Pension & Postretirement Expenses (Summary Of Net Periodic Pension And Net Postretirement Plan Expenses) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Pension And Postretirement Plan Expenses [Line Items]
Service cost	$ 27	$ 24	$ 81	$ 71
Interest cost	60	62	181	184
Expected return on plan assets	(92)	(86)	(276)	(258)
Net amortization	43	37	128	110
Total	$ 38	$ 37	$ 114	$ 107