Retirement Benefit (Details Textuals) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2014
Defined Benefit Plan Disclosure [Line Items]
Company contribution range	3% to 7%
Recognized prior service credits	$ 14.0
Recognized prior service credits, net of tax	8.9
Recognized net actuarial losses	126.8
Recognized net actuarial losses, net of tax	82.7
Accumulated benefit obligation for pension plans	4,429.1	$ 3,979.3
(Decrease) increase in projected benefit obligation due to change in mortality assumption	(28.0)	222.1
Expense related to defined contribution savings plans	38.6	46.3	$ 43.8
Defined Benefit Plan, Amounts that will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year
Prior service credits	9.8
Prior service credits, net of tax	6.5
Net actuarial losses	155.5
Net actuarial losses, net of tax	102.1
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Recognized prior service credits	2.9	2.7	2.7
Recognized net actuarial losses	124.5	118.7	99.7
Lump-sum distributions to deferred vested participants in the U.S. defined benefit plans, total payments		108.8
Estimated future payments, during next fiscal year	49.2
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Recognized prior service credits	11.1	14.5	10.2
Recognized net actuarial losses	2.3	$ 4.5	$ 2.9
Estimated future payments, during next fiscal year	$ 10.6
U.S. Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Ultimate gross health care cost trend rate	5.50%
Year that gross health care cost trend rate will be reached	2018
Non-U.S. Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Ultimate gross health care cost trend rate	4.50%
Year that gross health care cost trend rate will be reached	2017