Consolidated Statements of Financial Position (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 68	$ 78
Common stock, par value	$ 1.00	$ 1.00
Common stock, shares authorized	1,800,000,000	1,800,000,000
Common stock, shares issued	700,718,785	688,483,873
Treasury stock, at cost, shares	15,643,146	6,176,266