Retirement Benefits (Schedule of Allocation of Plan Assets, Actual and Target Allocations) (Details) - Defined Benefit Pension Plan [Member]	Sep. 30, 2023	Sep. 30, 2022
United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	100.00%	100.00%
United States [Member] | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	31.90%	29.50%
United States [Member] | Equity Securities | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	2.30%	2.40%
United States [Member] | Equity Securities | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	51.20%	51.20%
United States [Member] | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	66.60%	69.00%
United States [Member] | Debt Securities | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	58.80%	58.80%
United States [Member] | Debt Securities | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	96.50%	87.60%
United States [Member] | Other Investment Asset
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	1.50%	1.50%
United States [Member] | Other Investment Asset | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	0.00%	0.00%
United Kingdom
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	100.00%	100.00%
United Kingdom | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	20.70%	46.20%
United Kingdom | Equity Securities | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	10.00%	50.00%
United Kingdom | Equity Securities | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	30.00%	90.00%
United Kingdom | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	79.20%	52.30%
United Kingdom | Debt Securities | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	70.00%	45.00%
United Kingdom | Debt Securities | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	90.00%	70.00%
United Kingdom | Other Investment Asset
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	0.10%	1.50%
United Kingdom | Other Investment Asset | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	0.00%	0.00%
Japan
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	100.00%	100.00%
Japan | Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	40.00%	39.90%
Japan | Equity Securities | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	36.00%	36.00%
Japan | Equity Securities | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	44.00%	44.00%
Japan | Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	60.00%	60.10%
Japan | Debt Securities | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	55.00%	55.00%
Japan | Debt Securities | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	63.00%	63.00%
Japan | Other Investment Asset
Defined Benefit Plan Disclosure [Line Items]
Percentage of Plan Assets	0.00%	0.00%
Japan | Other Investment Asset | Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	0.00%	0.00%
Japan | Other Investment Asset | Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Target Allocation Ranges	2.00%	2.00%