Long-term and Short-term Debt (Details Textuals) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Date	Mar. 15, 2015
Unsecured revolving credit facility	$ 750.0	$ 750.0
Long term and Short term (Textuals) [Abstract]
Maximum debt to total capital ratio required by debt covenants	60.00%
Commercial Paper	157.0	0
Short-term Debt, Weighted Average Interest Rate	0.27%
Short Term Debt Weighted Average Maturity Period	6 days
Interest payments	59.0	60.1	59.4
Non US Facilities [Member]
Line of Credit Facility [Line Items]
Unsecured revolving credit facility	$ 120.6