SEGMENT INFORMATION - EBITDA Expense Reconciliation (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Reconciliation of consolidated Segment Adjusted EBITDA Expense to operating expenses (excluding depreciation, depletion and amortization)
Segment Adjusted EBITDA Expense	[1]	$ 246,338	$ 374,890	$ 499,550	$ 709,456
Outside coal purchases			(2)		(324)
Other income		161	177	252	295
Operating expenses (excluding depreciation, depletion and amortization)		$ 246,499	$ 375,065	$ 499,802	$ 709,427

[1] Segment Adjusted EBITDA Expense includes operating expenses, outside coal purchases and other income. Transportation expenses are excluded as these expenses are passed through to the ARLP Partnership’s customers and consequently it does not realize any gain or loss on transportation revenues. We review Segment Adjusted EBITDA Expense per ton for cost trends.