BUSINESS COMBINATIONS (Narrative) (Details) $ in Thousands		1 Months Ended	3 Months Ended	6 Months Ended
	Apr. 11, 2015 USD ($)	Dec. 31, 2015 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2016 USD ($) aquisition
Business Acquisition [Line Items]
Goodwill, acquired during period				$ 1,197
2016 Acquisitions
Business Acquisition [Line Items]
Number of acquisitions | aquisition				2
Purchase price				$ 59,000
Revenue from acquisitions			$ 12,100	12,100
Acquisition-related costs			$ 400	$ 500
Thermo Fluids Inc.
Business Acquisition [Line Items]
Purchase price	$ 79,300
Privately Owned Domestic Company
Business Acquisition [Line Items]
Payments to acquire business		$ 14,700
Goodwill, acquired during period		$ 7,400