NONCONTROLLING INTERESTS (Details 5) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Increase (Decrease) in Partners' Capital
Balance			$ 1,018,274	$ 855,593
Net income	$ 94,257	$ 137,058	200,191	252,394
Other comprehensive income (loss)			1,452	(139)
Settlement of directors deferred compensation			(177)	(218)
Vesting of ARLP Long-Term Incentive Plan			(2,719)	(2,991)
Common unit-based compensation			6,121	5,445
Distributions on ARLP common unit-based compensation			(1,363)	(1,140)
Contributions to consolidated company from affiliate noncontrolling interest			1,147
Distributions to AHGP Partners			(110,897)	(100,271)
Distributions paid by consolidated partnership to noncontrolling interest			(56,520)	(51,945)
Balance	1,055,509	956,728	1,055,509	956,728
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Partners' Capital
Balance			(15,456)	(4,198)
Other comprehensive income (loss)			650	(52)
Balance	(14,806)	(4,250)	(14,806)	(4,250)
Noncontrolling Interest
Increase (Decrease) in Partners' Capital
Balance			453,496	359,721
Net income			73,711	107,600
Other comprehensive income (loss)			802	(87)
Vesting of ARLP Long-Term Incentive Plan			(2,719)	(2,991)
Common unit-based compensation			6,008	5,290
Distributions on ARLP common unit-based compensation			(1,363)	(1,140)
Contributions to consolidated company from affiliate noncontrolling interest			1,147
Distributions paid by consolidated partnership to noncontrolling interest			(56,520)	(51,945)
Balance	474,562	416,448	474,562	416,448
Limited Partners' Capital
Increase (Decrease) in Partners' Capital
Balance			580,234	500,070
Net income			126,480	144,794
Settlement of directors deferred compensation			(177)	(218)
Common unit-based compensation			113	155
Distributions to AHGP Partners			(110,897)	(100,271)
Balance	$ 595,753	$ 544,530	$ 595,753	$ 544,530