ACQUISITIONS (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended										1 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	Dec. 31, 2012 Tennessee Rand, Inc.	Nov. 12, 2012 Kaliburn	Apr. 30, 2012 Wayne Trail Technologies Inc.	Dec. 31, 2011 Weartech International Inc.	Jun. 30, 2011 Techalloy	Jun. 30, 2011 Torchmate	Dec. 31, 2010 OOO Severstal-metiz	Jan. 31, 2011 SSCO Manufacturing, Inc. (d/b/a Arc Products)	Dec. 31, 2012 SSCO Manufacturing, Inc. (d/b/a Arc Products)	Dec. 31, 2010 SSCO Manufacturing, Inc. (d/b/a Arc Products)	Oct. 31, 2010 MGM	Oct. 29, 2010 MGM
Acquisitions
Consideration paid in cash and assumed debt	$ 143,504				$ 65,321				$ 143,504	$ 65,321													$ 28,500
Fair value of assets acquired	75,764				46,837				75,764	46,837
Goodwill from acquisition	67,740				22,290				67,740	22,290
Annual sales at the date of acquisition	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	35,000	36,000	50,000	40,000	70,000	13,000					30,000
Sales for last annual period																		40,000
Fair value of contingent consideration liability																			$ 3,806	$ 4,894
Period of estimated sales as basis for contingent consideration (in years)																			5 years	5 years
Sales for prior annual period																					not significant