SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013 segment	Mar. 31, 2012	Dec. 31, 2012
Segment reporting information
Third party revenues	$ 862,163	$ 572,022
Intersegment revenues, net
Corporate Items, net
Total revenues	862,163	572,022
Adjusted EBITDA, Total	111,228	100,948
Property, plant and equipment, net	1,549,806		1,531,763
Goodwill	572,406		593,771
Permits and other intangibles, net	566,910		572,817
Total assets	3,803,378		3,825,806
Reconciliation to Consolidated Statements of Income:
Reporting segments number	5
Number of operations for which the revenues are insignificant	2
Pre-tax, non-cash acquisition accounting adjustments	13,559	0
Accretion of environmental liabilities	2,835	2,416
Depreciation and amortization	60,006	36,831
Income from operations	34,828	61,701
Other (income) expense	(525)	299
Interest expense, net of interest income	19,873	11,272
Income before provision for income taxes	15,480	50,130
United States
Segment reporting information
Total assets	2,540,639		2,564,609
Canada
Segment reporting information
Total assets	1,260,024		1,260,421
Other foreign
Segment reporting information
Total assets	2,715		776
Reportable Segment [Member]
Segment reporting information
Property, plant and equipment, net	1,549,806		1,531,763
Total Intangible assets	1,139,316		1,166,588
Total assets	3,803,378		3,825,806
Technical Services [Member]
Segment reporting information
Third party revenues	233,939	221,637
Intersegment revenues, net	24,419	9,067
Corporate Items, net	852	492
Total revenues	259,210	231,196
Adjusted EBITDA, Total	60,045	51,911
Property, plant and equipment, net	389,594		402,260
Goodwill	47,929		48,157
Permits and other intangibles, net	84,514		85,842
Total Intangible assets	132,443		133,999
Total assets	700,279		714,777
Oil Re-Refining and Recycling [Member]
Segment reporting information
Third party revenues	146,931	0
Intersegment revenues, net	(56,561)	0
Corporate Items, net	0	0
Total revenues	90,370	0
Adjusted EBITDA, Total	15,312	0
Property, plant and equipment, net	223,187		224,289
Goodwill	206,095		215,704
Permits and other intangibles, net	221,783		222,182
Total Intangible assets	427,878		437,886
Total assets	782,069		797,650
S K Environmental Services [Member]
Segment reporting information
Third party revenues	152,955	0
Intersegment revenues, net	41,405	0
Corporate Items, net	84	0
Total revenues	194,444	0
Adjusted EBITDA, Total	27,040	0
Property, plant and equipment, net	203,671		195,172
Goodwill	141,809		148,422
Permits and other intangibles, net	190,130		190,472
Total Intangible assets	331,939		338,894
Total assets	663,335		647,746
Industrial and Field Services [Member]
Segment reporting information
Third party revenues	221,418	202,779
Intersegment revenues, net	(13,356)	(11,221)
Corporate Items, net	138	12
Total revenues	208,200	191,570
Adjusted EBITDA, Total	36,346	34,078
Property, plant and equipment, net	387,502		371,335
Goodwill	137,564		141,726
Permits and other intangibles, net	39,535		41,143
Total Intangible assets	177,099		182,869
Total assets	612,650		607,654
Oil and Gas Field Services [Member]
Segment reporting information
Third party revenues	116,696	146,905
Intersegment revenues, net	4,093	2,154
Corporate Items, net	(151)	(231)
Total revenues	120,638	148,828
Adjusted EBITDA, Total	27,551	40,196
Property, plant and equipment, net	251,126		257,985
Goodwill	39,009		39,762
Permits and other intangibles, net	30,948		33,178
Total Intangible assets	69,957		72,940
Total assets	331,758		348,771
Corporate Items [Member]
Segment reporting information
Third party revenues	(9,776)	701
Intersegment revenues, net	0	0
Corporate Items, net	(923)	(273)
Total revenues	(10,699)	428
Adjusted EBITDA, Total	(55,066)	(25,237)
Property, plant and equipment, net	94,726		80,722
Total assets	713,287		709,208
Reconciliation to Consolidated Statements of Income:
Pre-tax, non-cash acquisition accounting adjustments	$ 10,200