SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED)
Total revenues	$ 483,130	$ 453,087	$ 398,619	$ 461,005	$ 527,291	$ 551,966	$ 439,041	$ 412,725	$ 1,795,841	$ 1,931,023	$ 2,273,311
Income from operations	76,998	64,342	78,279	107,043	123,796	95,450	89,280	54,428	326,662	362,954	359,415
Income before income taxes	74,095	60,947	62,877	104,550	119,198	88,850	81,638	46,881	302,469	336,567	304,179
Net income of AHGP	$ 49,272	$ 39,122	$ 42,583	$ 55,011	$ 61,212	$ 48,507	$ 45,373	$ 30,842	$ 185,988	$ 185,934	$ 211,312
Basic net income per limited partner unit (in dollars per unit)	$ 0.82	$ 0.65	$ 0.71	$ 0.92	$ 1.02	$ 0.81	$ 0.76	$ 0.52	$ 3.11	$ 3.11	$ 3.53
Diluted net income per limited partner unit (in dollars per unit)	$ 0.82	$ 0.65	$ 0.71	$ 0.92	$ 1.02	$ 0.81	$ 0.76	$ 0.52	$ 3.11	$ 3.11	$ 3.53
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	59,863,000	59,863,000	59,863,000
ARLP Credit Agreement | ARLP Series B Senior Notes
Other information
Debt extinguishment loss			$ 8,100