Retirement Benefits (Amount of accumulated other comprehensive income expected to be recognized in next fiscal year) (Details) $ in Millions	12 Months Ended
	Sep. 30, 2015 USD ($)
US [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 84.4
Prior service cost	2.7
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	40.5
Prior service cost	(0.1)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 0.7