ORGANIZATION AND PRESENTATION (Policies)	3 Months Ended
Mar. 31, 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 March 31, 2020 and December 31, 2019 and the results of our operations, comprehensive income and cash flows for the three months ended March 31, 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.

ORGANIZATION AND PRESENTATION (Policies)

3 Months Ended

Mar. 31, 2020

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 March 31, 2020 and December 31, 2019 and the results of our operations, comprehensive income and cash flows for the three months ended March 31, 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.