Derivatives (Details 1)	Dec. 31, 2014 lb	Dec. 31, 2013 lb
Copper [Member] | Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount	29,400,000	22,900,000
Copper [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount	2,900,000	2,000,000
Aluminum [Member] | Not Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative, nonmonetary notional amount	2,200,000	2,700,000