SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2011		Sep. 30, 2010		Sep. 30, 2011		Sep. 30, 2010		Dec. 31, 2010
Segment reporting information
Third party revenues	$ 556,053		$ 487,651		$ 1,438,250		$ 1,314,186
Intersegment revenues, net
Direct revenues	556,053		487,651		1,438,250		1,314,186
Property, plant and equipment, net	880,719				880,719				655,394
Goodwill	134,696				134,696				60,252
Permits and other intangibles, net	140,970				140,970				114,400
Total assets	2,010,385				2,010,385				1,602,475
Reconciliation to Consolidated Statements of Income:
Accretion of environmental liabilities	2,435		2,495		7,231		7,799
Depreciation and amortization	34,604		22,892		87,000		67,671
Income from operations	66,792		73,372		158,418		168,914
Other income	(164)		669		(5,931)		(2,485)
Loss on early extinguishment of debt	0		2,294		0		2,294
Interest expense, net of interest income	10,927		7,198		28,047		21,772
Income from continuing operations, before provision for income taxes	56,029		63,211		136,302		147,333
Reporting segments number					4
Number of operations for which the revenues are insignificant					2
Reportable segments
Segment reporting information
Adjusted EBITDA, Total	103,831		98,759		252,649		244,384
Property, plant and equipment, net	880,719				880,719				655,394
Total Intangible assets	275,666				275,666				174,652
Total assets	2,010,385				2,010,385				1,602,475
Technical Services
Segment reporting information
Third party revenues	209,245		177,266		597,022		498,202
Intersegment revenues, net	4,612		5,577		13,963		17,653
Direct revenues	213,857		182,843		610,985		515,855
Adjusted EBITDA, Total	59,005		46,195		163,956		123,760
Property, plant and equipment, net	292,652				292,652				259,582
Goodwill	45,965				45,965				33,448
Permits and other intangibles, net	79,509				79,509				66,075
Total Intangible assets	125,474				125,474				99,523
Total assets	588,389				588,389				525,286
Field Services
Segment reporting information
Third party revenues	117,448	[1]	183,120	[2]	252,322	[1]	396,496	[2]
Intersegment revenues, net	(6,274)	[1]	(8,814)	[2]	(15,848)	[1]	(22,077)	[2]
Direct revenues	111,174	[1]	174,306	[2]	236,474	[1]	374,419	[2]
Adjusted EBITDA, Total	22,746		48,430		41,592		95,064
Property, plant and equipment, net	36,130				36,130				32,311
Goodwill	3,088				3,088				3,088
Permits and other intangibles, net	3,331				3,331				3,651
Total Intangible assets	6,419				6,419				6,739
Total assets	44,998				44,998				35,253
Field Services | Yellowstone River [Member]
Segment reporting information
Third party revenues	41,500				41,500
Field Services | Gulf of Mexico
Segment reporting information
Third party revenues			123,800				232,400
Industrial Services
Segment reporting information
Third party revenues	113,543		79,723		333,502		270,847
Intersegment revenues, net	4,323		2,239		363		608
Direct revenues	117,866		81,962		333,865		271,455
Adjusted EBITDA, Total	22,677		18,947		71,882		62,929
Property, plant and equipment, net	231,979				231,979				180,781
Goodwill	45,941				45,941				10,934
Permits and other intangibles, net	20,531				20,531				17,906
Total Intangible assets	66,472				66,472				28,840
Total assets	322,631				322,631				221,472
Oil and Gas Field Services
Segment reporting information
Third party revenues	115,554		47,503		254,805		148,666
Intersegment revenues, net	(2,091)		1,529		3,066		5,151
Direct revenues	113,463		49,032		257,871		153,817
Adjusted EBITDA, Total	28,416		10,473		51,508		27,935
Property, plant and equipment, net	278,546				278,546				151,244
Goodwill	39,702				39,702				12,782
Permits and other intangibles, net	37,599				37,599				26,768
Total Intangible assets	77,301				77,301				39,550
Total assets	463,863				463,863				272,479
Corporate Items
Segment reporting information
Third party revenues	263		39		599		(25)
Intersegment revenues, net	(570)		(531)		(1,544)		(1,335)
Direct revenues	(307)		(492)		(945)		(1,360)
Adjusted EBITDA, Total	(29,013)		(25,286)		(76,289)		(65,304)
Property, plant and equipment, net	41,412				41,412				31,476
Total assets	590,504				590,504				547,985
United States
Segment reporting information
Total assets	1,109,827				1,109,827				933,550
Canada
Segment reporting information
Total assets	894,850				894,850				664,534
Other foreign
Segment reporting information
Total assets	$ 5,708				$ 5,708				$ 4,391

[1] During the three and nine months ended September 30, 2011, third party revenues for the Field Services segment included revenues associated with the Yellowstone River oil spill response efforts of $41.5 million.

[2] During the three and nine months ended September 30, 2010, third party revenues for the Field Services segment included revenues associated with the oil spill response efforts in the Gulf of Mexico and Michigan of $123.8 million and $232.4 million, respectively.