SIGNIFICANT ACCOUNTING POLICIES REMEDIAL LIABILITIES (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Regulatory Liabilities [Line Items]
Accrual for Environmental Loss Contingencies	$ 135,320	$ 137,613	$ 145,486
Superfund sites owned by third parties	35
Superfund sites	65
Minimum [Member]
Regulatory Liabilities [Line Items]
Remedial Liabilities at Acquistion	1.01%
Remedial Liabilities Discounted Risk Free Interest Rate	3.65%
Maximum [Member]
Regulatory Liabilities [Line Items]
Remedial Liabilities at Acquistion	2.44%
Remedial Liabilities Discounted Risk Free Interest Rate	4.90%