QUARTERLY FINANCIAL DATA (UNAUDITED) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Quarterly financial data (unaudited)
Net sales	$ 684,648	$ 697,552	$ 744,045	$ 727,122	$ 694,513	$ 701,624	$ 699,293	$ 599,179	$ 2,853,367	$ 2,694,609	$ 2,070,172
Gross profit	213,032	213,362	224,997	215,265	194,343	185,452	195,504	161,438	866,656	736,737	563,819
Income before income taxes	87,605	90,889	98,157	92,919	83,427	75,873	81,494	60,537	369,570	301,331	187,108
Net income	62,084	64,765	66,319	64,243	57,733	55,530	57,013	46,910	257,411	217,186	130,244
Basic earnings per share (in dollars per share)	$ 0.75	$ 0.78	$ 0.80	$ 0.77	$ 0.69	$ 0.66	$ 0.69	$ 0.56	$ 3.10	$ 2.60	$ 1.54
Diluted earnings per share (in dollars per share)	$ 0.74	$ 0.77	$ 0.79	$ 0.76	$ 0.68	$ 0.66	$ 0.68	$ 0.55	$ 3.06	$ 2.56	$ 1.53
Rationalization and asset impairment net gains (charges)	(5,037)	(3,059)	(1,258)						(9,354)	(282)	384
Rationalization and asset impairment net gains (charges), after-tax	(3,823)	(2,704)	(915)
Asia Pacific Welding
Quarterly financial data (unaudited)
Net sales									324,482	376,276	324,092
Rationalization and asset impairment net gains (charges)							75		(3,151)	(93)	(427)
Rationalization and asset impairment net gains (charges), after-tax							44
Europe Welding and Asia Pacific Welding
Quarterly financial data (unaudited)
Rationalization and asset impairment net gains (charges)								(357)
Rationalization and asset impairment net gains (charges), after-tax								(281)
North America Welding
Quarterly financial data (unaudited)
Net sales									1,580,818	1,309,499	1,013,193
Rationalization and asset impairment net gains (charges)									(827)
Gain related to a favorable adjustment for tax audit settlements								4,844
South America Welding
Quarterly financial data (unaudited)
Net sales									161,483	156,684	117,419
Rationalization and asset impairment net gains (charges)			(1,381)
Rationalization and asset impairment net gains (charges), after-tax			$ (906)