RETIREMENT AND POSTRETIREMENT BENEFIT PLANS (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement charges (1)					$ 758
Foreign Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		$ 701	$ 832	$ 1,429	1,683
Interest cost		922	937	1,858	1,907
Expected return on plan assets		(1,106)	(1,266)	(2,230)	(2,540)
Amortization of prior service cost		15	0	31	1
Amortization of net loss		572	555	1,157	1,130
Settlement charges (1)	[1]	0	0	0	0
Defined benefit plans		1,104	1,058	2,245	2,181
Multi-employer plans		243	234	490	461
Defined contribution plans		424	1,036	923	1,865
Total pension cost		1,771	2,328	3,658	4,507
Domestic Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost		35	35	70	70
Interest cost		4,653	4,493	9,306	8,987
Expected return on plan assets		(6,245)	(6,915)	(12,490)	(13,831)
Amortization of prior service cost		0	0	0	0
Amortization of net loss		414	384	827	768
Settlement charges (1)	[1]	0	0	0	758
Defined benefit plans		(1,143)	(2,003)	(2,287)	(3,248)
Multi-employer plans		0	0	0	0
Defined contribution plans		5,791	5,610	11,699	11,504
Total pension cost		$ 4,648	$ 3,607	$ 9,412	8,256
Americas Welding
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement charges (1)					$ 758

[1] Pension settlement charges resulting from lump sum pension payments in the six months ended June 30, 2018.