GOODWILL AND OTHER INTANGIBLE ASSETS (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Jun. 30, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill	$ 447,918		$ 447,918			$ 452,669
Property, plant and equipment, net	1,531,548		1,531,548			1,558,834
Goodwill impairment charge	0	$ 123,414	31,992	$ 123,414
Permits and other intangible, net	518,995		518,995			530,080
Oil and Gas Field Services
Goodwill [Line Items]
Goodwill	32,000		32,000		$ 32,000
Goodwill	0		0		$ 0	33,744
Property, plant and equipment, net	168,630		168,630			215,574
Goodwill impairment charge			31,992
Permits and other intangible, net	17,719		17,719			22,727
Kleen Performance Products
Goodwill [Line Items]
Goodwill	49,972		49,972			50,883
Property, plant and equipment, net	193,576		193,576			201,451
Permits and other intangible, net	142,898		142,898			$ 151,041
Customer and Supplier Relationships | Oil and Gas Field Services
Goodwill [Line Items]
Permits and other intangible, net	9,200		9,200
Other intangible assets | Oil and Gas Field Services
Goodwill [Line Items]
Permits and other intangible, net	$ 8,500		$ 8,500