PROPERTY AND EQUIPMENT (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
PROPERTY AND EQUIPMENT
Total property and equipment	$ 341,877		$ 341,877		$ 221,540
Accumulated depreciation and amortization	(121,559)		(121,559)		(106,681)
Property and equipment, net	220,318		220,318		114,859
Depreciation and amortization expense	8,400	3,700	16,773	10,792
Cell development costs
PROPERTY AND EQUIPMENT
Total property and equipment	93,402		93,402		77,348
Land and improvements
PROPERTY AND EQUIPMENT
Total property and equipment	35,359		35,359		18,073
Buildings and improvements
PROPERTY AND EQUIPMENT
Total property and equipment	78,955		78,955		59,101
Railcars
PROPERTY AND EQUIPMENT
Total property and equipment	17,375		17,375		17,375
Vehicles and other equipment
PROPERTY AND EQUIPMENT
Total property and equipment	96,119		96,119		42,859
Construction in progress
PROPERTY AND EQUIPMENT
Total property and equipment	$ 20,667		$ 20,667		$ 6,784