COMMITMENTS AND CONTINGENCIES (Narrative) (Details) (USD $)	1 Months Ended		12 Months Ended
	May 31, 2007 entity mi	Sep. 30, 2001 mi	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009 entity	Dec. 31, 2007	Jun. 18, 2012 entity
Commitments And Contingencies Disclosure [Line Items]
Expenditures under the noncapital purchase commitments			$ 83,699,000	$ 83,599,000	$ 89,407,000
Commitments of minimum royalties under mineral leases			185,868,000
Expenditures for mineral royalties under mineral leases			53,768,000	46,007,000	45,690,000
Line of credit			500,000,000		600,000,000
Line of credit fee			0.125%
Applicable margin for LIBOR based borrowing			1.75%
Unrecognized tax benefits			12,155,000	13,550,000	13,488,000	28,075,000
Number of mile of road invovled in a suit		0.9
Payment to Illinois Department of Transportaion (IDOT)						40,000,000
Insurance Recoveries					49,657,000
Number of other parties sued in the Lower Passaic River Clean-Up							300
Number of other companies to perform a Remedial Investigation/ Feasibility Study related to the Lower Passaic River Clean-Up lawsuit	70
Number of miles of the River used in the Remedial Investigation/Feasibility Study	17
Range of estimated cost, minimum								900,000,000
Range of estimated cost, maximum								3,500,000,000
Number of Other Companies Entered in to Administrative Settlement Agreement and Order									69
Property, Plant and Equipment [Member]
Commitments And Contingencies Disclosure [Line Items]
Unconditional purchase obligations			5,813,000
Noncapital [Member]
Commitments And Contingencies Disclosure [Line Items]
Unconditional purchase obligations			$ 75,052,000
Minimum
Commitments And Contingencies Disclosure [Line Items]
Applicable margin for LIBOR based borrowing			1.50%
Maximum
Commitments And Contingencies Disclosure [Line Items]
Applicable margin for LIBOR based borrowing			2.00%
Line of Credit | Minimum
Commitments And Contingencies Disclosure [Line Items]
Applicable margin for LIBOR based borrowing			1.50%
Line of Credit | Maximum
Commitments And Contingencies Disclosure [Line Items]
Applicable margin for LIBOR based borrowing			2.00%