Market Concentrations and Risks (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2011 Customers Distributers lb	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Workforce subject to collective bargaining arrangements [Member]	Dec. 31, 2012 Workforce subject to collective bargaining arrangements expiring within one year [Member]	Dec. 31, 2011 Senior Subordinated notes due 2017 [Member]	Dec. 31, 2010 Senior Subordinated notes due 2017 [Member]	Dec. 31, 2011 Senior Subordinated notes due 2019 [Member]	Dec. 31, 2010 Senior Subordinated notes due 2019 [Member]
Concentration Risk [Line Items]
Carrying amount of debt instruments	$ 550,926,000	$ 551,155,000				$ 350,000,000	$ 350,000,000	$ 200,926,000	$ 201,155,000
Fair value of debt instrument	561,400,000					347,400,000		214,000,000
Concentration risk, percentage	36.00%	33.00%	35.00%	14.00%	12.00%
Face value of senior subordinated notes						350,000,000		200,000,000
Market Concentrations and Risks (Textual) [Abstract]
Number of customers	10
Number of Distributers	7
Committed amounts to purchase of copper	7,000,000
Aggregate cost of copper	24,100,000
Recorded unconditional purchase obligation fixed cost	$ 100,000