Summary of Option Activity (Detail) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Sep. 30, 2013
Options
Beginning balance	5,185,675
Granted	579,318
Forfeited/expired	(51,766)
Exercised	(1,796,021)
Ending balance	3,917,206
Options exercisable at September 30, 2012	2,973,421
Options exercisable and expected to be vested at September 30, 2012	3,822,828	[1]
Weighted average price per share
Beginning balance	$ 59.46
Granted	$ 147.37
Forfeited/expired	$ 109.35
Exercised	$ 58.56
Ending balance	$ 72.21
Options exercisable at September 30, 2013	$ 57.74
Options exercisable and expected to be vested at September 30, 2013	$ 71.08	[1]
Weighted-Average Remaining Contractual Term
Outstanding at September 30, 2013	5 years 8 months 12 days
Options exercisable at September 30, 2013	4 years 9 months 18 days
Options exercisable and expected to be vested at September 30, 2013	5 years 7 months 6 days	[1]
Aggregate Intrinsic Value
Outstanding at September 30, 2013	$ 466
Options exercisable at September 30, 2013	397
Options exercisable and expected to be vested at September 30, 2013	$ 459	[1]

[1] Applies a forfeiture rate to unvested options outstanding at September 30, 2013 to estimate the number expected to vest in the future.