NONCONTROLLING INTERESTS - Distributions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Noncontrolling Interest
Distributions paid by consolidated partnership to noncontrolling interests	$ 84,973	$ 89,311	$ 117,362
SGP
Noncontrolling Interest
Distributions paid by consolidated partnership to noncontrolling interests	26	49	67
Non-Affiliates (ARLP's non-affiliate limited partners)
Noncontrolling Interest
Distributions paid by consolidated partnership to noncontrolling interests	$ 84,947	$ 89,262	$ 117,295