SEGMENT INFORMATION (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013 segment		Jun. 30, 2012		Dec. 31, 2012
Segment reporting information
Number of reportable segments					5
Number of reportable segments corresponding to major coal producing regions of eastern U.S.					3
Reportable segment results:
Total revenues	$ 553,478	[1]	$ 529,772	[1]	$ 1,101,448	[1]	$ 973,264	[1]
Segment Adjusted EBITDA Expense	347,874	[2]	348,417	[2]	696,777	[2]	635,898	[2]
Segment Adjusted EBITDA	194,934	[3],[4]	171,484	[3],[4]	383,200	[3],[4]	317,132	[3],[4]
Total assets	2,024,004	[5]	1,861,338	[5]	2,024,004	[5]	1,861,338	[5]	1,958,840
Capital expenditures	99,520	[6]	149,592	[6]	181,890	[6]	272,931	[6]
Equity in income (loss) of affiliates	(5,699)		(4,430)		(9,566)		(8,208)
Investments in affiliate	128,884				128,884				88,513
Payments to affiliate for acquisition and development of coal reserves	6,800		16,600		18,860		34,601
Illinois Basin
Reportable segment results:
Total revenues	400,386	[1]	374,708	[1]	805,209	[1]	716,938	[1]
Segment Adjusted EBITDA Expense	233,703	[2]	228,952	[2]	467,848	[2]	430,500	[2]
Segment Adjusted EBITDA	164,623	[3],[4]	142,734	[3],[4]	331,844	[3],[4]	279,626	[3],[4]
Total assets	1,056,953	[5]	1,021,050	[5]	1,056,953	[5]	1,021,050	[5]
Capital expenditures	52,995	[6]	67,970	[6]	105,026	[6]	122,115	[6]
Central Appalachia
Segment reporting information
Number of operating segments within the reportable segment					2
Reportable segment results:
Total revenues	41,541	[1]	40,033	[1]	86,566	[1]	81,199	[1]
Segment Adjusted EBITDA Expense	31,136	[2]	30,603	[2]	66,438	[2]	61,357	[2]
Segment Adjusted EBITDA	10,207	[3],[4]	9,180	[3],[4]	19,916	[3],[4]	19,390	[3],[4]
Total assets	84,413	[5]	98,622	[5]	84,413	[5]	98,622	[5]
Capital expenditures	2,396	[6]	11,647	[6]	6,299	[6]	15,748	[6]
Northern Appalachia
Reportable segment results:
Total revenues	105,536	[1]	99,857	[1]	199,328	[1]	146,962	[1]
Segment Adjusted EBITDA Expense	76,120	[2]	76,458	[2]	149,941	[2]	120,688	[2]
Segment Adjusted EBITDA	26,701	[3],[4]	21,231	[3],[4]	43,210	[3],[4]	21,513	[3],[4]
Total assets	538,205	[5]	516,881	[5]	538,205	[5]	516,881	[5]
Capital expenditures	29,991	[6]	29,383	[6]	38,870	[6]	60,898	[6]
White Oak
Segment reporting information
Number of operating segments within the reportable segment					2
Reportable segment results:
Segment Adjusted EBITDA Expense	427	[2]	(1,826)	[2]	528	[2]	(1,691)	[2]
Segment Adjusted EBITDA	(6,295)	[3],[4]	(2,758)	[3],[4]	(10,587)	[3],[4]	(6,884)	[3],[4]
Total assets	298,716	[5]	177,700	[5]	298,716	[5]	177,700	[5]
Capital expenditures	11,917	[6]	39,301	[6]	28,870	[6]	64,244	[6]
Equity in income (loss) of affiliates	(5,900)		(4,600)		(10,100)		(8,600)
Investments in affiliate	127,200		62,300		127,200		62,300
Payments to affiliate for acquisition and development of coal reserves	6,800		16,600		18,900		34,600
Other and Corporate
Reportable segment results:
Total revenues	9,929	[1]	20,960	[1]	17,816	[1]	37,970	[1]
Segment Adjusted EBITDA Expense	10,402	[2]	19,932	[2]	19,493	[2]	34,849	[2]
Segment Adjusted EBITDA	(302)	[3],[4]	1,182	[3],[4]	(1,183)	[3],[4]	3,487	[3],[4]
Total assets	46,653	[5]	49,645	[5]	46,653	[5]	49,645	[5]
Capital expenditures	2,221	[6]	1,291	[6]	2,825	[6]	9,926	[6]
Equity in income (loss) of affiliates	200		200		500		400
Investments in affiliate	1,700		1,600		1,700		1,600
Elimination
Reportable segment results:
Total revenues	(3,914)	[1]	(5,786)	[1]	(7,471)	[1]	(9,805)	[1]
Segment Adjusted EBITDA Expense	(3,914)	[2]	(5,702)	[2]	(7,471)	[2]	(9,805)	[2]
Segment Adjusted EBITDA			(85)	[3],[4]
Total assets	$ (936)	[5]	$ (2,560)	[5]	$ (936)	[5]	$ (2,560)	[5]

[1] Revenues included in the Other and Corporate column are primarily attributable to the Matrix Group revenues, Mt. Vernon transloading revenues and brokerage 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 income (loss) of affiliates for the three and six months ended June 30, 2013 of $(5.9) million and $(10.1) million, respectively, included in the White Oak segment and $0.2 million and $0.5 million, respectively, included in the Other and Corporate segment. Includes equity in income (loss) of affiliates for the three and six months ended June 30, 2012 of $(4.6) million and $(8.6) million, respectively, included in the White Oak segment and $0.2 million and $0.4 million, respectively, included in the Other and Corporate segment.

[4] Segment Adjusted EBITDA is defined as net income (prior to the allocation of noncontrolling interest) before income taxes, net interest expense, depreciation, depletion and amortization 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 for the White Oak and Other and Corporate Segments include investments in affiliate of $127.2 million and $1.7 million, respectively, at June 30, 2013 and $62.3 million and $1.6 million, respectively, at June 30, 2012.

[6] Capital expenditures shown above include funding to White Oak of $6.8 million and $18.9 million, respectively, for the three and six months ended June 30, 2013, and $16.6 million and $34.6 million, respectively, for the three and six months ended June 30, 2012, for the acquisition and development of coal reserves in our condensed consolidated statements of cash flow.