SEGMENT REPORTING (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014 segment	Jun. 30, 2013
Segment reporting information
Number of reportable segments			6
Number of operations for which the revenues are insignificant			2
Adjusted EBITDA, Total	$ 135,799	$ 123,590	$ 237,785	$ 234,818
Reconciliation to Consolidated Statements of Income:
Pre-tax, non-cash acquisition accounting inventory adjustment	0	0	0	13,559
Accretion of environmental liabilities	2,609	2,879	5,333	5,714
Depreciation and amortization	66,075	67,468	135,431	127,474
Income from operations	67,115	53,243	97,021	88,071
Other expense (income)	655	(1,655)	(3,523)	(2,180)
Interest expense, net of interest income	19,382	19,585	38,936	39,458
Income before provision for income taxes	47,078	35,313	61,608	50,793
Technical Services
Segment reporting information
Adjusted EBITDA, Total	84,297	69,390	146,474	129,435
Industrial and Field Services
Segment reporting information
Adjusted EBITDA, Total	30,716	34,760	47,088	48,572
Oil Re-refining and Recycling
Segment reporting information
Adjusted EBITDA, Total	15,196	12,752	27,779	28,098
SK Environmental Services
Segment reporting information
Adjusted EBITDA, Total	31,307	34,076	54,132	61,082
Lodging Services
Segment reporting information
Adjusted EBITDA, Total	15,487	19,259	33,224	41,560
Oil and Gas Field Services
Segment reporting information
Adjusted EBITDA, Total	1,812	4,144	18,143	31,928
Corporate Items
Segment reporting information
Adjusted EBITDA, Total	$ (43,016)	$ (50,791)	$ (89,055)	$ (105,857)