Aggregate Stock Option and SARs Activity (Detail) (USD $)	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2014 Stock Option Program and Stock Appreciation Rights Program (SARs)
Number of Options/SARs
Beginning balance (shares)			2,700,000
Granted	0	0	100,000
Exercised (shares)			(800,000)
Forfeited (shares)			0
Ending balance (shares)			2,000,000
Exercisable (shares)			1,600,000
Weighted Average Exercise Price
Beginning balance (US$ per share)			$ 37.60
Granted (US$ per share)			$ 40.89
Exercised (US$ per share)			$ 30.80
Forfeited (US$ per share)			$ 0.00
Ending balance (US$ per share)			$ 38.26
Exercisable (US$ per share)			$ 36.70