SEGMENT INFORMATION - EBITDA Expense Reconciliation (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Reconciliation of consolidated Segment Adjusted EBITDA Expense to operating expenses (excluding depreciation, depletion and amortization)
Segment Adjusted EBITDA Expense	[1]	$ 1,376,425	$ 1,381,808	$ 1,398,902
Outside coal purchases		(327)	(14)	(2,030)
Other income		955	1,566	1,891
Operating expenses (excluding depreciation, depletion and amortization)		$ 1,377,053	$ 1,383,360	$ 1,398,763

[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.