Carrying value as of the balance sheet date of short-term borrowings using unsecured obligations issued by banks, corporations and other borrowers to investors. The maturities of these money market securities generally do not exceed 270 days.

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Long-term and Short-term Debt (Details Textuals 1) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
Issuance of long-term debt
Net proceeds from debt offering	$ 594.3	$ 0.0	$ 0.0
Fair value of interest rate swap contracts	5.4
Short-term Debt
Commercial paper borrowings outstanding	0.0	$ 325.0
Weighted average interest rate of commercial paper outstanding		0.17%
2.050% notes, payable in March 2020
Issuance of long-term debt
Long-term debt issued	$ 300.0
Stated interest rate	2.05%
Maturity date	Mar. 01, 2020
Effective floating interest rate	0.763%
2.875% notes, payable in March 2025
Issuance of long-term debt
Long-term debt issued	$ 300.0
Stated interest rate	2.875%
Maturity date	Mar. 01, 2025
Effective floating interest rate	1.173%
Aggregate principal amount of notes issued
Issuance of long-term debt
Long-term debt issued	$ 600.0