QUARTERLY FINANCIAL DATA (UNAUDITED) (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	Dec. 31, 2010	Dec. 31, 2009
QUARTERLY FINANCIAL DATA (UNAUDITED)
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
Gross profit	194,343,000	185,452,000	195,504,000	161,438,000	147,832,000	144,071,000	148,583,000	123,333,000	736,737,000	563,819,000	456,268,000
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
Net income	57,733,000	55,530,000	57,013,000	46,910,000	41,503,000	32,473,000	32,540,000	23,728,000	217,186,000	130,244,000	48,576,000
Basic earnings per share (in dollars per share)	$ 0.69	$ 0.66	$ 0.69	$ 0.56	$ 0.49	$ 0.39	$ 0.38	$ 0.28	$ 2.60	$ 1.54	$ 0.57
Diluted earnings per share (in dollars per share)	$ 0.68	$ 0.66	$ 0.68	$ 0.55	$ 0.49	$ 0.38	$ 0.38	$ 0.28	$ 2.56	$ 1.53	$ 0.57
Quarterly financial data (unaudited)
Rationalization and asset impairment net gains			75,000						(282,000)	384,000	(29,897,000)
Rationalization and asset impairment net gains, after-tax			44,000
Asset impairment charges						496,000			23,000	883,000	2,061,000
Asset impairment charges, after-tax						496,000
Net charge for rationalization costs associated with the consolidation of manufacturing operations					(1,788,000)	227,000			282,000
Net charge for rationalization costs associated with the consolidation of manufacturing operations, after-tax					(1,697,000)	231,000
Gain (charge) in noncontrolling interests related to the impairment of assets for a majority-owned consolidated subsidiary, after-tax						(44,000)	(1,846,000)
Gain (charge) for the impact resulting from the change in functional currency to the U.S. dollar and devaluation of the Venezuelan currency						815,000
Gain (charge) for the impact resulting from the change in functional currency to the U.S. dollar and devaluation of the Venezuelan currency, after-tax						815,000
North America Welding
QUARTERLY FINANCIAL DATA (UNAUDITED)
Net sales									1,309,499,000	1,013,193,000	858,180,000
Quarterly financial data (unaudited)
Rationalization and asset impairment net gains											(10,386,000)
Gain related to a favorable adjustment for tax audit settlements				4,844,000
Europe Welding
QUARTERLY FINANCIAL DATA (UNAUDITED)
Net sales									508,692,000	359,925,000	346,383,000
Quarterly financial data (unaudited)
Rationalization and asset impairment net gains									(188,000)	(1,990,000)	(9,615,000)
Asset impairment charges									22,000	496,000	253,000
Asia Pacific Welding
QUARTERLY FINANCIAL DATA (UNAUDITED)
Net sales									376,276,000	324,092,000	208,280,000
Quarterly financial data (unaudited)
Rationalization and asset impairment net gains									(93,000)	(427,000)	(1,692,000)
Asset impairment charges					387,000					387,000	1,515,000
Asset impairment charges, after-tax					305,000
Gain related to a favorable adjustment for tax audit settlements					5,092,000
Gain (charge) in noncontrolling interests related to the impairment of assets for a majority-owned consolidated subsidiary, after-tax					108,000
South America Welding
QUARTERLY FINANCIAL DATA (UNAUDITED)
Net sales									156,684,000	117,419,000	99,171,000
Quarterly financial data (unaudited)
Rationalization and asset impairment net gains											(528,000)
Gain (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
Gain (charge) for the impact resulting from the change in functional currency to the U.S. dollar and devaluation of the Venezuelan currency, after-tax							2,319,000	426,000
Europe Welding and Asia Pacific Welding
Quarterly financial data (unaudited)
Rationalization and asset impairment net gains				(357,000)			3,629,000	(801,000)
Rationalization and asset impairment net gains, after-tax				$ (281,000)			$ 3,773,000	$ (612,000)