SIGNIFICANT ACCOUNTING POLICIES (Remedial Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014 sites	Dec. 31, 2013	Dec. 31, 2012
Regulatory Liabilities [Line Items]
Accrual for environmental loss contingencies	$ 155,121	$ 172,498	$ 183,346
Period of time in years over which business acquisitions have been acquired	13 years
Superfund sites owned by third parties	35
Superfund sites	126
Minimum
Regulatory Liabilities [Line Items]
Remedial liabilities at acquisition	1.01%
Remedial liabilities discounted risk free interest rate	2.88%
Maximum
Regulatory Liabilities [Line Items]
Remedial liabilities at acquisition	2.44%
Remedial liabilities discounted risk free interest rate	4.90%