RATIONALIZATION AND ASSET IMPAIRMENTS (Summary of Activity Related to Rationalization Liabilities by Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Activity related to the rationalization liabilities by segment
Balance at the beginning of the period	$ 5,190	$ 7,665
Payments and other adjustments	(3,536)	(2,475)
Charged to expense	5,149
Balance at the end of the period	6,803	5,190
Americas Welding [Member]
Activity related to the rationalization liabilities by segment
Balance at the beginning of the period	0	67
Payments and other adjustments	0	(67)
Charged to expense	0
Balance at the end of the period	0	0
International Welding [Member]
Activity related to the rationalization liabilities by segment
Balance at the beginning of the period	5,190	7,598
Payments and other adjustments	(3,536)	(2,408)
Charged to expense	5,149
Balance at the end of the period	$ 6,803	$ 5,190