Retirement Benefits (Assumption in calculating net periodic benefit Cost) (Details)	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013
US [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.30%	4.80%	3.90%
Expected return on plan assets	8.30%	8.30%	8.30%
Rate of compensation increase	3.50%	4.00%	4.00%
US [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	8.90%
US [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	5.60%
US [Member] | Real Estate [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	7.40%
International [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	3.60%	4.30%	4.30%
Expected return on plan assets	6.10%	6.50%	6.50%
Rate of compensation increase	3.60%	3.70%	3.40%
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Discount rate	2.60%	2.40%	1.90%
United Kingdom [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	6.80%
Percentage of International Plan Assets	over 80%
United Kingdom [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	7.50%
United Kingdom [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	3.80%