Derivative Instruments and Hedging Activities (Details)	Sep. 30, 2011 Age Plant lb MetricTon Person	Sep. 30, 2010 MetricTon lb
Outstanding commodity hedge contracts
Pounds of Copper	18,760,000	24,550,000
Metric Tons of Lead	25,600	18,450
Metric Tons of Aluminum	5,398	8,276
Metric Tons of Tin	260	0