Derivative Instruments (Details 2) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Cash flow hedges [Member]
Summary of change in fair value reclassified or expected to be reclassified from accumulated other comprehensive income (loss) to earnings
Expected release to pre - tax earnings
Fair value hedges [Member]
Summary of change in fair value reclassified or expected to be reclassified from accumulated other comprehensive income (loss) to earnings
Expected release to pre - tax earnings
Foreign currency sales contracts [Member] | Cash flow hedges [Member]
Summary of change in fair value reclassified or expected to be reclassified from accumulated other comprehensive income (loss) to earnings
Amount released to pre - tax earnings	197	228	999
Foreign currency sales contracts [Member] | Fair value hedges [Member]
Summary of change in fair value reclassified or expected to be reclassified from accumulated other comprehensive income (loss) to earnings
Amount released to pre - tax earnings
Foreign currency purchases contracts [Member]
Summary of change in fair value reclassified or expected to be reclassified from accumulated other comprehensive income (loss) to earnings
Expected release to pre - tax earnings	27
Amount released to pre - tax earnings	27	32	16
Futures contracts - copper and aluminum [Member]
Summary of change in fair value reclassified or expected to be reclassified from accumulated other comprehensive income (loss) to earnings
Expected release to pre - tax earnings	40
Amount released to pre - tax earnings	$ (398)	$ 353	$ 328