Document and Entity Information - shares	6 Months Ended
Document and Entity Information - shares	Jun. 30, 2020	Aug. 06, 2020
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Jun. 30, 2020
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Units Outstanding		127,195,219
Entity Central Index Key	0001086600
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 35,106	$ 36,482
Trade receivables	104,361	161,679
Other receivables	281	256
Inventories, net	88,393	101,305
Advance royalties	344	1,844
Prepaid expenses and other assets	12,697	18,019
Total current assets	241,182	319,585
PROPERTY, PLANT AND EQUIPMENT:
Property, plant and equipment, at cost	3,615,721	3,684,008
Less accumulated depreciation, depletion and amortization	(1,700,741)	(1,675,022)
Total property, plant and equipment, net	1,914,980	2,008,986
OTHER ASSETS:
Advance royalties	60,074	52,057
Equity method investments	27,705	28,529
Goodwill	4,373	136,399
Operating lease right-of-use assets	15,821	17,660
Other long-term assets	21,493	23,478
Total other assets	129,466	258,123
TOTAL ASSETS	2,285,628	2,586,694
CURRENT LIABILITIES:
Accounts payable	51,184	80,566
Accrued taxes other than income taxes	19,783	15,768
Accrued payroll and related expenses	39,234	36,575
Accrued interest	5,376	5,664
Workers' compensation and pneumoconiosis benefits	11,175	11,175
Current finance lease obligations	699	8,368
Current operating lease obligations	1,954	3,251
Other current liabilities	18,947	21,062
Current maturities, long-term debt, net	55,746	13,157
Total current liabilities	204,098	195,586
LONG-TERM LIABILITIES:
Long-term debt, excluding current maturities, net	704,661	768,194
Pneumoconiosis benefits	96,035	94,389
Accrued pension benefit	42,924	44,858
Workers' compensation	46,597	45,503
Asset retirement obligations	136,072	133,018
Long-term finance lease obligations	1,850	2,224
Long-term operating lease obligations	13,904	14,316
Other liabilities	16,335	23,182
Total long-term liabilities	1,058,378	1,125,684
Total liabilities	1,262,476	1,321,270
ARLP Partners' Capital:
Limited Partners - Common Unitholders 127,195,219 and 126,915,597 units outstanding, respectively	1,087,782	1,331,482
Accumulated other comprehensive loss	(76,116)	(77,993)
Total ARLP Partners' Capital	1,011,666	1,253,489
Noncontrolling interest	11,486	11,935
Total Partners' Capital	1,023,152	1,265,424
TOTAL LIABILITIES AND PARTNERS' CAPITAL	$ 2,285,628	$ 2,586,694

CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Jun. 30, 2020	Dec. 31, 2019
CONSOLIDATED BALANCE SHEETS
Common units outstanding	127,195,219	126,915,597

CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
SALES AND OPERATING REVENUES:
Revenues	$ 255,202	$ 517,054	$ 605,965	$ 1,043,656
EXPENSES:
Operating expenses (excluding depreciation, depletion and amortization)	187,164	314,273	421,506	617,001
Outside coal purchases		5,311		5,311
General and administrative	13,822	19,521	27,260	37,333
Depreciation, depletion and amortization	83,559	76,913	157,480	148,052
Asset impairments			24,977
Goodwill impairment			132,026
Total operating expenses	290,302	448,648	773,745	870,565
INCOME (LOSS) FROM OPERATIONS	(35,100)	68,406	(167,780)	173,091
Interest expense (net of interest capitalized for the three and six months ended June 30, 2020 and 2019 of $509, $238, $1,066 and $492, respectively)	(11,446)	(10,711)	(23,725)	(22,133)
Interest income	30	138	82	229
Equity method investment income	137	550	588	874
Equity securities income				12,906
Acquisition gain				177,043
Other expense	(377)	(13)	(733)	(142)
INCOME (LOSS) BEFORE INCOME TAXES	(46,756)	58,370	(191,568)	341,868
INCOME TAX EXPENSE (BENEFIT)	(77)	186	(182)	80
NET INCOME (LOSS)	(46,679)	58,184	(191,386)	341,788
LESS: NET LOSS (INCOME) ATTRIBUTABLE TO NONCONTROLLING INTEREST	15	(114)	(61)	(7,290)
NET INCOME (LOSS) ATTRIBUTABLE TO ARLP	$ (46,664)	$ 58,070	$ (191,447)	$ 334,498
EARNINGS PER LIMITED PARTNER UNIT - BASIC AND DILUTED	$ (0.37)	$ 0.44	$ (1.51)	$ 2.57
WEIGHTED-AVERAGE NUMBER OF UNITS OUTSTANDING - BASIC AND DILUTED	127,195,219	128,391,191	127,133,764	128,271,158
Coal sales
SALES AND OPERATING REVENUES:
Revenues	$ 236,286	$ 461,310	$ 550,923	$ 937,326
EXPENSES:
Operating expenses (excluding depreciation, depletion and amortization)	187,164	314,273	421,506	617,001
Oil & gas royalties
SALES AND OPERATING REVENUES:
Revenues	7,786	11,892	22,025	22,285
Transportation revenues
SALES AND OPERATING REVENUES:
Revenues	5,757	32,630	10,496	62,868
EXPENSES:
Transportation expenses	5,757	32,630	10,496	62,868
Other revenues
SALES AND OPERATING REVENUES:
Revenues	$ 5,373	$ 11,222	$ 22,521	$ 21,177

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
CONSOLIDATED STATEMENTS OF INCOME
Interest expense, interest capitalized	$ 509	$ 238	$ 1,066	$ 492

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
NET INCOME (LOSS)	$ (46,679)	$ 58,184	$ (191,386)	$ 341,788
OTHER COMPREHENSIVE INCOME (LOSS)
OTHER COMPREHENSIVE INCOME (LOSS)	939	(118)	1,877	(3,702)
COMPREHENSIVE INCOME (LOSS)	(45,740)	58,066	(189,509)	338,086
Less: Comprehensive loss (income) attributable to noncontrolling interest	15	(114)	(61)	(7,290)
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO ARLP	(45,725)	57,952	(189,570)	330,796
Defined benefit pension plan
OTHER COMPREHENSIVE INCOME (LOSS)
Amortization of prior service cost	47	46	93	93
Amortization of net actuarial loss	1,063	982	2,127	1,961
Total adjustments	1,110	1,028	2,220	2,054
Pneumoconiosis benefits
OTHER COMPREHENSIVE INCOME (LOSS)
Amortization of net actuarial loss	(171)	(1,146)	(343)	(2,291)
Net actuarial loss				(3,465)
Total adjustments	$ (171)	$ (1,146)	$ (343)	$ (5,756)

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
CONSOLIDATED STATEMENTS OF CASH FLOWS
CASH FLOWS FROM OPERATING ACTIVITIES	$ 170,168	$ 301,703
Property, plant and equipment:
Capital expenditures	(84,245)	(165,627)
Change in accounts payable and accrued liabilities	(6,508)	4,442
Proceeds from sale of property, plant and equipment	2,739	701
Distributions received from investments in excess of cumulative earnings	551	2,358
Payments for acquisitions of businesses, net of cash acquired		(185,935)
Cash received from redemption of equity securities		134,288
Net cash used in investing activities	(87,463)	(209,773)
CASH FLOWS FROM FINANCING ACTIVITIES:
Borrowings under securitization facility	12,800	118,000
Payments under securitization facility	(47,700)	(135,000)
Proceeds from equipment financings	14,705	10,000
Payments on equipment financings	(6,494)	(253)
Borrowings under revolving credit facilities	70,000	90,000
Payments under revolving credit facilities	(60,000)	(195,000)
Payments on finance lease obligations	(8,043)	(16,554)
Payment of debt issuance costs	(5,776)
Payments for purchases of units under unit repurchase program		(5,251)
Payments for taxes related to net settlement of issuance of units in deferred compensation plans	(1,310)	(7,817)
Distributions paid to Partners	(51,753)	(138,500)	$ (278,425)
Other	(510)	(490)
Net cash used in financing activities	(84,081)	(280,865)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(1,376)	(188,935)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	36,482	244,150	244,150
CASH AND CASH EQUIVALENTS AT END OF PERIOD	35,106	55,215	$ 36,482
SUPPLEMENTAL CASH FLOW INFORMATION:
Cash paid for interest	23,337	20,748
Cash paid for income taxes	4
SUPPLEMENTAL NON-CASH ACTIVITY:
Accounts payable for purchase of property, plant and equipment	7,996	19,027
Right-of-use assets acquired by operating lease	278	25,179
Market value of common units issued under deferred compensation plans before tax withholding requirements	$ 3,837	17,415
Fair value of liabilities assumed in acquisition of business		$ 1,921

ORGANIZATION AND PRESENTATION

6 Months Ended

Jun. 30, 2020

ORGANIZATION AND PRESENTATION

ORGANIZATION AND PRESENTATION

1.ORGANIZATION AND PRESENTATION

Significant Relationships Referenced in Notes to Condensed Consolidated Financial Statements

●

References to "we," "us," "our" or "ARLP Partnership" mean the business and operations of Alliance Resource Partners, L.P., the parent company, as well as its consolidated subsidiaries.

●

References to "ARLP" mean Alliance Resource Partners, L.P., individually as the parent company, and not on a consolidated basis.

●

References to "MGP" mean Alliance Resource Management GP, LLC, ARLP's general partner.

●

References to "Intermediate Partnership" mean Alliance Resource Operating Partners, L.P., the intermediate partnership of Alliance Resource Partners, L.P.

●

References to "Alliance Coal" mean Alliance Coal, LLC, the holding company for the coal mining operations of Alliance Resource Operating Partners, L.P.

●

References to "Alliance Minerals" mean Alliance Minerals, LLC, the holding company for the oil and gas minerals interests of Alliance Resource Partners, L.P.

Organization

ARLP is a Delaware limited partnership listed on the NASDAQ Global Select Market under the ticker symbol "ARLP." ARLP was formed in May 1999 and completed its initial public offering on August 19, 1999 when it acquired substantially all of the coal production and marketing assets of Alliance Resource Holdings, Inc., a Delaware corporation, and its subsidiaries. We are managed by our general partner, MGP, a Delaware limited liability company which holds a non-economic general partner interest in ARLP.

Basis of Presentation

The accompanying condensed consolidated financial statements include the accounts and operations of the ARLP Partnership and present our financial position as of June 30, 2020 and December 31, 2019 and the results of our operations, comprehensive income for the three and six months ended June 30, 2020 and 2019, and cash flows for the six months ended June 30, 2020 and 2019. All intercompany transactions and accounts have been eliminated.

These condensed consolidated financial statements and notes are prepared pursuant to the rules and regulations of the Securities and Exchange Commission for interim reporting and do not include all of the information normally included with financial statements prepared in accordance with generally accepted accounting principles ("GAAP") of the United States. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2019.

These condensed consolidated financial statements and notes are unaudited. However, in the opinion of management, these condensed consolidated financial statements reflect all normal recurring adjustments necessary for a fair presentation of the results for the periods presented. Results for interim periods are not necessarily indicative of results to be expected for the full year ending December 31, 2020.

Use of Estimates

The preparation of the ARLP Partnership's condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosures in our condensed consolidated financial statements. Actual results could differ from those estimates.

NEW ACCOUNTING STANDARDS

6 Months Ended

Jun. 30, 2020

NEW ACCOUNTING STANDARDS

NEW ACCOUNTING STANDARDS

2.NEW ACCOUNTING STANDARDS

New Accounting Standards Issued and Adopted

In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirement for Fair Value Measurement. ASU 2018-13 amended the fair value measurement guidance by removing and modifying certain disclosure requirements, while also adding new disclosure requirements including the requirement to disclose the range and weighted average of significant unobservable inputs used to develop certain Level 3 measurements. These changes are to be applied prospectively for only the most recent interim or annual period presented in the year of adoption. We adopted ASU 2018-13 on January 1, 2020.

In June 2016, the FASB issued ASU 2016-13, Financial Instruments–Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments to require the use of a new forward-looking "expected loss" model that generally will result in earlier recognition of allowances for losses. The new standard requires disclosure of significantly more information related to these items. We adopted ASU 2016-13 on January 1, 2020 and because we do not have a history of credit losses on our financial instruments and have no material expected losses, the adoption of ASU 2016-13 did not have any material impact on our condensed consolidated financial statements.

ACQUISITIONS

6 Months Ended

Jun. 30, 2020

ACQUISITIONS

ACQUISITIONS

3.ACQUISITION

Wing

On August 2, 2019 (the "Wing Acquisition Date"), our subsidiary, AR Midland, LP ("AR Midland") acquired from Wing Resources LLC and Wing Resources II LLC (collectively, "Wing") approximately 9,000 net royalty acres in the Midland Basin, with exposure to more than 400,000 gross acres, for a cash purchase price of $144.9 million (the "Wing Acquisition"). The purchase price was funded with cash on hand and borrowings under the Revolving Credit Facility discussed in Note 9 – Long-Term Debt. The Wing Acquisition enhances our ownership position in the Permian Basin, expands our exposure to industry leading operators and furthers our business strategy to grow our Minerals segment. Concurrent with the Wing Acquisition, JC Resources LP, an entity owned by Joseph W. Craft III, the Chairman, President and Chief Executive Officer of MGP ("Mr. Craft"), acquired from Wing, in a separate transaction, mineral interests that we elected not to acquire.

Because the mineral interests acquired in the Wing Acquisition include royalty interests in both producing properties and unproved 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 Wing Acquisition Date on our condensed consolidated balance sheet. During the six months ended June 30, 2020, we recorded adjustments to our mineral interests in proved and unproved properties after receiving additional information regarding proved and unproved reserve quantities, production and projections as of the Wing Acquisition Date. In addition, we increased our receivables by $0.3 million as a result of information received from operators concerning royalty payments owed to us from production that occurred prior to the Wing Acquisition Date.

The following table summarizes our final fair value allocation of assets acquired as of the Wing Acquisition Date incorporating measurement period adjustments made to the allocation:


	As Previously
	Reported		Adjustments		Final
			(in thousands)

Mineral interests in proved properties	$	58,084		16,987	$	75,071
Mineral interests in unproved properties		84,976		(17,275)		67,701
Receivables		1,867		288		2,155
Net assets acquired	$	144,927			$	144,927

The fair value of the mineral interests was determined using a weighting of both income and market approaches. Our income approach primarily comprised 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 a weighted average cost of

capital. Our market approach consisted of the observation of recent acquisitions in the Permian Basin to determine a market price for similar mineral interests. Certain assumptions used in our valuation are not observable in active markets; therefore, the fair value measurements represent Level 3 fair value measurements. The carrying value of the receivables represents the fair value given the short-term nature of the receivables.

LONG-LIVED ASSET IMPAIRMENTS

6 Months Ended

Jun. 30, 2020

LONG-LIVED ASSET IMPAIRMENTS

LONG-LIVED ASSET IMPAIRMENTS

4.LONG-LIVED ASSET IMPAIRMENTS

During the six months ended June 30, 2020, we recorded $25.0 million of non-cash asset impairment charges in our Illinois Basin 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 reserves as a result of weakened coal market conditions. The fair values of the impaired assets were determined using a market approach, which represent Level 3 fair value measurements under the fair value hierarchy. The fair value analysis used assumptions regarding the marketability of certain assets in the Illinois Basin.

With the uncertainty related to energy demand as a result of a) weak electricity demand and b) an oversupply and lack of storage for oil and natural gas during the first quarter, both due in part to the COVID-19 pandemic and other market and production factors impacting both our coal mining operations and our mineral interests activities, we performed recoverability tests during the first quarter using undiscounted cash flows based on our estimate of both volume and prices from information available to us and determined we would be able to recover the costs of our assets, excluding the impaired assets discussed above. Amid cost reduction efforts, increased customer commitments for coal, a modest recovery in commodity futures prices and increased clarity into production levels by operators of our oil & gas mineral interests, we updated certain recoverability tests in the second quarter due to continuing weak market conditions and reaffirmed our belief we would recover the costs of our assets. The cash flow estimates used in our assessment, by their very nature, are dependent on conditions that could materially change in future periods based on new information. If in future periods changes to these estimates were to materially reduce our expected cash flows, additional impairments could be necessary.

GOODWILL IMPAIRMENT

6 Months Ended

Jun. 30, 2020

GOODWILL IMPAIRMENT

GOODWILL IMPAIRMENT

5.GOODWILL IMPAIRMENT

At December 31, 2019, our consolidated balance sheet included $136.4 million of goodwill, of which $132.0 million was associated with the reporting unit representing our Hamilton County Coal, LLC ("Hamilton") mine, which is included in our Illinois Basin segment. The goodwill associated with our Hamilton mine was recorded in conjunction with our acquisition of the Hamilton mine on July 31, 2015. During the first quarter of 2020, 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 Hamilton and c) our actual performance during the first quarter of 2020. After consideration of these events and changes in circumstances, we performed an interim test of the goodwill associated with the Hamilton reporting unit comparing Hamilton's carrying amount to its fair value.

We estimated the fair value of the Hamilton reporting unit 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 are not observable in active markets; therefore, the fair value measurements represent Level 3 fair value measurements. The fair value of the Hamilton reporting unit was determined to be below its carrying amount (including goodwill) by more than the recorded balance of goodwill associated with the reporting unit. Accordingly, we recognized an impairment charge of $132.0 million consisting of the total carrying amount of goodwill allocated to the Hamilton reporting unit. This impairment change reduced our consolidated goodwill balance to $4.4 million. During the first quarter, we also performed an interim test on ARLP's remaining goodwill balances not associated with Hamilton and concluded no impairment was necessary for our other reporting units.

CONTINGENCIES

6 Months Ended

Jun. 30, 2020

COMMITMENTS AND CONTINGENCIES

CONTINGENCIES

6.CONTINGENCIES

Various lawsuits, claims and regulatory proceedings incidental to our business are pending against the ARLP Partnership. We record an accrual for a potential loss related to these matters when, in management's opinion, such loss is probable and reasonably estimable. Based on known facts and circumstances, we believe the ultimate outcome of these outstanding lawsuits, claims and regulatory proceedings will not have a material adverse effect on our financial condition,

results of operations or liquidity. However, if the results of these matters are different from management's current expectations and in amounts greater than our accruals, such matters could have a material adverse effect on our business and operations.

INVENTORIES

6 Months Ended

Jun. 30, 2020

INVENTORIES

INVENTORIES

7.INVENTORIES

Inventories consist of the following:


	June 30,		December 31,
	2020		2019

	(in thousands)

Coal	$	51,418	$	63,645
Supplies (net of reserve for obsolescence of $5,762 and $5,555, respectively)		36,975		37,660
Total inventories, net	$	88,393	$	101,305

During the six months ended June 30, 2020, we recorded lower of cost or net realizable value adjustments of $16.9 million to our coal inventories as a result of lower coal sale prices and higher cost per ton due to the impact of lower production on our fixed costs per ton in addition to the impact of challenging market conditions on our production levels. The lower of cost or net realizable value adjustments reflect the impacts of the challenging market conditions and were primarily attributable to the Hamilton and MC Mining complexes.

FAIR VALUE MEASUREMENTS

6 Months Ended

Jun. 30, 2020

FAIR VALUE MEASUREMENTS

FAIR VALUE MEASUREMENTS

8.FAIR VALUE MEASUREMENTS

The following table summarizes our fair value measurements within the hierarchy not included elsewhere in these notes:


	June 30, 2020						December 31, 2019
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3

	(in thousands)
Long-term debt	$	—	$	559,564	$	—	$	—	$	736,206	$	—
Total	$	—	$	559,564	$	—	$	—	$	736,206	$	—

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 9 – Long-Term Debt). The fair value of debt, which is based upon these interest rates, is classified as a Level 2 measurement under the fair value hierarchy.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

LONG-TERM DEBT

6 Months Ended

Jun. 30, 2020

LONG-TERM DEBT

LONG-TERM DEBT

9.LONG-TERM DEBT

Long-term debt consists of the following:


					Unamortized Discount and
	Principal				Debt Issuance Costs
	June 30,		December 31,		June 30,		December 31,
	2020		2019		2020		2019

	(in thousands)
Revolving credit facility	$	265,000	$	255,000	$	(7,763)	$	(3,050)
Senior notes		400,000		400,000		(4,421)		(4,879)
Securitization facility		38,900		73,800		—		—
May 2019 equipment financing		6,603		8,199		—		—
November 2019 equipment financing		47,383		52,281		—		—
June 2020 equipment financing		14,705		—		—		—
		772,591		789,280		(12,184)		(7,929)
Less current maturities		(55,746)		(13,157)		—		—
Total long-term debt	$	716,845	$	776,123	$	(12,184)	$	(7,929)

Credit Facility. On March 9, 2020, our Intermediate Partnership entered into a Fifth Amended and Restated Credit Agreement (the "Credit Agreement") with various financial institutions. The Credit Agreement provides for a $537.75 million revolving credit facility, reducing to $459.5 million on May 23, 2021, including a sublimit of $125 million for the issuance of letters of credit and a sublimit of $15.0 million for swingline borrowings (the "Revolving Credit Facility"), with a termination date of March 9, 2024. The Credit Facility replaced the $494.75 million revolving credit facility extended to the Intermediate Partnership under its Fourth Amended and Restated Credit Agreement, dated as of January 27, 2017, by various banks and other lenders that would have expired on May 23, 2021. Concurrently with the entry into the Credit Agreement, we reorganized the entities holding our oil & gas interests such that Alliance Royalty, LLC became a direct wholly-owned subsidiary of Alliance Minerals.

The Credit Agreement is guaranteed by certain of our Intermediate Partnership's material direct and indirect subsidiaries (the "Restricted Subsidiaries") and is secured by substantially all of the assets of the Restricted Subsidiaries. The Credit Agreement is not guaranteed or secured by the assets of the Intermediate Partnership's oil & gas minerals subsidiary, Alliance Minerals, or its direct and indirect subsidiaries (collectively the "Unrestricted Subsidiaries"). Borrowings under the Revolving Credit Facility bear interest, at our option, at either (i) the Base Rate at the greater of three benchmarks or (ii) a Eurodollar Rate, plus margins for (i) or (ii), as applicable, that fluctuate depending upon the ratio of Consolidated Debt to Consolidated Cash Flow (each as defined in the Credit Agreement). The Eurodollar Rate, with applicable margin, under the Revolving Credit Facility was 3.03% as of June 30, 2020. At June 30, 2020, we had $9.3 million of letters of credit outstanding with $263.5 million available for borrowing under the Revolving Credit Facility. We incur an annual commitment fee of 0.35% on the undrawn portion of the Revolving Credit Facility. We utilize the Revolving Credit Facility, as appropriate, for working capital requirements, capital expenditures and investments, scheduled debt payments and distribution payments.

The Credit Agreement contains various restrictions affecting the Intermediate Partnership and its Restricted Subsidiaries including, among other things, restrictions on incurrence of additional indebtedness and liens, sale of assets, investments, mergers and consolidations and transactions with affiliates, including transactions with Unrestricted Subsidiaries. In each case, these restrictions are subject to various exceptions. In addition, the payment of cash distributions is restricted if such payment would result in a fixed charge coverage ratio of less than 1.0 to 1.0 (as defined in the Credit Agreement) for the four most recently ended fiscal quarters. The Credit Agreement requires the Intermediate Partnership to maintain (a) a debt to cash flow ratio of not more than 2.5 to 1.0, (b) a cash flow to interest expense ratio of not less than 3.0 to 1.0 and (c) a first lien debt to cash flow ratio of not more than 1.5 to 1.0, in each case, during the four most recently ended fiscal quarters. The debt to cash flow ratio, cash flow to interest expense ratio and first lien debt to cash flow ratio were 1.82 to 1.0, 8.63 to 1.0 and 0.88 to 1.0, respectively, for the trailing twelve months ended June 30, 2020. We remain in compliance with the covenants of the Credit Agreement as of June 30, 2020.

Senior Notes. On April 24, 2017, the Intermediate Partnership and Alliance Resource Finance Corporation (as co-issuer), a wholly owned subsidiary of the Intermediate Partnership ("Alliance Finance"), issued an aggregate principal amount of $400.0 million of senior unsecured notes due 2025 ("Senior Notes") in a private placement to qualified

institutional buyers. The Senior Notes have a term of eight years, maturing on May 1, 2025 (the "Term") and accrue interest at an annual rate of 7.5%. Interest is payable semi-annually in arrears on each May 1 and November 1. The indenture governing the Senior Notes contains customary terms, events of default and covenants relating to, among other things, the incurrence of debt, the payment of distributions or similar restricted payments, undertaking transactions with affiliates and limitations on asset sales. The issuers of the Senior Notes may redeem all or a part of the notes at any time at redemption prices set forth in the indenture governing the Senior Notes.

Accounts Receivable Securitization. On December 5, 2014, certain direct and indirect wholly owned subsidiaries of our Intermediate Partnership entered into a $100.0 million accounts receivable securitization facility ("Securitization Facility"). Under the Securitization Facility, certain subsidiaries sell certain trade receivables on an ongoing basis to our Intermediate Partnership, which then sells the trade receivables to AROP Funding, LLC ("AROP Funding"), a wholly owned bankruptcy-remote special purpose subsidiary of our Intermediate Partnership, which in turn borrows on a revolving basis up to $100.0 million secured by the trade receivables. After the sale, Alliance Coal, as servicer of the assets, collects the receivables on behalf of AROP Funding. The Securitization Facility bears interest based on a Eurodollar Rate. The agreement governing the Securitization Facility contains customary terms and conditions, including limitations with regards to certain customer credit ratings. In October 2019, we extended the term of the Securitization Facility to January 2021. At June 30, 2020, we had a $38.9 million outstanding balance under the Securitization Facility.

May 2019 Equipment Financing. On May 17, 2019, the Intermediate Partnership entered into an equipment financing arrangement accounted for as debt, wherein the Intermediate Partnership received $10.0 million in exchange for conveying its interest in certain equipment owned indirectly by the Intermediate Partnership and entering into a master lease agreement for that equipment (the "May 2019 Equipment Financing"). The May 2019 Equipment Financing contains customary terms and events of default and provides for thirty-six monthly payments with an implicit interest rate of 6.25%, maturing on May 1, 2022. Upon maturity, the equipment will revert back to the Intermediate Partnership.

November 2019 Equipment Financing. On November 6, 2019, the Intermediate Partnership entered into an equipment financing arrangement accounted for as debt, wherein the Intermediate Partnership received $53.1 million in exchange for conveying its interest in certain equipment owned indirectly by the Intermediate Partnership and entering into a master lease agreement for that equipment (the "November 2019 Equipment Financing"). The November 2019 Equipment Financing contains customary terms and events of default and an implicit interest rate of 4.75% that provides for a four year term with forty-seven monthly payments of $1.0 million and a balloon payment of $11.6 million upon maturity on November 6, 2023. At maturity, the equipment will revert back to the Intermediate Partnership.

June 2020 Equipment Financing. On June 5, 2020, the Intermediate Partnership entered into an equipment financing arrangement accounted for as debt, wherein the Intermediate Partnership received $14.7 million in exchange for conveying its interest in certain equipment owned indirectly by the Intermediate Partnership and entering into a master lease agreement for that equipment (the "June 2020 Equipment Financing"). The June 2020 Equipment Financing contains customary terms and events of default and provides for forty-eight monthly payments with an implicit interest rate of 6.1%, maturing on June 5, 2024. Upon maturity, the equipment will revert back to the Intermediate Partnership.

VARIABLE INTEREST ENTITIES

6 Months Ended

Jun. 30, 2020

VARIABLE INTEREST ENTITIES

VARIABLE INTEREST ENTITIES

10.VARIABLE INTEREST ENTITIES

Cavalier Minerals

On November 10, 2014, our subsidiary, Alliance Minerals and Bluegrass Minerals Management, LLC ("Bluegrass Minerals") entered into a limited liability company agreement (the "Cavalier Agreement") to create Cavalier Minerals JV, LLC ("Cavalier Minerals"), which was formed to indirectly acquire oil & gas mineral interests through its ownership in AllDale Minerals LP ("AllDale I") and AllDale Minerals II, LP ("AllDale II", and collectively with AllDale I, "AllDale I & II"). Alliance Minerals owns a 96% member interest in Cavalier Minerals, and Bluegrass Minerals owns a 4% member interest in Cavalier Minerals and a profits interest which entitles it to receive distributions equal to 25% of all distributions (including in liquidation) after all members have recovered their investment. Distributions with respect to Bluegrass Minerals' profits interest will be offset by all distributions received by Bluegrass Minerals from the former general partners of AllDale I & II. To date, there has been no profits interest distribution. We hold the managing member interest in Cavalier Minerals. Total contributions to and cumulative distributions from Cavalier Minerals are as follows:


	Alliance		Bluegrass
	Minerals		Minerals
	(in thousands)
Contributions	$	143,112	$	5,963
Distributions		84,153		3,505

We have concluded that Cavalier Minerals is a variable interest entity ("VIE") which we consolidate as the primary beneficiary because we are the managing member and a substantial equity owner in Cavalier Minerals. Bluegrass Minerals' equity ownership of Cavalier Minerals is accounted for as noncontrolling ownership interest in our condensed consolidated balance sheets. In addition, earnings attributable to Bluegrass Minerals are recognized as noncontrolling interest in our condensed consolidated statements of income.

AllDale III

In February 2017, Alliance Minerals committed to directly invest $30.0 million in AllDale Minerals III, LP ("AllDale III") which was created for similar investment purposes as AllDale I & II. Alliance Minerals completed funding of this commitment in 2018. Alliance Minerals' limited partner interest in AllDale III at June 30, 2020 was 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 11 – Investments for more information.

WKY CoalPlay

On November 17, 2014, SGP Land, LLC ("SGP Land"), an entity owned indirectly by the Chairman, President and CEO of MGP ("Mr. Craft") and Kathleen S. Craft, jointly, and two limited liability companies ("Craft Companies") owned by irrevocable trusts established by Mr. Craft and his children, entered into a limited liability company agreement to form WKY CoalPlay, LLC ("WKY CoalPlay"). WKY CoalPlay was formed, in part, to purchase and lease coal reserves. WKY CoalPlay is managed by an individual who is an officer and director of Alliance Resource Holdings II, Inc. and trustee of the irrevocable trusts owning one of the Craft Companies. In December 2014 and February 2015, we entered into various coal reserve leases with WKY CoalPlay. During the six months ended June 30, 2020, we paid $10.8 million of advanced royalties to WKY CoalPlay.

As discussed in Item 8. Financial Statements and Supplementary Data—Note 20 – Related-Party Transactions in our Annual Report on Form 10-K for the year ended December 31, 2019, we have the option to acquire the coal reserves leased from WKY CoalPlay at any time during a three-year period ending in December 2020, with respect to a portion of the reserves, and ending in February 2021 with respect to the remainder of the reserves. In all cases, the options provide for a purchase price that would provide WKY CoalPlay a 7.0% internal rate of return on its investment in the reserves taking into account payments previously made under the leases.

We have concluded that WKY CoalPlay is a VIE because of our ability to exercise options to acquire reserves under lease with WKY CoalPlay, which is not within the control of the equity holders and, if it occurs, could potentially limit the expected residual return to the owners of WKY CoalPlay. Once the options expire in December 2020 and February 2021, WKY CoalPlay will cease to be a VIE. We do not have any economic or governance rights related to WKY CoalPlay and our options that provide us with a variable interest in WKY CoalPlay's reserve assets do not give us any rights that constitute power to direct the primary activities that most significantly impact WKY CoalPlay's economic performance. SGP Land has the sole ability to replace the manager of WKY CoalPlay at its discretion and therefore has power to direct the activities of WKY CoalPlay. Consequently, we concluded that SGP Land is the primary beneficiary of WKY CoalPlay.

INVESTMENTS

6 Months Ended

Jun. 30, 2020

INVESTMENTS

INVESTMENTS

11.INVESTMENTS

AllDale III

As discussed in Note 10 – 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:


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Beginning balance	$	28,114	$	28,770	$	28,529	$	28,974
Equity method investment income		137		550		588		874
Distributions received		(546)		(648)		(1,139)		(1,176)
Other		—		—		(273)		—
Ending balance	$	27,705	$	28,672	$	27,705	$	28,672

As discussed in Note 4 – Long-Lived Asset Impairments, there was uncertainty related to energy demand in the first quarter as a result of a) weak electricity demand and b) an oversupply and lack of storage for oil and natural gas, both due in part to the COVID-19 pandemic and other market and production factors, which could have impacted our investment in AllDale III. As a result, as part of our first quarter impairment assessment, we compared the fair value of our investment to its carrying value and concluded that the fair value exceeded the carrying value and no impairment in our investment was necessary. In our second quarter impairment assessment, amid a modest recovery in commodity futures prices and increased clarity into production levels by operators, we again compared the fair value of our investment to its carrying value and concluded no impairment was necessary. To calculate the fair value of the investment we used an income approach utilizing a discounted cash flow model based on our estimate of both volume, prices and expenses from information available to us. Key assumptions used in our valuation are not observable in active markets; therefore, the fair value measurements represent Level 3 fair value measurements. The cash flow estimates used in our assessments, by their very nature, are dependent on conditions that could materially change in future periods based on new information. If in future periods changes to these estimates were to materially reduce our expected cash flows, an impairment of our investment could be necessary.

Kodiak

On July 19, 2017, Alliance Minerals purchased $100 million of Series A-1 Preferred Interests from Kodiak Gas Services, LLC ("Kodiak"), a privately-held company providing large-scale, high-utilization gas compression assets to customers operating primarily in the Permian Basin. This structured investment provided us with a quarterly cash or payment-in-kind return. On February 8, 2019, Kodiak redeemed our preferred interest for $135.0 million in cash resulting in an $11.5 million gain due to an early redemption premium. The gain is included in the Equity securities income line item. We no longer hold any ownership interests in Kodiak. Prior to redemption, we accounted for our ownership interests in Kodiak as equity securities without readily determinable fair values.

PARTNERS' CAPITAL

6 Months Ended

Jun. 30, 2020

PARTNERS' CAPITAL

PARTNERS' CAPITAL

12.PARTNERS' CAPITAL

Distributions

Distributions paid or declared during 2019 and 2020 were as follows:


Payment Date	Per Unit Cash Distribution		Total Cash Distribution
			(in thousands)

February 14, 2019	$	0.5300	$	69,011
May 15, 2019		0.5350		69,489
August 14, 2019		0.5400		70,153
November 14, 2019		0.5400		69,772
Total	$	2.1450	$	278,425

February 14, 2020	$	0.4000	$	51,753
Total	$	0.4000	$	51,753

In response to the disruptions to the economy and the uncertainty surrounding the COVID-19 pandemic, the Board of Directors of ARLP's general partner suspended the cash distribution to unitholders for the quarters ended March 31, 2020, June 30, 2020 and September 30, 2020.

Unit Repurchase Program

In May 2018, the MGP board of directors approved the establishment of a unit repurchase program authorizing us to repurchase and retire up to $100 million of ARLP common units. The program has no time limit and we may repurchase units from time to time in the open market or in other privately negotiated transactions. The unit repurchase program authorization does not obligate us to repurchase any dollar amount or number of units. No unit repurchases were made during the six months ended June 30, 2020. 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. Total units repurchased include the repurchase and retirement of 35 units representing fractional units as part of the simplification transactions completed by the ARLP Partnership on May 31, 2018 which are not part of the unit repurchase program.

Change in Partners' Capital

The following tables present the quarterly change in Partners' Capital for the six months ended June 30, 2020 and 2019:


				Accumulated
	Number of	Limited		Other
	Limited Partner	Partners'		Comprehensive		Noncontrolling		Total Partners'
	Units	Capital		Income (Loss)		Interest		Capital

	(in thousands, except unit data)
Balance at January 1, 2020	126,915,597	$	1,331,482	$	(77,993)	$	11,935	$	1,265,424
Comprehensive income (loss):
Net income (loss)	—		(144,783)		—		76		(144,707)
Actuarially determined long-term liability adjustments	—		—		938		—		938
Total comprehensive loss									(143,769)
Settlement of deferred compensation plans	279,622		(1,310)		—		—		(1,310)
Common unit-based compensation	—		(527)		—		—		(527)
Distributions on deferred common unit-based compensation	—		(986)		—		—		(986)
Distributions from consolidated company to noncontrolling interest	—		—		—		(288)		(288)
Distributions to Partners	—		(50,767)		—		—		(50,767)
Other	—		(273)		—		—		(273)
Balance at March 31, 2020	127,195,219		1,132,836		(77,055)		11,723		1,067,504
Comprehensive income (loss):
Net loss	—		(46,664)		—		(15)		(46,679)
Actuarially determined long-term liability adjustments	—		—		939		—		939
Total comprehensive loss									(45,740)
Common unit-based compensation	—		1,610		—		—		1,610
Distributions from consolidated company to noncontrolling interest	—		—		—		(222)		(222)
Balance at June 30, 2020	127,195,219	$	1,087,782	$	(76,116)	$	11,486	$	1,023,152


				Accumulated
	Number of	Limited		Other
	Limited Partner	Partners'		Comprehensive		Noncontrolling		Total Partners'
	Units	Capital		Loss		Interest		Capital

	(in thousands, except unit data)
Balance at January 1, 2019	128,095,511	$	1,229,268	$	(46,871)	$	5,290	$	1,187,687
Comprehensive income:
Net income	—		276,428		—		7,176		283,604
Actuarially determined long-term liability adjustments	—		—		(3,584)		—		(3,584)
Total comprehensive income									280,020
Settlement of deferred compensation plans	596,650		(7,817)		—		—		(7,817)
Purchase of units under unit repurchase program	(300,970)		(5,251)		—		—		(5,251)
Common unit-based compensation	—		2,743		—		—		2,743
Distributions on deferred common unit-based compensation	—		(1,280)		—		—		(1,280)
Distributions from consolidated company to noncontrolling interest	—		—		—		(262)		(262)
Distributions to Partners	—		(67,731)		—		—		(67,731)
Balance at March 31, 2019	128,391,191		1,426,360		(50,455)		12,204		1,388,109
Comprehensive income:
Net income	—		58,070		—		114		58,184
Actuarially determined long-term liability adjustments	—		—		(118)		—		(118)
Total comprehensive income									58,066
Common unit-based compensation	—		3,021		—		—		3,021
Distributions on deferred common unit-based compensation	—		(799)		—		—		(799)
Distributions from consolidated company to noncontrolling interest	—		—		—		(228)		(228)
Distributions to Partners	—		(68,690)		—		—		(68,690)
Balance at June 30, 2019	128,391,191	$	1,417,962	$	(50,573)	$	12,090	$	1,379,479

REVENUE FROM CONTRACTS WITH CUSTOMERS

6 Months Ended

Jun. 30, 2020

REVENUE FROM CONTRACTS WITH CUSTOMERS

REVENUE FROM CONTRACTS WITH CUSTOMERS

13.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 18 – Segment Information.


	Illinois						Other and
	Basin		Appalachia		Minerals		Corporate		Elimination		Consolidated

	(in thousands)
Three Months Ended June 30, 2020

Coal sales	$	134,160	$	102,126	$	—	$	—	$	—	$	236,286
Oil & gas royalties		—		—		7,786		—		—		7,786
Transportation revenues		3,153		2,604		—		—		—		5,757
Other revenues		474		2,380		61		4,955		(2,497)		5,373
Total revenues	$	137,787	$	107,110	$	7,847	$	4,955	$	(2,497)	$	255,202

Three Months Ended June 30, 2019

Coal sales	$	301,981	$	157,951	$	—	$	5,551	$	(4,173)	$	461,310
Oil & gas royalties		—		—		11,892		—		—		11,892
Transportation revenues		31,287		1,343		—		—		—		32,630
Other revenues		2,405		950		536		10,439		(3,108)		11,222
Total revenues	$	335,673	$	160,244	$	12,428	$	15,990	$	(7,281)	$	517,054

Six Months Ended June 30, 2020

Coal sales	$	333,258	$	217,665	$	—	$	—	$	—	$	550,923
Oil & gas royalties		—		—		22,025		—		—		22,025
Transportation revenues		7,009		3,487		—		—		—		10,496
Other revenues		1,392		14,061		85		12,339		(5,356)		22,521
Total revenues	$	341,659	$	235,213	$	22,110	$	12,339	$	(5,356)	$	605,965

Six Months Ended June 30, 2019

Coal sales	$	619,251	$	315,404	$	—	$	10,841	$	(8,170)	$	937,326
Oil & gas royalties		—		—		22,285		—		—		22,285
Transportation revenues		60,525		2,343		—		—		—		62,868
Other revenues		5,293		1,901		871		19,311		(6,199)		21,177
Total revenues	$	685,069	$	319,648	$	23,156	$	30,152	$	(14,369)	$	1,043,656

The following table illustrates the amount of our transaction price for all current coal supply contracts allocated to performance obligations that are unsatisfied or partially unsatisfied as of June 30, 2020 and disaggregated by segment and contract duration.


							2023 and
	2020		2021		2022		Thereafter		Total

	(in thousands)

Illinois Basin coal revenues	$	462,549	$	598,941	$	222,514	$	274,195	$	1,558,199
Appalachia coal revenues		239,780		93,177		57,878		—		390,835
Total coal revenues (1)	$	702,329	$	692,118	$	280,392	$	274,195	$	1,949,034

(1) Coal revenues generally consists of consolidated revenues excluding our Minerals segment.

EARNINGS PER LIMITED PARTNER UNIT

6 Months Ended

Jun. 30, 2020

EARNINGS PER LIMITED PARTNER UNIT

EARNINGS PER LIMITED PARTNER UNIT

14.EARNINGS PER LIMITED PARTNER UNIT

We utilize the two-class method in calculating basic and diluted earnings per limited partner unit ("EPU"). Net income (loss) attributable to ARLP is allocated to limited partners and participating securities under deferred compensation plans, which include rights to nonforfeitable distributions or distribution equivalents. Our participating securities are outstanding awards under our Long-Term Incentive Plan ("LTIP") and phantom units in notional accounts under our

Supplemental Executive Retirement Plan ("SERP") and the MGP Amended and Restated Deferred Compensation Plan for Directors ("Directors' Deferred Compensation Plan").

The following is a reconciliation of net income (loss) attributable to ARLP used for calculating basic and diluted earnings per unit and the weighted-average units used in computing EPU for the three and six months ended June 30, 2020 and 2019:


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands, except per unit data)
Net income (loss) attributable to ARLP	$	(46,664)	$	58,070	$	(191,447)	$	334,498

Less:
Distributions to participating securities		—		(1,122)		—		(2,227)
Undistributed earnings attributable to participating securities		—		—		—		(3,196)

Net income (loss) attributable to ARLP available to limited partners	$	(46,664)	$	56,948	$	(191,447)	$	329,075

Weighted-average limited partner units outstanding – basic and diluted		127,195		128,391		127,134		128,271

Earnings per limited partner unit - basic and diluted (1)	$	(0.37)	$	0.44	$	(1.51)	$	2.57

(1)

Diluted EPU gives effect to all potentially dilutive common units outstanding during the period using the treasury stock method. Diluted EPU excludes all potentially dilutive units calculated under the treasury stock method if their effect is anti-dilutive. The combined total of LTIP, SERP and Directors' Deferred Compensation Plan units of 661 and 654 for the three and six months ended June 30, 2020, respectively, and 1,060 and 1,227 for the three and six months ended June 30, 2019, respectively, were considered anti-dilutive under the treasury stock method.

WORKERS' COMPENSATION AND PNEUMOCONIOSIS

6 Months Ended

Jun. 30, 2020

ACCRUED WORKERS' COMPENSATION AND PNEUMOCONIOSIS BENEFITS

WORKERS' COMPENSATION AND PNEUMOCONIOSIS

15.WORKERS' COMPENSATION AND PNEUMOCONIOSIS

The changes in the workers' compensation liability, including current and long-term liability balances, for each of the periods presented were as follows:


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Beginning balance	$	52,880	$	48,428	$	53,384	$	49,539
Accruals increase		192		2,247		1,940		4,208
Payments		(1,992)		(2,452)		(4,563)		(5,925)
Interest accretion		320		401		639		802
Valuation loss (1)		3,078		4,801		3,078		4,801
Ending balance	$	54,478	$	53,425	$	54,478	$	53,425

(1)

Our estimate of the liability for the present value of current workers′ compensation benefits is based on our actuarial calculations. Our actuarial calculations are based on a blend of actuarial projection methods and numerous assumptions including claims development patterns, mortality, medical costs and interest rates. We conducted a mid-year 2020 review of our actuarial assumptions which resulted in a valuation loss in 2020 due to unfavorable changes in claims development and a decrease in the discount rate from 2.81% to 2.05%. Our mid-year 2019 actuarial review resulted in a valuation loss in 2019 due to unfavorable changes in claims development and a decrease in the discount rate from 3.89% to 3.06%.

We limit our exposure to traumatic injury claims by purchasing a high deductible insurance policy that starts paying benefits after deductibles for a claim have been met. The deductible level may vary by claim year. Our workers' compensation liability above is presented on a gross basis and does not include our expected receivables on our insurance policy. Our receivables for traumatic injury claims under this policy as of June 30, 2020 are $7.1 million and are included in Other long-term assets on our condensed consolidated balance sheet.

Certain of our mine operating entities are liable under state statutes and the Federal Coal Mine Health and Safety Act of 1969, as amended, to pay pneumoconiosis, or black lung, benefits to eligible employees and former employees and their dependents. Components of the net periodic benefit cost for each of the periods presented are as follows:


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Service cost	$	883	$	646	$	1,761	$	1,291
Interest cost (1)		749		762		1,499		1,522
Net amortization (1)		(171)		(1,146)		(343)		(2,291)
Net periodic benefit cost	$	1,461	$	262	$	2,917	$	522

(1)	Interest cost and net amortization are included in the Other expense line item within our condensed consolidated statements of income.

COMPENSATION PLANS

6 Months Ended

Jun. 30, 2020

COMPENSATION PLANS

COMPENSATION PLANS

16.COMPENSATION PLANS

Long-Term Incentive Plan

We maintain the LTIP for certain employees and officers of MGP and its affiliates who perform services for us. The LTIP awards are grants of non-vested "phantom" or notional units, also referred to as "restricted units", which upon satisfaction of time and performance-based vesting requirements, entitle the LTIP participant to receive ARLP common units. Annual grant levels and vesting provisions for designated participants are recommended by the Chairman, President and Chief Executive Officer of MGP, subject to review and approval of the compensation committee of the MGP board of directors (the "Compensation Committee"). Vesting of all grants outstanding is subject to the satisfaction of certain financial tests. If it is not probable the financial tests for a particular grant will be met, any previously expensed amounts for the grant are reversed and no future expense will be recognized for those grants. Assuming the financial tests are met, grants issued to LTIP participants are expected to cliff vest on January 1st of the third year following issuance of the grants. We expect to settle these grants by delivery of ARLP common units, except for the portion of the grants that will satisfy employee tax withholding obligations of LTIP participants. We account for forfeitures of non-vested LTIP grants as they occur. As provided under the distribution equivalent rights ("DERs") provisions of the LTIP and the terms of the LTIP awards, all non-vested grants include contingent rights to receive quarterly distributions in cash or, at the discretion of the Compensation Committee, phantom units in lieu of cash credited to a bookkeeping account with value equal to the cash distributions we make to unitholders during the vesting period.

A summary of non-vested LTIP grants as of and for the six months ended June 30, 2020 is as follows:


	Number of units	Weighted average grant date fair value per unit


Non-vested grants at January 1, 2020	1,603,378
Granted	950,035	$	9.62
Vested (1)	(424,486)		23.22
Forfeited	(13,835)		16.13
Non-vested grants at June 30, 2020 (2)	2,115,092

(1)	During the six months ended June 30, 2020, we issued 279,622 unrestricted common units to the LTIP participants. The remaining vested units were settled in cash to satisfy tax withholding obligations of the LTIP participants.

(2)	Represents total non-vested grants outstanding including 675,302 restricted units that were granted in 2019 (the "2019 Grants"). During the first quarter of 2020, it was determined that the vesting requirements for the 2019 Grants were not probable of being satisfied.

LTIP expense was $1.6 million and $2.7 million for the three months ended June 30, 2020 and 2019, respectively, and $0.9 million and $5.1 million for the six months ended June 30, 2020 and 2019, respectively. LTIP expense for the six months ended June 30, 2020 includes the reversal in the first quarter of $4.8 million of cumulative previously recognized expense for the 2019 Grants, which were determined to be not probable of vesting, offset in part by related DERs for the 2019 Grants previously recorded to equity and then expensed. The total obligation associated with the LTIP as of June 30, 2020 was $9.7 million and is included in the partners' capital Limited partners-common unitholders line item in our condensed consolidated balance sheets.

As of June 30, 2020, we had 1,439,790 restricted units that are expected to vest, with a weighted average grant date fair value of $13.33 per unit and an intrinsic value of $4.7 million. There was $9.5 million in total unrecognized compensation expense related to the non-vested LTIP grants that are expected to vest. That expense is expected to be recognized over a weighted-average period of 1.8 years.

After consideration of the January 1, 2020 vesting and subsequent issuance of 279,622 common units, approximately 1.0 million units remain available under the LTIP for issuance in the future. This available issuance excludes all grants currently outstanding. Adding back the 2019 Grants that are not probable to vest, approximately 1.7 million units remain available under the LTIP for issuance in the future.

Supplemental Executive Retirement Plan and Directors' Deferred Compensation Plan

We utilize the SERP to provide deferred compensation benefits for certain officers and key employees. All allocations made to participants under the SERP are made in the form of "phantom" ARLP units and SERP distributions will be settled in the form of ARLP common units. The SERP is administered by the Compensation Committee.

Our directors participate in the Directors' Deferred Compensation Plan. Pursuant to the Directors' Deferred Compensation Plan, for amounts deferred either automatically or at the election of the director, a notional account is established and credited with notional common units of ARLP, described in the Directors' Deferred Compensation Plan as "phantom" units. Distributions from the Directors' Deferred Compensation Plan will be settled in the form of ARLP common units.

For both the SERP and Directors' Deferred Compensation Plan, when quarterly cash distributions are made with respect to ARLP common units, an amount equal to such quarterly distribution is credited to each participant's notional account as additional phantom units. All grants of phantom units under the SERP and Directors' Deferred Compensation Plan vest immediately.

A summary of SERP and Directors' Deferred Compensation Plan activity as of and for the six months ended June 30, 2020 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	29,544		7.87
Phantom units outstanding as of June 30, 2020	660,909		24.69		2,155

Total SERP and Directors' Deferred Compensation Plan expense was $0.1 million and $0.4 million for the three months ended June 30, 2020 and 2019, respectively, and $0.4 million and $0.7 million for the six months ended June 30, 2020 and 2019, respectively. As of June 30, 2020, the total obligation associated with the SERP and Directors' Deferred Compensation Plan was $16.3 million and is included in the partners' capital Limited partners-common unitholders line item in our condensed consolidated balance sheets.

COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS

6 Months Ended

Jun. 30, 2020

EMPLOYEE BENEFIT PLANS

COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS

17.COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS

Eligible employees at certain of our mining operations participate in a defined benefit plan (the "Pension Plan") that we sponsor. The Pension Plan is currently closed to new applicants and participants in the Pension Plan are no longer receiving benefit accruals for service. The benefit formula for the Pension Plan is a fixed dollar unit based on years of service. Components of the net periodic benefit cost for each of the periods presented are as follows:


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Interest cost	$	1,054	$	1,216	$	2,108	$	2,432
Expected return on plan assets		(1,491)		(1,234)		(2,983)		(2,466)
Amortization of prior service cost		47		46		93		93
Amortization of net loss		1,063		982		2,127		1,961
Net periodic benefit cost (1)	$	673	$	1,010	$	1,345	$	2,020

(1)

Net periodic benefit cost for the Pension Plan is included in the Other expense line item within our condensed consolidated statements of income.

During the six months ended June 30, 2020, we made a contribution payment of $1.1 million to the Pension Plan for the 2019 plan year. We expect to defer all remaining contributions to the Pension Plan during 2020 until January 2021 as provided for under the Coronavirus Aid Relief and Economic Security Act of 2020 enacted in response to the COVID-19 pandemic.

SEGMENT INFORMATION

6 Months Ended

Jun. 30, 2020

SEGMENT INFORMATION

SEGMENT INFORMATION

18.SEGMENT INFORMATION

We operate in the United States as a diversified natural resource company that generates income from the production and marketing of coal to major domestic and international utilities and industrial users as well as income from oil & gas mineral interests. We aggregate multiple operating segments into three reportable segments, Illinois Basin, Appalachia, and Minerals. We also have an "all other" category referred to as Other and Corporate. Our two coal 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 segments include seven mining complexes operating in Illinois, Indiana, Kentucky, Maryland and West Virginia and a coal loading terminal in Indiana on the Ohio River. The Minerals reportable segment aggregates our oil & gas mineral interests which are located primarily in the Permian (Delaware and Midland), Anadarko (SCOOP/STACK), and Williston (Bakken) basins. We have no operations within our Minerals reportable segment other than receiving royalties and lease bonuses for our oil & gas mineral interests.

The Illinois Basin reportable segment includes currently operating mining complexes (a) Gibson County Coal, LLC's ("Gibson") mining complex, which includes the Gibson South mine, (b) Warrior Coal, LLC's ("Warrior") mining complex, (c) River View Coal, LLC's ("River View") mining complex and (d) Hamilton's mining complex. The Illinois Basin reportable segment also includes our currently operating Mt. Vernon Transfer Terminal, LLC ("Mt. Vernon") coal loading terminal in Indiana on the Ohio River.

The Illinois Basin reportable segment also includes Mid-America Carbonates, LLC ("MAC") and other support services as well as non-operating mining complexes (a) Gibson North mine, which ceased production in the fourth quarter of 2019, (b) Webster County Coal, LLC's Dotiki mining complex, which ceased production in August 2019, (c) White County Coal, LLC's Pattiki mining complex, (d) Hopkins County Coal, LLC's mining complex, and (e) Sebree Mining, LLC's mining complex.

The Appalachia reportable segment includes currently operating mining complexes (a) Mettiki mining complex, (b) Tunnel Ridge, LLC mining complex and (c) MC Mining, LLC ("MC Mining") mining complex. The Mettiki mining complex includes Mettiki Coal (WV), LLC's Mountain View mine and Mettiki Coal, LLC's preparation plant. The Appalachia reportable segment also includes the Penn Ridge assets, which are primarily coal mineral interests.

The Minerals reportable segment includes oil & gas mineral interests held by AR Midland and AllDale I & II and includes Alliance Minerals' equity interests in both AllDale III (Note 11 – Investments) and Cavalier Minerals. AR Midland acquired its mineral interest in the Wing Acquisition (Note 3 – Acquisition).

Other and Corporate includes marketing and administrative activities, Matrix Design Group, LLC and its subsidiaries ("Matrix Design"), Alliance Design Group, LLC ("Alliance Design") (collectively, Matrix Design and Alliance Design referred to as the "Matrix Group"), Alliance Coal's coal brokerage activity and Alliance Minerals' prior equity investment in Kodiak. In February 2019, Kodiak redeemed our equity investment (see Note 11 – Investments). In addition, Other and Corporate includes certain Alliance Resource Properties' land and coal mineral interest activities, Pontiki Coal, LLC's workers' compensation and pneumoconiosis liabilities, Wildcat Insurance, which assists the ARLP Partnership with its insurance requirements, and AROP Funding and Alliance Finance (both discussed in Note 9 – Long-Term Debt).

In response to the impacts of the COVID-19 pandemic, we announced on March 30, 2020 a temporary cessation of coal production at our River View, Gibson, Hamilton and Warrior mining complexes in our Illinois Basin segment and on April 9, 2020 a temporary cessation of coal production at our MC Mining complex in our Appalachia segment. Underground production operations resumed in May at the River View and Warrior mines in the Illinois Basin and subsequently at each of the remaining mining complexes – Gibson and Hamilton in the Illinois Basin and MC Mining in Appalachia. All of our seven mining complexes are now producing coal. However, several mines will be running at less than capacity due to a limited spot market in the U.S. and a seaborne market that continues to be sub-economic for U.S. production. Due to the ongoing and unforeseen impacts of the COVID-19 pandemic, on April 15, 2020, 116 employees of the Gibson County mining complex and 78 employees of the Hamilton mining complex were notified that their employment would be terminated permanently on April 26, 2020. In addition to reduced production levels and employment adjustments, we have also taken numerous actions to optimize cash flows and preserve liquidity by reducing capital expenditures, working capital, costs and expenses, including adjusting our corporate support structure to better align to current operating levels.

Reportable segment results are presented below.


	Illinois						Other and		Elimination
	Basin		Appalachia		Minerals		Corporate		(1)		Consolidated

	(in thousands)
Three Months Ended June 30, 2020

Revenues - Outside	$	137,787	$	107,110	$	7,847	$	2,458	$	—	$	255,202
Revenues - Intercompany		—		—		—		2,497		(2,497)		—
Total revenues (2)		137,787		107,110		7,847		4,955		(2,497)		255,202

Segment Adjusted EBITDA Expense (3)		108,478		73,959		1,119		4,147		(162)		187,541
Segment Adjusted EBITDA (4)		26,157		30,548		6,881		805		(2,335)		62,056
Capital expenditures		14,029		19,686		—		166		—		33,881

Three Months Ended June 30, 2019

Revenues - Outside	$	331,500	$	160,244	$	12,428	$	12,882	$	—	$	517,054
Revenues - Intercompany		4,173		—		—		3,108		(7,281)		—
Total revenues (2)		335,673		160,244		12,428		15,990		(7,281)		517,054

Segment Adjusted EBITDA Expense (3)		208,309		105,122		1,765		9,442		(5,041)		319,597
Segment Adjusted EBITDA (4)		96,075		53,779		11,098		6,551		(2,240)		165,263
Capital expenditures		59,476		20,987		—		1,121		—		81,584

Six Months Ended June 30, 2020

Revenues - Outside	$	341,659	$	235,213	$	22,110	$	6,983	$	—	$	605,965
Revenues - Intercompany		—		—		—		5,356		(5,356)		—
Total revenues (2)		341,659		235,213		22,110		12,339		(5,356)		605,965

Segment Adjusted EBITDA Expense (3)		258,465		153,669		2,002		8,789		(686)		422,239
Segment Adjusted EBITDA (4)		76,186		78,058		20,636		3,547		(4,670)		173,757
Total assets		1,099,463		501,614		628,308		462,936		(406,693)		2,285,628
Capital expenditures		40,258		43,257		—		730		—		84,245

Six Months Ended June 30, 2019

Revenues - Outside	$	676,899	$	319,648	$	23,156	$	23,953	$	—	$	1,043,656
Revenues - Intercompany		8,170		—		—		6,199		(14,369)		—
Total revenues (2)		685,069		319,648		23,156		30,152		(14,369)		1,043,656

Segment Adjusted EBITDA Expense (3)		405,731		204,871		3,592		18,148		(9,888)		622,454
Segment Adjusted EBITDA (4)		218,812		112,434		20,230		24,912		(4,481)		371,907
Total assets		1,407,019		483,265		516,503		460,353		(364,419)		2,502,721
Capital expenditures (5)		107,930		54,333		—		3,364		—		165,627

(1)

The elimination column represents the elimination of intercompany transactions and is primarily comprised of sales from the Matrix Group to our mining operations, coal sales and purchases between operations within different segments, sales of receivables to AROP Funding, financing between segments and insurance premiums paid to Wildcat Insurance.

(2)	Revenues included in the Other and Corporate column are primarily attributable to the Matrix Group revenues, administrative service revenues from affiliates, Wildcat Insurance revenues and brokerage coal sales.

(3)	Segment Adjusted EBITDA Expense includes operating expenses, coal purchases and other income. Transportation expenses are excluded as transportation revenues are recognized in an amount equal to transportation expenses when title passes to the customer.

The following is a reconciliation of consolidated Segment Adjusted EBITDA Expense to Operating expenses (excluding depreciation, depletion and amortization):


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Segment Adjusted EBITDA Expense	$	187,541	$	319,597	$	422,239	$	622,454
Outside coal purchases		—		(5,311)		—		(5,311)
Other expense		(377)		(13)		(733)		(142)
Operating expenses (excluding depreciation, depletion and amortization)	$	187,164	$	314,273	$	421,506	$	617,001

(4)

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 expenses, settlement gain, 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. Consolidated Segment Adjusted EBITDA is reconciled to net income as follows:


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Consolidated Segment Adjusted EBITDA	$	62,056	$	165,263	$	173,757	$	371,907
General and administrative		(13,822)		(19,521)		(27,260)		(37,333)
Depreciation, depletion and amortization		(83,559)		(76,913)		(157,480)		(148,052)
Asset impairments		—		—		(24,977)		—
Goodwill impairment		—		—		(132,026)		—
Interest expense, net		(11,416)		(10,573)		(23,643)		(21,904)
Acquisition gain		—		—		—		177,043
Income tax (expense) benefit		77		(186)		182		(80)
Acquisition gain attributable to noncontrolling interest		—		—		—		(7,083)
Net income (loss) attributable to ARLP	$	(46,664)	$	58,070	$	(191,447)	$	334,498
Noncontrolling interest		(15)		114		61		7,290
Net income (loss)	$	(46,679)	$	58,184	$	(191,386)	$	341,788

(5)	Capital Expenditures shown exclude the AllDale Acquisition which occurred in January 2019.

SUBSEQUENT EVENTS

6 Months Ended

Jun. 30, 2020

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS

19.SUBSEQUENT EVENTS

Other than the event described in Note 12, there were no subsequent events.

We continue to closely monitor the impact of the COVID-19 pandemic on all aspects of our business. While there have been some signs of increasing economic activity, some states have paused or reversed re-opening plans, impacting economic recovery efforts. With the timing and pace of recovery remaining unclear, the full extent of the operational and financial impact that the COVID-19 pandemic may have on us has yet to be determined. As a result of these uncertainties, we are currently unable to accurately predict how COVID-19 will affect our results of operations in the future.

ORGANIZATION AND PRESENTATION (Policies)	6 Months Ended
ORGANIZATION AND PRESENTATION (Policies)	Jun. 30, 2020
ORGANIZATION AND PRESENTATION
Basis of Presentation	Basis of Presentation The accompanying condensed consolidated financial statements include the accounts and operations of the ARLP Partnership and present our financial position as of June 30, 2020 and December 31, 2019 and the results of our operations, comprehensive income for the three and six months ended June 30, 2020 and 2019, and cash flows for the six months ended June 30, 2020 and 2019. All intercompany transactions and accounts have been eliminated. These condensed consolidated financial statements and notes are prepared pursuant to the rules and regulations of the Securities and Exchange Commission for interim reporting and do not include all of the information normally included with financial statements prepared in accordance with generally accepted accounting principles ("GAAP") of the United States. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2019. These condensed consolidated financial statements and notes are unaudited. However, in the opinion of management, these condensed consolidated financial statements reflect all normal recurring adjustments necessary for a fair presentation of the results for the periods presented. Results for interim periods are not necessarily indicative of results to be expected for the full year ending December 31, 2020.
Use of Estimates	Use of Estimates The preparation of the ARLP Partnership's condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts and disclosures in our condensed consolidated financial statements. Actual results could differ from those estimates.
New Accounting Standards	New Accounting Standards Issued and Adopted In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework – Changes to the Disclosure Requirement for Fair Value Measurement. ASU 2018-13 amended the fair value measurement guidance by removing and modifying certain disclosure requirements, while also adding new disclosure requirements including the requirement to disclose the range and weighted average of significant unobservable inputs used to develop certain Level 3 measurements. These changes are to be applied prospectively for only the most recent interim or annual period presented in the year of adoption. We adopted ASU 2018-13 on January 1, 2020. In June 2016, the FASB issued ASU 2016-13, Financial Instruments–Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments ("ASU 2016-13"). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments to require the use of a new forward-looking "expected loss" model that generally will result in earlier recognition of allowances for losses. The new standard requires disclosure of significantly more information related to these items. We adopted ASU 2016-13 on January 1, 2020 and because we do not have a history of credit losses on our financial instruments and have no material expected losses, the adoption of ASU 2016-13 did not have any material impact on our condensed consolidated financial statements.

ACQUISITIONS (Tables)

6 Months Ended

Jun. 30, 2020

ACQUISITIONS

Summary of fair value allocation of assets acquired and liabilities assumed


	As Previously
	Reported		Adjustments		Final
			(in thousands)

Mineral interests in proved properties	$	58,084		16,987	$	75,071
Mineral interests in unproved properties		84,976		(17,275)		67,701
Receivables		1,867		288		2,155
Net assets acquired	$	144,927			$	144,927

INVENTORIES (Tables)

6 Months Ended

Jun. 30, 2020

INVENTORIES

Schedule of inventories


	June 30,		December 31,
	2020		2019

	(in thousands)

Coal	$	51,418	$	63,645
Supplies (net of reserve for obsolescence of $5,762 and $5,555, respectively)		36,975		37,660
Total inventories, net	$	88,393	$	101,305

FAIR VALUE MEASUREMENTS (Tables)

6 Months Ended

Jun. 30, 2020

FAIR VALUE MEASUREMENTS

Summary of fair value measurements within the hierarchy


	June 30, 2020						December 31, 2019
	Level 1		Level 2		Level 3		Level 1		Level 2		Level 3

	(in thousands)
Long-term debt	$	—	$	559,564	$	—	$	—	$	736,206	$	—
Total	$	—	$	559,564	$	—	$	—	$	736,206	$	—

LONG-TERM DEBT (Tables)

6 Months Ended

Jun. 30, 2020

LONG-TERM DEBT

Schedule of long-term debt


					Unamortized Discount and
	Principal				Debt Issuance Costs
	June 30,		December 31,		June 30,		December 31,
	2020		2019		2020		2019

	(in thousands)
Revolving credit facility	$	265,000	$	255,000	$	(7,763)	$	(3,050)
Senior notes		400,000		400,000		(4,421)		(4,879)
Securitization facility		38,900		73,800		—		—
May 2019 equipment financing		6,603		8,199		—		—
November 2019 equipment financing		47,383		52,281		—		—
June 2020 equipment financing		14,705		—		—		—
		772,591		789,280		(12,184)		(7,929)
Less current maturities		(55,746)		(13,157)		—		—
Total long-term debt	$	716,845	$	776,123	$	(12,184)	$	(7,929)

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21475-112644

+ Details

VARIABLE INTEREST ENTITIES (Tables)

6 Months Ended

Jun. 30, 2020

VARIABLE INTEREST ENTITIES

Schedule of distributions


	Alliance		Bluegrass
	Minerals		Minerals
	(in thousands)
Contributions	$	143,112	$	5,963
Distributions		84,153		3,505

INVESTMENTS (Tables)

6 Months Ended

Jun. 30, 2020

INVESTMENTS

Schedule of changes in equity method investment


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Beginning balance	$	28,114	$	28,770	$	28,529	$	28,974
Equity method investment income		137		550		588		874
Distributions received		(546)		(648)		(1,139)		(1,176)
Other		—		—		(273)		—
Ending balance	$	27,705	$	28,672	$	27,705	$	28,672

PARTNERS' CAPITAL (Tables)

6 Months Ended

Jun. 30, 2020

PARTNERS' CAPITAL

Summary of quarterly per unit distribution paid


Payment Date	Per Unit Cash Distribution		Total Cash Distribution
			(in thousands)

February 14, 2019	$	0.5300	$	69,011
May 15, 2019		0.5350		69,489
August 14, 2019		0.5400		70,153
November 14, 2019		0.5400		69,772
Total	$	2.1450	$	278,425

February 14, 2020	$	0.4000	$	51,753
Total	$	0.4000	$	51,753

Summary of changes to Partners' Capital


				Accumulated
	Number of	Limited		Other
	Limited Partner	Partners'		Comprehensive		Noncontrolling		Total Partners'
	Units	Capital		Income (Loss)		Interest		Capital

	(in thousands, except unit data)
Balance at January 1, 2020	126,915,597	$	1,331,482	$	(77,993)	$	11,935	$	1,265,424
Comprehensive income (loss):
Net income (loss)	—		(144,783)		—		76		(144,707)
Actuarially determined long-term liability adjustments	—		—		938		—		938
Total comprehensive loss									(143,769)
Settlement of deferred compensation plans	279,622		(1,310)		—		—		(1,310)
Common unit-based compensation	—		(527)		—		—		(527)
Distributions on deferred common unit-based compensation	—		(986)		—		—		(986)
Distributions from consolidated company to noncontrolling interest	—		—		—		(288)		(288)
Distributions to Partners	—		(50,767)		—		—		(50,767)
Other	—		(273)		—		—		(273)
Balance at March 31, 2020	127,195,219		1,132,836		(77,055)		11,723		1,067,504
Comprehensive income (loss):
Net loss	—		(46,664)		—		(15)		(46,679)
Actuarially determined long-term liability adjustments	—		—		939		—		939
Total comprehensive loss									(45,740)
Common unit-based compensation	—		1,610		—		—		1,610
Distributions from consolidated company to noncontrolling interest	—		—		—		(222)		(222)
Balance at June 30, 2020	127,195,219	$	1,087,782	$	(76,116)	$	11,486	$	1,023,152


				Accumulated
	Number of	Limited		Other
	Limited Partner	Partners'		Comprehensive		Noncontrolling		Total Partners'
	Units	Capital		Loss		Interest		Capital

	(in thousands, except unit data)
Balance at January 1, 2019	128,095,511	$	1,229,268	$	(46,871)	$	5,290	$	1,187,687
Comprehensive income:
Net income	—		276,428		—		7,176		283,604
Actuarially determined long-term liability adjustments	—		—		(3,584)		—		(3,584)
Total comprehensive income									280,020
Settlement of deferred compensation plans	596,650		(7,817)		—		—		(7,817)
Purchase of units under unit repurchase program	(300,970)		(5,251)		—		—		(5,251)
Common unit-based compensation	—		2,743		—		—		2,743
Distributions on deferred common unit-based compensation	—		(1,280)		—		—		(1,280)
Distributions from consolidated company to noncontrolling interest	—		—		—		(262)		(262)
Distributions to Partners	—		(67,731)		—		—		(67,731)
Balance at March 31, 2019	128,391,191		1,426,360		(50,455)		12,204		1,388,109
Comprehensive income:
Net income	—		58,070		—		114		58,184
Actuarially determined long-term liability adjustments	—		—		(118)		—		(118)
Total comprehensive income									58,066
Common unit-based compensation	—		3,021		—		—		3,021
Distributions on deferred common unit-based compensation	—		(799)		—		—		(799)
Distributions from consolidated company to noncontrolling interest	—		—		—		(228)		(228)
Distributions to Partners	—		(68,690)		—		—		(68,690)
Balance at June 30, 2019	128,391,191	$	1,417,962	$	(50,573)	$	12,090	$	1,379,479

REVENUE FROM CONTRACTS WITH CUSTOMERS (Tables)

6 Months Ended

Jun. 30, 2020

REVENUE FROM CONTRACTS WITH CUSTOMERS

Schedule of disaggregation of revenues by type


	Illinois						Other and
	Basin		Appalachia		Minerals		Corporate		Elimination		Consolidated

	(in thousands)
Three Months Ended June 30, 2020

Coal sales	$	134,160	$	102,126	$	—	$	—	$	—	$	236,286
Oil & gas royalties		—		—		7,786		—		—		7,786
Transportation revenues		3,153		2,604		—		—		—		5,757
Other revenues		474		2,380		61		4,955		(2,497)		5,373
Total revenues	$	137,787	$	107,110	$	7,847	$	4,955	$	(2,497)	$	255,202

Three Months Ended June 30, 2019

Coal sales	$	301,981	$	157,951	$	—	$	5,551	$	(4,173)	$	461,310
Oil & gas royalties		—		—		11,892		—		—		11,892
Transportation revenues		31,287		1,343		—		—		—		32,630
Other revenues		2,405		950		536		10,439		(3,108)		11,222
Total revenues	$	335,673	$	160,244	$	12,428	$	15,990	$	(7,281)	$	517,054

Six Months Ended June 30, 2020

Coal sales	$	333,258	$	217,665	$	—	$	—	$	—	$	550,923
Oil & gas royalties		—		—		22,025		—		—		22,025
Transportation revenues		7,009		3,487		—		—		—		10,496
Other revenues		1,392		14,061		85		12,339		(5,356)		22,521
Total revenues	$	341,659	$	235,213	$	22,110	$	12,339	$	(5,356)	$	605,965

Six Months Ended June 30, 2019

Coal sales	$	619,251	$	315,404	$	—	$	10,841	$	(8,170)	$	937,326
Oil & gas royalties		—		—		22,285		—		—		22,285
Transportation revenues		60,525		2,343		—		—		—		62,868
Other revenues		5,293		1,901		871		19,311		(6,199)		21,177
Total revenues	$	685,069	$	319,648	$	23,156	$	30,152	$	(14,369)	$	1,043,656

Schedule of current coal supply contracts allocated to performance obligations that are unsatisfied or partially unsatisfied


							2023 and
	2020		2021		2022		Thereafter		Total

	(in thousands)

Illinois Basin coal revenues	$	462,549	$	598,941	$	222,514	$	274,195	$	1,558,199
Appalachia coal revenues		239,780		93,177		57,878		—		390,835
Total coal revenues (1)	$	702,329	$	692,118	$	280,392	$	274,195	$	1,949,034

(1) Coal revenues generally consists of consolidated revenues excluding our Minerals segment.

EARNINGS PER LIMITED PARTNER UNIT (Tables)

6 Months Ended

Jun. 30, 2020

EARNINGS PER LIMITED PARTNER UNIT

Reconciliation of net income and EPU calculations


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands, except per unit data)
Net income (loss) attributable to ARLP	$	(46,664)	$	58,070	$	(191,447)	$	334,498

Less:
Distributions to participating securities		—		(1,122)		—		(2,227)
Undistributed earnings attributable to participating securities		—		—		—		(3,196)

Net income (loss) attributable to ARLP available to limited partners	$	(46,664)	$	56,948	$	(191,447)	$	329,075

Weighted-average limited partner units outstanding – basic and diluted		127,195		128,391		127,134		128,271

Earnings per limited partner unit - basic and diluted (1)	$	(0.37)	$	0.44	$	(1.51)	$	2.57

(1)

Diluted EPU gives effect to all potentially dilutive common units outstanding during the period using the treasury stock method. Diluted EPU excludes all potentially dilutive units calculated under the treasury stock method if their effect is anti-dilutive. The combined total of LTIP, SERP and Directors' Deferred Compensation Plan units of 661 and 654 for the three and six months ended June 30, 2020, respectively, and 1,060 and 1,227 for the three and six months ended June 30, 2019, respectively, were considered anti-dilutive under the treasury stock method.

WORKERS' COMPENSATION AND PNEUMOCONIOSIS (Tables)

6 Months Ended

Jun. 30, 2020

Accrued Workers Compensation And Pneumoconiosis Benefits

Reconciliation of changes in workers' compensation liability


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Beginning balance	$	52,880	$	48,428	$	53,384	$	49,539
Accruals increase		192		2,247		1,940		4,208
Payments		(1,992)		(2,452)		(4,563)		(5,925)
Interest accretion		320		401		639		802
Valuation loss (1)		3,078		4,801		3,078		4,801
Ending balance	$	54,478	$	53,425	$	54,478	$	53,425

(1)

Our estimate of the liability for the present value of current workers′ compensation benefits is based on our actuarial calculations. Our actuarial calculations are based on a blend of actuarial projection methods and numerous assumptions including claims development patterns, mortality, medical costs and interest rates. We conducted a mid-year 2020 review of our actuarial assumptions which resulted in a valuation loss in 2020 due to unfavorable changes in claims development and a decrease in the discount rate from 2.81% to 2.05%. Our mid-year 2019 actuarial review resulted in a valuation loss in 2019 due to unfavorable changes in claims development and a decrease in the discount rate from 3.89% to 3.06%.

Pneumoconiosis benefits

Accrued Workers Compensation And Pneumoconiosis Benefits

Components of net periodic benefit cost


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Service cost	$	883	$	646	$	1,761	$	1,291
Interest cost (1)		749		762		1,499		1,522
Net amortization (1)		(171)		(1,146)		(343)		(2,291)
Net periodic benefit cost	$	1,461	$	262	$	2,917	$	522

(1)	Interest cost and net amortization are included in the Other expense line item within our condensed consolidated statements of income.

COMPENSATION PLANS (Tables)

6 Months Ended

Jun. 30, 2020

ARLP LTIP

Compensation Plans

Summary of activity in share-based plans


	Number of units	Weighted average grant date fair value per unit


Non-vested grants at January 1, 2020	1,603,378
Granted	950,035	$	9.62
Vested (1)	(424,486)		23.22
Forfeited	(13,835)		16.13
Non-vested grants at June 30, 2020 (2)	2,115,092

(1)	During the six months ended June 30, 2020, we issued 279,622 unrestricted common units to the LTIP participants. The remaining vested units were settled in cash to satisfy tax withholding obligations of the LTIP participants.

(2)	Represents total non-vested grants outstanding including 675,302 restricted units that were granted in 2019 (the "2019 Grants"). During the first quarter of 2020, it was determined that the vesting requirements for the 2019 Grants were not probable of being satisfied.

SERP and Directors' Compensation Plans

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	29,544		7.87
Phantom units outstanding as of June 30, 2020	660,909		24.69		2,155

COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS (Tables)

6 Months Ended

Jun. 30, 2020

Defined benefit pension plan

Employee Benefit Plans

Components of net periodic benefit cost


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Interest cost	$	1,054	$	1,216	$	2,108	$	2,432
Expected return on plan assets		(1,491)		(1,234)		(2,983)		(2,466)
Amortization of prior service cost		47		46		93		93
Amortization of net loss		1,063		982		2,127		1,961
Net periodic benefit cost (1)	$	673	$	1,010	$	1,345	$	2,020

(1)

Net periodic benefit cost for the Pension Plan is included in the Other expense line item within our condensed consolidated statements of income.

SEGMENT INFORMATION (Tables)

6 Months Ended

Jun. 30, 2020

SEGMENT INFORMATION

Schedule of reportable segment results


	Illinois						Other and		Elimination
	Basin		Appalachia		Minerals		Corporate		(1)		Consolidated

	(in thousands)
Three Months Ended June 30, 2020

Revenues - Outside	$	137,787	$	107,110	$	7,847	$	2,458	$	—	$	255,202
Revenues - Intercompany		—		—		—		2,497		(2,497)		—
Total revenues (2)		137,787		107,110		7,847		4,955		(2,497)		255,202

Segment Adjusted EBITDA Expense (3)		108,478		73,959		1,119		4,147		(162)		187,541
Segment Adjusted EBITDA (4)		26,157		30,548		6,881		805		(2,335)		62,056
Capital expenditures		14,029		19,686		—		166		—		33,881

Three Months Ended June 30, 2019

Revenues - Outside	$	331,500	$	160,244	$	12,428	$	12,882	$	—	$	517,054
Revenues - Intercompany		4,173		—		—		3,108		(7,281)		—
Total revenues (2)		335,673		160,244		12,428		15,990		(7,281)		517,054

Segment Adjusted EBITDA Expense (3)		208,309		105,122		1,765		9,442		(5,041)		319,597
Segment Adjusted EBITDA (4)		96,075		53,779		11,098		6,551		(2,240)		165,263
Capital expenditures		59,476		20,987		—		1,121		—		81,584

Six Months Ended June 30, 2020

Revenues - Outside	$	341,659	$	235,213	$	22,110	$	6,983	$	—	$	605,965
Revenues - Intercompany		—		—		—		5,356		(5,356)		—
Total revenues (2)		341,659		235,213		22,110		12,339		(5,356)		605,965

Segment Adjusted EBITDA Expense (3)		258,465		153,669		2,002		8,789		(686)		422,239
Segment Adjusted EBITDA (4)		76,186		78,058		20,636		3,547		(4,670)		173,757
Total assets		1,099,463		501,614		628,308		462,936		(406,693)		2,285,628
Capital expenditures		40,258		43,257		—		730		—		84,245

Six Months Ended June 30, 2019

Revenues - Outside	$	676,899	$	319,648	$	23,156	$	23,953	$	—	$	1,043,656
Revenues - Intercompany		8,170		—		—		6,199		(14,369)		—
Total revenues (2)		685,069		319,648		23,156		30,152		(14,369)		1,043,656

Segment Adjusted EBITDA Expense (3)		405,731		204,871		3,592		18,148		(9,888)		622,454
Segment Adjusted EBITDA (4)		218,812		112,434		20,230		24,912		(4,481)		371,907
Total assets		1,407,019		483,265		516,503		460,353		(364,419)		2,502,721
Capital expenditures (5)		107,930		54,333		—		3,364		—		165,627

(1)

The elimination column represents the elimination of intercompany transactions and is primarily comprised of sales from the Matrix Group to our mining operations, coal sales and purchases between operations within different segments, sales of receivables to AROP Funding, financing between segments and insurance premiums paid to Wildcat Insurance.

(2)	Revenues included in the Other and Corporate column are primarily attributable to the Matrix Group revenues, administrative service revenues from affiliates, Wildcat Insurance revenues and brokerage coal sales.

(3)	Segment Adjusted EBITDA Expense includes operating expenses, coal purchases and other income. Transportation expenses are excluded as transportation revenues are recognized in an amount equal to transportation expenses when title passes to the customer.

Reconciliation of consolidated Segment Adjusted EBITDA Expense to operating expenses (excluding depreciation, depletion and amortization)


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Segment Adjusted EBITDA Expense	$	187,541	$	319,597	$	422,239	$	622,454
Outside coal purchases		—		(5,311)		—		(5,311)
Other expense		(377)		(13)		(733)		(142)
Operating expenses (excluding depreciation, depletion and amortization)	$	187,164	$	314,273	$	421,506	$	617,001

(4)

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 expenses, settlement gain, 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. Consolidated Segment Adjusted EBITDA is reconciled to net income as follows:

Reconciliation of consolidated Segment Adjusted EBITDA to net income


	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019

	(in thousands)
Consolidated Segment Adjusted EBITDA	$	62,056	$	165,263	$	173,757	$	371,907
General and administrative		(13,822)		(19,521)		(27,260)		(37,333)
Depreciation, depletion and amortization		(83,559)		(76,913)		(157,480)		(148,052)
Asset impairments		—		—		(24,977)		—
Goodwill impairment		—		—		(132,026)		—
Interest expense, net		(11,416)		(10,573)		(23,643)		(21,904)
Acquisition gain		—		—		—		177,043
Income tax (expense) benefit		77		(186)		182		(80)
Acquisition gain attributable to noncontrolling interest		—		—		—		(7,083)
Net income (loss) attributable to ARLP	$	(46,664)	$	58,070	$	(191,447)	$	334,498
Noncontrolling interest		(15)		114		61		7,290
Net income (loss)	$	(46,679)	$	58,184	$	(191,386)	$	341,788

(5)	Capital Expenditures shown exclude the AllDale Acquisition which occurred in January 2019.

ACQUISITIONS - Assets and Liabilities (Details) - Wing $ in Thousands	Aug. 02, 2019 USD ($) a	Jun. 30, 2020 USD ($)
ACQUISITIONS
Royalty acres, net \| a	9,000
Royalty acres, gross \| a	400,000
Cash	$ 144,900
Assets acquired and liabilities assumed
Mineral interests in proved properties	75,071
Mineral interests in unproved properties	67,701
Receivables	2,155
Net assets acquired	144,927
Previously Reported
Assets acquired and liabilities assumed
Mineral interests in proved properties	58,084
Mineral interests in unproved properties	84,976
Receivables	1,867
Net assets acquired	144,927
Adjustments
Assets acquired and liabilities assumed
Mineral interests in proved properties	16,987
Mineral interests in unproved properties	(17,275)
Receivables	$ 288	$ 300

LONG-LIVED ASSET IMPAIRMENTS (Details) $ in Thousands	6 Months Ended
LONG-LIVED ASSET IMPAIRMENTS (Details) $ in Thousands	Jun. 30, 2020 USD ($)
Asset impairment charges
Asset impairments	$ 24,977
Illinois Basin
Asset impairment charges
Asset impairments	$ 25,000

GOODWILL (Details) - USD ($) $ in Thousands	6 Months Ended
GOODWILL (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Goodwill
Goodwill	$ 4,373	$ 136,399
Impairments of goodwill	132,026
Hamilton mining complex
Goodwill
Goodwill		$ 132,000
Impairments of goodwill	$ 132,000

INVENTORIES (Details) - USD ($) $ in Thousands	6 Months Ended
INVENTORIES (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
INVENTORIES
Coal	$ 51,418	$ 63,645
Supplies (net of reserve for obsolescence of $5,762 and $5,555, respectively)	36,975	37,660
Total inventories, net	88,393	101,305
Reserve for obsolescence	5,762	$ 5,555
Reduce inventory carrying value to market	$ 16,900

FAIR VALUE MEASUREMENTS (Details) - Estimated fair value - Significant Observable Inputs (Level 2) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
FAIR VALUE MEASUREMENTS
Long-term debt	$ 559,564	$ 736,206
Total	$ 559,564	$ 736,206

LONG-TERM DEBT - Components (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Principal
Aggregate maturities of long-term debt	$ 772,591	$ 789,280
Less current maturities	(55,746)	(13,157)
Total long-term debt	716,845	776,123
Unamortized Discount and Debt Issuance Costs
Unamortized debt issuance costs including current and non-current	(12,184)	(7,929)
Total unamortized debt issuance costs	(12,184)	(7,929)
Revolving credit facility
Principal
Aggregate maturities of long-term debt	265,000	255,000
Unamortized Discount and Debt Issuance Costs
Unamortized debt issuance costs including current and non-current	(7,763)	(3,050)
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	(4,421)	(4,879)
Securitization Facility
Principal
Aggregate maturities of long-term debt	38,900	73,800
May 2019 equipment financing
Principal
Aggregate maturities of long-term debt	6,603	8,199
November 2019 equipment financing
Principal
Aggregate maturities of long-term debt	47,383	$ 52,281
June 2020 equipment financing
Principal
Aggregate maturities of long-term debt	$ 14,705

LONG-TERM DEBT - Credit Facility (Details) $ in Thousands		6 Months Ended
LONG-TERM DEBT - Credit Facility (Details) $ in Thousands	Mar. 09, 2020 USD ($) item	Jun. 30, 2020 USD ($)	Jan. 27, 2017 USD ($)
Long-Term Debt
Debt issuance costs incurred		$ 5,776
Credit Agreement
Long-Term Debt
Maximum borrowing capacity	$ 537,750
Number of benchmarks \| item	3
ARLP debt arrangements requirements, fixed charge coverage ratio	1.0
ARLP debt arrangements requirements, debt to cash flow ratio	2.5
ARLP debt arrangements requirements, cash flow to interest expense ratio	3.0
ARLP debt arrangements requirements, period over which the ratios are required to be maintained	12 months
Actual debt to cash flow ratio for trailing twelve months		1.82
Actual cash flow to interest expense ratio for trailing twelve months		8.63
Credit Agreement \| Eurodollar Rate
Long-Term Debt
Effective interest rate (as a percent)		3.03%
Credit Agreement \| Extended Commitment to May 23, 2021
Long-Term Debt
Maximum borrowing capacity	$ 459,500
Credit Agreement \| Credit Agreement, first lien
Long-Term Debt
ARLP debt arrangements requirements, debt to cash flow ratio	1.5
Actual debt to cash flow ratio for trailing twelve months		0.88
Revolving credit facility
Long-Term Debt
Line of credit facility, available for borrowing		$ 263,500
Annual commitment fee percentage, undrawn portion		0.35%
Letters of credit subfacility
Long-Term Debt
Maximum borrowing capacity	$ 125,000
Letters of credit outstanding		$ 9,300
Swingline subfacility
Long-Term Debt
Maximum borrowing capacity	$ 15,000
Fourth Amended and Restated Credit Agreement
Long-Term Debt
Maximum borrowing capacity			$ 494,750

LONG-TERM DEBT - 2025 Senior Notes (Details) - USD ($) $ in Thousands	Apr. 24, 2017	Jun. 30, 2020	Dec. 31, 2019
Issuance of Senior Notes
Discount and debt issuance costs incurred		$ 12,184	$ 7,929
Senior notes due 2025
Issuance of Senior Notes
Principal amount	$ 400,000
Term	8 years
Interest rate (as a percent)	7.50%
Discount and debt issuance costs incurred		$ 4,421	$ 4,879

LONG-TERM DEBT - Securitization Facility (Details) - Securitization Facility - USD ($) $ in Millions	Jun. 30, 2020	Dec. 05, 2014
Long-Term Debt
Maximum borrowing capacity		$ 100.0
Facility outstanding amount	$ 38.9

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References + Details

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			$ 10.0
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		$ 1.0
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%

VARIABLE INTEREST ENTITIES - Cavalier (Details) - USD ($) $ in Thousands						6 Months Ended		12 Months Ended
	Feb. 14, 2020	Nov. 14, 2019	Aug. 14, 2019	May 15, 2019	Feb. 14, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Variable Interest Entities
Distributions paid to Partners	$ 51,753	$ 69,772	$ 70,153	$ 69,489	$ 69,011	$ 51,753	$ 138,500	$ 278,425
Cavalier Minerals \| Alliance Minerals
Variable Interest Entities
Contributions						143,112
Distributions paid to Partners						84,153
Cavalier Minerals \| Bluegrass Minerals
Variable Interest Entities
Contributions						5,963
Distributions paid to Partners						$ 3,505
Cavalier Minerals \| Bluegrass Minerals
Variable Interest Entities
Incentive distribution of available cash (as a percent)						25.00%
Cavalier Minerals \| Bluegrass Minerals
Variable Interest Entities
Noncontrolling ownership interest (as a percent)						4.00%
Cavalier Minerals \| Alliance Minerals
Variable Interest Entities
Ownership interest in VIE (as a percent)						96.00%

VARIABLE INTEREST ENTITIES - All Dale III (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018	Feb. 28, 2017
Equity Investments
Investments in affiliate	$ 27,705		$ 27,705			$ 28,529
All Dale Minerals III
Equity Investments
Distribution after hurdles (as a percent)			25.00%
Specified internal rate of return (as a percent)			10.00%
Percentage of available cash distributed			125.00%
All Dale Minerals III
Equity Investments
Investments in affiliate	27,705	$ 28,672	$ 27,705	$ 28,672	$ 28,114	$ 28,529	$ 28,770	$ 28,974
Other Commitment									$ 30,000
Distributions received	$ 546	$ 648	$ 1,139	$ 1,176
All Dale Minerals III \| All Dale Minerals III
Equity Investments
Ownership percentage by limited partners			13.90%

VARIABLE INTEREST ENTITIES - WKY CoalPlay (Details) - WKY CoalPlay $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)
Variable Interest Entities
Payments	$ 10.8
Percentage of internal rate of return on purchase price, if leased reserves acquired	7.00%

INVESTMENTS - AllDale (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
INVESTMENTS - AllDale (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Changes in equity method investment
Beginning balance			$ 28,529
Equity method investment income	$ 137	$ 550	588	$ 874
Ending balance	27,705		27,705
All Dale Minerals III
Changes in equity method investment
Beginning balance	28,114	28,770	28,529	28,974
Equity method investment income	137	550	588	874
Distributions received	(546)	(648)	(1,139)	(1,176)
Other			(273)
Ending balance	$ 27,705	$ 28,672	$ 27,705	$ 28,672

INVESTMENTS - Kodiak (Details) - USD ($) $ in Thousands		6 Months Ended
INVESTMENTS - Kodiak (Details) - USD ($) $ in Thousands	Feb. 08, 2019	Jun. 30, 2019	Jul. 19, 2017
Equity securities without readily determinable fair value
Redemption of preferred interest		$ 134,288
Kodiak
Equity securities without readily determinable fair value
Equity securities	$ 0		$ 100,000
Redemption of preferred interest	135,000
Gain on redemption	$ 11,500

PARTNERS' CAPITAL - Distributions (Details) - USD ($) $ / shares in Units, $ in Thousands						6 Months Ended		12 Months Ended
	Feb. 14, 2020	Nov. 14, 2019	Aug. 14, 2019	May 15, 2019	Feb. 14, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
PARTNERS' CAPITAL
Quarterly distribution paid (in dollars per unit)	$ 0.4000	$ 0.5400	$ 0.5400	$ 0.5350	$ 0.5300	$ 0.4000		$ 2.1450
Total Cash Distribution	$ 51,753	$ 69,772	$ 70,153	$ 69,489	$ 69,011	$ 51,753	$ 138,500	$ 278,425

PARTNERS' CAPITAL - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended	26 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	May 31, 2018
Partners' capital
Repurchase and retire authorization			$ 100
Treasury units retired	$ 0
Number of units retired		5,460,639
Repurchase price (in dollars per unit)		$ 17.12
Simplification Transactions
Partners' capital
Number of units retired		35

PARTNERS' CAPITAL - Change (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		26 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020
Increase (Decrease) in Partners's Capital
Balance at beginning of period	$ 1,067,504	$ 1,265,424	$ 1,388,109	$ 1,187,687	$ 1,265,424	$ 1,187,687
Balance at beginning of period (in units)		126,915,597			126,915,597
Comprehensive income (loss):
Net income (loss)	(46,679)	$ (144,707)	58,184	283,604	$ (191,386)	341,788
Actuarially determined long-term liability adjustments	939	938	(118)	(3,584)	1,877	(3,702)
COMPREHENSIVE INCOME (LOSS)	(45,740)	(143,769)	58,066	280,020	(189,509)	338,086
Settlement of deferred compensation plans		(1,310)		(7,817)
Purchase of units under unit repurchase program				(5,251)			$ (93,500)
Common unit-based compensation	1,610	(527)	3,021	2,743
Distributions on deferred common unit-based compensation		(986)	(799)	(1,280)
Distributions from consolidated company to noncontrolling interest	(222)	(288)	(228)	(262)
Distributions to Partners		(50,767)	(68,690)	(67,731)
Other		(273)
Balance at end of period	$ 1,023,152	1,067,504	1,379,479	1,388,109	$ 1,023,152	1,379,479	$ 1,023,152
Balance at end of period (in units)	127,195,219				127,195,219		127,195,219
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partners's Capital
Balance at beginning of period	$ (77,055)	(77,993)	(50,455)	(46,871)	$ (77,993)	(46,871)
Comprehensive income (loss):
Actuarially determined long-term liability adjustments	939	938	(118)	(3,584)
Balance at end of period	(76,116)	(77,055)	(50,573)	(50,455)	(76,116)	(50,573)	$ (76,116)
Noncontrolling Interest
Increase (Decrease) in Partners's Capital
Balance at beginning of period	11,723	11,935	12,204	5,290	11,935	5,290
Comprehensive income (loss):
Net income (loss)	(15)	76	114	7,176
Distributions from consolidated company to noncontrolling interest	(222)	(288)	(228)	(262)
Balance at end of period	11,486	11,723	12,090	12,204	11,486	12,090	11,486
Limited Partners' Capital
Increase (Decrease) in Partners's Capital
Balance at beginning of period	$ 1,132,836	$ 1,331,482	$ 1,426,360	$ 1,229,268	$ 1,331,482	$ 1,229,268
Balance at beginning of period (in units)	127,195,219	126,915,597	128,391,191	128,095,511	126,915,597	128,095,511
Comprehensive income (loss):
Net income (loss)	$ (46,664)	$ (144,783)	$ 58,070	$ 276,428
Settlement of deferred compensation plans		$ (1,310)		$ (7,817)
Settlement of deferred compensation plans (in units)		279,622		596,650
Purchase of units under unit repurchase program				$ (5,251)
Purchase of units under unit repurchase program (in units)				(300,970)
Common unit-based compensation	1,610	$ (527)	3,021	$ 2,743
Distributions on deferred common unit-based compensation		(986)	(799)	(1,280)
Distributions to Partners		(50,767)	(68,690)	(67,731)
Other		(273)
Balance at end of period	$ 1,087,782	$ 1,132,836	$ 1,417,962	$ 1,426,360	$ 1,087,782	$ 1,417,962	$ 1,087,782
Balance at end of period (in units)	127,195,219	127,195,219	128,391,191	128,391,191	127,195,219	128,391,191	127,195,219

REVENUE FROM CONTRACTS WITH CUSTOMERS - Disaggregation of revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of revenues
Revenues	$ 255,202	$ 517,054	$ 605,965	$ 1,043,656
Coal sales
Disaggregation of revenues
Revenues	236,286	461,310	550,923	937,326
Oil & gas royalties
Disaggregation of revenues
Revenues	7,786	11,892	22,025	22,285
Transportation revenues
Disaggregation of revenues
Revenues	5,757	32,630	10,496	62,868
Other revenues
Disaggregation of revenues
Revenues	5,373	11,222	22,521	21,177
Illinois Basin
Disaggregation of revenues
Revenues	137,787	335,673	341,659	685,069
Illinois Basin \| Coal sales
Disaggregation of revenues
Revenues	134,160	301,981	333,258	619,251
Illinois Basin \| Transportation revenues
Disaggregation of revenues
Revenues	3,153	31,287	7,009	60,525
Illinois Basin \| Other revenues
Disaggregation of revenues
Revenues	474	2,405	1,392	5,293
Appalachia
Disaggregation of revenues
Revenues	107,110	160,244	235,213	319,648
Appalachia \| Coal sales
Disaggregation of revenues
Revenues	102,126	157,951	217,665	315,404
Appalachia \| Transportation revenues
Disaggregation of revenues
Revenues	2,604	1,343	3,487	2,343
Appalachia \| Other revenues
Disaggregation of revenues
Revenues	2,380	950	14,061	1,901
Minerals
Disaggregation of revenues
Revenues	7,847	12,428	22,110	23,156
Minerals \| Oil & gas royalties
Disaggregation of revenues
Revenues	7,786	11,892	22,025	22,285
Minerals \| Other revenues
Disaggregation of revenues
Revenues	61	536	85	871
Other and Corporate
Disaggregation of revenues
Revenues	4,955	15,990	12,339	30,152
Other and Corporate \| Coal sales
Disaggregation of revenues
Revenues		5,551		10,841
Other and Corporate \| Other revenues
Disaggregation of revenues
Revenues	4,955	10,439	12,339	19,311
Elimination
Disaggregation of revenues
Revenues	(2,497)	(7,281)	(5,356)	(14,369)
Elimination \| Coal sales
Disaggregation of revenues
Revenues		(4,173)		(8,170)
Elimination \| Other revenues
Disaggregation of revenues
Revenues	(2,497)	(3,108)	(5,356)	(6,199)
Elimination \| Illinois Basin
Disaggregation of revenues
Revenues		4,173		8,170
Elimination \| Other and Corporate
Disaggregation of revenues
Revenues	$ 2,497	$ 3,108	$ 5,356	$ 6,199

REVENUE FROM CONTRACTS WITH CUSTOMERS - Coal supply contracts (Details) $ in Thousands	Jun. 30, 2020 USD ($)
Performance obligations unsatisfied or partially unsatisfied
Total	$ 1,949,034
Illinois Basin
Performance obligations unsatisfied or partially unsatisfied
Total	1,558,199
Appalachia
Performance obligations unsatisfied or partially unsatisfied
Total	390,835
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 702,329
Expected timing of satisfaction period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01 \| Illinois Basin
Performance obligations unsatisfied or partially unsatisfied
Total	$ 462,549
Expected timing of satisfaction period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-07-01 \| Appalachia
Performance obligations unsatisfied or partially unsatisfied
Total	$ 239,780
Expected timing of satisfaction period	6 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 692,118
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 \| Illinois Basin
Performance obligations unsatisfied or partially unsatisfied
Total	$ 598,941
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 \| Appalachia
Performance obligations unsatisfied or partially unsatisfied
Total	$ 93,177
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 280,392
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 \| Illinois Basin
Performance obligations unsatisfied or partially unsatisfied
Total	$ 222,514
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 \| Appalachia
Performance obligations unsatisfied or partially unsatisfied
Total	$ 57,878
Expected timing of satisfaction period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Performance obligations unsatisfied or partially unsatisfied
Total	$ 274,195
Expected timing of satisfaction period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 \| Illinois Basin
Performance obligations unsatisfied or partially unsatisfied
Total	$ 274,195
Expected timing of satisfaction period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 \| Appalachia
Performance obligations unsatisfied or partially unsatisfied
Expected timing of satisfaction period

EARNINGS PER LIMITED PARTNER UNIT - Reconciliation (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss) attributable to ARLP	$ (46,664)	$ 58,070	$ (191,447)	$ 334,498
Distributions to participating securities		$ (1,122)		(2,227)
Undistributed earnings attributable to participating securities				$ (3,196)
Weighted-average limited partner units outstanding - basic and diluted	127,195,219	128,391,191	127,133,764	128,271,158
Earnings per limited partner unit - basic and diluted	$ (0.37)	$ 0.44	$ (1.51)	$ 2.57
Anti-dilutive under the treasury stock method (in units)	661,000	1,060,000	654,000	1,227,000
ARLP
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income (loss) attributable to ARLP	$ (46,664)	$ 58,070	$ (191,447)	$ 334,498
Net income (loss) attributable to ARLP available to limited partners	$ (46,664)	$ 56,948	$ (191,447)	$ 329,075

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References + Details

WORKERS' COMPENSATION AND PNEUMOCONIOSIS - Workers' Compensation Liability (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of changes in the workers' compensation liability
Beginning balance	$ 52,880	$ 48,428	$ 53,384	$ 49,539	$ 49,539
Accruals increase	192	2,247	1,940	4,208
Payments	(1,992)	(2,452)	(4,563)	(5,925)
Interest accretion	320	401	639	802
Valuation loss	3,078	4,801	3,078	4,801
Ending balance	54,478	$ 53,425	$ 54,478	$ 53,425	$ 53,384	$ 49,539
Workers' compensation discount rate			2.05%	3.06%	2.81%	3.89%
Receivables for traumatic injury claims	$ 7,100		$ 7,100

WORKERS' COMPENSATION AND PNEUMOCONIOSIS - Periodic Benefit Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accrued Workers Compensation And Pneumoconiosis Benefits
Interest cost	$ 1,054	$ 1,216	$ 2,108	$ 2,432
Net amortization	1,063	982	2,127	1,961
Net periodic benefit cost	673	1,010	1,345	2,020
Pneumoconiosis benefits
Accrued Workers Compensation And Pneumoconiosis Benefits
Service cost	883	646	1,761	1,291
Interest cost	749	762	1,499	1,522
Net amortization	(171)	(1,146)	(343)	(2,291)
Net periodic benefit cost	$ 1,461	$ 262	$ 2,917	$ 522

COMPENSATION PLANS - LTIP Grants Activity (Details) - ARLP LTIP	6 Months Ended
	Jun. 30, 2020 $ / shares shares
Number of units
Balance at the beginning of the period (in units)	1,603,378
Granted (in units)	950,035
Vested (in units)	(424,486)
Forfeited (in units)	(13,835)
Balance at the end of the period (in units)	2,115,092
Weighted average grant date fair value per unit
Granted (in dollars per unit) \| $ / shares	$ 9.62
Vested (in dollars per unit) \| $ / shares	23.22
Forfeited (in dollars per unit) \| $ / shares	$ 16.13
Other information
Common units issued upon vesting	279,622
Units not expected to vest (in units)	675,302

COMPENSATION PLANS - LTIP Other Information (Details) - ARLP LTIP - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Jan. 01, 2020
Other information
Unit-based compensation expense	$ 1.6	$ 2.7	$ 0.9	$ 5.1
Reversal of cumulative previously recognized expenses			4.8
Total unit-based obligation recorded	9.7		$ 9.7
Units expected to vest (in units)			1,439,790
Units expected to vest (in dollars per units)			$ 13.33
Intrinsic value of unvested units	4.7		$ 4.7
Unrecognized compensation expense (in dollars)	$ 9.5		$ 9.5
Weighted-average period for recognition of expense			1 year 9 months 18 days
Units available for grant	1,700,000		1,700,000		1,000,000.0
Units for which vesting requirements were deemed satisfied			424,486
Forfeitures (in units)			13,835
Common units issued upon vesting			279,622
Units granted			950,035

COMPENSATION PLANS - SERP and Directors Compensation Activity (Details) - SERP and Directors' Compensation Plans - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Other information
Unit-based compensation expense	$ 100	$ 400	$ 400	$ 700
Total unit-based obligation recorded	$ 16,300		$ 16,300
Phantom Share Units (PSUs)
Summary of units
Balance at the beginning of the period (in units)			631,365
Granted (in units)			29,544
Balance at the end of the period (in units)	660,909		660,909
Weighted average grant date fair value per unit
Balance at the beginning of the period (in dollars per unit)			$ 25.48
Granted (in dollars per unit)			7.87
Balance at the end of the period (in dollars per unit)	$ 24.69		$ 24.69
Intrinsic value (in dollars)
Intrinsic value of outstanding grants (in dollars)	$ 2,155		$ 2,155		$ 6,831

COMPONENTS OF PENSION PLAN NET PERIODIC BENEFIT COSTS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Components of net periodic benefit cost:
Interest cost	$ 1,054	$ 1,216	$ 2,108	$ 2,432
Expected return on plan assets	(1,491)	(1,234)	(2,983)	(2,466)
Amortization of prior service cost	47	46	93	93
Amortization of net loss	1,063	982	2,127	1,961
Net periodic benefit cost	$ 673	$ 1,010	1,345	$ 2,020
2019 plan year
Components of net periodic benefit cost:
Employer contribution			$ 1,100

SEGMENT INFORMATION - General (Details)	6 Months Ended
SEGMENT INFORMATION - General (Details)	Jun. 30, 2020 segment
SEGMENT INFORMATION
Number of reportable segments	3

SEGMENT INFORMATION - Segment Results (Details) $ in Thousands		3 Months Ended		6 Months Ended
	Apr. 15, 2020 employee	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Reportable segment results
Revenues		$ 255,202	$ 517,054	$ 605,965	$ 1,043,656
Segment Adjusted EBITDA Expense		187,541	319,597	422,239	622,454
Segment Adjusted EBITDA		62,056	165,263	173,757	371,907
Total assets		2,285,628	2,502,721	2,285,628	2,502,721	$ 2,586,694
Capital expenditures		33,881	81,584	84,245	165,627
Gibson County mining complex
Segment Information
Number of employees terminated \| employee	116
Hamilton mining complex
Segment Information
Number of employees terminated \| employee	78
Illinois Basin
Reportable segment results
Revenues		137,787	335,673	341,659	685,069
Segment Adjusted EBITDA Expense		108,478	208,309	258,465	405,731
Segment Adjusted EBITDA		26,157	96,075	76,186	218,812
Total assets		1,099,463	1,407,019	1,099,463	1,407,019
Capital expenditures		14,029	59,476	40,258	107,930
Appalachia
Reportable segment results
Revenues		107,110	160,244	235,213	319,648
Segment Adjusted EBITDA Expense		73,959	105,122	153,669	204,871
Segment Adjusted EBITDA		30,548	53,779	78,058	112,434
Total assets		501,614	483,265	501,614	483,265
Capital expenditures		19,686	20,987	43,257	54,333
Minerals
Reportable segment results
Revenues		7,847	12,428	22,110	23,156
Segment Adjusted EBITDA Expense		1,119	1,765	2,002	3,592
Segment Adjusted EBITDA		6,881	11,098	20,636	20,230
Total assets		628,308	516,503	628,308	516,503
Other and Corporate
Reportable segment results
Revenues		4,955	15,990	12,339	30,152
Segment Adjusted EBITDA Expense		4,147	9,442	8,789	18,148
Segment Adjusted EBITDA		805	6,551	3,547	24,912
Total assets		462,936	460,353	462,936	460,353
Capital expenditures		166	1,121	730	3,364
Operating segments
Reportable segment results
Revenues		255,202	517,054	605,965	1,043,656
Operating segments \| Illinois Basin
Reportable segment results
Revenues		137,787	331,500	341,659	676,899
Operating segments \| Appalachia
Reportable segment results
Revenues		107,110	160,244	235,213	319,648
Operating segments \| Minerals
Reportable segment results
Revenues		7,847	12,428	22,110	23,156
Operating segments \| Other and Corporate
Reportable segment results
Revenues		2,458	12,882	6,983	23,953
Elimination
Reportable segment results
Revenues		(2,497)	(7,281)	(5,356)	(14,369)
Segment Adjusted EBITDA Expense		(162)	(5,041)	(686)	(9,888)
Segment Adjusted EBITDA		(2,335)	(2,240)	(4,670)	(4,481)
Total assets		(406,693)	(364,419)	(406,693)	(364,419)
Elimination \| Illinois Basin
Reportable segment results
Revenues			4,173		8,170
Elimination \| Other and Corporate
Reportable segment results
Revenues		$ 2,497	$ 3,108	$ 5,356	$ 6,199

SEGMENT INFORMATION - EBITDA Expense Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Reconciliation of consolidated Segment Adjusted EBITDA Expense to operating expenses (excluding depreciation, depletion and amortization)
Segment Adjusted EBITDA Expense	$ 187,541	$ 319,597	$ 422,239	$ 622,454
Outside coal purchases		(5,311)		(5,311)
Other expense	(377)	(13)	(733)	(142)
Operating expenses (excluding depreciation, depletion and amortization)	$ 187,164	$ 314,273	$ 421,506	$ 617,001

SEGMENT INFORMATION - EBITDA Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Reconciliation of consolidated Segment Adjusted EBITDA to net income
Consolidated Segment Adjusted EBITDA	$ 62,056		$ 165,263		$ 173,757	$ 371,907
General and administrative	(13,822)		(19,521)		(27,260)	(37,333)
Depreciation, depletion and amortization	(83,559)		(76,913)		(157,480)	(148,052)
Asset impairment					(24,977)
Goodwill impairment					(132,026)
Interest expense, net	(11,416)		(10,573)		(23,643)	(21,904)
Acquisition gain						177,043
Income tax (expense) benefit	77		(186)		182	(80)
Acquisition gain attributable to noncontrolling interest						(7,083)
NET INCOME (LOSS) ATTRIBUTABLE TO ARLP	(46,664)		58,070		(191,447)	334,498
Noncontrolling interest	(15)		114		61	7,290
NET INCOME (LOSS)	$ (46,679)	$ (144,707)	$ 58,184	$ 283,604	$ (191,386)	$ 341,788