INVENTORIES (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
INVENTORIES
Coal	$ 12,791	$ 14,763
Supplies (net of reserve for obsolescence of $3,150 and $2,721, respectively)	31,423	31,897
Total inventory	44,214	46,660
Reserve for obsolescence	$ 3,150	$ 2,721