Debt (Long-term Debt) (Details) (USD $) In Millions, unless otherwise specified			12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended			12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012 United States 5.0%	Sep. 30, 2011 United States 5.0%	Sep. 30, 2012 Foreign 4.1%	Sep. 30, 2011 Foreign 4.1%	Sep. 30, 2012 Debentures 8.75%	Sep. 30, 2011 Debentures 8.75%	Sep. 30, 2012 Series D 7.3%	Sep. 30, 2011 Series D 7.3%	Sep. 30, 2012 Series E 7.6%	Sep. 30, 2011 Series E 7.6%	Sep. 30, 2012 Note 4.15%	Sep. 30, 2011 Note 4.15%	Sep. 30, 2012 Note 2.0%	Sep. 30, 2011 Note 2.0%	Sep. 30, 2012 Note 1.2%	Sep. 13, 2012 Note 1.2%	Sep. 30, 2011 Note 1.2%	Sep. 30, 2012 Note 4.375%	Sep. 30, 2011 Note 4.375%	Sep. 30, 2012 Note 3.0%	Nov. 03, 2011 Note 3.0%	Sep. 30, 2011 Note 3.0%	Sep. 30, 2012 Variable-rate industrial revenue bonds 0.2%	Sep. 30, 2011 Variable-rate industrial revenue bonds 0.2%	Sep. 30, 2012 Other 2.7%	Sep. 30, 2011 Other 2.7%	Sep. 30, 2012 Eurobonds 4.25%	Sep. 30, 2011 Eurobonds 4.25%	Sep. 30, 2012 Eurobonds 3.75%	Sep. 30, 2011 Eurobonds 3.75%	Sep. 30, 2012 Eurobonds 3.875%	Sep. 30, 2011 Eurobonds 3.875%	Sep. 30, 2012 Eurobonds 4.625%	Sep. 30, 2011 Eurobonds 4.625%	Sep. 30, 2012 Other 2.6%	Sep. 30, 2011 Other 2.6%	Sep. 30, 2012 RMB Syndicated Credit Facility 4.6%	Sep. 30, 2011 RMB Syndicated Credit Facility 4.6%
Debt Instrument [Line Items]
Interest rate of debt, stated percentage			5.00%		4.10%		8.75%						4.15%		2.00%		1.20%	1.20%		4.375%		3.00%	3.00%						4.25%		3.75%		3.875%		4.625%		2.60%
Weighted average interest rate									7.30%		7.60%														0.20%		2.70%
Debt Instruments Maturity Year							2021		2016		2026		2013		2016		2018			2019		2022							2012		2014		2015		2017				2015
Debt Instrument, Maturity Year Range, Start			2013		2013																				2021		2013										2013
Debt Instrument, Maturity Year Range, End			2018		2017																				2050		2019										2018
Senior Notes							$ 18.4	$ 18.4					$ 300.0	$ 300.0	$ 350.0	$ 350.0	$ 400.0	$ 400.0	$ 0	$ 400.0	$ 400.0	$ 400.0	$ 400.0	$ 0
Medium-term Notes									32.1	32.1	17.2	17.2
Other Long-term Debt																									917.1	975.1	67.8	58.5
Debt Payable In Other Currencies																													0	401.6	385.8	401.6	385.8	401.6	385.8	401.6	569.3	241.9	31.7	0
Capital Lease Obligations	2.5	7.5	1.5	4.8	1.0	2.7
Less: Unamortized discount	(5.0)	(7.4)
Total	4,658.5	3,999.7
Less: Current portion	(74.3)	(72.2)
Long-term debt	$ 4,584.2	$ 3,927.5