Share-Based Compensation - Summary of SARs Outstanding (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
SARs, Beginning Balance	9,027,037
SARs, Granted	1,431,558
SARs, Exercised	(351,857)
SARs, Forfeited, canceled or expired	(324,726)
SARs, Ending Balance	9,782,012
SARs, Vested and expected to vest at ending balance	9,418,066
SARs, Exercisable at ending balance	6,142,551
SARs, Weighted Average Exercise Price, Beginning balance	$ 72.14
SARs, Weighted Average Exercise Price, Granted	$ 72.12
SARs, Weighted Average Exercise Price, Exercised	$ 65.28
SARs, Weighted Average Exercise Price, Forfeited, canceled or expired	$ 75.42
SARs, Weighted Average Exercise Price, Ending balance	$ 72.28
SARs, Weighted Average Exercise Price, Vested and expected to vest	$ 72.23
SARs, Weighted Average Exercise Price, Exercisable	$ 71.56
SARs, Weighted Average Remaining Contractual Term	6 years 6 months 7 days
SARs, Weighted Average Remaining Contractual Term, Vested and expected to vest	6 years 5 months 16 days
SARs, Weighted Average Remaining Contractual Term, Exercisable	5 years 6 months 18 days
SARs, Aggregate Intrinsic Value	$ 68,123
SARs, Aggregate Intrinsic Value, Vested and expected to vest	66,275
SARs, Aggregate Intrinsic Value, Exercisable	$ 49,643