Goodwill and Intangible Assets (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 Customer Relationships [Member]	Sep. 30, 2012 Noncompete Agreements [Member]	Sep. 30, 2012 Trade name [Member]	Sep. 30, 2012 Developed technology [Member]	Sep. 30, 2012 Transtar [Member]	Sep. 30, 2012 Tube Supply [Member]	Dec. 15, 2011 Tube Supply [Member]
Business Acquisition [Line Items]
Date of acquisition of Transtar									Sep. 05, 2006	Dec. 15, 2011
Common stock acquired											100.00%
Aggregate purchase price of Tube Supply											$ 184,385
weighted-average amortization period for intangible assets			10 years 9 months 18 days		11 years 3 months 18 days	3 years	9 years 4 months 24 days	3 years
Goodwill and Intangible Assets (Textual) [Abstract]
Amortization expense	$ 2,961	$ 1,657	$ 8,880	$ 4,979