Product Line Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Revenue from External Customer [Line Items]
Revenue from External Customers	$ 132,257	$ 129,269	$ 259,128	$ 245,766
Gas equipment
Revenue from External Customer [Line Items]
Revenue from External Customers	46,843	48,178	95,814	90,861
Plasma power supplies, torches and related consumable parts
Revenue from External Customer [Line Items]
Revenue from External Customers	22,541	20,903	43,291	41,053
Arc accessories, including torches, related consumable parts and accessories
Revenue from External Customer [Line Items]
Revenue from External Customers	25,066	22,965	46,036	43,677
Welding equipment
Revenue from External Customer [Line Items]
Revenue from External Customers	13,913	11,804	23,142	21,959
Filler metals and hardfacing alloys
Revenue from External Customer [Line Items]
Revenue from External Customers	$ 23,894	$ 25,419	$ 50,845	$ 48,216