SEGMENT INFORMATION (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011 segment	Dec. 31, 2010	Dec. 31, 2009
SEGMENT INFORMATION
Number of operating segments									5
Percentage of total inventories valued using the LIFO method	31.00%				30.00%				31.00%	30.00%	31.00%
Financial information for the reportable segments
Net sales	$ 694,513,000	$ 701,624,000	$ 699,293,000	$ 599,179,000	$ 564,292,000	$ 519,338,000	$ 515,584,000	$ 470,958,000	$ 2,694,609,000	$ 2,070,172,000	$ 1,729,285,000
Total									2,694,609,000	2,070,172,000	1,729,285,000
EBIT, as adjusted									305,196,000	194,157,000	121,826,000
Special items charge (Gain)									282,000	2,739,000	30,029,000
EBIT									304,914,000	191,418,000	91,797,000
Interest income									3,121,000	2,381,000	3,462,000
Interest expense									(6,704,000)	(6,691,000)	(8,521,000)
Income before income taxes	83,427,000	75,873,000	81,494,000	60,537,000	51,976,000	48,819,000	51,572,000	34,741,000	301,331,000	187,108,000	86,738,000
Total assets	1,976,776,000				1,783,788,000				1,976,776,000	1,783,788,000	1,705,292,000
Equity investments in affiliates	24,618,000				22,909,000				24,618,000	22,909,000	22,899,000
Capital expenditures									65,813,000	60,565,000	38,201,000
Depreciation and amortization									62,051,000	57,357,000	56,598,000
Special items
Special items, net charges for rationalization actions			(75,000)						282,000	(384,000)	29,897,000
Special items, asset impairment charges						496,000			23,000	883,000	2,061,000
Special items, gain (loss) on the sale of assets at a rationalized operation										4,555,000
Special items, charge for the impact resulting from the change in functional currency to the U.S. dollar and devaluation of the Venezuelan currency						815,000
Special items, net charge related to environmental costs associated with the sale of property at a rationalized operation										871,000
Special items, intangible asset impairment charges											879,000
Special items, gain on the settlement of a pension obligation											(185,000)
North America Welding
Financial information for the reportable segments
Net sales									1,309,499,000	1,013,193,000	858,180,000
Inter-segment sales									136,314,000	108,849,000	85,630,000
Total									1,445,813,000	1,122,042,000	943,810,000
EBIT, as adjusted									227,924,000	162,192,000	134,544,000
Special items charge (Gain)											10,386,000
EBIT									227,924,000	162,192,000	124,158,000
Total assets	771,315,000				611,725,000				771,315,000	611,725,000	606,846,000
Capital expenditures									31,826,000	25,746,000	13,726,000
Depreciation and amortization									29,237,000	27,652,000	30,254,000
Special items
Special items, net charges for rationalization actions											10,386,000
Europe Welding
Financial information for the reportable segments
Net sales									508,692,000	359,925,000	346,383,000
Inter-segment sales									17,422,000	13,330,000	8,725,000
Total									526,114,000	373,255,000	355,108,000
EBIT, as adjusted									36,171,000	17,023,000	(2,196,000)
Special items charge (Gain)									392,000	2,486,000	4,335,000
EBIT									35,779,000	14,537,000	(6,531,000)
Total assets	436,327,000				413,789,000				436,327,000	413,789,000	359,093,000
Equity investments in affiliates	20,500,000				19,194,000				20,500,000	19,194,000	19,455,000
Capital expenditures									8,566,000	10,373,000	7,543,000
Depreciation and amortization									11,736,000	9,527,000	9,779,000
Special items
Special items, net charges for rationalization actions									188,000	1,990,000	9,615,000
Special items, asset impairment charges									22,000	496,000	253,000
Special items, gain (loss) on the sale of assets at a rationalized operation									(204,000)		5,667,000
Special items, intangible asset impairment charges											134,000
Asia Pacific Welding
Financial information for the reportable segments
Net sales									376,276,000	324,092,000	208,280,000
Inter-segment sales									15,614,000	12,546,000	4,051,000
Total									391,890,000	336,638,000	212,331,000
EBIT, as adjusted									2,629,000	1,752,000	(18,835,000)
Special items charge (Gain)									(110,000)	(3,741,000)	9,006,000
EBIT									2,739,000	5,493,000	(27,841,000)
Total assets	380,282,000				350,975,000				380,282,000	350,975,000	310,329,000
Capital expenditures									21,498,000	22,973,000	15,887,000
Depreciation and amortization									14,663,000	13,542,000	9,397,000
Special items
Special items, net charges for rationalization actions									93,000	427,000	1,692,000
Special items, asset impairment charges					387,000					387,000	1,515,000
Special items, gain (loss) on the sale of assets at a rationalized operation									203,000	4,555,000
Special items, gain on the settlement of a pension obligation											2,144,000
Special items, loss associated with the acquisition of Jin Tai and related divestiture of Kuang Tai											7,943,000
South America Welding
Financial information for the reportable segments
Net sales									156,684,000	117,419,000	99,171,000
Inter-segment sales									494,000	1,216,000	308,000
Total									157,178,000	118,635,000	99,479,000
EBIT, as adjusted									12,895,000	7,554,000	10,648,000
Special items charge (Gain)										3,123,000	528,000
EBIT									12,895,000	4,431,000	10,120,000
Total assets	110,781,000				94,836,000				110,781,000	94,836,000	81,734,000
Equity investments in affiliates	4,118,000				3,715,000				4,118,000	3,715,000	3,444,000
Capital expenditures									2,314,000	3,573,000	796,000
Depreciation and amortization									2,033,000	1,564,000	1,543,000
Special items
Special items, net charges for rationalization actions											528,000
Special items, charge for the impact resulting from the change in functional currency to the U.S. dollar and devaluation of the Venezuelan currency							2,319,000	(11,000)		3,123,000
The Harris Products Group
Financial information for the reportable segments
Net sales									343,458,000	255,543,000	217,271,000
Inter-segment sales									8,496,000	6,641,000	7,739,000
Total									351,954,000	262,184,000	225,010,000
EBIT, as adjusted									25,151,000	12,311,000	1,009,000
Special items charge (Gain)										871,000	5,774,000
EBIT									25,151,000	11,440,000	(4,765,000)
Total assets	181,916,000				193,474,000				181,916,000	193,474,000	181,753,000
Capital expenditures									1,792,000	884,000	2,457,000
Depreciation and amortization									4,714,000	5,012,000	5,485,000
Special items
Special items, net charges for rationalization actions											4,736,000
Special items, asset impairment charges											293,000
Special items, net charge related to environmental costs associated with the sale of property at a rationalized operation										871,000
Special items, intangible asset impairment charges											745,000
Corporate / Eliminations
Financial information for the reportable segments
Inter-segment sales									(178,340,000)	(142,582,000)	(106,453,000)
Total									(178,340,000)	(142,582,000)	(106,453,000)
EBIT, as adjusted									426,000	(6,675,000)	(3,344,000)
EBIT									426,000	(6,675,000)	(3,344,000)
Total assets	96,155,000				118,989,000				96,155,000	118,989,000	165,537,000
Capital expenditures									(183,000)	(2,984,000)	(2,208,000)
Depreciation and amortization									$ (332,000)	$ 60,000	$ 140,000