Goodwill and Intangible Assets Intangibles (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	10 years 9 months 18 days
Gross Carrying Amount	$ 132,703	$ 132,104
Accumulated Amortization	50,226	38,291
Transtar
Finite-Lived Intangible Assets [Line Items]
Date of acquisition	Sep. 05, 2006
Tube Supply
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	11 years 5 months
Date of acquisition	Dec. 15, 2011
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	11 years 3 months 18 days
Gross Carrying Amount	119,118	118,567
Accumulated Amortization	45,317	34,960
Non-compete agreements
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Gross Carrying Amount	3,888	3,888
Accumulated Amortization	3,235	2,902
Trade name
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	9 years 4 months 24 days
Gross Carrying Amount	8,297	8,249
Accumulated Amortization	1,188	410
Developed technology
Finite-Lived Intangible Assets [Line Items]
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life	3 years
Gross Carrying Amount	1,400	1,400
Accumulated Amortization	$ 486	$ 19