SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013 segment	Jun. 30, 2012	Dec. 31, 2012
Segment reporting information
Number of reportable segments			5
Number of operations for which the revenues are insignificant			2
Third party revenues	$ 860,528	$ 523,118	$ 1,722,691	$ 1,095,140
Intersegment revenues, net
Corporate Items, net
Total revenues	860,528	523,118	1,722,691	1,095,140
Adjusted EBITDA, Total	123,590	88,701	234,818	189,649
Reconciliation to Consolidated Statements of Income:
Pre-tax, non-cash acquisition accounting adjustments	0	0	13,559	0
Accretion of environmental liabilities	2,879	2,505	5,714	4,921
Depreciation and amortization	67,468	38,663	127,474	75,494
Income from operations	53,243	47,533	88,071	109,234
Other (income) expense	(1,655)	75	(2,180)	374
Interest expense, net of interest income	19,585	10,968	39,458	22,240
Income before provision for income taxes	35,313	36,490	50,793	86,620
Property, plant and equipment, net	1,554,972		1,554,972		1,531,763
Goodwill	575,275		575,275		593,771
Permits and other intangibles, net	555,422		555,422		572,817
Total assets	3,832,113		3,832,113		3,825,806
United States
Reconciliation to Consolidated Statements of Income:
Total assets	2,611,158		2,611,158		2,564,609
Canada
Reconciliation to Consolidated Statements of Income:
Total assets	1,217,786		1,217,786		1,260,421
Other foreign
Reconciliation to Consolidated Statements of Income:
Total assets	3,169		3,169		776
Reportable Segment [Member]
Reconciliation to Consolidated Statements of Income:
Property, plant and equipment, net	1,554,972		1,554,972		1,531,763
Total Intangible assets	1,130,697		1,130,697		1,166,588
Total assets	3,832,113		3,832,113		3,825,806
Technical Services [Member]
Segment reporting information
Third party revenues	256,262	243,321	490,201	464,958
Intersegment revenues, net	25,789	8,217	50,208	17,284
Corporate Items, net	1,339	648	2,191	1,140
Total revenues	283,390	252,186	542,600	483,382
Adjusted EBITDA, Total	69,390	68,521	129,435	120,432
Reconciliation to Consolidated Statements of Income:
Property, plant and equipment, net	393,412		393,412		402,260
Goodwill	47,756		47,756		48,157
Permits and other intangibles, net	82,610		82,610		85,842
Total Intangible assets	130,366		130,366		133,999
Total assets	697,293		697,293		714,777
Oil Re-Refining and Recycling [Member]
Segment reporting information
Third party revenues	139,695	0	286,626	0
Intersegment revenues, net	(64,574)	0	(121,135)	0
Corporate Items, net	0	0	0	0
Total revenues	75,121	0	165,491	0
Adjusted EBITDA, Total	12,657	0	27,969	0
Reconciliation to Consolidated Statements of Income:
Property, plant and equipment, net	219,719		219,719		224,289
Goodwill	208,543		208,543		215,704
Permits and other intangibles, net	218,600		218,600		222,182
Total Intangible assets	427,143		427,143		437,886
Total assets	749,788		749,788		797,650
S K Environmental Services [Member]
Segment reporting information
Third party revenues	149,835	0	302,790	0
Intersegment revenues, net	48,520	0	89,925	0
Corporate Items, net	0	0	84	0
Total revenues	198,355	0	392,799	0
Adjusted EBITDA, Total	34,171	0	61,211	0
Reconciliation to Consolidated Statements of Income:
Property, plant and equipment, net	201,639		201,639		195,172
Goodwill	143,494		143,494		148,422
Permits and other intangibles, net	187,400		187,400		190,472
Total Intangible assets	330,894		330,894		338,894
Total assets	687,374		687,374		647,746
Industrial and Field Services [Member]
Segment reporting information
Third party revenues	244,495	202,618	465,913	405,397
Intersegment revenues, net	(11,638)	(11,148)	(24,994)	(22,369)
Corporate Items, net	(27)	(64)	111	(52)
Total revenues	232,830	191,406	441,030	382,976
Adjusted EBITDA, Total	54,196	40,558	90,542	74,636
Reconciliation to Consolidated Statements of Income:
Property, plant and equipment, net	389,097		389,097		371,335
Goodwill	137,606		137,606		141,726
Permits and other intangibles, net	37,587		37,587		41,143
Total Intangible assets	175,193		175,193		182,869
Total assets	615,332		615,332		607,654
Oil and Gas Field Services [Member]
Segment reporting information
Third party revenues	69,860	76,849	186,556	223,754
Intersegment revenues, net	1,903	2,931	5,996	5,085
Corporate Items, net	(49)	(62)	(200)	(293)
Total revenues	71,714	79,718	192,352	228,546
Adjusted EBITDA, Total	3,967	7,971	31,518	48,167
Reconciliation to Consolidated Statements of Income:
Property, plant and equipment, net	240,259		240,259		257,985
Goodwill	37,876		37,876		39,762
Permits and other intangibles, net	29,225		29,225		33,178
Total Intangible assets	67,101		67,101		72,940
Total assets	314,292		314,292		348,771
Corporate Items [Member]
Segment reporting information
Third party revenues	381	330	(9,395)	1,031
Intersegment revenues, net	0	0	0	0
Corporate Items, net	(1,263)	(522)	(2,186)	(795)
Total revenues	(882)	(192)	(11,581)	236
Adjusted EBITDA, Total	(50,791)	(28,349)	(105,857)	(53,586)
Reconciliation to Consolidated Statements of Income:
Pre-tax, non-cash acquisition accounting adjustments			10,200
Property, plant and equipment, net	110,846		110,846		80,722
Total assets	$ 768,034		$ 768,034		$ 709,208