Organization, Consolidation and Presentation of Financial Statements [Abstract]

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 September 30, 2025 and December 31, 2024, the results of our operations and comprehensive income for the three and nine months ended September 30, 2025 and 2024 and cash flows for the nine months ended September 30, 2025 and 2024. All intercompany transactions and accounts have been eliminated.

These condensed consolidated financial statements and notes are prepared pursuant to the rules and regulations of the Securities and Exchange Commission for interim reporting and do not include all the information normally included with financial statements prepared in accordance with generally accepted accounting principles (“GAAP”) of the United States. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2024.

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, 2025.

Investments

Our investments and ownership interests in equity securities without readily determinable fair values in entities in which we do not have a controlling financial interest or significant influence are accounted for using a measurement alternative other than fair value. The measurement alternative is historical cost minus impairment, if any, plus or minus changes resulting from observable price changes in orderly transactions for identical or similar investments of the same entity. Distributions received on those investments are recorded as income unless those distributions are considered a return on investment, in which case the historical cost is reduced. We account for our ownership interests in Infinitum Electric, Inc. (“Infinitum”) and Ascend Elements, Inc. (“Ascend”) as equity securities without readily determinable fair values. See Note 7 – Investments for further discussion of these investments.

Our investments and ownership interests in entities in which we do not have a controlling financial interest are accounted for under the equity method of accounting if we have the ability to exercise significant influence over the entity. Investments accounted for under the equity method are initially recorded at cost, and the difference between the basis of our investment and the underlying equity in the net assets of the entity at the investment date, if any, is amortized over the lives of the related assets that gave rise to the difference.

In the event our ownership requires the recording of income or loss such that our capital accounts reflect what we would receive in liquidation, we use the hypothetical liquidation at book value (“HLBV”) method to determine the appropriate allocation of income or loss. Under the HLBV method, income or loss of the investee is allocated based on hypothetical amounts that each investor would be entitled to receive if the net assets held were liquidated at book value at the end of each period, adjusted for any contributions made and distributions received during the period.

We hold equity method investments in AllDale Minerals III, LP (“AllDale III”), NGP Energy Transition, L.P. (“NGP ET IV”) and Gavin Generation Holdings A, LP (“Gavin Generation”). See Note 3 – Variable Interest Entities for further discussion of our equity method investments.

We review our investments for impairment whenever events or changes in circumstances indicate a loss in the value of the investment may be other-than-temporary.

Our investments in debt securities classified as available-for-sale are reported at fair value with unrealized gains and losses included in other comprehensive income in partners’ capital. Credit losses, if any, are recorded as an expense. Upon maturity or conversion, any associated unrealized gain or loss will be reclassified from other comprehensive income to our condensed consolidated income statement as a realized gain or loss. We hold debt securities in Ascend. See Note 7 – Investments for further discussion of this investment.