Reconciliation of the numerators and denominators (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Income Available to Common Shareholders
Basic income available to common shareholders	$ 1,178	$ 1,184	$ 1,415
Interest expense, net of tax	0	1	3
Diluted income available to common shareholders	$ 1,178	$ 1,185	$ 1,418
Weighted Average Shares Outstanding
Basic weighted average shares outstanding	683.7	681.5	677.7
Effect of dilutive securities:
Stock options and unvested restricted stock	5.5	5.2	8.1
Equity units	0	1.9	4.1
Diluted weighted average shares outstanding	689.2	688.6	689.9
Antidilutive Securities
Options to purchase common shares	0.8	1.4	0.3