PRODUCT WARRANTY COSTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Changes in the carrying amount of product warranty accruals
Balance at beginning of year		$ 22,029	$ 21,053	$ 19,469
Accruals for warranties		8,897	9,901	13,058
Settlements		(11,403)	(11,500)	(11,434)
Standard And Extended Product Warranty Accrual Foreign Currency Translation Gain (Loss) and Other Adjustments	[1]	255	2,575	(40)
Balance at end of year		$ 19,778	22,029	$ 21,053
Air Liquide Welding [Member]
Changes in the carrying amount of product warranty accruals
Standard And Extended Product Warranty Accrual Foreign Currency Translation Gain (Loss) and Other Adjustments			$ 2,299

[1] At December 31, 2017, Foreign currency translation and other adjustments includes $2,299 for an acquired liability related to the Air Liquide Welding acquisition as discussed in Note 4 to the consolidated financial statements.