Retirement Plan And Other Post-Retirement Benefits (Schedule Of Health Care Cost Trend Rates) (Details)	12 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2010
Retirement Plan And Other Post-Retirement Benefits [Abstract]
Rate of Increase for Pre Age 65 Participants	7.46%	[1]	7.64%	[1]	7.82%	[1]
Rate of Increase for Post Age 65 Participants	6.84%	[1]	6.89%	[1]	6.95%	[1]
Annual Rate of Increase in the Per Capita Cost of Covered Prescription Drug Benefits	8.08%	[1]	8.39%	[1]	8.69%	[1]
Annual Rate of Increase in the Per Capita Medicare Part B Reimbursement	6.84%	[1]	6.89%	[1]	6.95%	[1]
Annual Rate of Increase in the Per Capita Medicare Part D Subsidy	7.13%	[1]	7.30%	[1]	7.60%	[1]
Ultimate health care trend rate by 2028	4.50%

[1] (1) It was assumed that this rate would gradually decline to 4.5% by 2028.