XML 53 R112.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

COMMITMENTS AND CONTINGENCIES - Purchase Commitments (Details) - USD ($) $ in Millions | Dec. 31, 2019 | Mar. 09, 2018
--- | --- | ---
Contractual Commitments |  |
Commitments to purchase coal |  | $ 2.0
Commitments for external coal purchases |  |
Contractual Commitments |  |
Commitments to purchase coal | $ 0.0 |
Commitments related to planned capital projects |  |
Contractual Commitments |  |
Contractual amount | $ 28.6 |

X
- Definition Amount of contractual obligation, including but not limited to, long-term debt, capital lease obligations, operating lease obligations, purchase obligations, and other commitments. + References No definition available. + Details
Name: | us-gaap_ContractualObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_LongTermPurchaseCommitmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum amount of purchase arrangement maturing in the next fiscal year following the latest fiscal year. Includes, but not limited to, recorded and unrecorded purchase obligations, long-term purchase commitments, and short-term purchase commitments. + References No definition available. + Details
Name: | us-gaap_PurchaseObligationDueInNextTwelveMonths
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_PurchaseCommitmentExcludingLongtermCommitmentAxis=arlp_ExternalCoalPurchaseCommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongTermPurchaseCommitmentByCategoryOfItemPurchasedAxis=us-gaap_CapitalAdditionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |