Derivative Instruments (Details) (Textual) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Customers	Dec. 31, 2011	Dec. 31, 2010
Derivative Instruments (Textual) [Abstract]
Anticipated foreign-denominated sales hedge	$ 13,037
Foreign-denominated sales cash flow contracts	0
Percentage of purchase commitments covering anticipated natural gas usage	46.00%
Purchase commitment amount of anticipated natural gas usage	7,000
Number of subsidiaries purchased commitments for natural gas usage	1
Gains (losses) on foreign exchange transactions included in other income (expense)	107	(371)	655
Purchase commitments covering period usage, years	3 years
Foreign currency exchange contracts [Member]
Derivative [Line Items]
Fair value of assets held as collateral related to forward exchange contracts	812
Copper purchases [Member]
Derivative [Line Items]
Percentage of anticipated purchases hedged	57.00%
Anticipated purchases, hedged	3,267
Time period for hedged purchases	9 months
Aluminum purchases [Member]
Derivative [Line Items]
Percentage of anticipated purchases hedged	63.00%
Anticipated purchases, hedged	769
Time period for hedged purchases	6 months
Fair value of assets held as collateral related to futures	$ 500