Basis of Presentation and Significant Accounting Policies - Supplemental cash flow information (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended			12 Months Ended
	Oct. 31, 2013	Feb. 29, 2012	Jan. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract]
Capital expenditures financed by accounts payable				$ 1,219	$ 479	$ 1,123
Capital lease obligations				21	1,009	0
Deferred debt origination fees				0	0	886
Additional purchase price paid in 2012 for Tube Supply acquisition				0	0	6,472
Cash paid during the year for:
Interest				33,266	34,051	7,234
Income taxes				2,417	5,557	9,555
Cash received during the year for:
Income tax refunds	$ 2,590	$ 2,025	$ 6,344	$ 3,015	$ 3,184	$ 6,724