021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ Weighted average remaining lease term ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 13.4 years ​ ​ 15.5 years ​ Finance leases ​ ​ 5.0 years ​ ​ 3.5 years ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted average discount rate ​ ​ ​ ​ ​ ​ ​ Operating leases ​ ​ 6.0 % ​ ​ 6.0 % ​ Finance leases ​ 4.8 % ​ ​ 7.4 % ​ ​
Summary of supplemental lease information	​
Schedule of maturities of operating lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases Finance leases ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ $ 3,253 ​ $ 140 ​ 2024 ​ ​ 2,918 ​ ​ 140 ​ 2025 ​ ​ 1,734 ​ ​ 140 ​ 2026 ​ ​ 1,106 ​ ​ 140 ​ 2027 ​ ​ 1,112 ​ ​ 140 ​ Thereafter ​ ​ 11,901 ​ ​ — ​ Total lease payments ​ ​ 22,024 ​ ​ 700 ​ Less imputed interest ​ ​ (7,100) ​ ​ (82) ​ Total ​ $ 14,924 ​ $ 618 ​ ​
Schedule of maturities of finance lease liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Operating leases Finance leases ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ 2023 ​ $ 3,253 ​ $ 140 ​ 2024 ​ ​ 2,918 ​ ​ 140 ​ 2025 ​ ​ 1,734 ​ ​ 140 ​ 2026 ​ ​ 1,106 ​ ​ 140 ​ 2027 ​ ​ 1,112 ​ ​ 140 ​ Thereafter ​ ​ 11,901 ​ ​ — ​ Total lease payments ​ ​ 22,024 ​ ​ 700 ​ Less imputed interest ​ ​ (7,100) ​ ​ (82) ​ Total ​ $ 14,924 ​ $ 618 ​ ​

FAIR VALUE MEASUREMENTS (Tables

FAIR VALUE MEASUREMENTS (Tables)	12 Months Ended
	Dec. 31, 2022
FAIR VALUE MEASUREMENTS
Summary of fair value measurements within the hierarchy	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2022 ​ December 31, 2021 ​ ​ Level 1 Level 2 Level 3 Level 1 Level 2 Level 3 ​ ​ (in thousands) ​ Long-term debt ​ $ — ​ $ 424,420 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​ Total ​ $ — ​ $ 424,420 ​ $ — ​ $ — ​ $ 457,758 ​ $ — ​ ​

PARTNERS' CAPITAL (Tables)

PARTNERS' CAPITAL (Tables)	12 Months Ended
	Dec. 31, 2022
PARTNERS' CAPITAL
Summary of quarterly per unit distribution paid	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 First Quarter ​ $ 0.250 ​ $ — ​ $ 0.400 ​ Second Quarter ​ $ 0.350 ​ $ 0.100 ​ $ — ​ Third Quarter ​ $ 0.400 ​ $ 0.100 ​ $ — ​ Fourth Quarter ​ $ 0.500 ​ $ 0.200 ​ $ — ​ ​

VARIABLE INTEREST ENTITIES (Tab

VARIABLE INTEREST ENTITIES (Tables)	12 Months Ended
	Dec. 31, 2022
VARIABLE INTEREST ENTITIES
Schedule of distributions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Alliance ​ Bluegrass ​ ​ ​ ​ ​ Minerals ​ Minerals ​ ​ ​ ​ ​ (in thousands) Contributions ​ ​ ​ ​ $ 143,112 ​ $ 5,963 Distributions ​ ​ ​ ​ ​ 146,484 ​ ​ 6,179 ​

INVESTMENTS (Tables)

INVESTMENTS (Tables)	12 Months Ended
	Dec. 31, 2022
All Dale Minerals III
INVESTMENTS
Schedule of changes in equity method investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ (in thousands) Beginning balance ​ $ 26,325 ​ $ 27,268 ​ $ 28,529 Equity method investment income ​ ​ 5,634 ​ ​ 2,130 ​ ​ 907 Distributions received ​ ​ (6,675) ​ ​ (3,073) ​ ​ (1,895) Other ​ ​ — ​ ​ — ​ ​ (273) Ending balance ​ $ 25,284 ​ $ 26,325 ​ $ 27,268 ​
Francis Renewable Energy
INVESTMENTS
Schedule of changes in equity method investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2022 ​ ​ ​ (in thousands) ​ Beginning balance ​ ​ $ — ​ Contributions ​ ​ ​ 20,000 ​ Ending balance ​ ​ $ 20,000 ​ ​
Infinitum Electric
INVESTMENTS
Schedule of changes in equity securities without readily determinable fair value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2022 ​ ​ ​ ​ (in thousands) ​ Beginning balance ​ ​ $ — ​ Contributions ​ ​ ​ 42,000 ​ Ending balance ​ ​ $ 42,000 ​ ​
NGP ETP
INVESTMENTS
Schedule of changes in equity method investments	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ ​ 2022 ​ ​ ​ ​ (in thousands) ​ Beginning balance ​ ​ $ — ​ Contributions ​ ​ ​ 4,087 ​ Ending balance ​ ​ $ 4,087 ​ ​

REVENUE FROM CONTRACTS WITH C_2

REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)	12 Months Ended
	Dec. 31, 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) ​ Year Ended December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 1,219,943 ​ $ 882,286 ​ $ — ​ $ — ​ $ — ​ $ 2,102,229 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 138,402 ​ ​ — ​ ​ — ​ ​ 138,402 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 60,624 ​ ​ (60,624) ​ ​ — ​ Transportation revenues ​ ​ 69,540 ​ ​ 44,320 ​ ​ — ​ ​ — ​ ​ — ​ ​ 113,860 ​ Other revenues ​ ​ 6,822 ​ ​ 1,481 ​ ​ 3,039 ​ ​ 56 ​ ​ 40,622 ​ ​ 52,020 ​ Total revenues ​ $ 1,296,305 ​ $ 928,087 ​ $ 141,441 ​ $ 60,680 ​ $ (20,002) ​ $ 2,406,511 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 873,930 ​ $ 512,993 ​ $ — ​ $ — ​ $ — ​ $ 1,386,923 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 74,988 ​ ​ — ​ ​ — ​ ​ 74,988 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 51,402 ​ ​ (51,402) ​ ​ — ​ Transportation revenues ​ ​ 41,001 ​ ​ 28,606 ​ ​ — ​ ​ — ​ ​ — ​ ​ 69,607 ​ Other revenues ​ ​ 4,666 ​ ​ 3,940 ​ ​ 2,197 ​ ​ 69 ​ ​ 27,586 ​ ​ 38,458 ​ Total revenues ​ $ 919,597 ​ $ 545,539 ​ $ 77,185 ​ $ 51,471 ​ $ (23,816) ​ $ 1,569,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal sales ​ $ 755,208 ​ $ 477,064 ​ $ — ​ $ — ​ $ — ​ $ 1,232,272 ​ Oil & gas royalties ​ ​ — ​ ​ — ​ ​ 42,912 ​ ​ — ​ ​ — ​ ​ 42,912 ​ Coal royalties ​ ​ — ​ ​ — ​ ​ — ​ ​ 42,112 ​ ​ (42,112) ​ ​ — ​ Transportation revenues ​ ​ 12,817 ​ ​ 8,312 ​ ​ — ​ ​ — ​ ​ — ​ ​ 21,129 ​ Other revenues ​ ​ 1,932 ​ ​ 14,954 ​ ​ 229 ​ ​ 105 ​ ​ 14,596 ​ ​ 31,816 ​ Total revenues ​ $ 769,957 ​ $ 500,330 ​ $ 43,141 ​ $ 42,217 ​ $ (27,516) ​ $ 1,328,129 ​ ​
Schedule of current coal supply contracts allocated to performance obligations that are unsatisfied or partially unsatisfied	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2026 and ​ ​ ​ ​ 2023 2024 2025 Thereafter Total ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Illinois Basin Coal Operations coal revenues ​ $ 1,230,551 ​ $ 730,825 ​ $ 344,601 ​ $ 243,600 ​ $ 2,549,577 ​ Appalachia Coal Operations coal revenues ​ ​ 721,143 ​ ​ 532,647 ​ ​ 308,925 ​ ​ 1,600 ​ ​ 1,564,315 ​ Total coal revenues (1) ​ $ 1,951,694 ​ $ 1,263,472 ​ $ 653,526 ​ $ 245,200 ​ $ 4,113,892 ​ (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)	12 Months Ended
	Dec. 31, 2022
EARNINGS PER LIMITED PARTNER UNIT
Reconciliation of net income (loss) and EPU calculations	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ ​ (in thousands, except per unit data) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to ARLP ​ $ 577,190 ​ $ 178,157 ​ $ (129,220) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Less: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Distributions to participating securities ​ (8,527) ​ (2,334) ​ — ​ Undistributed earnings attributable to participating securities ​ (10,576) ​ (2,403) ​ — ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net income (loss) attributable to ARLP available to limited partners ​ $ 558,087 ​ $ 173,420 ​ $ (129,220) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average limited partner units outstanding – basic and diluted ​ 127,195 ​ 127,195 ​ 127,165 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Earnings per limited partner unit - basic and diluted (1) ​ $ 4.39 ​ $ 1.36 ​ $ (1.02) ​ (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. For the years ended December 31, 2022, 2021 and 2020, the combined total of LTIP, SERP and Directors' Deferred Compensation Plan units of 3,540,385 , 1,967,672 and 773,664 , respectively, were considered anti-dilutive under the treasury stock method.

EMPLOYEE BENEFIT PLANS (Tables)

EMPLOYEE BENEFIT PLANS (Tables) - Defined benefit pension plan	12 Months Ended
	Dec. 31, 2022
Employee Benefit Plans
Summary of benefit plans for employees	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ (dollars in thousands) ​ Change in benefit obligations: ​ ​ ​ ​ ​ ​ ​ Benefit obligations at beginning of year ​ $ 139,566 ​ $ 147,934 ​ Interest cost ​ 3,749 ​ 3,438 ​ Actuarial gain ​ (32,996) ​ (6,406) ​ Benefits paid ​ (5,637) ​ (5,400) ​ Benefit obligations at end of year ​ 104,682 ​ 139,566 ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in plan assets: ​ ​ ​ ​ ​ ​ ​ Fair value of plan assets at beginning of year ​ 113,976 ​ 100,969 ​ Employer contribution ​ — ​ 3,312 ​ Actual return on plan assets ​ (16,210) ​ 15,095 ​ Benefits paid ​ (5,637) ​ (5,400) ​ Fair value of plan assets at end of year ​ 92,129 ​ 113,976 ​ Funded status at the end of year ​ $ (12,553) ​ $ (25,590) ​ ​ ​ ​ ​ ​ ​ ​ ​ Amounts recognized in balance sheet: ​ ​ ​ ​ ​ ​ ​ Non-current liability ​ $ (12,553) ​ $ (25,590) ​ ​ ​ ​ ​ ​ ​ ​ ​ Amounts recognized in accumulated other comprehensive income consists of: ​ ​ ​ ​ ​ ​ ​ Prior service cost ​ $ (382) ​ $ (568) ​ Net actuarial loss ​ ​ (15,160) ​ ​ (27,271) ​ ​ ​ $ (15,542) ​ $ (27,839) ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average assumption to determine benefit obligations as of December 31, ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 5.10% ​ 2.73% ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average assumptions used to determine net periodic benefit cost for the year ended December 31, ​ ​ ​ ​ ​ ​ ​ Discount rate ​ 2.73% ​ 2.37% ​ Expected return on plan assets ​ 6.00% ​ 6.50% ​ ​
Schedule of long-term rate of return assumptions	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Asset allocation ​ As of December 31, 2022 assumption Equity securities ​ 60% ​ Fixed income securities 35% ​ Real estate 5% ​ ​ 100% ​ ​
Components of net periodic benefit cost	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ ​ (in thousands) Components of net periodic benefit cost: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest cost ​ $ 3,749 ​ $ 3,438 ​ $ 4,185 ​ Expected return on plan assets ​ (6,638) ​ (6,580) ​ (5,861) ​ Amortization of prior service cost ​ ​ 186 ​ ​ 186 ​ ​ 186 ​ Amortization of net loss ​ 1,963 ​ 4,327 ​ 4,128 ​ Net periodic benefit cost (1) ​ $ (740) ​ $ 1,371 ​ $ 2,638 ​ (1) Nonservice components of net periodic benefit cost are included in the Other income (expense) line item within our consolidated statements of operations. ​
Schedule of other changes in plan assets and benefit obligation recognized in accumulated other comprehensive income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ Other changes in plan assets and benefit obligation recognized in accumulated other comprehensive loss: ​ ​ ​ ​ ​ ​ ​ Net actuarial gain ​ $ 10,148 ​ $ 14,921 ​ Reversal of amortization item: ​ ​ ​ ​ ​ ​ ​ Prior service cost ​ ​ 186 ​ ​ 186 ​ Net actuarial loss ​ 1,963 ​ 4,327 ​ Total recognized in accumulated other comprehensive loss ​ 12,297 ​ 19,434 ​ Net periodic benefit cost (credit) ​ 740 ​ (1,371) ​ Total recognized in net periodic benefit cost and accumulated other comprehensive loss ​ $ 13,037 ​ $ 18,063 ​ ​
Schedule of estimated future benefit payments	​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ ​ December 31, (in thousands) ​ ​ ​ ​ ​ 2023 ​ $ 6,239 ​ 2024 ​ 6,416 ​ 2025 ​ 6,605 ​ 2026 ​ 6,816 ​ 2027 ​ 6,907 ​ 2028-2032 ​ 35,293 ​ ​ ​ $ 68,276 ​ ​
Schedule of asset allocation guidelines, actual asset allocations and fair value of Pension Plan assets	​ ​ ​ ​ ​ ​ ​ ​ ​ Percentage of Total Portfolio ​ Minimum Maximum ​ ​ ​ ​ ​ ​ Equity securities ​ 35% ​ 80% ​ Fixed income securities ​ 15% ​ 65% ​ Convertible securities ​ 0% ​ 10% ​ Alternatives ​ 0% ​ 20% ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 ​ 2021 ​ ​ ​ (in thousands) Cash and cash equivalents (a) ​ $ 5,422 ​ $ 4,426 ​ ​ ​ ​ ​ ​ ​ ​ ​ Commingled investment funds measured at net asset value (b): ​ ​ ​ ​ ​ ​ ​ Equities - Global ​ ​ — ​ ​ 24,868 ​ Equities - United States ​ ​ 36,259 ​ ​ 41,140 ​ Equities - United States futures ​ ​ (697) ​ ​ (2,055) ​ Equities - International developed markets ​ ​ 14,214 ​ ​ 16,382 ​ Equities - International developed markets futures ​ ​ (1,693) ​ ​ (16,260) ​ Equities - International emerging markets ​ ​ 782 ​ ​ (3,363) ​ Equities - International emerging markets futures ​ ​ 3,289 ​ ​ 7,024 ​ Fixed income - Investment grade ​ ​ 13,856 ​ ​ 27,095 ​ Fixed income - High yield ​ ​ 156 ​ ​ 177 ​ Fixed income - Futures ​ ​ 8,590 ​ ​ (689) ​ Alternatives ​ ​ 11,951 ​ ​ 15,231 ​ Total ​ $ 92,129 ​ $ 113,976 ​ (a) Cash and cash equivalents represents a Level 1 fair value measurement. See Note 2 – Summary of Significant Accounting Policies – Fair Value Measurements for more information regarding the definitions of fair value hierarchy levels. (b) Investments measured at fair value using the net asset value per share (or its equivalent) have not been classified within the fair value hierarchy. The fair values of all commingled investment funds are determined based on the net asset values per unit of each of the funds. The net asset values per unit represent the aggregate value of the fund's assets at fair value less liabilities, divided by the number of units outstanding. ​

COMMON UNIT-BASED COMPENSATIO_2

COMMON UNIT-BASED COMPENSATION PLANS (Tables)	12 Months Ended
	Dec. 31, 2022
ARLP LTIP
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) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-vested grants at January 1, 2020 ​ 1,603,378 ​ $ 20.39 ​ $ 17,349 ​ Granted (1) ​ 1,430,489 ​ ​ 5.02 ​ ​ ​ ​ Vested (2) ​ (919,524) ​ ​ 21.70 ​ ​ ​ ​ Grants canceled (3) ​ (675,302) ​ 18.62 ​ ​ ​ ​ Forfeited ​ (8,552) ​ 20.16 ​ ​ ​ ​ Non-vested grants at December 31, 2020 ​ 1,430,489 ​ ​ 5.02 ​ ​ 6,409 ​ Granted (4) ​ 1,818,190 ​ ​ 6.03 ​ ​ ​ ​ Forfeited ​ (118,204) ​ 5.48 ​ ​ ​ ​ Non-vested grants at December 31, 2021 ​ 3,130,475 ​ ​ 5.59 ​ ​ 39,569 ​ Granted (4) 769,907 ​ ​ 14.65 ​ ​ ​ ​ Forfeited (203,249) ​ 6.93 ​ ​ ​ ​ Non-vested grants at December 31, 2022 3,697,133 ​ 7.40 ​ ​ 75,126 ​ (1) In December 2020, we modified the vesting requirements for certain restricted units that we granted in February 2020 which were determined to be improbable of vesting under the original vesting requirements (the "2020 Grants"). The new vesting requirements make it probable the modified restricted units will vest. Also in December 2020, an additional 578,114 restricted units under these modified vesting requirements were granted. The grant date fair value reflects the modification date fair value for those awards that were modified. (2) In February 2020, we issued 279,622 unrestricted common units to LTIP participants as a result of satisfying the vesting requirements for 424,486 restricted units that were granted in 2017. The remaining vested units were settled in cash to satisfy tax withholding obligations of the LTIP participants. In December 2020, we accelerated the vesting requirements for 495,038 restricted units that were granted in 2018 (the "2018 Grants") and settled these restricted units in cash. (3) In December 2020, 675,302 restricted units that were granted in 2019 (the "2019 Grants") were canceled since it was determined that the vesting requirements for these restricted units were not probable of being satisfied. (4) The restricted units granted during 2021 and 2022 have certain minimum-value guarantees 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, 2020 ​ 631,365 ​ $ 25.48 ​ $ 6,831 ​ Granted ​ 129,265 ​ ​ 5.25 ​ ​ ​ ​ Phantom units outstanding as of December 31, 2020 ​ 760,630 ​ ​ 22.04 ​ ​ 3,408 ​ Granted ​ 46,638 ​ ​ 9.45 ​ ​ ​ ​ Issued (1) ​ (138,570) ​ ​ 25.86 ​ ​ ​ ​ Phantom units outstanding as of December 31, 2021 ​ 668,698 ​ ​ 20.37 ​ ​ 8,452 ​ Granted ​ 73,842 ​ ​ 19.44 ​ ​ ​ ​ Phantom units outstanding as of December 31, 2022 742,540 ​ 20.28 ​ ​ 15,088 ​ (1) During the year ended December 31, 2021, we purchased 102,962 ARLP common units on the open market to settle the account of a participant under the SERP. Units purchased were net of units settled in cash to satisfy tax-withholding obligations.

SUPPLEMENTAL CASH FLOW INFORM_2

SUPPLEMENTAL CASH FLOW INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2022
SUPPLEMENTAL CASH FLOW INFORMATION
Schedule of supplemental cash flow information	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Cash Paid For: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Interest ​ $ 34,844 ​ $ 36,402 ​ $ 44,226 ​ Income taxes ​ $ 23,794 ​ $ 11 ​ $ 12 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Non-Cash Activity: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Accounts payable for purchase of property, plant and equipment ​ $ 44,281 ​ $ 8,325 ​ $ 5,731 ​ Right-of-use assets acquired by operating lease ​ $ 1,315 ​ $ 189 ​ $ 278 ​ Market value of common units issued under deferred compensation plans before tax withholding requirements ​ $ — ​ $ 1,082 ​ $ 3,837 ​

ASSET RETIREMENT OBLIGATIONS (T

ASSET RETIREMENT OBLIGATIONS (Tables)	12 Months Ended
	Dec. 31, 2022
ASSET RETIREMENT OBLIGATIONS
Schedule of activity affecting the asset retirement and mine closing liability	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 131,099 ​ $ 127,898 ​ Accretion expense ​ 3,731 ​ 3,688 ​ Payments ​ (2,445) ​ (1,383) ​ Allocation of liability associated with mine development and change in assumptions ​ 17,428 ​ 896 ​ Ending balance ​ $ 149,813 ​ $ 131,099 ​ ​
Schedule of estimated payments of asset retirement obligations	​ ​ ​ ​ ​ ​ Year Ended ​ ​ ​ ​ December 31, (in thousands) ​ ​ ​ ​ ​ 2023 ​ $ 7,559 ​ 2024 ​ 4,936 ​ 2025 ​ 1,935 ​ 2026 ​ 1,569 ​ 2027 ​ 3,182 ​ Thereafter ​ 241,065 ​ Aggregate undiscounted asset retirement obligations ​ 260,246 ​ Effect of discounting ​ (110,433) ​ Total asset retirement obligations ​ 149,813 ​ Less: current portion ​ (7,559) ​ Non-current asset retirement obligations ​ $ 142,254 ​ ​

ACCRUED WORKERS' COMPENSATION_2

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS (Tables)	12 Months Ended
	Dec. 31, 2022
Black lung benefits:
Reconciliation of changes in workers' compensation liability	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2022 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ Beginning balance ​ $ 53,448 ​ $ 54,739 ​ Changes in accruals ​ 7,384 ​ 5,168 ​ Payments ​ (12,708) ​ (10,725) ​ Interest accretion ​ 1,147 ​ 926 ​ Valuation loss ​ 181 ​ 3,340 ​ Ending balance ​ $ 49,452 ​ $ 53,448 ​ ​
Reconciliation of changes in pneumoconiosis benefit obligation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Benefit obligations at beginning of year ​ $ 111,316 ​ $ 108,496 ​ Service cost ​ 3,798 ​ 4,021 ​ Interest cost ​ 2,991 ​ 2,545 ​ Actuarial loss (gain) ​ (9,840) ​ 161 ​ Benefits and expenses paid ​ (3,978) ​ (3,907) ​ Benefit obligations at end of year ​ $ 104,287 ​ $ 111,316 ​ ​
Components of pneumoconiosis and workers' compensation expense	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ ​ (in thousands) ​ Black lung benefits: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Service cost $ 3,798 ​ $ 4,021 ​ $ 3,526 ​ Interest cost (1) ​ 2,991 ​ 2,545 ​ 2,998 ​ Net amortization (1) ​ 1,038 ​ 4,172 ​ (686) ​ Total pneumoconiosis expense ​ 7,827 ​ 10,738 ​ 5,838 ​ Workers' compensation expense ​ 11,675 ​ 8,339 ​ 12,305 ​ Net periodic benefit cost ​ $ 19,502 ​ $ 19,077 ​ $ 18,143 ​ ________________________________________ (1) Interest cost and net amortization is included in the Other income (expense) line item within our consolidated statements of income ( see Note 2 – Summary of Significant Accounting Policies). ​
Pneumoconiosis benefits
Black lung benefits:
Reconciliation of changes in the pneumoconiosis benefit obligation recognized in AOCI	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net actuarial gain (loss) ​ $ 9,840 ​ $ (161) ​ $ (7,787) ​ Reversal of amortization item: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net actuarial loss (gain) ​ 1,038 ​ 4,172 ​ (686) ​ Total recognized in accumulated other comprehensive loss ​ $ 10,878 ​ $ 4,011 ​ $ (8,473) ​ ​
Schedule of amount recognized in accumulated other comprehensive income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2022 2021 2020 ​ ​ (in thousands) ​ Amount recognized in accumulated other comprehensive loss consists of: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net actuarial loss ​ $ 25,510 ​ $ 36,388 ​ $ 40,399 ​ ​
Summary of information about amounts recognized in the consolidated balance sheets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2022 2021 ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ Workers' compensation claims ​ $ 49,452 ​ $ 53,448 ​ Pneumoconiosis benefit claims ​ ​ 104,287 ​ ​ 111,316 ​ Total obligations ​ 153,739 ​ 164,764 ​ Less current portion ​ (14,099) ​ (12,293) ​ Non-current obligations ​ $ 139,640 ​ $ 152,471 ​ ​

RELATED-PARTY TRANSACTIONS (Tab

RELATED-PARTY TRANSACTIONS (Tables)	12 Months Ended
	Dec. 31, 2022
RELATED-PARTY TRANSACTIONS
Summary of advanced royalties outstanding	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ WKY CoalPlay ​ ​ ​ ​ ​ ​ ​ Towhead ​ Webster ​ Henderson ​ WKY ​ ​ ​ ​ ​ Craft Foundations ​ Coal ​ Coal ​ Coal ​ CoalPlay ​ ​ ​ ​ ​ ​ ​ Henderson ​ ​ ​ ​ ​ Henderson ​ ​ ​ ​ ​ ​ Tunnel ​ & Union ​ Webster ​ Henderson ​ & Union ​ ​ ​ ​ ​ ​ Ridge ​ Counties, KY ​ County, KY ​ County, KY ​ Counties, KY ​ Total ​ ​ ​ Acquired ​ Acquired ​ Acquired ​ Acquired ​ Acquired ​ ​ ​ ​ ​ ​ 2005 ​ December 2014 ​ December 2014 ​ December 2014 ​ February 2015 ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ As of January 1, 2020 ​ $ 1,500 ​ $ 16,603 ​ $ — ​ $ 12,607 ​ $ 10,506 ​ $ 41,216 ​ Payments ​ ​ 3,000 ​ ​ 3,597 ​ ​ 2,568 ​ ​ 2,522 ​ ​ 2,132 ​ ​ 13,819 ​ Recoupment ​ ​ (3,000) ​ ​ (1,022) ​ ​ — ​ ​ — ​ ​ (56) ​ ​ (4,078) ​ Unrecoupable ​ ​ — ​ ​ — ​ ​ (2,568) ​ ​ — ​ ​ — ​ ​ (2,568) ​ As of December 31, 2020 ​ ​ 1,500 ​ ​ 19,178 ​ ​ — ​ ​ 15,129 ​ ​ 12,582 ​ ​ 48,389 ​ Payments ​ ​ 3,000 ​ ​ 3,597 ​ ​ 2,568 ​ ​ 2,521 ​ ​ 2,131 ​ ​ 13,817 ​ Recoupment ​ ​ (3,000) ​ ​ (1,025) ​ ​ — ​ ​ — ​ ​ — ​ ​ (4,025) ​ Unrecoupable ​ ​ — ​ ​ — ​ ​ (2,568) ​ ​ — ​ ​ — ​ ​ (2,568) ​ As of December 31, 2021 ​ ​ 1,500 ​ ​ 21,750 ​ ​ — ​ ​ 17,650 ​ ​ 14,713 ​ ​ 55,613 ​ Payments ​ ​ 3,000 ​ ​ 3,597 ​ ​ — ​ ​ 2,522 ​ ​ 2,131 ​ ​ 11,250 ​ Recoupment ​ ​ (3,000) ​ ​ (3,255) ​ ​ — ​ ​ — ​ ​ — ​ ​ (6,255) ​ Unrecoupable ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ ​ — ​ As of December 31, 2022 ​ $ 1,500 ​ $ 22,092 ​ $ — ​ $ 20,172 ​ $ 16,844 ​ $ 60,608 ​ ​

CONCENTRATION OF CREDIT RISK _2

CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS (Tables)	12 Months Ended
	Dec. 31, 2022
CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS
Schedule of total revenues from major customers	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ Segment 2022 ​ 2021 ​ 2020 ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Customer A Illinois Basin ​ $ 328,406 ​ $ 239,482 ​ $ 197,379 ​ Customer B ​ Illinois Basin ​ ​ 260,146 ​ ​ — ​ ​ 157,271 ​ Customer C ​ Illinois Basin/Appalachia ​ ​ 228,480 ​ ​ — ​ ​ — ​ Customer D Illinois Basin/Appalachia ​ — ​ ​ — ​ 137,785 ​ ​

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2022
SEGMENT INFORMATION
Schedule of reportable segment results	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Coal Operations ​ Royalties ​ Other, ​ ​ ​ ​ ​ Illinois ​ ​ ​ ​ ​ Corporate and ​ ​ ​ ​ Basin Appalachia Oil & Gas Coal ​ Elimination Consolidated ​ ​ (in thousands) Year Ended December 31, 2022 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 1,296,305 ​ $ 928,087 ​ $ 141,441 ​ $ 56 ​ $ 40,622 ​ $ 2,406,511 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 60,624 ​ ​ (60,624) ​ ​ — ​ Total revenues (1) ​ ​ 1,296,305 ​ ​ 928,087 ​ ​ 141,441 ​ ​ 60,680 ​ ​ (20,002) ​ ​ 2,406,511 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 806,080 ​ ​ 464,029 ​ ​ 13,950 ​ ​ 21,871 ​ ​ (23,497) ​ 1,282,433 ​ Segment Adjusted EBITDA (3) ​ 420,684 ​ ​ 426,402 ​ ​ 131,168 ​ ​ 38,809 ​ ​ 3,495 ​ 1,020,558 ​ Total assets ​ 779,018 ​ ​ 431,913 ​ ​ 711,917 ​ ​ 321,587 ​ ​ 417,038 ​ 2,661,473 ​ Capital expenditures (4) ​ 158,624 ​ ​ 76,603 ​ ​ — ​ ​ 38,276 ​ ​ 12,891 ​ 286,394 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2021 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 919,597 ​ $ 545,539 ​ $ 77,185 ​ $ 69 ​ $ 27,586 ​ $ 1,569,976 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 51,402 ​ ​ (51,402) ​ ​ — ​ Total revenues (1) ​ ​ 919,597 ​ ​ 545,539 ​ ​ 77,185 ​ ​ 51,471 ​ ​ (23,816) ​ ​ 1,569,976 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 613,303 ​ ​ 344,332 ​ ​ 9,943 ​ ​ 18,269 ​ ​ (33,198) ​ 952,649 ​ Segment Adjusted EBITDA (3) ​ 265,292 ​ ​ 172,601 ​ ​ 68,774 ​ ​ 33,202 ​ ​ 9,383 ​ 549,252 ​ Total assets ​ 676,091 ​ ​ 420,144 ​ ​ 630,627 ​ ​ 285,943 ​ ​ 146,601 ​ 2,159,406 ​ Capital expenditures (4) ​ 60,166 ​ ​ 47,577 ​ ​ — ​ ​ 45 ​ ​ 15,196 ​ 122,984 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, 2020 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Revenues - Outside ​ $ 769,957 ​ $ 500,330 ​ $ 43,141 ​ $ 105 ​ $ 14,596 ​ $ 1,328,129 ​ Revenues - Intercompany ​ ​ — ​ ​ — ​ ​ — ​ ​ 42,112 ​ ​ (42,112) ​ ​ — ​ Total revenues (1) ​ ​ 769,957 ​ ​ 500,330 ​ ​ 43,141 ​ ​ 42,217 ​ ​ (27,516) ​ ​ 1,328,129 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Segment Adjusted EBITDA Expense (2) ​ 543,264 ​ 320,656 ​ 4,106 ​ 18,249 ​ ​ (25,026) ​ 861,249 ​ Segment Adjusted EBITDA (3) ​ 213,876 ​ 171,362 ​ 39,773 ​ 23,968 ​ ​ (2,490) ​ 446,489 ​ Total assets ​ 738,315 ​ 440,815 ​ 613,916 ​ 288,525 ​ ​ 84,445 ​ 2,166,016 ​ Capital expenditures ​ 48,636 ​ 70,960 ​ — ​ 12 ​ ​ 1,493 ​ 121,101 ​ (1) Revenues included in the Other, Corporate and Elimination column are attributable to intercompany eliminations, which are primarily intercompany coal royalties 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 Operating expenses (excluding depreciation, depletion and amortization) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Operating expenses (excluding depreciation, depletion and amortization) ​ $ 1,286,635 ​ $ 943,257 ​ $ 859,656 ​ Outside coal purchases ​ 151 ​ 6,372 ​ — ​ Other expense (income) ​ (4,353) ​ 3,020 ​ 1,593 ​ Segment Adjusted EBITDA Expense ​ $ 1,282,433 ​ $ 952,649 ​ $ 861,249 ​ ​ (3) Segment Adjusted EBITDA is defined as net income (loss) attributable to ARLP before net interest expense, income taxes, depreciation, depletion and amortization, general and administrative expense, asset and goodwill impairments and acquisition gain. 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. Net income (loss) , the most comparable GAAP financial measure, is reconciled to consolidated Segment Adjusted EBITDA: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Net income (loss) ​ $ 579,148 ​ $ 178,755 ​ $ (129,051) ​ Noncontrolling interest ​ ​ (1,958) ​ ​ (598) ​ ​ (169) ​ Net income (loss) attributable to ARLP ​ $ 577,190 ​ $ 178,157 ​ $ (129,220) ​ General and administrative ​ 80,334 ​ 70,160 ​ 59,806 ​ Depreciation, depletion and amortization ​ 273,759 ​ 261,377 ​ 313,387 ​ Asset impairments ​ — ​ — ​ 24,977 ​ Goodwill impairment ​ ​ — ​ ​ — ​ ​ 132,026 ​ Interest expense, net ​ 35,297 ​ 39,141 ​ 45,478 ​ Income tax expense ​ 53,978 ​ 417 ​ 35 ​ Consolidated Segment Adjusted EBITDA ​ $ 1,020,558 ​ $ 549,252 $ 446,489 ​ ​ . (4) Capital Expenditures shown exclude the Belvedere Acquisition on September 9, 2022, Jase Acquisition on October 26, 2022 and the Boulders Acquisition on October 13, 2021. (Note 3 – Acquisitions).
Reconciliation of consolidated Segment Adjusted EBITDA Expense to operating expenses (excluding depreciation, depletion and amortization)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Operating expenses (excluding depreciation, depletion and amortization) ​ $ 1,286,635 ​ $ 943,257 ​ $ 859,656 ​ Outside coal purchases ​ 151 ​ 6,372 ​ — ​ Other expense (income) ​ (4,353) ​ 3,020 ​ 1,593 ​ Segment Adjusted EBITDA Expense ​ $ 1,282,433 ​ $ 952,649 ​ $ 861,249 ​ ​ (3) Segment Adjusted EBITDA is defined as net income (loss) attributable to ARLP before net interest expense, income taxes, depreciation, depletion and amortization, general and administrative expense, asset and goodwill impairments and acquisition gain. 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. Net income (loss) , the most comparable GAAP financial measure, is reconciled to consolidated Segment Adjusted EBITDA:
Reconciliation of consolidated Segment Adjusted EBITDA to net income	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ 2022 2021 2020 ​ ​ (in thousands) ​ Net income (loss) ​ $ 579,148 ​ $ 178,755 ​ $ (129,051) ​ Noncontrolling interest ​ ​ (1,958) ​ ​ (598) ​ ​ (169) ​ Net income (loss) attributable to ARLP ​ $ 577,190 ​ $ 178,157 ​ $ (129,220) ​ General and administrative ​ 80,334 ​ 70,160 ​ 59,806 ​ Depreciation, depletion and amortization ​ 273,759 ​ 261,377 ​ 313,387 ​ Asset impairments ​ — ​ — ​ 24,977 ​ Goodwill impairment ​ ​ — ​ ​ — ​ ​ 132,026 ​ Interest expense, net ​ 35,297 ​ 39,141 ​ 45,478 ​ Income tax expense ​ 53,978 ​ 417 ​ 35 ​ Consolidated Segment Adjusted EBITDA ​ $ 1,020,558 ​ $ 549,252 $ 446,489 ​

ORGANIZATION AND PRESENTATION (

ORGANIZATION AND PRESENTATION (Details) $ in Thousands						12 Months Ended
	Nov. 02, 2022 USD ($)	Oct. 26, 2022 USD ($) a	Sep. 09, 2022 USD ($) a	Apr. 29, 2022 USD ($)	Oct. 13, 2021 USD ($) a	Dec. 31, 2022 USD ($) a	Dec. 31, 2021 USD ($)	Jun. 02, 2022 USD ($)
Ownership interests
Royalty acres, net | a						61,400
Payments for acquisitions of businesses						$ 92,618
Oil & gas royalty acquisition							$ 30,960
Equity method investments						49,371	$ 26,325
Payment to acquire investment						$ 42,000
Percentage of qualifying income for tax purposes						90%
Boulders
Ownership interests
Royalty acres, net | a					1,480
Oil & gas royalty acquisition					$ 31,000
Belvedere
Ownership interests
Royalty acres, net | a			394
Payments for acquisitions of businesses			$ 11,400
Jase
Ownership interests
Royalty acres, net | a		3,928
Payments for acquisitions of businesses		$ 81,200
Francis Renewable Energy
Ownership interests
Equity method investments						$ 20,000
Infinitum Electric
Ownership interests
Payment to acquire investment	$ 9,400			$ 32,600		42,000
NGP ETP
Ownership interests
Funding commitment								$ 25,000
Equity method investments						$ 4,087

SUMMARY OF SIGNIFICANT ACCOUN_4

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Goodwill
Impairments of goodwill	$ 0	$ 0	$ 132,026

SUMMARY OF SIGNIFICANT ACCOUN_5

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Tangible Assets (Details)	12 Months Ended
	Dec. 31, 2022
Preparation plants, processing facilities and mineral rights | Minimum
Property, Plant and Equipment
Estimated useful life	1 year
Preparation plants, processing facilities and mineral rights | Maximum
Property, Plant and Equipment
Estimated useful life	26 years
Other plant and equipment and mining equipment | Minimum
Property, Plant and Equipment
Estimated useful life	1 year
Other plant and equipment and mining equipment | Maximum
Property, Plant and Equipment
Estimated useful life	26 years
Buildings, Office Equipment And Improvements | Minimum
Property, Plant and Equipment
Estimated useful life	1 year
Buildings, Office Equipment And Improvements | Maximum
Property, Plant and Equipment
Estimated useful life	26 years

SUMMARY OF SIGNIFICANT ACCOUN_6

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Leases (Details)	12 Months Ended
	Dec. 31, 2022
Lease renewal term	10 years
Lease termination option term	1 year
Minimum
Lease term	1 year
Maximum
Lease term	26 years

SUMMARY OF SIGNIFICANT ACCOUN_7

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Intangible Assets
Amortization expense attributable to intangible assets	$ 1,200	$ 3,800	$ 4,900
Original Cost	12,123	12,123
Accumulated Amortization	(11,095)	(9,922)
Intangibles, Net	1,028	2,201
Estimated amortization expense attributable to intangible assets
2023	54
2024	54
2025	54
2026	54
2027	54
Thereafter	758
Customer contracts, net
Intangible Assets
Original Cost	10,623	10,623
Accumulated Amortization	(10,623)	(9,504)
Intangibles, Net		1,119
Permits
Intangible Assets
Original Cost	1,500	1,500
Accumulated Amortization	(472)	(418)
Intangibles, Net	$ 1,028	$ 1,082

SUMMARY OF SIGNIFICANT ACCOUN_8

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Advance Royalties (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Advance Royalties
Advance royalties, affiliates	$ 60,608	$ 55,613
Advance royalties, third-parties	14,661	12,869
Total advance royalties, net	$ 75,269	$ 68,482

SUMMARY OF SIGNIFICANT ACCOUN_9

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Additional Information (Details)	12 Months Ended
	Dec. 31, 2022
Income Taxes
Percentage of qualifying income for tax purposes	90%
Minimum
Revenue Recognition
Coal shipments, payment period	14 days
Maximum
Revenue Recognition
Coal shipments, payment period	28 days
Defined benefit pension plan
Employee Benefit Plans
Threshold for amortization of unrecognized actuarial gains and losses (as a percent)	10%

ACQUISITIONS - Asset Acquisitio

ACQUISITIONS - Asset Acquisition (Details) $ in Thousands		12 Months Ended
	Oct. 13, 2021 USD ($) a	Dec. 31, 2022 a	Dec. 31, 2021 USD ($)
Asset acquisition
Royalty acres, net | a		61,400
Oil & gas royalty acquisition			$ 30,960
Boulders
Asset acquisition
Royalty acres, net | a	1,480
Oil & gas royalty acquisition	$ 31,000
Mineral interests in proved properties	12,542
Mineral interests in unproved properties	18,418
Total mineral interest	$ 30,960

ACQUISITIONS - Business Combina

ACQUISITIONS - Business Combination (Details) $ in Thousands			12 Months Ended
	Oct. 26, 2022 USD ($) a	Sep. 09, 2022 USD ($) a	Dec. 31, 2022 USD ($) a
Acquisition
Royalty acres, net | a			61,400
Payments for acquisitions of businesses			$ 92,618
Belvedere
Acquisition
Royalty acres, net | a		394
Payments for acquisitions of businesses		$ 11,400
Assets acquired and liabilities assumed
Mineral interests in proved properties		7,724
Mineral interests in unproved properties		3,667
Net assets acquired		$ 11,391
Jase
Acquisition
Royalty acres, net | a	3,928
Payments for acquisitions of businesses	$ 81,200
Assets acquired and liabilities assumed
Mineral interests in proved properties	35,918
Mineral interests in unproved properties	43,740
Receivables	1,569
Net assets acquired	$ 81,227

ACQUISITIONS - Pro Forma (Detai

ACQUISITIONS - Pro Forma (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Belvedere
Acquisitions, additional information
Revenue of acquired business	$ 722
Net income of acquired business	488
Pro forma condensed consolidated income statement
Total revenues, Pro forma	2,407,368	$ 1,571,119
Net income, Pro forma	579,906	179,747
Jase
Acquisitions, additional information
Revenue of acquired business	1,689
Net income of acquired business	854
Pro forma condensed consolidated income statement
Total revenues, Pro forma	2,417,278	1,579,660
Net income, Pro forma	$ 587,749	$ 186,151

LONG-LIVED ASSET IMPAIRMENTS (D

LONG-LIVED ASSET IMPAIRMENTS (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Asset impairment charges
Asset impairments	$ 24,977
Illinois Basin
Asset impairment charges
Asset impairments	23,500
Coal Royalties
Asset impairment charges
Asset impairments	$ 1,500

GOODWILL IMPAIRMENT (Details)

GOODWILL IMPAIRMENT (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
GOODWILL IMPAIRMENT
Goodwill					$ 136,400
Impairments of goodwill		$ 0	$ 0	$ 132,026
Hamilton mining complex
GOODWILL IMPAIRMENT
Goodwill					$ 132,000
Impairments of goodwill	$ 132,000

INVENTORIES (Details)

INVENTORIES (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
INVENTORIES
Coal	$ 23,553	$ 24,845
Supplies (net of reserve for obsolescence)	53,773	35,457
Total inventories, net	77,326	60,302
Reserve for obsolescence	$ 6,601	$ 5,554

PROPERTY, PLANT AND EQUIPMENT -

PROPERTY, PLANT AND EQUIPMENT - Summary (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, at cost	$ 3,857,390	$ 3,608,347
Less accumulated depreciation, depletion and amortization	(2,040,468)	(1,909,669)
Total property, plant and equipment, net	1,816,922	1,698,678
Depreciation	270,900	256,900	$ 297,000
Mining Equipment
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, at cost	1,927,603	1,896,470
Land And Mineral Rights
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, at cost	499,950	458,440
Coal reserves not subject to depletion	29,900	37,400
Oil and gas mineral interests
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, at cost	740,635	647,864
Unproved properties	383,600	355,100
Buildings, Office Equipment And Improvements
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, at cost	300,436	282,902
Construction and mine development in progress
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, at cost	99,042	44,217
Mine development costs
PROPERTY, PLANT AND EQUIPMENT
Property, plant and equipment, at cost	289,724	$ 278,454
Mine development costs	$ 11,300

LONG-TERM DEBT - Components (De

LONG-TERM DEBT - Components (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Principal
Aggregate maturities of long-term debt	$ 427,009	$ 443,080
Less current maturities	(24,970)	(16,071)
Total long-term debt	402,039	427,009
Unamortized Discount and Debt Issuance Costs
Unamortized debt issuance costs including current and non-current	(4,836)	(8,067)
Total unamortized debt issuance costs	(4,836)	(8,067)
Replaced credit facility
Unamortized Discount and Debt Issuance Costs
Unamortized debt issuance costs including current and non-current	(2,702)	(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	(2,134)	(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	21,072	31,972
June 2020 equipment financing
Principal
Aggregate maturities of long-term debt	$ 5,937	$ 9,605

LONG-TERM DEBT - Credit Facilit

LONG-TERM DEBT - Credit Facility (Details) $ in Millions			12 Months Ended
	Jan. 13, 2023 USD ($)	Mar. 09, 2020 USD ($)	Dec. 31, 2022 USD ($)
Credit Agreement
Long-Term Debt
Maximum borrowing capacity	$ 425
Minimum liquidity to extend maturity	$ 200
Interest rate (as a percent)	6.25%
Interest coverage ratio	3
Credit Agreement | Overnight Bank Funding Rate
Long-Term Debt
Basis spread for variable interest rate (as a percent)	0.50%
Credit Agreement | Daily Simple Secured Overnight Financing Rate
Long-Term Debt
Basis spread for variable interest rate (as a percent)	1%
Credit Agreement | Alliance Coal
Long-Term Debt
ARLP debt arrangements requirements, debt to cash flow ratio	1.5
Credit Agreement | Alliance Coal and Intermediate Partnership
Long-Term Debt
ARLP debt arrangements requirements, debt to cash flow ratio	2.5
Letters of credit subfacility
Long-Term Debt
Maximum borrowing capacity	$ 425	$ 125
Swingline subfacility
Long-Term Debt
Maximum borrowing capacity	15	15
Term Loan
Long-Term Debt
Maximum borrowing term loan	$ 75
Replaced credit facility
Long-Term Debt
Maximum borrowing capacity		$ 459.5
Letters of credit outstanding			$ 41.1
Debt available for borrowing			$ 418.4
Annual commitment fee percentage, undrawn portion			0.35%
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			0.52
Actual cash flow to interest expense ratio for trailing twelve months			21.76
Restricted net assets of subsidiaries			$ 537.3
Replaced credit facility | Eurodollar Rate
Long-Term Debt
Effective interest rate (as a percent)			6.74%
Replaced credit facility | 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			0.03
Other
Long-Term Debt
Maximum borrowing capacity			$ 5
Letters of credit outstanding			$ 5

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 $ in Millions	Dec. 31, 2022 USD ($)
Long-Term Debt
Maximum borrowing capacity	$ 60
Letters of credit outstanding	11.7
Debt available for borrowing	48.3
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%

LONG-TERM DEBT - Maturities (De

LONG-TERM DEBT - Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Aggregate maturities of long-term debt
2023	$ 24,970
2024	2,039
2025	400,000
Aggregate maturities of long-term debt	$ 427,009	$ 443,080

INCOME TAXES - Components (Deta

INCOME TAXES - Components (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ 17,572	$ (1)	$ (78)
State	1,605	70	1
Total current income tax expense	19,177	69	(77)
Deferred:
Federal	33,038	356	(178)
State	1,763	(8)	290
Total deferred income tax expense	34,801	348	112
Income tax expense	$ 53,978	$ 417	$ 35

INCOME TAXES - Tax election (De

INCOME TAXES - Tax election (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Taxes
Deferred tax liability	$ 35,126	$ 350
Income tax expense	$ 53,978	$ 417	$ 35
Earnings per limited partner unit - basic (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
Earnings per limited partner unit - diluted (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
AllDale I and II
Taxes
Non - cash acquisition gain recognized				$ 177,000
Change in tax accounting
Taxes
Deferred tax liability	$ 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	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
INCOME TAXES
Income taxes at statutory rate	$ 132,956	$ 37,626	$ (27,093)
Less: Income taxes at statutory rate on Partnership income not subject to income taxes	(112,032)	(36,577)	26,293
Increase/(decrease) resulting from:
State taxes, net of federal income tax	1,492	275	(192)
Change in valuation allowance of deferred tax assets	(317)	(834)	1,151
Deferred taxes related to tax election	37,253
Tax effect of noncontrolling interest income not subject to income taxes	(5,399)
Other	25	(73)	(124)
Income tax expense	$ 53,978	$ 417	$ 35

INCOME TAXES - Deferred tax (De

INCOME TAXES - Deferred tax (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Deferred tax liabilities:
Property, plant and equipment	$ (38,349)	$ (2,169)
Deferred tax liabilities	(38,349)	(2,169)
Deferred tax assets:
Federal loss carryovers and credits	2,139	1,328
Other	1,084	808
Total deferred tax assets	3,223	2,136
Less valuation allowance		(317)
Net deferred tax assets	3,223	1,819
Overall net deferred tax liabilities	$ (35,126)	$ (350)

LEASES - Lease expense (Details

LEASES - Lease expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
LEASES
Amortization of right-of-use assets	$ 597	$ 597	$ 704
Interest on lease liabilities	73	147	377
Operating lease cost	274	2,404	3,873
Short-term lease cost		200	84
Variable lease cost	1,665	1,306	1,375
Total lease cost	2,609	4,654	6,413
Rental expense	$ 5,100	$ 3,300	$ 5,200

LEASES - Cash flow (Details)

LEASES - Cash flow (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
LEASES
Operating cash flows for operating leases	$ 2,880	$ 2,367	$ 3,870
Operating cash flows for finance leases	73	147	377
Financing cash flows for finance leases	840	766	8,368
Operating leases, Right-of-use assets obtained in exchange for lease obligations	$ 1,315	$ 189	$ 278

LEASES - Balance Sheet (Details

LEASES - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Lease balance sheet information
Property and equipment finance lease assets, gross	$ 5,485	$ 5,485
Accumulated depreciation	(5,061)	(4,464)
Property and equipment finance lease assets, net	$ 424	$ 1,021
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization	Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization

LEASES - Weighted Average (Deta

LEASES - Weighted Average (Details)	Dec. 31, 2022	Dec. 31, 2021
LEASES
Weighted average remaining lease term of operating leases	13 years 4 months 24 days	15 years 6 months
Weighted average remaining lease term of finance leases	5 years	3 years 6 months
Weighted average discount rate of operating leases (as a percent)	6%	6%
Weighted average discount rate of finance leases (as a percent)	4.80%	7.40%

LEASES - Maturities (Details)

LEASES - Maturities (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Operating leases
2023	$ 3,253
2024	2,918
2025	1,734
2026	1,106
2027	1,112
Thereafter	11,901
Total lease payments	22,024
Less imputed interest	$ (7,100)
Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Operating Lease, Liability, Noncurrent, Other Liabilities, Current	Operating Lease, Liability, Noncurrent, Other Liabilities, Current
Finance leases
2023	$ 140
2024	140
2025	140
2026	140
2027	140
Total lease payments	700
Less imputed interest	$ (82)
Finance Lease, Liability, Statement of Financial Position [Extensible Enumeration]	Other Liabilities, Current, Other Liabilities, Noncurrent	Other Liabilities, Current, Other Liabilities, Noncurrent

FAIR VALUE MEASUREMENTS (Detail

FAIR VALUE MEASUREMENTS (Details) - Estimated fair value - Significant Observable Inputs (Level 2) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
FAIR VALUE MEASUREMENTS
Long-term debt	$ 424,420	$ 457,758
Total	$ 424,420	$ 457,758

PARTNERS' CAPITAL - Distributio

PARTNERS' CAPITAL - Distributions (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended								12 Months Ended
	Jan. 27, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2020	Dec. 31, 2022
PARTNERS' CAPITAL
Period following quarter end for distribution of available cash										45 days
Quarterly distribution paid (in dollars per unit)		$ 0.500	$ 0.400	$ 0.350	$ 0.250	$ 0.200	$ 0.100	$ 0.100	$ 0.400
Distribution declared (in dollars per unit)	$ 0.70
Quarterly distribution declared	$ 89

PARTNERS' CAPITAL - Narrative (

PARTNERS' CAPITAL - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended	56 Months Ended	57 Months Ended
	Jan. 31, 2023	Dec. 31, 2022	Dec. 31, 2022	Jan. 31, 2023	May 31, 2018
Partners' capital
Treasury units retired		$ 0
Limited Partners' Capital
Partners' capital
Repurchase and retire authorization	$ 100			$ 100	$ 100
Treasury units retired			$ 93.5	$ 18.1
Number of units retired			5,460,639	856,629
Repurchase price (in dollars per unit)			$ 17.12	$ 21.15
Increase in authorization amount	$ 93.5
Available Capacity		$ 6.5	$ 6.5

VARIABLE INTEREST ENTITIES - Ca

VARIABLE INTEREST ENTITIES - Cavalier (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Variable Interest Entities
Distributions paid to Partners	$ 196,347	$ 52,158	$ 51,753
Cavalier Minerals | Alliance Minerals
Variable Interest Entities
Contributions	143,112
Distributions paid to Partners	146,484
Cavalier Minerals | Bluegrass Minerals
Variable Interest Entities
Contributions	5,963
Distributions paid to Partners	$ 6,179
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	12 Months Ended
	Dec. 31, 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		12 Months Ended
	Apr. 05, 2022	Dec. 31, 2022	Jun. 02, 2022
Investments
Contributions to equity method investments		$ 24,087
Francis Renewable Energy
Investments
Contributions to equity method investments	$ 20,000	20,000
NGP ETP
Investments
Funding commitment			$ 25,000
Contributions to equity method investments		$ 4,087

INVESTMENTS - Equity method (De

INVESTMENTS - Equity method (Details) - USD ($) $ in Thousands		12 Months Ended
	Apr. 05, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Investments
Beginning balance		$ 26,325
Contributions		24,087
Equity method investment income		5,634	$ 2,130	$ 907
Ending balance		49,371	26,325
All Dale Minerals III
Investments
Beginning balance		26,325	27,268	28,529
Equity method investment income		5,634	2,130	907
Distributions received		(6,675)	(3,073)	(1,895)
Other				(273)
Ending balance		25,284	$ 26,325	$ 27,268
Francis Renewable Energy
Investments
Contributions	$ 20,000	20,000
Ending balance		20,000
NGP ETP
Investments
Contributions		4,087
Ending balance		$ 4,087

INVESTMENTS - Non-equity method

INVESTMENTS - Non-equity method (Details) - USD ($) $ in Thousands			12 Months Ended
	Nov. 02, 2022	Apr. 29, 2022	Dec. 31, 2022
Investments
Contributions			$ 42,000
Ending balance			42,000
Infinitum Electric
Investments
Contributions	$ 9,400	$ 32,600	42,000
Ending balance			$ 42,000

REVENUE FROM CONTRACTS WITH C_3

REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of revenues
Revenues	$ 2,406,511	$ 1,569,976	$ 1,328,129
Illinois Basin
Disaggregation of revenues
Revenues	1,296,305	919,597	769,957
Appalachia
Disaggregation of revenues
Revenues	928,087	545,539	500,330
Oil & Gas Royalties
Disaggregation of revenues
Revenues	141,441	77,185	43,141
Coal Royalties
Disaggregation of revenues
Revenues	60,680	51,471	42,217
Other, Corporate and Elimination
Disaggregation of revenues
Revenues	(20,002)	(23,816)	(27,516)
Coal sales
Disaggregation of revenues
Revenues	2,102,229	1,386,923	1,232,272
Coal sales | Illinois Basin
Disaggregation of revenues
Revenues	1,219,943	873,930	755,208
Coal sales | Appalachia
Disaggregation of revenues
Revenues	882,286	512,993	477,064
Oil & gas royalties
Disaggregation of revenues
Revenues	138,402	74,988	42,912
Oil & gas royalties | Oil & Gas Royalties
Disaggregation of revenues
Revenues	138,402	74,988	42,912
Coal royalties | Coal Royalties
Disaggregation of revenues
Revenues	60,624	51,402	42,112
Coal royalties | Other, Corporate and Elimination
Disaggregation of revenues
Revenues	(60,624)	(51,402)	(42,112)
Transportation
Disaggregation of revenues
Revenues	113,860	69,607	21,129
Transportation | Illinois Basin
Disaggregation of revenues
Revenues	69,540	41,001	12,817
Transportation | Appalachia
Disaggregation of revenues
Revenues	44,320	28,606	8,312
Other revenues
Disaggregation of revenues
Revenues	52,020	38,458	31,816
Other revenues | Illinois Basin
Disaggregation of revenues
Revenues	6,822	4,666	1,932
Other revenues | Appalachia
Disaggregation of revenues
Revenues	1,481	3,940	14,954
Other revenues | Oil & Gas Royalties
Disaggregation of revenues
Revenues	3,039	2,197	229
Other revenues | Coal Royalties
Disaggregation of revenues
Revenues	56	69	105
Other revenues | Other, Corporate and Elimination
Disaggregation of revenues
Revenues	$ 40,622	$ 27,586	$ 14,596

REVENUE FROM CONTRACTS WITH C_4

REVENUE FROM CONTRACTS WITH CUSTOMERS - Supply contracts (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Performance obligations unsatisfied or partially unsatisfied
Total	$ 4,113,892
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 1,951,694
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	$ 1,263,472
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	$ 653,526
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 245,200
Expected timing of satisfaction period	1 year
Illinois Basin
Performance obligations unsatisfied or partially unsatisfied
Total	$ 2,549,577
Illinois Basin | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 1,230,551
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	$ 730,825
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	$ 344,601
Expected timing of satisfaction period	1 year
Illinois Basin | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 243,600
Expected timing of satisfaction period	1 year
Appalachia
Performance obligations unsatisfied or partially unsatisfied
Total	$ 1,564,315
Appalachia | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 721,143
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	$ 532,647
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	$ 308,925
Expected timing of satisfaction period	1 year
Appalachia | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 1,600
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	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
EARNINGS PER LIMITED PARTNER UNIT
Net income (loss) attributable to ARLP	$ 577,190	$ 178,157	$ (129,220)
Distributions to participating securities	(8,527)	(2,334)
Undistributed earnings attributable to participating securities	(10,576)	(2,403)
Net income (loss) attributable to ARLP available to limited partners	$ 558,087	$ 173,420	$ (129,220)
Weighted-average limited partner units outstanding - basic (in units)	127,195,219	127,195,219	127,164,659
Weighted-average limited partner units outstanding - diluted (in units)	127,195,000	127,195,000	127,165,000
Earnings per limited partner unit - basic (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
Earnings per limited partner unit - diluted (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
Anti-dilutive under the treasury stock method (in units)	3,540,385	1,967,672	773,664

EMPLOYEE BENEFIT PLANS - Define

EMPLOYEE BENEFIT PLANS - Defined Contribution (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
PSSP
Defined Contribution Plans
Contribution expense	$ 19.4	$ 17.7	$ 16.1

EMPLOYEE BENEFIT PLANS - Obliga

EMPLOYEE BENEFIT PLANS - Obligations, Assets, Reported Amounts (Details) - Defined benefit pension plan - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Change in benefit obligations:
Benefit obligations at beginning of year	$ 139,566	$ 147,934
Interest cost	3,749	3,438	$ 4,185
Actuarial gain	(32,996)	(6,406)
Benefits paid	(5,637)	(5,400)
Benefit obligations at end of year	104,682	139,566	147,934
Change in plan assets:
Fair value of plan assets at beginning of year	113,976	100,969
Employer contribution		3,312
Actual return on plan assets	(16,210)	15,095
Benefits paid	(5,637)	(5,400)
Fair value of plan assets at end of year	92,129	113,976	$ 100,969
Funded status at the end of year	(12,553)	(25,590)
Amounts recognized in balance sheet:
Non-current liability	(12,553)	(25,590)
Amount recognized in accumulated other comprehensive income consists of:
Prior service cost	(382)	(568)
Net actuarial loss	(15,160)	(27,271)
Amounts recognized in accumulated other comprehensive income	$ (15,542)	$ (27,839)
Weighted-average assumption to determine benefit obligations
Discount rate	5.10%	2.73%
Weighted-average assumptions used to determine net periodic benefit cost
Discount rate	2.73%	2.37%
Expected return on plan assets	6%	6.50%

EMPLOYEE BENEFIT PLANS - Assump

EMPLOYEE BENEFIT PLANS - Assumptions (Details) - Defined benefit pension plan	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Asset allocation assumptions
Active management premium percentage	1.50%
Asset allocation assumption	100%
Actual return on plan assets (as a percent)	(14.60%)	15.10%
Equity securities
Asset allocation assumptions
Asset allocation assumption	60%
Fixed income securities
Asset allocation assumptions
Asset allocation assumption	35%
Real estate
Asset allocation assumptions
Asset allocation assumption	5%

EMPLOYEE BENEFIT PLANS - Period

EMPLOYEE BENEFIT PLANS - Periodic Benefit Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive loss:
Total recognized in accumulated other comprehensive loss	$ 23,175	$ 23,445	$ (9,681)
Defined benefit pension plan
Components of net periodic benefit cost:
Interest cost	$ 3,749	$ 3,438	$ 4,185
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)
Expected return on plan assets	$ (6,638)	$ (6,580)	$ (5,861)
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)
Amortization of prior service cost	$ 186	$ 186	$ 186
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)
Amortization of net loss	$ 1,963	$ 4,327	$ 4,128
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)
Net periodic benefit cost	$ (740)	$ 1,371	$ 2,638
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive loss:
Net actuarial gain	10,148	14,921	(5,522)
Reversal of amortization item: Prior service cost	186	186	186
Reversal of amortization item: Net actuarial loss	1,963	4,327	4,128
Total recognized in accumulated other comprehensive loss	12,297	19,434	(1,208)
Net periodic benefit cost (credit)	740	(1,371)	$ (2,638)
Total recognized in net periodic benefit cost and accumulated other comprehensive loss	$ 13,037	$ 18,063

EMPLOYEE BENEFIT PLANS - Estima

EMPLOYEE BENEFIT PLANS - Estimated Benefit Payments (Details) - Defined benefit pension plan $ in Thousands	Dec. 31, 2022 USD ($)
Estimated future benefit payments
2023	$ 6,239
2024	6,416
2025	6,605
2026	6,816
2027	6,907
2028-2032	35,293
Estimated future benefit payments	68,276
Expected contribution for pension plan in next year	$ 0

EMPLOYEE BENEFIT PLANS - Asset

EMPLOYEE BENEFIT PLANS - Asset Allocations (Details) - Defined benefit pension plan	Dec. 31, 2022
Equity securities | Minimum
Employee Benefit Plans
Target allocation	35%
Equity securities | Maximum
Employee Benefit Plans
Target allocation	80%
Fixed income securities | Minimum
Employee Benefit Plans
Target allocation	15%
Fixed income securities | Maximum
Employee Benefit Plans
Target allocation	65%
Convertible securities | Minimum
Employee Benefit Plans
Target allocation	0%
Convertible securities | Maximum
Employee Benefit Plans
Target allocation	10%
Alternatives | Minimum
Employee Benefit Plans
Target allocation	0%
Alternatives | Maximum
Employee Benefit Plans
Target allocation	20%

EMPLOYEE BENEFIT PLANS - Fair V

EMPLOYEE BENEFIT PLANS - Fair Value of Plan Assets (Details) - Defined benefit pension plan - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	$ 92,129	$ 113,976	$ 100,969
Cash And Cash Equivalents | Quoted Prices In Active Markets For Identical Assets (Level 1)
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	5,422	4,426
Equities - Global | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets		24,868
Equities - United States | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	36,259	41,140
Equities - United States futures | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	(697)	(2,055)
Equities - International developed markets | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	14,214	16,382
Equities - International developed markets futures | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	(1,693)	(16,260)
Equities - International emerging markets | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	782	(3,363)
Equities - International emerging markets futures | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	3,289	7,024
Fixed income - Investment grade | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	13,856	27,095
Fixed income - High yield | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	156	177
Fixed income - Futures | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	8,590	(689)
Alternatives | Net asset value per share
Employee Benefit Plans
Defined benefit plan, fair value of plan assets	$ 11,951	$ 15,231

COMMON UNIT-BASED COMPENSATIO_3

COMMON UNIT-BASED COMPENSATION PLANS - LTIP Grants (Details) - ARLP LTIP - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		12 Months Ended
	Jan. 27, 2023	Dec. 31, 2020	Feb. 29, 2020	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017	Dec. 31, 2019
Number of units
Balance at the beginning of the period (in units)				3,130,475	1,430,489	1,603,378
Granted (in units)	447,225			769,907	1,818,190	1,430,489	424,486
Vested (in units)						(919,524)
Grants canceled (in units)						(675,302)
Forfeited (in units)				(203,249)	(118,204)	(8,552)
Balance at the end of the period (in units)		1,430,489		3,697,133	3,130,475	1,430,489
Weighted average grant date fair value per unit
Balance at the beginning of the period (in dollars per unit)				$ 5.59	$ 5.02	$ 20.39
Granted (in dollars per unit)				14.65	6.03	5.02
Vested (in dollars per unit)						$ 21.70
Grants canceled (in dollars per unit)						18.62
Forfeited (in dollars per unit)				6.93	5.48	$ 20.16
Balance at the end of the period (in dollars per unit)		$ 5.02		$ 7.40	$ 5.59	$ 5.02
Intrinsic value (in dollars)
Intrinsic value of outstanding grants (in dollars)		$ 6,409		$ 75,126	$ 39,569	$ 6,409		$ 17,349
Other information
Common units issued			279,622
2018 Grants
Number of units
Vested (in units)		(495,038)
2019 Grants
Number of units
Grants canceled (in units)		675,302
2020 Grants
Number of units
Granted (in units)		578,114

COMMON UNIT-BASED COMPENSATIO_4

COMMON UNIT-BASED COMPENSATION PLANS - LTIP Other (Details) - USD ($) $ in Thousands		12 Months Ended
	Jan. 27, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other information
Cash settlement of grants				$ 2,490
ARLP LTIP
Other information
Unit-based compensation expense		$ 9,400	$ 5,400	$ 8,100
Reduction in compensation expense			1,000
Total unit-based obligation recorded		16,000	$ 6,700
Unrecognized compensation expense (in dollars)		$ 11,400
Weighted-average period for recognition of expense		9 months 18 days
Additional grants authorized (in units)	462,225
2018 Grants | ARLP LTIP
Other information
Incremental compensation cost		$ 5,400
2019 Grants | ARLP LTIP
Other information
Reversal of cumulative previously recognized expenses		$ 4,800

COMMON UNIT-BASED COMPENSATIO_5

COMMON UNIT-BASED COMPENSATION PLANS - SERP and Directors (Details) - SERP and Deferred Compensation Plans - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other information
Unit-based compensation expense	$ 1,400	$ 400	$ 700
Total unit-based obligation recorded	$ 15,100	$ 13,500
Phantom Share Units (PSUs)
Number of units
Balance at the beginning of the period (in units)	668,698	760,630	631,365
Granted (in units)	73,842	46,638	129,265
Issued (in units)		(138,570)
Balance at the end of the period (in units)	742,540	668,698	760,630
Weighted average grant date fair value per unit
Balance at the beginning of the period (in dollars per unit)	$ 20.37	$ 22.04	$ 25.48
Granted (in dollars per unit)	19.44	9.45	5.25
Issued (in dollars per unit)		25.86
Balance at the end of the period (in dollars per unit)	$ 20.28	$ 20.37	$ 22.04
Intrinsic value (in dollars)
Intrinsic value of outstanding grants (in dollars)	$ 15,088	$ 8,452	$ 3,408	$ 6,831
Other information
Purchased for awards (in shares)	102,962

SUPPLEMENTAL CASH FLOW INFORM_3

SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Paid For:
Interest	$ 34,844	$ 36,402	$ 44,226
Income taxes	23,794	11	12
Non-Cash Activity:
Accounts payable for purchase of property, plant and equipment	44,281	8,325	5,731
Right-of-use assets acquired by operating lease	$ 1,315	189	278
Market value of common units issued under deferred compensation plans before tax withholding requirements		$ 1,082	$ 3,837

ASSET RETIREMENT OBLIGATIONS -

ASSET RETIREMENT OBLIGATIONS - Activity (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Asset retirement and mine closing liability
Balance at the beginning of the period	$ 131,099	$ 127,898
Accretion expense	3,731	3,688
Payments	(2,445)	(1,383)
Allocation of liability associated with mine development and change in assumptions	17,428	896
Balance at the end of the period	$ 149,813	$ 131,099

ASSET RETIREMENT OBLIGATIONS _2

ASSET RETIREMENT OBLIGATIONS - Estimated Payments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Estimated payments of asset retirement obligations:
2023	$ 7,559
2024	4,936
2025	1,935
2026	1,569
2027	3,182
Thereafter	241,065
Aggregate undiscounted asset retirement obligations	260,246
Effect of discounting	(110,433)	$ (98,300)
Total asset retirement obligations	149,813	131,099	$ 127,898
Less: current portion	(7,559)
Asset retirement obligations	142,254	123,517
Surety bonds outstanding to performance of reclamation obligations	$ 174,300	$ 173,900

ACCRUED WORKERS' COMPENSATION_3

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS - Workers' Comp (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Reconciliation of changes in the workers' compensation liability
Beginning balance	$ 53,448	$ 54,739
Changes in accruals	7,384	5,168
Payments	(12,708)	(10,725)
Interest accretion	1,147	926
Valuation loss	181	3,340
Ending balance	$ 49,452	$ 53,448
Estimated present value of future obligations and other information
Workers' compensation discount rate	4.87%	2.41%
Letters of credit outstanding to secure workers compensation obligations	$ 99,800	$ 100,400
Other long-term assets
Estimated present value of future obligations and other information
Receivables for traumatic injury claims	$ 4,100	$ 5,700

ACCRUED WORKERS' COMPENSATION_4

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS - Obligations (Details) - Pneumoconiosis benefits - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of the changes in black lung benefit obligations
Benefit obligations at beginning of year	$ 111,316	$ 108,496
Service cost	3,798	4,021	$ 3,526
Interest cost	2,991	2,545	2,998
Actuarial loss (gain)	(9,840)	161
Benefits and expenses paid	(3,978)	(3,907)
Benefit obligations at end of year	$ 104,287	$ 111,316	$ 108,496

ACCRUED WORKERS' COMPENSATION_5

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS - AOCL (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive loss:
Total recognized in accumulated other comprehensive loss	$ 23,175	$ 23,445	$ (9,681)
Pneumoconiosis benefits
Other changes in plan assets and benefit obligations recognized in accumulated other comprehensive loss:
Net actuarial gain (loss)	9,840	(161)	(7,787)
Reversal of amortization item: Net actuarial loss (gain)	1,038	4,172	(686)
Total recognized in accumulated other comprehensive loss	$ 10,878	$ 4,011	$ (8,473)
Estimated present value of future obligations and other information
Pneumoconiosis discount rate	5%	2.73%	2.38%
Amount recognized in accumulated other comprehensive income consists of:
Net actuarial loss	$ 25,510	$ 36,388	$ 40,399

ACCRUED WORKERS' COMPENSATION_6

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS - Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
WORKERS' COMPENSATION AND PNEUMOCONIOSIS
Workers' compensation claims	$ 49,452	$ 53,448	$ 54,739
Pneumoconiosis benefit claims	104,287	111,316
Total obligations	153,739	164,764
Less current portion	(14,099)	(12,293)
Non-current obligations	$ 139,640	$ 152,471

ACCRUED WORKERS' COMPENSATION_7

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS - Expense (Details) - Pneumoconiosis benefits - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Black lung benefits:
Service cost	$ 3,798	$ 4,021	$ 3,526
Interest cost	$ 2,991	$ 2,545	$ 2,998
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)
Net amortization	$ 1,038	$ 4,172	$ (686)
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)
Total pneumoconiosis expense	$ 7,827	$ 10,738	$ 5,838
Workers' compensation expense	11,675	8,339	12,305
Net periodic benefit cost	$ 19,502	$ 19,077	$ 18,143

RELATED-PARTY TRANSACTIONS - Li

RELATED-PARTY TRANSACTIONS - Line of Credit (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Nov. 04, 2021	Feb. 19, 2021
Related Party Transaction
Proceeds from line of credit	$ 5,340
Payments under line of credit	5,340
Line of credit
Related Party Transaction
Maximum borrowing capacity		$ 5,500	$ 5,000
Interest rate (as a percent)		3.50%
Proceeds from line of credit	5,300
Payments under line of credit	$ 5,300

RELATED-PARTY TRANSACTIONS - Af

RELATED-PARTY TRANSACTIONS - Affiliate Royalty Agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction
As of the beginning of period	$ 55,613
As of the end of period	60,608	$ 55,613
Coal lease
Related Party Transaction
As of the beginning of period	55,613	48,389	$ 41,216
Payments	11,250	13,817	13,819
Recoupment	(6,255)	(4,025)	(4,078)
Unrecoupable		(2,568)	(2,568)
As of the end of period	60,608	55,613	48,389
Tunnel Ridge
Related Party Transaction
As of the beginning of period	1,500	1,500	1,500
Payments	3,000	3,000	3,000
Recoupment	(3,000)	(3,000)	(3,000)
As of the end of period	1,500	1,500	1,500
WKY CoalPlay | December 2014 coal lease - Henderson and Union Counties, Kentucky
Related Party Transaction
As of the beginning of period	21,750	19,178	16,603
Payments	3,597	3,597	3,597
Recoupment	(3,255)	(1,025)	(1,022)
As of the end of period	22,092	21,750	19,178
WKY CoalPlay | December 2014 coal lease - Webster County, Kentucky
Related Party Transaction
Payments		2,568	2,568
Unrecoupable		(2,568)	(2,568)
WKY CoalPlay | December 2014 coal lease - Henderson County, Kentucky
Related Party Transaction
As of the beginning of period	17,650	15,129	12,607
Payments	2,522	2,521	2,522
As of the end of period	20,172	17,650	15,129
WKY CoalPlay | February 2015 coal lease - Henderson and Union Counties, Kentucky
Related Party Transaction
As of the beginning of period	14,713	12,582	10,506
Payments	2,131	2,131	2,132
Recoupment			(56)
As of the end of period	$ 16,844	$ 14,713	$ 12,582

RELATED-PARTY TRANSACTIONS - Cr

RELATED-PARTY TRANSACTIONS - Craft Foundations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2018
Tunnel Ridge
Related Party Transaction
Related party purchase	$ 0.2
Tunnel Ridge
Related Party Transaction
Annual minimum coal royalties	3
Payments for earned royalties	$ 12.3	$ 5.8	$ 6.1
Tunnel Ridge | Joseph W Craft III Foundation | Tunnel Ridge
Related Party Transaction
Property ownership (as a percent)				50%
Tunnel Ridge | Kathleen S Craft Foundation | Tunnel Ridge
Related Party Transaction
Property ownership (as a percent)				50%

RELATED-PARTY TRANSACTIONS - WK

RELATED-PARTY TRANSACTIONS - WKY CoalPlay and Cavalier Minerals (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Feb. 28, 2015	Dec. 31, 2014	Dec. 31, 2022
WKY CoalPlay | February 2015 coal lease - Henderson and Union Counties, Kentucky
Related Party Transaction
Initial term of lease	20 years
Percentage of earned royalty on coal sale price	4%
Annual minimum coal royalties	$ 2.1
WKY CoalPlay | December 2014 coal lease - Henderson and Union Counties, Kentucky
Related Party Transaction
Initial term of lease		20 years
Percentage of earned royalty on coal sale price		4%
Annual minimum coal royalties		$ 3.6
WKY CoalPlay | December 2014 coal lease - Webster County, Kentucky
Related Party Transaction
Initial term of lease		7 years
Percentage of earned royalty on coal sale price		4%
Annual minimum coal royalties		$ 2.6
WKY CoalPlay | December 2014 coal lease - Henderson County, Kentucky
Related Party Transaction
Annual minimum coal royalties		$ 2.5
Cavalier Minerals
Related Party Transaction
Ownership interest in VIE (as a percent)			96%
Cavalier Minerals | Bluegrass Minerals
Related Party Transaction
Noncontrolling ownership interest (as a percent)			4%
Profits interest (as a percent)			25%

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Purchase Commitments (Details) $ in Millions	Dec. 31, 2022 USD ($)
Commitments for external coal purchases
Contractual Commitments
Commitments to purchase coal	$ 0
Commitments related to planned capital projects
Contractual Commitments
Contractual amount	$ 147.7

COMMITMENTS AND CONTINGENCIES_2

COMMITMENTS AND CONTINGENCIES - Insurance (Details) - Property and casualty insurance $ in Millions	Dec. 01, 2022 USD ($)
Commitments And Contingencies
Aggregate maximum insurance limit	$ 100
Insurance deductible	$ 1.5
Waiting period one	75 days
Waiting period	90 days
Overall aggregate deductible	$ 25

CONCENTRATION OF CREDIT RISK _3

CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Major Customers
Revenues	$ 2,406,511	$ 1,569,976	$ 1,328,129
Trade receivables	$ 238,610	$ 129,531
Revenue | Geographic Concentration Risk | End users in Europe, Africa, Asia, North America and South America
Major Customers
Concentration of risk (as a percent)	12.50%	12.50%	3.30%
Revenue | Customer Concentration Risk | Customer A
Major Customers
Revenues	$ 328,406	$ 239,482	$ 197,379
Revenue | Customer Concentration Risk | Customer B
Major Customers
Revenues	260,146		157,271
Revenue | Customer Concentration Risk | Customer C
Major Customers
Revenues	228,480
Revenue | Customer Concentration Risk | Customer D
Major Customers
Revenues			$ 137,785
Trade accounts receivable | Customer Concentration Risk | Major Customers
Major Customers
Trade receivables	$ 63,600	$ 10,800

SEGMENT INFORMATION - General (

SEGMENT INFORMATION - General (Details)	12 Months Ended
	Dec. 31, 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	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reportable segment results
Revenues	$ 2,406,511	$ 1,569,976	$ 1,328,129
Segment Adjusted EBITDA Expense	1,282,433	952,649	861,249
Segment Adjusted EBITDA	1,020,558	549,252	446,489
Total assets	2,661,473	2,159,406	2,166,016
Capital expenditures	286,394	122,984	121,101
Illinois Basin
Reportable segment results
Revenues	1,296,305	919,597	769,957
Segment Adjusted EBITDA Expense	806,080	613,303	543,264
Segment Adjusted EBITDA	420,684	265,292	213,876
Total assets	779,018	676,091	738,315
Capital expenditures	158,624	60,166	48,636
Appalachia
Reportable segment results
Revenues	928,087	545,539	500,330
Segment Adjusted EBITDA Expense	464,029	344,332	320,656
Segment Adjusted EBITDA	426,402	172,601	171,362
Total assets	431,913	420,144	440,815
Capital expenditures	76,603	47,577	70,960
Oil & Gas Royalties
Reportable segment results
Revenues	141,441	77,185	43,141
Segment Adjusted EBITDA Expense	13,950	9,943	4,106
Segment Adjusted EBITDA	131,168	68,774	39,773
Total assets	711,917	630,627	613,916
Coal Royalties
Reportable segment results
Revenues	60,680	51,471	42,217
Segment Adjusted EBITDA Expense	21,871	18,269	18,249
Segment Adjusted EBITDA	38,809	33,202	23,968
Total assets	321,587	285,943	288,525
Capital expenditures	38,276	45	12
Other, Corporate and Elimination
Reportable segment results
Revenues	(20,002)	(23,816)	(27,516)
Segment Adjusted EBITDA Expense	(23,497)	(33,198)	(25,026)
Segment Adjusted EBITDA	3,495	9,383	(2,490)
Total assets	417,038	146,601	84,445
Capital expenditures	12,891	15,196	1,493
Operating segments
Reportable segment results
Revenues	2,406,511	1,569,976	1,328,129
Operating segments | Illinois Basin
Reportable segment results
Revenues	1,296,305	919,597	769,957
Operating segments | Appalachia
Reportable segment results
Revenues	928,087	545,539	500,330
Operating segments | Oil & Gas Royalties
Reportable segment results
Revenues	141,441	77,185	43,141
Operating segments | Coal Royalties
Reportable segment results
Revenues	56	69	105
Operating segments | Other, Corporate and Elimination
Reportable segment results
Revenues	40,622	27,586	14,596
Elimination | Coal Royalties
Reportable segment results
Revenues	60,624	51,402	42,112
Elimination | Other, Corporate and Elimination
Reportable segment results
Revenues	$ (60,624)	$ (51,402)	$ (42,112)

SEGMENT INFORMATION - EBITDA Ex

SEGMENT INFORMATION - EBITDA Expense Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of consolidated Segment Adjusted EBITDA Expense
Segment Adjusted EBITDA Expense	$ 1,282,433	$ 952,649	$ 861,249
Outside coal purchases	151	6,372
Other expense (income)	(4,353)	3,020	1,593
Product
Reconciliation of consolidated Segment Adjusted EBITDA Expense
Operating expenses (excluding depreciation, depletion and amortization)	$ 1,286,635	$ 943,257	$ 859,656

SEGMENT INFORMATION - EBITDA Re

SEGMENT INFORMATION - EBITDA Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Reconciliation of consolidated Segment Adjusted EBITDA to net income
Consolidated Segment Adjusted EBITDA	$ 1,020,558	$ 549,252	$ 446,489
Income tax expense	53,978	417	35
Interest expense, net	35,297	39,141	45,478
Goodwill impairment	0	0	132,026
Asset impairment			24,977
Depreciation, depletion and amortization	273,759	261,377	313,387
General and administrative	80,334	70,160	59,806
NET INCOME (LOSS) ATTRIBUTABLE TO ARLP	577,190	178,157	(129,220)
LESS: NET INCOME ATTRIBUTABLE TO NONCONTROLLING INTEREST	(1,958)	(598)	(169)
NET INCOME (LOSS)	$ 579,148	$ 178,755	$ (129,051)

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) $ in Millions		12 Months Ended
	Feb. 22, 2023 USD ($) a	Dec. 31, 2022 a	Jan. 27, 2023 USD ($)
Subsequent Event
Royalty acres, net | a		61,400
Subsequent event
Subsequent Event
Funding commitment | $			$ 35
Subsequent event | JC Resources
Subsequent Event
Royalty acres, net | a	2,682
Payments to acquire royalty interests | $	$ 72.3

SCHEDULE I - CONDENSED FINANCIA

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - BALANCE SHEETS (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CURRENT ASSETS:
Cash and cash equivalents	$ 296,023	$ 122,403
Total current assets	654,791	339,228
OTHER ASSETS:
Total other assets	189,760	121,500
TOTAL ASSETS	2,661,473	2,159,406	$ 2,166,016
CURRENT LIABILITIES:
Accrued taxes other than income taxes	22,967	17,787
Total current liabilities	255,571	177,577
Total liabilities	1,019,995	933,337
PARTNERS' CAPITAL:
Limited Partners - Common Unitholders 127,195,219 units outstanding	1,656,025	1,279,183
TOTAL LIABILITIES AND PARTNERS' CAPITAL	2,661,473	2,159,406
AHGP as the parent company
CURRENT ASSETS:
Cash and cash equivalents	2,174	2,173
Total current assets	2,174	2,173
OTHER ASSETS:
Investments in consolidated subsidiaries	1,653,951	1,277,110
Total other assets	1,653,951	1,277,110
TOTAL ASSETS	1,656,125	1,279,283
CURRENT LIABILITIES:
Accrued taxes other than income taxes	100	100
Total current liabilities	100	100
Total liabilities	100	100
PARTNERS' CAPITAL:
Limited Partners - Common Unitholders 127,195,219 units outstanding	1,656,025	1,279,183
TOTAL LIABILITIES AND PARTNERS' CAPITAL	$ 1,656,125	$ 1,279,283

SCHEDULE I - CONDENSED FINANC_2

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - BALANCE SHEETS (Parenthetical) (Details) - shares	Dec. 31, 2022	Dec. 31, 2021
Condensed Financial Statements, Captions [Line Items]
Common units outstanding	127,195,219	127,195,219
AHGP as the parent company
Condensed Financial Statements, Captions [Line Items]
Common units outstanding	127,195,219	127,195,219

SCHEDULE I - CONDENSED FINANC_3

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - OPERATIONS (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Interest income	$ 2,035	$ 88	$ 135
NET INCOME (LOSS) ATTRIBUTABLE TO ARLP	$ 577,190	$ 178,157	$ (129,220)
EARNINGS PER LIMITED PARTNER UNIT - BASIC (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
EARNINGS PER LIMITED PARTNER UNIT - DILUTED (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - BASIC (in units)	127,195,219	127,195,219	127,164,659
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - DILUTED (in units)	127,195,000	127,195,000	127,165,000
AHGP as the parent company
Condensed Financial Statements, Captions [Line Items]
Interest income			$ 24
Equity in earnings of consolidated subsidiaries	$ 577,190	$ 178,157	(129,244)
NET INCOME (LOSS) ATTRIBUTABLE TO ARLP	$ 577,190	$ 178,157	$ (129,220)
EARNINGS PER LIMITED PARTNER UNIT - BASIC (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
EARNINGS PER LIMITED PARTNER UNIT - DILUTED (in dollars per unit)	$ 4.39	$ 1.36	$ (1.02)
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - BASIC (in units)	127,195,219	127,195,219	127,164,659
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - DILUTED (in units)	127,195,219	127,195,219	127,164,659

SCHEDULE I - CONDENSED FINANC_4

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - CASH FLOWS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES:
CASH FLOWS FROM OPERATING ACTIVITIES	$ 791,812	$ 425,202	$ 400,645
CASH FLOWS FROM FINANCING ACTIVITIES:
Distributions paid to Partners	(196,347)	(52,158)	(51,753)
Net cash used in financing activities	(214,854)	(215,685)	(256,429)
NET CHANGE IN CASH AND CASH EQUIVALENTS	173,620	66,829	19,092
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	122,403	55,574	36,482
CASH AND CASH EQUIVALENTS AT END OF PERIOD	296,023	122,403	55,574
AHGP as the parent company
CASH FLOWS FROM OPERATING ACTIVITIES:
CASH FLOWS FROM OPERATING ACTIVITIES	196,348	52,157	51,751
CASH FLOWS FROM FINANCING ACTIVITIES:
Distributions paid to Partners	(196,347)	(52,158)	(51,753)
Net cash used in financing activities	(196,347)	(52,158)	(51,753)
NET CHANGE IN CASH AND CASH EQUIVALENTS	1	(1)	(2)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	2,173	2,174	2,176
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$ 2,174	$ 2,173	$ 2,174

SCHEDULE I - CONDENSED FINANC_5

SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF REGISTRANT - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Condensed Financial Statements, Captions [Line Items]
Maximum undiscounted future payment obligation	$ 425.6
AHGP as the parent company
Condensed Financial Statements, Captions [Line Items]
Cash contribution by affiliated entity	$ 196.3	$ 52.2	$ 51.8