Derivative Instruments and Hedging Activities (Details)	Jun. 30, 2011	Sep. 30, 2010	Jun. 30, 2010
Outstanding commodity hedge contracts
Pounds of Copper	13,150,000	24,550,000	16,735,000
Metric Tons of Lead	26,517	18,450	25,961
Metric Tons of Aluminum	1,134	8,276