SUBSEQUENT EVENTS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		0 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Apr. 22, 2014 Subsequent Event PSC Environmental Services, LLC
Business Acquisition [Line Items]
Total consideration	$ 25,357	$ 29,353	$ 275,000
Consideration paid in cash	12,262	18,899	245,000
Consideration paid with note	$ 0	$ 955	$ 30,000
Note payable term			2 years