Segment Reporting - Information by Reportable Segment (Details) (USD $) In Thousands, unless otherwise specified	3 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
Summary of segment information
Net Sales	$ 274,021		$ 304,039	$ 329,392	$ 362,916	$ 282,150		$ 294,860	$ 282,568	$ 272,788	$ 1,270,368		$ 1,132,366		$ 943,706
Operating Income (Loss)											41,145		5,194		(9,338)
Total Assets	788,806					822,323					788,806		822,323		529,352
Capital Expenditures											11,650		12,867		7,572
Depreciation and amortization expense											25,867		20,472		20,649
Metals Segment
Summary of segment information
Net Sales											1,143,884	[1]	1,014,130	[1]	841,067
Operating Income (Loss)											49,822	[1]	13,524	[1]	(5,478)
Total Assets	693,803	[1]				729,692	[1]				693,803	[1]	729,692	[1]	454,345
Capital Expenditures											9,819	[1]	10,639	[1]	6,815
Depreciation and amortization expense											24,480	[1]	19,329	[1]	19,392
Plastics Segment
Summary of segment information
Net Sales											126,484		118,236		102,639
Operating Income (Loss)											3,188		2,860		3,559
Total Assets	56,149					56,171					56,149		56,171		47,128
Capital Expenditures											1,831		2,228		757
Depreciation and amortization expense											1,387		1,143		1,257
Other
Summary of segment information
Net Sales											0	[2]	0	[2]	0	[2]
Operating Income (Loss)											(11,865)	[2]	(11,190)	[2]	(7,419)	[2]
Total Assets	38,854	[2]				36,460	[2]				38,854	[2]	36,460	[2]	27,879	[2]
Capital Expenditures											0	[2]	0	[2]	0	[2]
Depreciation and amortization expense											$ 0	[2]	$ 0	[2]	$ 0	[2]

[1] The results of Tube Supply, acquired on December 15, 2011, are included in the Company's Metals segment.

[2] “Other” – Operating loss includes the costs of executive, legal and finance departments, which are shared by both the Metals and Plastics segments. The “Other” category’s total assets consist of the Company’s investment in joint venture.