Retirement Benefits (Schedule of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
US [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 45.1	$ 43.6	$ 42.5
Interest cost	124.2	122.8	123.4
Expected return on plan assets	(178.2)	(179.4)	(164.3)
Prior service cost amortization	2.7	2.6	2.7
Actuarial loss amortization	78.6	63.9	46.9
Settlement and curtailment charges	0	0	10.7
Special termination benefits	4.6	0	(0.9)
Other	0	0	0
Net periodic benefit cost	77.0	53.5	61.0
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	24.1	29.5	24.2
Interest cost	62.3	64.2	60.2
Expected return on plan assets	(66.7)	(68.1)	(64.3)
Prior service cost amortization	0.5	0.6	0.7
Actuarial loss amortization	17.4	30.9	19.9
Settlement and curtailment charges	1.4	1.0	0.8
Special termination benefits	2.2	0.3	4.2
Other	2.2	2.2	2.3
Net periodic benefit cost	43.4	60.6	48.0
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	4.5	5.7	4.7
Interest cost	3.9	3.3	4.6
Prior service cost amortization	0	0	(0.1)
Actuarial loss amortization	2.9	3.8	2.9
Net periodic benefit cost	$ 11.3	$ 12.8	$ 12.1