SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013 ReportableSegments	Dec. 31, 2012	Dec. 31, 2011
Segment Reporting Information [Line Items]
Reporting segments number									5
Number of operations for which the revenues are insignificant									2
Total revenues	$ 879,430	$ 907,535	$ 860,528	$ 862,163	$ 558,962	$ 533,806	$ 523,118	$ 572,022	$ 3,509,656	$ 2,187,908	$ 1,984,136
Adjusted EBITDA, Total									510,105	373,767	350,008
Reconciliation to Consolidated Statements of Income:
Pre-tax, non-cash acquisition accounting inventory adjustment									13,559	0	0
Accretion of environmental liabilities									11,541	9,917	9,680
Depreciation and amortization									264,449	161,646	122,663
Income from operations	58,877	73,608	53,243	34,828	36,231	56,739	47,533	61,701	220,556	202,204	217,665
Other (income) expense	325	150	(1,655)	(525)	337	91	75	299	(1,705)	802	(6,402)
Loss on early extinguishment of debt									0	26,385	0
Interest expense, net of interest income									78,376	47,287	39,389
Income before provision (benefit) for income taxes									143,885	127,730	184,678
Technical Services
Segment Reporting Information [Line Items]
Total revenues									1,147,815	991,696	945,741
Adjusted EBITDA, Total									285,520	249,829	240,494
Oil Refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									336,981
Adjusted EBITDA, Total									57,314
Environmental Services
Segment Reporting Information [Line Items]
Total revenues									770,745	0	0
Adjusted EBITDA, Total									112,413	0	0
Environmental Services | Yellowstone River
Segment Reporting Information [Line Items]
Total revenues											43,600
Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									866,979	787,253	695,893
Adjusted EBITDA, Total									176,952	158,931	136,380
Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									399,500	409,353	343,192
Adjusted EBITDA, Total									68,063	77,048	77,870
Corporate Items
Segment Reporting Information [Line Items]
Total revenues									(12,364)	(394)	(690)
Adjusted EBITDA, Total									(190,157)	(112,041)	(104,736)
Operating segments
Segment Reporting Information [Line Items]
Total revenues									3,509,656	2,187,908	1,984,136
Operating segments | Technical Services
Segment Reporting Information [Line Items]
Total revenues									1,023,926	957,764	910,896
Operating segments | Oil Refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									583,567	0	0
Operating segments | Environmental Services
Segment Reporting Information [Line Items]
Total revenues									610,076	0	0
Operating segments | Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									908,556	828,119	731,626
Operating segments | Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									392,472	400,549	340,563
Operating segments | Corporate Items
Segment Reporting Information [Line Items]
Total revenues									(8,941)	1,476	1,051
Intersegment
Segment Reporting Information [Line Items]
Total revenues
Intersegment | Technical Services
Segment Reporting Information [Line Items]
Total revenues									120,382	31,637	32,340
Intersegment | Oil Refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									(246,586)	0	0
Intersegment | Environmental Services
Segment Reporting Information [Line Items]
Total revenues									160,585	0	0
Intersegment | Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									(41,751)	(40,930)	(35,370)
Intersegment | Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									7,370	9,293	3,030
Intersegment | Corporate Items
Segment Reporting Information [Line Items]
Total revenues									0	0	0
Corporate Items (non-segment)
Segment Reporting Information [Line Items]
Total revenues									0	0	0
Corporate Items (non-segment) | Technical Services
Segment Reporting Information [Line Items]
Total revenues									3,507	2,295	2,505
Corporate Items (non-segment) | Oil Refining and Recycling
Segment Reporting Information [Line Items]
Total revenues									0	0	0
Corporate Items (non-segment) | Environmental Services
Segment Reporting Information [Line Items]
Total revenues									84	0	0
Corporate Items (non-segment) | Industrial and Field Services
Segment Reporting Information [Line Items]
Total revenues									174	64	(363)
Corporate Items (non-segment) | Oil and Gas Field Services
Segment Reporting Information [Line Items]
Total revenues									(342)	(489)	(401)
Corporate Items (non-segment) | Corporate Items
Segment Reporting Information [Line Items]
Total revenues									$ (3,423)	$ (1,870)	$ (1,741)