The minimum amount of coal royalties to be paid annually to the related party, per the terms of the agreement.

No definition available.

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Namespace Prefix:	arlp_
Data Type:	xbrli:monetaryItemType
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- Definition

Term of lessee's lease, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Excludes operating, finance and capital lease obligations.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

The percentage of earned royalty on the coal sales price provided to the counterparty under the lease agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	arlp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of internal rate of return provided to the counterparty in the purchase price under the option to acquire the leased coal reserves.

+ References

No definition available.

+ Details

Name:	arlp_PercentageOfInternalRateOfReturnOnPurchasePriceIfLeasedReservesAcquired
Namespace Prefix:	arlp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Period following a specified date, within which the entity has the option to acquire the coal reserves under the lease agreement.

+ References

No definition available.

+ Details

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Namespace Prefix:	arlp_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=123419778&loc=SL6759159-111685

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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Balance Type:
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- Details

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- Details

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- Details

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- Details

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Data Type:	na
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- Details

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Namespace Prefix:
Data Type:	na
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- Details

Name:	dei_LegalEntityAxis=arlp_BluegrassMineralsManagementLlcMember
Namespace Prefix:
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RELATED-PARTY TRANSACTIONS - WKY CoalPlay and Cavalier Minerals (Details) - USD ($) $ in Millions	1 Months Ended		12 Months Ended
	Feb. 28, 2015	Dec. 31, 2014	Dec. 31, 2021	Jan. 03, 2019
WKY CoalPlay \| February 2015 coal lease - Henderson and Union Counties, Kentucky
Related Party Transaction
Initial term of lease	20 years
Percentage of earned royalty on coal sale price	4.00%
Annual minimum coal royalties	$ 2.1
Period for option to acquire the leased reserves	3 years
Percentage of internal rate of return on purchase price, if leased reserves acquired	7.00%
WKY CoalPlay \| December 2014 coal lease - Henderson and Union Counties, Kentucky
Related Party Transaction
Initial term of lease		20 years
Percentage of earned royalty on coal sale price		4.00%
Annual minimum coal royalties		$ 3.6
Period for option to acquire the leased reserves		3 years
Percentage of internal rate of return on purchase price, if leased reserves acquired		7.00%
WKY CoalPlay \| December 2014 coal lease - Webster County, Kentucky
Related Party Transaction
Initial term of lease		7 years
Percentage of earned royalty on coal sale price		4.00%
Annual minimum coal royalties		$ 2.6
Period for option to acquire the leased reserves		3 years
Percentage of internal rate of return on purchase price, if leased reserves acquired		7.00%
WKY CoalPlay \| December 2014 coal lease - Henderson County, Kentucky
Related Party Transaction
Annual minimum coal royalties		$ 2.5
Cavalier Minerals
Related Party Transaction
Ownership interest in VIE (as a percent)			96.00%
Cavalier Minerals \| Bluegrass Minerals
Related Party Transaction
Noncontrolling ownership interest (as a percent)			4.00%	4.00%