Long-term and Short-term Debt (Details Textuals 2) $ in Millions	12 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2015 USD ($)
Debt Disclosure [Abstract]
Interest payments	$ 74.2	$ 69.2	$ 60.8
Line of Credit [Member]
Line of Credit Facility [Line Items]
Borrowing capacity	$ 1,000.0
Expiration date	Mar. 24, 2020
Option to increase borrowing capacity of credit facility	$ 350.0
Non US Facilities [Member]
Line of Credit Facility [Line Items]
Borrowing capacity	$ 128.4
Maximum [Member] | Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum debt to total capital ratio required by debt covenants		0.60
Maximum ratio of EBITDA to interest expense under credit facility	3.0