SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended											12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)
Revenues	$ 566,615	[1]	$ 537,136	$ 553,478	$ 547,970	$ 549,318	[1]	$ 511,348	[2]	$ 529,772	$ 443,492	$ 2,205,199	[3]	$ 2,033,930	[3]	$ 1,843,203	[3]
Income from operations	117,226	[1]	97,565	115,067	111,764	106,184	[1]	68,561	[2]	103,886	91,501	441,622		370,132		409,908
Net income	98,887	[1]	86,750	103,573	102,384	96,126	[1]	58,733	[2]	93,881	82,486	391,594		331,226		386,343
Net income of AHGP	$ 58,683	[1]	$ 54,211	$ 60,977	$ 60,002	$ 52,895	[1]	$ 39,495	[2]	$ 54,364	$ 49,314	$ 233,873		$ 196,068		$ 214,143
Basic and diluted net income per limited partner unit (in dollars per unit)	$ 0.98	[1]	$ 0.91	$ 1.02	$ 1.00	$ 0.88	[1]	$ 0.66	[2]	$ 0.91	$ 0.82	$ 3.91		$ 3.28		$ 3.58
Weighted average number of units outstanding - basic and diluted (in units)	59,863,000	[1]	59,863,000	59,863,000	59,863,000	59,863,000	[1]	59,863,000		59,863,000	59,863,000	59,863,000		59,863,000		59,863,000

[1] The comparability of our December 31, 2013 and 2012 quarterly results to other quarters presented were affected by a $12.9 million and $14.0 million, respectively, decrease in the ARLP Partnership's workers' compensation liability, excluding discount rate changes, due to the completion of its annual actuarial study, which reflected a favorable development in the ARLP Partnership's disability emergence patterns and claims estimates (Note 17).

[2] During the quarter ended September 30, 2012, the ARLP Partnership recorded a $19.0 million impairment of the carrying value of assets at the Pontiki mine (Note 4).

[3] Revenues included in the Other and Corporate column are primarily attributable to Matrix Group revenues, Mt. Vernon transloading revenues and brokerage sales.