Retirement Benefits - Narrative (Details) - USD ($)	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Expense related to defined contribution savings plans	$ 63,800,000	$ 58,500,000	$ 50,900,000
Defined benefit plan, percentage of benefit obligation relating to domestic plan	76.00%
Recognized prior service credits	$ 38,400,000
Recognized prior service credits, net of tax	30,000,000
Recognized net actuarial losses	60,100,000
Recognized net actuarial losses, net of tax	$ 45,600,000
Defined benefit plan, net periodic benefit cost (credit) excluding service cost, statement of income or comprehensive income [extensible enumeration]	Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest
Defined benefit plan, accumulated benefit obligation	$ 2,982,000,000	4,393,000,000
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Voluntary contribution to U.S. qualified pension plan	54,300,000	34,900,000
Recognized prior service credits	600,000	1,400,000	900,000
Recognized net actuarial losses	59,400,000	$ 141,400,000	$ 147,300,000
Estimated future payments, during next fiscal year	$ 26,100,000
Pension Benefits | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.65%	3.10%	2.90%
Pension Benefits | Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	4.35%	2.03%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Voluntary contribution to U.S. qualified pension plan	$ 7,900,000	$ 5,700,000
Recognized prior service credits	(800,000)	(5,400,000)	$ (5,400,000)
Recognized net actuarial losses	700,000	$ 1,100,000	1,400,000
Estimated future payments, during next fiscal year	$ 6,600,000
Other Postretirement Benefits | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.70%	2.50%
Other Postretirement Benefits | Non-U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Discount rate	5.10%	2.90%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Company contribution to defined contribution plan (percentage)	3.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Company contribution to defined contribution plan (percentage)	7.00%
Qualified Plan | U.S. Plans
Defined Benefit Plan Disclosure [Line Items]
Voluntary contribution to U.S. qualified pension plan	$ 0	$ 0	$ 50,000,000