DEFERRED REVENUE (Narrative) (Details) T in Millions	1 Months Ended		3 Months Ended		6 Months Ended
	Sep. 30, 2013 USD ($) T	Dec. 31, 2012 USD ($) T	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) property agreement	Jun. 30, 2014 USD ($)	Jun. 30, 2016 USD ($)
Deferred Revenue Arrangement [Line Items]
Number of volumetric production payment transactions | agreement					2
Number of facilities					8
Owned quarries					7
Leased quarries					1
Purchaser's proceeds from sale of production | $	$ 153,282,000	$ 73,644,000	$ 0	$ 0	$ 0	$ 187,000
Volumetric production payment termination date	Sep. 30, 2051	Dec. 31, 2052
Volumetric production payment estimated percentage sold	11.50%	10.50%
Volumetric production payment estimated tons to be delivered | T	29.0	15.0
Maximum [Member]
Deferred Revenue Arrangement [Line Items]
Tons subject to volumetric production payment | T	250.8	143.2
Scenario, Forecast [Member]
Deferred Revenue Arrangement [Line Items]
Estimated deferred revenue to be recognized in the next 12 months | $							$ 6,000,000