Retirement Benefits (Change in Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
US [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	$ 2,746.2	$ 2,534.2
Actual return on plan assets	(14.0)	317.6
Company contributions	63.1	17.5
Participant contributions	0.0	0.0
Benefits paid	(181.8)	(123.1)
Settlements	0.0	0.0
Currency translation/other	0.1	0.0
Fair Value at End of Year	2,613.6	2,746.2
Funded Status at End of Year	(526.3)	(256.7)
International [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value at beginning of year	1,368.4	1,266.6
Actual return on plan assets	25.9	116.3
Company contributions	74.4	60.7
Participant contributions	2.1	2.4
Benefits paid	(50.3)	(50.1)
Settlements	(8.6)	(1.9)
Currency translation/other	(109.1)	(25.6)
Fair Value at End of Year	1,302.8	1,368.4
Funded Status at End of Year	(345.1)	(367.3)
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Benefits paid	$ (9.3)	$ (9.0)