SEGMENT INFORMATION - Segment Results (Details) $ in Thousands		3 Months Ended									12 Months Ended
		Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)		Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) segment	Dec. 31, 2015 USD ($)		Dec. 31, 2014 USD ($)
Segment information
Number of reportable segments | segment											2
Reportable segment results
Total revenues		$ 527,291	$ 551,966	$ 439,041	$ 412,725	$ 542,050		$ 566,342	$ 604,619	$ 560,300	$ 1,931,023	$ 2,273,311	[1]	$ 2,300,324	[1]
Segment Adjusted EBITDA Expense											1,139,637	1,376,425	[2]	1,381,808	[2]
Segment Adjusted EBITDA											764,818	814,243	[3],[4]	875,847	[3],[4]
Total assets		2,197,687				2,366,516	[5]				2,197,687	2,366,516	[5]	2,288,755	[5]
Capital expenditures											91,056	212,797	[6]	311,469	[6]
Additional information
Equity in income (loss) of affiliates											3,543	(49,046)		(16,648)
Investments in affiliate		138,817				64,509					138,817	64,509
Payments to affiliate for acquisition and development of coal reserves														4,082
Illinois Basin
Reportable segment results
Total revenues											1,275,543	1,527,596		1,647,694
Appalachia
Reportable segment results
Total revenues											541,108	584,962		630,452
Other and Corporate
Reportable segment results
Total revenues											114,372	160,753		22,178
Operating segments | Illinois Basin
Reportable segment results
Total revenues	[1]										1,337,160	1,636,217		1,647,694
Segment Adjusted EBITDA Expense	[2]										775,851	949,271		1,000,028
Segment Adjusted EBITDA	[4]										538,077	617,148	[3]	616,727	[3]
Total assets	[5]	1,460,924				1,694,044					1,460,924	1,694,044		1,581,279
Capital expenditures											52,505	145,352	[6]	243,167	[6]
Additional information
Equity in income (loss) of affiliates												48,500		16,600
Investments in affiliate														211,700
Operating segments | Appalachia
Reportable segment results
Total revenues	[1]										544,914	596,299		630,452
Segment Adjusted EBITDA Expense	[2]										346,505	400,681		364,689
Segment Adjusted EBITDA	[4]										191,694	183,908	[3]	254,037	[3]
Total assets	[5]	480,745				517,972					480,745	517,972		604,352
Capital expenditures											36,213	61,279	[6]	56,840	[6]
Operating segments | Other and Corporate
Reportable segment results
Total revenues	[1]										132,124	180,622		33,693
Segment Adjusted EBITDA Expense	[2]										89,594	153,720		25,487
Segment Adjusted EBITDA	[4]										45,909	25,767	[3]	8,202	[3]
Total assets	[5]	408,798				269,047					408,798	269,047		262,120
Capital expenditures											2,338	6,166	[6]	11,462	[6]
Additional information
Investments in affiliate		138,800				64,500					138,800	64,500		12,900
Elimination
Reportable segment results
Total revenues	[1],[7]										(83,175)	(139,827)		(11,515)
Segment Adjusted EBITDA Expense	[2],[7]										(72,313)	(127,247)		(8,396)
Segment Adjusted EBITDA	[4],[7]										(10,862)	(12,580)	[3]	(3,119)	[3]
Total assets	[5],[7]	$ (152,780)				$ (114,547)					(152,780)	(114,547)		(158,996)
Elimination | Illinois Basin
Reportable segment results
Total revenues											61,617	108,621
Elimination | Appalachia
Reportable segment results
Total revenues											3,806	11,337
Elimination | Other and Corporate
Reportable segment results
Total revenues											$ 17,752	$ 19,869		$ 11,515

[1] Revenues included in the Other and Corporate column are primarily attributable to the Matrix Group revenues, Mt. Vernon transloading revenues, administrative service revenues from affiliates, MAC revenues, Wildcat Insurance revenues and brokerage coal sales.

[2] Segment Adjusted EBITDA Expense includes operating expenses, outside coal purchases and other income. Transportation expenses are excluded as these expenses are passed through to the ARLP Partnership's customers and consequently it does not realize any gain or loss on transportation revenues. We review Segment Adjusted EBITDA Expense per ton for cost trends.

[3] Includes equity in loss of affiliates for the years ended December 31, 2015 and 2014 of $48.5 million and $16.6 million, respectively, for the Illinois Basin segment.

[4] Segment Adjusted EBITDA is defined as net income (prior to the allocation of noncontrolling interest) before net interest expense, income taxes, depreciation, depletion and amortization, asset impairment, acquisition gain, net and general and administrative expenses. Management therefore is able to focus solely on the evaluation of segment operating profitability as it relates to the ARLP Partnership's revenues and operating expenses, which are primarily controlled by our segments.

[5] Total assets at December 31, 2016, 2015 and 2014 include investments in affiliates of $138.8 million, $64.5 million and $12.9 million, respectively, within Other and Corporate. Total assets at December 31, 2014 include investments in affiliate of $211.7 million for the Illinois Basin segment.

[6] Capital expenditures shown above exclude the Hamilton Acquisition on July 31, 2015, the Patriot acquisition on February 3, 2015, the MAC acquisition on January 1, 2015, purchase of coal supply agreements from Patriot on December 31, 2014 (Note 3 - Acquisitions) and the payment for acquisition of customer contracts in 2016 (see consolidated statements of cash flows).

[7] The elimination column represents the elimination of intercompany transactions and is primarily comprised of sales from the Matrix Group and MAC to the ARLP Partnership's mining operations, coal sales and purchases between operations within different segments, sales of receivables to AROP Funding and insurance premiums paid to Wildcat Insurance.