SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2010
SEGMENT REPORTING
Reporting segments number			4
Number of operations for which the revenues are insignificant			2
Segment reporting information
Third party revenues	$ 447,235	$ 471,639	$ 882,197	$ 826,535
Direct revenues	447,235	471,639	882,197	826,535
Property, plant and equipment, net	848,276		848,276		655,394
Goodwill	88,511		88,511		60,252
Permits and other intangibles, net	127,068		127,068		114,400
Total assets	1,965,080		1,965,080		1,602,475
Reconciliation to Consolidated Statements of Income:
Accretion of environmental liabilities	2,407	2,602	4,796	5,304
Depreciation and amortization	26,936	22,105	52,396	44,779
Income from operations	51,884	71,923	91,626	95,542
Other income	(2,868)	(2,708)	(5,767)	(3,154)
Interest expense, net of interest income	10,642	7,646	17,120	14,574
Income from continuing operations, before provision for income taxes	44,110	66,985	80,273	84,122
Reportable segments
Segment reporting information
Third party revenues	487,651	471,639	1,314,186	826,535
Direct revenues	487,651	471,639	1,314,186	826,535
Adjusted EBITDA, Total	81,227	96,630	148,818	145,625
Property, plant and equipment, net	848,276		848,276		655,394
Total Intangible assets	215,579		215,579		174,652
Total assets	1,965,080		1,965,080		1,602,475
Technical Services
Segment reporting information
Third party revenues	202,330	167,409	387,777	320,936
Intersegment revenues, net	4,210	7,137	9,351	12,076
Direct revenues	206,540	174,546	397,128	333,012
Adjusted EBITDA, Total	59,614	44,385	104,951	77,565
Property, plant and equipment, net	266,968		266,968		259,582
Goodwill	33,654		33,654		33,448
Permits and other intangibles, net	65,089		65,089		66,075
Total Intangible assets	98,743		98,743		99,523
Total assets	529,173		529,173		525,286
Field Services
Segment reporting information
Third party revenues	72,615	162,723	134,874	213,376
Intersegment revenues, net	(5,623)	(9,086)	(9,574)	(13,263)
Direct revenues	66,992	153,637	125,300	200,113
Adjusted EBITDA, Total	12,515	41,603	18,846	46,634
Property, plant and equipment, net	34,821		34,821		32,311
Goodwill	3,088		3,088		3,088
Permits and other intangibles, net	3,491		3,491		3,651
Total Intangible assets	6,579		6,579		6,739
Total assets	44,494		44,494		35,253
Field Services | Gulf of Mexico
Segment reporting information
Third party revenues		108,600		108,600
Industrial Services
Segment reporting information
Third party revenues	111,376	98,804	219,959	191,124
Intersegment revenues, net	(1,087)	(405)	(3,960)	(1,631)
Direct revenues	110,289	98,399	215,999	189,493
Adjusted EBITDA, Total	25,862	24,122	49,205	43,982
Property, plant and equipment, net	221,852		221,852		180,781
Goodwill	28,583		28,583		10,934
Permits and other intangibles, net	18,147		18,147		17,906
Total Intangible assets	46,730		46,730		28,840
Total assets	279,602		279,602		221,472
Oil and Gas Field Services
Segment reporting information
Third party revenues	60,617	42,663	139,251	101,163
Intersegment revenues, net	2,964	2,715	5,157	3,622
Direct revenues	63,581	45,378	144,408	104,785
Adjusted EBITDA, Total	8,427	5,966	23,092	17,462
Property, plant and equipment, net	283,384		283,384		151,244
Goodwill	23,186		23,186		12,782
Permits and other intangibles, net	40,341		40,341		26,768
Total Intangible assets	63,527		63,527		39,550
Total assets	419,870		419,870		272,479
Corporate Items
Segment reporting information
Third party revenues	297	40	336	(64)
Intersegment revenues, net	(464)	(361)	(974)	(804)
Direct revenues	(167)	(321)	(638)	(868)
Adjusted EBITDA, Total	(25,191)	(19,446)	(47,276)	(40,018)
Property, plant and equipment, net	41,251		41,251		31,476
Total assets	691,941		691,941		547,985
United States
Segment reporting information
Total assets	1,060,846		1,060,846		933,550
Canada
Segment reporting information
Total assets	899,986		899,986		664,534
Other foreign
Segment reporting information
Total assets	$ 4,248		$ 4,248		$ 4,391