SEGMENT INFORMATION (Details) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019 USD ($)		Jun. 30, 2018 USD ($)		Jun. 30, 2019 USD ($) segment		Jun. 30, 2018 USD ($)
Financial information for the reportable segments
Restructuring, Settlement and Impairment Provisions	$ 1,307		$ 11,542		$ 4,842		$ 21,717
Number of operating segments | segment					3
Net sales	777,008		790,052		$ 1,536,182		1,547,748
Inter-segment sales	0		0		0		0
Total	777,008		790,052		1,536,182		1,547,748
EBIT, as adjusted	109,548		111,405		212,114		212,884
Special items charge (gain)	166	[1]	12,330	[2]	4,491	[1]	25,170	[2]
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Gain (Loss) Due to Settlement and Curtailment							(758)
EBIT	109,382		99,075		207,623		187,714
Interest income	592		1,808		1,556		3,280
Interest expense	(6,490)		(6,620)		(12,777)		(12,533)
Income before income taxes	103,484		94,263		196,402		178,461
The Harris Products Group
Financial information for the reportable segments
Net sales	88,095		84,164		171,464		159,768
Inter-segment sales	2,113		2,003		3,980		3,910
Total	90,208		86,167		175,444		163,678
EBIT, as adjusted	13,488		10,157		24,007		19,382
Special items charge (gain)	0	[1]	0	[2]	0	[1]	0	[2]
EBIT	13,488		10,157		24,007		19,382
Corporate / Eliminations
Financial information for the reportable segments
Acquisition Transaction and Integration Costs	1,014		788		1,804		2,695
Net sales	0		0		0		0
Inter-segment sales	(41,112)		(38,740)		(76,576)		(71,742)
Total	(41,112)		(38,740)		(76,576)		(71,742)
EBIT, as adjusted	(3,969)		(3,186)		(7,011)		(3,344)
Special items charge (gain)	1,014	[1]	788	[2]	1,804	[1]	2,695	[2]
EBIT	(4,983)		(3,974)		(8,815)		(6,039)
Americas Welding
Financial information for the reportable segments
Restructuring, Settlement and Impairment Provisions	380				1,716
Net sales	476,607		462,515		934,326		897,287
Inter-segment sales	34,811		31,240		64,199		57,826
Total	511,418		493,755		998,525		955,113
EBIT, as adjusted	84,851		88,158		166,603		165,597
Special items charge (gain)	1,779	[1]	0	[2]	3,115	[1]	758	[2]
Defined Benefit Plan, Net Periodic Benefit (Cost) Credit, Gain (Loss) Due to Settlement and Curtailment							(758)
Business Combination, Inventory Step Up	1,399				1,399
EBIT	83,072		88,158		163,488		164,839
International Welding
Financial information for the reportable segments
Restructuring, Settlement and Impairment Provisions	927		11,542		3,126		21,717
Net sales	212,306		243,373		430,392		490,693
Inter-segment sales	4,188		5,497		8,397		10,006
Total	216,494		248,870		438,789		500,699
EBIT, as adjusted	15,178		16,276		28,515		31,249
Special items charge (gain)	(2,627)	[1]	11,542	[2]	(428)	[1]	21,717	[2]
Gain (Loss) on Disposition of Assets	3,554				3,554
EBIT	$ 17,805		$ 4,734		$ 28,943		$ 9,532

[1] In the three months ended June 30, 2019, special items reflect Rationalization and asset impairment charges of $380 in Americas Welding and $927 in International Welding, amortization of step up in value of acquired inventories of $1,399 in Americas Welding, gains on disposal of assets of $3,554 in International Welding and transaction and integration costs of $1,014 in Corporate / Eliminations related to the Air Liquide Welding acquisition. In the six months ended June 30, 2019, special items reflect Rationalization and asset impairment charges of $1,716 in Americas Welding and $3,126 in International Welding, amortization of step up in value of acquired inventories of $1,399 in Americas Welding, gains on disposals of assets of $3,554 in International Welding and transaction and integration costs of $1,804 in Corporate / Eliminations related to the Air Liquide Welding acquisition.

[2] In the three months ended June 30, 2018, special items reflect rationalization and asset impairment charges of $11,542 in International Welding and transaction and integration costs of $788 in Corporate / Eliminations related to the Air Liquide Welding acquisition. In the six months ended June 30, 2018, special items reflect pension settlement charges of $758 in Americas Welding, Rationalization and asset impairment charges of $21,717 in International Welding and transaction and integration costs of $2,695 in Corporate / Eliminations related to the Air Liquide Welding acquisition.