CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS (Tables)

12 Months Ended

Dec. 31, 2015

CONCENTRATION OF CREDIT RISK AND MAJOR CUSTOMERS

Schedule of total revenues from major customers

		Year Ended December 31,
	Segment	2015		2014		2013
		(in thousands)
Customer A	Illinois Basin	$	343,483	$	301,191	$	319,932
Customer B	Illinois Basin	305,048		276,094		263,582