Document and Entity Information Document Information [Table] Document Information [Line Items] Document Type Document Quarterly Report Document Period End Date Document Fiscal Year Focus Document Transition Report Securities Act File Number Entity Registrant Name Entity Incorporation, State or Country Code Entity Tax Identification Number Entity Address, Address Line One Entity Address, Address Line Two Entity Address, City or Town Entity Address, State or Province Entity Address, Postal Zip Code City Area Code Local Phone Number Entity Current Reporting Status Entity Interactive Data Current Entity Filer Category Entity Small Business Entity Emerging Growth Company Entity Shell Company Trading Symbol Title of 12(b) Security Security Exchange Name Entity Common Stock, Shares Outstanding Entity Common Units Outstanding Entity Central Index Key Current Fiscal Year End Date Document Fiscal Period Focus Amendment Flag Statement of Financial Position [Abstract] Statement [Table] Statement [Line Items] Assets [Abstract] Assets Assets, Current [Abstract] Current Assets: Cash and Cash Equivalent Cash and cash equivalents Accounts Receivable, after Allowance for Credit Loss, Current Trade receivables (net of allowance of $5,659 and $5,360, respectively) Trade receivables Nontrade Receivables, Current Other receivables Inventory, Net Inventories, net Total inventories, net Prepaid Royalties Advance royalties Crypto Asset, Fair Value, Current Digital assets Prepaid Expense and Other Assets, Current Prepaid expenses and other assets Assets, Current Total current assets Property, Plant and Equipment, Net [Abstract] Property, Plant and Equipment: Property, plant and equipment: Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization Property, plant and equipment Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, Accumulated Depreciation and Amortization Less accumulated depreciation, depletion and amortization Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, after Accumulated Depreciation and Amortization Total property, plant and equipment, net Other Assets, Noncurrent [Abstract] Other Assets: Prepaid Mineral Royalties, Noncurrent Advance royalties Equity Method Investments Ending balance Beginning balance Equity method investments Carrying value of investment Equity Securities without Readily Determinable Fair Value, Amount Equity securities Investment in equity securities Operating Lease, Right-of-Use Asset Operating lease right-of-use assets Other Assets, Noncurrent Other long-term assets Sum of the carrying amounts as of the balance sheet date of all noncurrent assets, excluding physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Assets, Noncurrent, Excluding Property, Plant and Equipment Total other assets Assets Total assets Total Assets Carrying value Liabilities and Equity [Abstract] Liabilities and Partners' Capital Liabilities, Current [Abstract] Current Liabilities: Accounts Payable, Current Accounts payable Accounts payable Accrual for Taxes Other than Income Taxes, Current Accrued taxes other than income taxes Accrued taxes other than income taxes Employee-related Liabilities, Current Accrued payroll and related expenses Interest Payable, Current Accrued interest Carrying value as of the balance sheet date of obligations and payables pertaining to claims incurred of a workers compensation nature. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Also includes, the current portion of the liability for benefits payable to workers affected by coal workers pneumoconiosis. Workers Compensation and Pneumoconiosis Benefits Current Workers' compensation and pneumoconiosis benefits Other Liabilities, Current Other current liabilities Long-Term Debt, Current Maturities Current maturities, long-term debt, net Liabilities, Current Total current liabilities Liabilities, Noncurrent [Abstract] Long-Term Liabilities: Long-Term Debt, Excluding Current Maturities Long-term debt, excluding current maturities, net This represents the noncurrent portion of the liability for benefits payable to workers affected by coal workers' pneumoconiosis Pneumoconiosis Benefits. Pneumoconiosis benefits Workers' Compensation Liability, Noncurrent Workers' compensation Asset Retirement Obligations, Noncurrent Asset retirement obligations Operating Lease, Liability, Noncurrent Long-term operating lease obligations Deferred Income Tax Liabilities, Net Deferred income tax liabilities Other Liabilities, Noncurrent Other liabilities Liabilities, Noncurrent Total long-term liabilities Liabilities Total liabilities Commitments and Contingencies Commitments and Contingencies Partners' Capital, Including Portion Attributable to Noncontrolling Interest [Abstract] Partners' Capital: Partners' Capital [Abstract] ARLP Partners' Capital: Limited Partners' Capital Account Limited Partners - Common Unitholders 128,658,801 and 128,428,024 units outstanding, respectively Accumulated Other Comprehensive Income (Loss), Net of Tax Accumulated other comprehensive loss Partners' Capital Total ARLP Partners' Capital Partners' Capital Attributable to Noncontrolling Interest Noncontrolling interest Partners' Capital, Including Portion Attributable to Noncontrolling Interest Balance at end of period Balance at beginning of period Total Partners' Capital Liabilities and Equity Total Liabilities and Partners' Capital Accounts Receivable, Allowance for Credit Loss, Current Trade receivables allowance Limited Partners' Capital Account, Units Outstanding Balance at end of period (in units) Balance at beginning of period (in units) Common units outstanding Income Statement [Abstract] Product and Service [Axis] Product and Service [Domain] Product [Member] Product Revenue derived from sale of coal and related products. Coal Products and Services Revenue [Member] Coal sales Royalty [Member] Oil & gas royalties Shipping and Handling [Member] Transportation revenues Product and Service, Other [Member] Other revenues Revenues [Abstract] Sales and Operating Revenues: Revenue from Contract with Customer, Excluding Assessed Tax Revenues Operating Costs and Expenses [Abstract] Expenses: Cost of Goods and Service, Excluding Depreciation, Depletion, and Amortization Transportation expenses Operating expenses (excluding depreciation, depletion and amortization) Costs incurred during the reporting period for purchased coal. Outside Coal Purchases Outside coal purchases General and Administrative Expense General and administrative General and administrative Depreciation, Depletion and Amortization Depreciation, depletion and amortization Depreciation, depletion and amortization Impairment of Ongoing Project Asset Impairments Asset impairments Costs and Expenses Total operating expenses Operating Income (Loss) Income from Operations Interest Expense, Nonoperating Interest expense (net of interest capitalized for the three and six months ended June 30, 2026 and 2025 of $443, $3,360, $1,356 and $7,848, respectively) Investment Income, Interest Interest income Income (Loss) from Equity Method Investments Net income (loss) on equity method investments Crypto Asset, Unrealized Gain (Loss), Nonoperating Change in fair value of digital assets Amount of impairment on investment in debt and equity securities. Debt And Equity Securities, Impairment Impairment loss on investments Other Nonoperating Income (Expense) Other income Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Income Before Income Taxes Income Tax Expense (Benefit) Income Tax Expense Income tax expense Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net Income Net Income Net income Net Income (Loss) Attributable to Noncontrolling Interest Less: Net Income Attributable to Noncontrolling Interest Noncontrolling interest Net Income Attributable to ARLP Net Income (Loss), Per Outstanding Limited Partnership Unit, Basic, Net of Tax Earnings per limited partner unit - basic (in dollars per unit) Earnings per Limited Partner Unit - Basic (in dollars per unit) Net Income (Loss), Net of Tax, Per Outstanding Limited Partnership Unit, Diluted Earnings per limited partner unit - diluted (in dollars per unit) Earnings per Limited Partner Unit - Diluted (in dollars per unit) Weighted Average Limited Partnership Units Outstanding, Basic Weighted-average limited partner units outstanding - basic (in units) Weighted-Average Number of Units Outstanding - Basic (in units) Weighted Average Limited Partnership Units Outstanding, Diluted Weighted-average limited partner units outstanding - diluted (in units) Weighted-Average Number of Units Outstanding - Diluted (in units) Interest Costs Capitalized Interest expense, interest capitalized Statement of Comprehensive Income [Abstract] Retirement Plan Type [Axis] Retirement Plan Type [Domain] Pension Plan [Member] Defined benefit pension plan Pension Plan Other Postretirement Benefits Plan [Member] Pneumoconiosis benefits Other Comprehensive Income (Loss), Net of Tax [Abstract] Other Comprehensive Income (loss): Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax Amortization of prior service cost Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Amortization of net actuarial loss Amount, after tax, of correction of actuarial assumption from accumulated other comprehensive (income) loss of defined benefit plan. Other Comprehensive (Income) Loss, Defined Benefit Plan, Correction of Actuarial Assumption, After Tax Other adjustments Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Total recognized in accumulated other comprehensive income Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Tax Foreign currency translation adjustment OCI, Debt Securities, Available-for-Sale, Unrealized Holding Gain (Loss), before Adjustment, after Tax Change in unrealized gains on debt securities Other Comprehensive Income (Loss), Net of Tax Other Comprehensive Income (Loss) Other comprehensive income (loss) Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Comprehensive Income Comprehensive Income (Loss), Net of Tax, Attributable to Noncontrolling Interest Less: Comprehensive income attributable to noncontrolling interest Comprehensive Income (Loss), Net of Tax, Attributable to Parent Comprehensive Income Attributable to ARLP Statement of Cash Flows [Abstract] Cash Provided by (Used in) Operating Activity, Including Discontinued Operation Cash Flows from Operating Activities Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract] Cash Flows from Investing Activities: Payments to Acquire Property, Plant, and Equipment Capital expenditures The increase (decrease) during the reporting period in the amounts payable to vendors for obligations and expenses incurred but not paid related to investing activities. Increase (Decrease) in Accounts Payable and Accrued Liabilities for Investing Activities Change in accounts payable and accrued liabilities Proceeds from Sale of Property, Plant, and Equipment Proceeds from sale of property, plant and equipment Payments to Acquire Equity Method Investments Contributions to equity method investments Contributions Payments to Acquire Debt Securities, Available-for-Sale Purchase of debt securities Payment to acquire convertible notes Payments to Acquire Businesses, Net of Cash Acquired Oil & gas reserve business combinations Payments for acquisitions of businesses Asset Acquisition, Consideration Transferred Oil & gas reserve asset acquisitions Amount paid towards coal reserve acquisition Payment for (Proceeds from) Other Investing Activity Other Cash Provided by (Used in) Investing Activity, Including Discontinued Operation Net cash used in investing activities Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract] Cash Flows from Financing Activities: Proceeds from Accounts Receivable Securitization Borrowings under securitization facility Repayments of Accounts Receivable Securitization Payments under securitization facility Repayments of Secured Debt Payments on equipment financings Proceeds from Long-Term Lines of Credit Borrowings under revolving credit facilities Repayments of Long-Term Lines of Credit Payments under revolving credit facilities Proceeds from Issuance of Senior Long-Term Debt Borrowing under long-term debt Repayments of Senior Debt Payments on long-term debt Payment, Tax Withholding, Share-Based Payment Arrangement Payments for tax withholdings related to settlements under deferred compensation plan Payments of Distributions to Affiliates Distributions paid to Partners Proceeds from (Payment for) Other Financing Activity Other Cash Provided by (Used in) Financing Activity, Including Discontinued Operation Net cash used in financing activities Effect of Exchange Rate on Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Including Discontinued Operation Effect of exchange rate changes on cash and cash equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Including Exchange Rate Effect and Discontinued Operation Net Change in Cash and Cash Equivalents Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation Cash and Cash Equivalents at End of Period Cash and Cash Equivalents at Beginning of Period Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Supplemental Non-Cash Activity: Capital Expenditures Incurred but Not yet Paid Accounts payable for purchase of property, plant and equipment Adjustment of property, plant and equipment related to reclamation assets. Change In P P E For Reclamation Assets Change in property, plant and equipment for reclamation assets Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Right-of-use assets acquired by operating lease Shares Issued, Value, Share-Based Payment Arrangement, before Forfeiture Market value of common units issued under deferred compensation plan before tax withholding requirements Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Organization and Presentation Accounting Standards Update and Change in Accounting Principle [Abstract] Accounting Standards Update and Change in Accounting Principle [Text Block] New Accounting Standards Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures [Abstract] Variable Interest Entity Disclosure [Text Block] Variable Interest Entities Business Combination [Abstract] Business Combination [Text Block] Acquisitions Fair Value Disclosures [Abstract] Fair Value Disclosures [Text Block] Fair Value Measurements Inventory Disclosure [Abstract] Inventory Disclosure [Text Block] Inventories Crypto Asset, Fair Value [Abstract] Crypto Asset [Text Block] Digital Assets Asset Impairment Charges [Abstract] Asset Impairment Charges [Text Block] Long-Lived Asset Impairment Investments [Abstract] The entire disclosure for equity method investments and marketable securities without readily determinable fair value. Investments In Equity Method And Marketable Equity Securities Without Readily Determinable Fv Disclosure [Text Block] Investments Debt Disclosure [Abstract] Long-Term Debt [Text Block] Long-Term Debt Workers' Compensation And Pneumoconiosis Disclosure [Abstract] Represents the entire disclosure for workers' compensation and pneumoconiosis benefits. Workers Compensation and Pneumoconiosis [Text Block] Workers' Compensation and Pneumoconiosis Retirement Benefits [Abstract] Defined Benefit Plan [Table] Defined Benefit Plan Disclosure [Line Items]