Debt and Financing Arrangements - Components of Net Financing Charges (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012
Debt Disclosure [Abstract]
Interest expense, net of capitalized interest costs	$ 69	$ 62	$ 129	$ 111
Banking fees and bond cost amortization	5	7	10	14
Interest income	(3)	(4)	(7)	(7)
Net foreign exchange results for financing activities	(5)	(2)	(5)	(6)
Net financing charges	$ 66	$ 63	$ 127	$ 112