SEGMENT REPORTING (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Total revenues	$ 851,465	$ 907,535	$ 2,556,612	$ 2,630,226
Third party revenues
Segment Reporting Information [Line Items]
Total revenues	851,465	907,535	2,556,612	2,630,226
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	851,465	907,535	2,556,612	2,630,226
Technical Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	272,478	269,465	766,057	759,666
Technical Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	39,296	35,406	116,812	85,614
Technical Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	1,628	964	2,805	3,155
Technical Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	313,402	305,835	885,674	848,435
Industrial and Field Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	163,582	174,829	510,696	543,675
Industrial and Field Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	(9,234)	(8,109)	(32,039)	(34,549)
Industrial and Field Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	29	(72)	220	(178)
Industrial and Field Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	154,377	166,648	478,877	508,948
Oil Re-refining and Recycling | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	140,345	131,934	413,282	395,026
Oil Re-refining and Recycling | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	(52,606)	(45,566)	(155,583)	(143,853)
Oil Re-refining and Recycling | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	0	0	(5)	0
Oil Re-refining and Recycling | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	87,739	86,368	257,694	251,173
SK Environmental Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	170,980	170,166	503,692	496,491
SK Environmental Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	21,212	17,164	64,476	84,241
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	192,192	187,330	568,110	580,816
Lodging Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	36,582	55,571	136,148	155,586
Lodging Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	697	812	1,991	2,621
Lodging Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	26	145	52	362
Lodging Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	37,305	56,528	138,191	158,569
Oil and Gas Field Services | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	67,370	104,981	226,319	288,588
Oil and Gas Field Services | Intersegment revenues, net
Segment Reporting Information [Line Items]
Total revenues	635	293	4,343	5,926
Oil and Gas Field Services | Corporate Items, net
Segment Reporting Information [Line Items]
Total revenues	4	(114)	(6)	(314)
Oil and Gas Field Services | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	68,009	105,160	230,656	294,200
Corporate Items | Third party revenues
Segment Reporting Information [Line Items]
Total revenues	128	589	418	(8,806)
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	(1,687)	(923)	(3,008)	(3,109)
Corporate Items | Direct revenues
Segment Reporting Information [Line Items]
Total revenues	$ (1,559)	$ (334)	$ (2,590)	$ (11,915)