Pension And Postretirement Plan Expenses (Summary Of Net Periodic Pension And Net Postretirement Plan Expenses) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Pension And Postretirement Plan Expenses [Line Items]
Service cost	$ 26	$ 22
Interest cost	56	60
Expected return on plan assets	(83)	(80)
Net amortization	58	43
Total	$ 57	$ 45