SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014 segment	Dec. 31, 2013 operation	Dec. 31, 2012
Segment Reporting Information [Line Items]
Reporting segments number									6
Number of operations for which the revenues are insignificant										2
Total revenues	$ 845,024	$ 851,465	$ 858,480	$ 846,667	$ 879,430	$ 907,535	$ 860,528	$ 862,163	$ 3,401,636	$ 3,509,656	$ 2,187,908
Adjusted EBITDA, total									521,919	510,105	373,767
Reconciliation to Consolidated Statements of (Loss) Income:
Pre-tax, non-cash acquisition accounting inventory adjustment									0	13,559	0
Accretion of environmental liabilities									10,612	11,541	9,917
Depreciation and amortization									276,083	264,449	161,646
Goodwill impairment charge									123,414	0	0
Income from operations	57,537	(42,748)	67,115	29,906	58,877	73,608	53,243	34,828	111,810	220,556	202,204
Other (income) expense	(244)	(613)	655	(4,178)	325	150	(1,655)	(525)	(4,380)	(1,705)	802
Loss on early extinguishment of debt									0	0	26,385
Interest expense, net of interest income									77,668	78,376	47,287
Technical Services
Segment Reporting Information [Line Items]
Total revenues									1,205,383	1,147,815	991,696
Adjusted EBITDA, total									328,130	285,520	249,829
Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									639,369	663,589	590,458
Adjusted EBITDA, total									87,591	96,804	82,819
Oil Re-refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									331,723	335,627	0
Adjusted EBITDA, total									51,561	57,003	0
Reconciliation to Consolidated Statements of (Loss) Income:
Goodwill impairment charge									123,414
SK Environmental Services
Segment Reporting Information [Line Items]
Total revenues									747,739	772,099	0
Adjusted EBITDA, total									113,986	112,722	0
Lodging Services
Segment Reporting Information [Line Items]
Total revenues									174,732	212,385	202,533
Adjusted EBITDA, total									61,438	80,358	76,092
Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									308,270	390,505	403,615
Adjusted EBITDA, total									40,114	67,855	77,068
Corporate Items
Segment Reporting Information [Line Items]
Total revenues									(5,580)	(12,364)	(394)
Adjusted EBITDA, total									(160,901)	(190,157)	(112,041)
Third party revenues
Segment Reporting Information [Line Items]
Total revenues									3,401,636	3,509,656	2,187,908
Third party revenues | Technical Services
Segment Reporting Information [Line Items]
Total revenues									1,043,267	1,023,926	957,764
Third party revenues | Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									681,779	708,523	634,254
Third party revenues | Oil Re-refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									533,587	528,636	0
Third party revenues | SK Environmental Services
Segment Reporting Information [Line Items]
Total revenues									667,320	665,008	0
Third party revenues | Lodging Services
Segment Reporting Information [Line Items]
Total revenues									172,218	208,545	199,497
Third party revenues | Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									303,189	383,959	394,917
Third party revenues | Corporate Items
Segment Reporting Information [Line Items]
Total revenues									276	(8,941)	1,476
Intersegment revenues, net | Technical Services
Segment Reporting Information [Line Items]
Total revenues									156,543	120,382	31,637
Intersegment revenues, net | Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									(42,681)	(44,717)	(43,795)
Intersegment revenues, net | Oil Re-refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									(201,859)	(193,009)	0
Intersegment revenues, net | SK Environmental Services
Segment Reporting Information [Line Items]
Total revenues									80,477	107,007	0
Intersegment revenues, net | Lodging Services
Segment Reporting Information [Line Items]
Total revenues									2,434	3,450	2,971
Intersegment revenues, net | Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									5,086	6,887	9,187
Intersegment revenues, net | Corporate Items
Segment Reporting Information [Line Items]
Total revenues									0	0	0
Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues									0	0	0
Corporate Items, net | Technical Services
Segment Reporting Information [Line Items]
Total revenues									5,573	3,507	2,295
Corporate Items, net | Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									271	(217)	(1)
Corporate Items, net | Oil Re-refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									(5)	0	0
Corporate Items, net | SK Environmental Services
Segment Reporting Information [Line Items]
Total revenues									(58)	84	0
Corporate Items, net | Lodging Services
Segment Reporting Information [Line Items]
Total revenues									80	390	65
Corporate Items, net | Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									(5)	(341)	(489)
Corporate Items, net | Corporate Items
Segment Reporting Information [Line Items]
Total revenues									$ (5,856)	$ (3,423)	$ (1,870)