SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Sep. 30, 2013	Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Total revenues	$ 542,050	$ 566,342	$ 604,619	$ 560,300	$ 590,696	$ 569,230	$ 598,464	$ 541,934		$ 2,273,311	[1]	$ 2,300,324	[1]	$ 2,205,199	[1]
Income from operations	5,841	106,706	123,931	122,937	133,055	125,225	152,439	128,945		359,415		539,664		441,622
Income before income taxes	21,108	82,874	94,265	105,932	122,585	117,690	137,058	115,336		304,179		492,669		392,991
Net income of AHGP	$ 28,735	$ 56,097	$ 60,950	$ 65,530	$ 71,008	$ 68,549	$ 77,347	$ 67,447		$ 211,312		$ 284,351		$ 233,873
Basic net income per limited partner unit (in dollars per unit)	$ 0.48	$ 0.94	$ 1.02	$ 1.09	$ 1.19	$ 1.15	$ 1.29	$ 1.13		$ 3.53		$ 4.75		$ 3.91
Diluted net income per limited partner unit (in dollars per unit)	$ 0.48	$ 0.94	$ 1.02	$ 1.09	$ 1.19	$ 1.15	$ 1.29	$ 1.13
Weighted average number of units outstanding - basic (in units)	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000		59,863,000		59,863,000		59,863,000
Weighted average number of units outstanding - diluted (in units)	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000	59,863,000
Asset impairment charges	$ 89,400	$ 10,700								$ 100,130
Net gain relating to final business combination accounting	$ 22,500									22,548
Insurance settlement related to adverse geological events							$ 7,000
Gain recognized on sale of assets										$ 1		$ 4,409		$ (3,475)
Other and Corporate | Pontiki mining complex
Gain recognized on sale of assets									$ 4,400			$ 4,400

[1] Revenues included in 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, brokerage sales and Pontiki’s coal sales revenue (2013 only).