SEGMENT REPORTING (Third Party Reveunes to Direct Revenues) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting Information [Line Items]
Total revenues	$ 732,499	$ 846,667
Third party revenues
Segment Reporting Information [Line Items]
Total revenues	732,499	846,667
Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	0	0
Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	0	0
Direct revenues
Segment Reporting Information [Line Items]
Total revenues	732,499	846,667
Technical Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	240,325	236,781
Technical Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	34,904	37,434
Technical Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	1,297	399
Technical Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	276,526	274,614
Industrial and Field Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	146,868	161,960
Industrial and Field Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	(6,561)	(11,758)
Industrial and Field Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	78	155
Industrial and Field Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	140,385	150,357
Oil Re-refining and Recycling | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	96,807	128,921
Oil Re-refining and Recycling | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	(18,257)	(48,116)
Oil Re-refining and Recycling | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	(1)	0
Oil Re-refining and Recycling | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	78,549	80,805
SK Environmental Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	160,684	161,388
SK Environmental Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	(11,582)	19,957
SK Environmental Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	0	(58)
SK Environmental Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	149,102	181,287
Lodging Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	34,104	56,694
Lodging Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	164	394
Lodging Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	17	1
Lodging Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	34,285	57,089
Oil and Gas Field Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	53,587	100,772
Oil and Gas Field Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	1,332	2,089
Oil and Gas Field Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	9	12
Oil and Gas Field Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	54,928	102,873
Corporate Items | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	124	151
Corporate Items | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	0	0
Corporate Items | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	(1,400)	(509)
Corporate Items | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	$ (1,276)	$ (358)