COMMITMENTS AND CONTINGENCIES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended			3 Months Ended			12 Months Ended
	Mar. 31, 2013 item	Mar. 31, 2012	Dec. 31, 2012	Mar. 31, 2013 Minimum	Mar. 31, 2013 Maximum	Mar. 31, 2013 Lake Charles, LA facility	Dec. 31, 2012 Calcasieu River Estuary and plant sites item	Mar. 31, 2013 Calcasieu River Estuary and plant sites	Mar. 31, 2013 Natrium, West Virginia facility
Environmental Matters
Accrual of remediation costs	$ 52.1		$ 7.2			$ 15.7	$ 7.2	$ 13.2	$ 14.1
Current reserves for environmental contingencies	3.8
Number of plant site locations	2						4
Pre-tax charges against income for environmental remediation	1	1
Expected cash outlays for environmental remediation through 2015				10	20
Cash outlays for environmental remediation from 2016 through 2017				3	5
Accrual of remediation costs in non-current liabilities						$ 3.0