SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Total revenues	$ 858,480	$ 860,528	$ 1,705,147	$ 1,722,691
Third party revenues
Segment Reporting Information [Line Items]
Total revenues	858,480	860,528	1,705,147	1,722,691
Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Direct revenues
Segment Reporting Information [Line Items]
Total revenues	858,480	860,528	1,705,147	1,722,691
Technical Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	256,798	256,262	493,579	490,201
Technical Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	40,082	25,789	77,516	50,208
Technical Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	778	1,339	1,177	2,191
Technical Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	297,658	283,390	572,272	542,600
Industrial and Field Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	185,154	199,225	347,114	368,846
Industrial and Field Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	(11,047)	(12,680)	(22,805)	(26,440)
Industrial and Field Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	36	(128)	191	(106)
Industrial and Field Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	174,143	186,417	324,500	342,300
Oil Re-refining and Recycling | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	144,016	123,008	272,937	263,092
Oil Re-refining and Recycling | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	(54,861)	(48,261)	(102,977)	(98,287)
Oil Re-refining and Recycling | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	(5)	0	(5)	0
Oil Re-refining and Recycling | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	89,150	74,747	169,955	164,805
SK Environmental Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	171,324	166,523	332,712	326,325
SK Environmental Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	23,307	32,207	43,264	67,077
SK Environmental Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	0	0	(58)	84
SK Environmental Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	194,631	198,730	375,918	393,486
Lodging Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	42,872	46,685	99,566	100,015
Lodging Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	900	1,207	1,294	1,809
Lodging Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	25	101	26	217
Lodging Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	43,797	47,993	100,886	102,041
Oil and Gas Field Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	58,177	68,444	158,949	183,607
Oil and Gas Field Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	1,619	1,738	3,708	5,633
Oil and Gas Field Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	(22)	(49)	(10)	(200)
Oil and Gas Field Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	59,774	70,133	162,647	189,040
Corporate Items | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	139	381	290	(9,395)
Corporate Items | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	0	0	0	0
Corporate Items | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	(812)	(1,263)	(1,321)	(2,186)
Corporate Items | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	$ (673)	$ (882)	$ (1,031)	$ (11,581)