GOODWILL AND OTHER INTANGIBLE ASSETS (Changes to Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 452,669	$ 570,960
Acquired from acquisitions	46,539	7,401
Measurement period adjustments	3,574	4,288
Goodwill impairment charge	(31,992)	(123,414)	$ 0
Foreign currency translation and other	(17,685)	(6,566)
Goodwill, end of period	453,105	452,669	570,960
Oil and Gas Field Services
Goodwill [Roll Forward]
Goodwill, beginning of period	33,744	36,506
Acquired from acquisitions	0	0
Measurement period adjustments	0	0
Goodwill impairment charge	(31,992)	0
Foreign currency translation and other	(1,752)	(2,762)
Goodwill, end of period	0	33,744	36,506
Technical Services
Goodwill [Roll Forward]
Goodwill, beginning of period	50,092	45,599
Acquired from acquisitions	0	5,018
Measurement period adjustments	0	0
Goodwill impairment charge	0	0
Foreign currency translation and other	(825)	(525)
Goodwill, end of period	49,267	50,092	45,599
Industrial and Field Services
Goodwill [Roll Forward]
Goodwill, beginning of period	109,214	109,873
Acquired from acquisitions	0	0
Measurement period adjustments	0	0
Goodwill impairment charge	0	0
Foreign currency translation and other	(3,928)	(659)
Goodwill, end of period	105,286	109,214	109,873
SK Environmental Services
Goodwill [Roll Forward]
Goodwill, beginning of period	173,873	172,309
Acquired from acquisitions	46,539	0
Measurement period adjustments	0	0
Goodwill impairment charge	0	0
Foreign currency translation and other	(3,823)	1,564
Goodwill, end of period	216,589	173,873	172,309
Lodging Services
Goodwill [Roll Forward]
Goodwill, beginning of period	34,863	35,512
Acquired from acquisitions	0	2,383
Measurement period adjustments	3,574	0
Goodwill impairment charge	0	0
Foreign currency translation and other	(6,229)	(3,032)
Goodwill, end of period	32,208	34,863	35,512
Kleen Performance Products
Goodwill [Roll Forward]
Goodwill, beginning of period	50,883	171,161
Acquired from acquisitions	0	0
Measurement period adjustments	0	4,288
Goodwill impairment charge	0	(123,414)
Foreign currency translation and other	(1,128)	(1,152)
Goodwill, end of period	$ 49,755	$ 50,883	$ 171,161