Basis of Presentation and Significant Accounting Policies - Supplemental cash flow information (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended		12 Months Ended
	Feb. 29, 2012	Jan. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Capital expenditures financed by accounts payable			$ 479	$ 1,123	$ 100
Capital lease obligations			1,009	0	0
Deferred debt origination fees			0	886	0
Additional purchase price paid in 2012 for Tube Supply acquisition			0	6,472	0
Cash paid during the year for:
Interest			34,051	7,234	4,392
Income taxes			5,557	9,555	1,631
Cash received during the year for:
Income tax refunds	$ 2,025	$ 6,344	$ 3,184	$ 6,724	$ 4,430