Retirement and Other Benefit Plans (Schedule Of Asset Allocation For Pension Plans Acceptable Range And Target Allocation By Asset Category) (Details)	Sep. 30, 2017	Sep. 30, 2016
Cash and Cash Equivalents [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	3.00%	3.00%
Cash and Cash Equivalents [Member] | Maximum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	5.00%
Cash and Cash Equivalents [Member] | Minimum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Cash and Cash Equivalents [Member] | Target Allocation 2017 [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	0.00%
Return seeking [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	62.00%	59.00%
Return seeking [Member] | Maximum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	65.00%
Return seeking [Member] | Minimum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	55.00%
Return seeking [Member] | Target Allocation 2017 [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	60.00%
Hedge Funds, Equity [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	35.00%	38.00%
Hedge Funds, Equity [Member] | Maximum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	45.00%
Hedge Funds, Equity [Member] | Minimum [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	35.00%
Hedge Funds, Equity [Member] | Target Allocation 2017 [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage	40.00%