Financial Instruments (Schedule Of Derivative Instruments) (Details) lb in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2017 USD ($) lb	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) lb	Jun. 30, 2016 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to earnings	$ (18)	$ (31)	$ (33)	$ (73)
Gain (loss) to other comprehensive income	12	(18)	49	(35)
Commodity Contract [Member] | Cash Flow Hedging [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to other comprehensive income	2	0	17	(10)
Commodity Contract [Member] | Cash Flow Hedging [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	4	(10)	6	(30)
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of foreign currency hedge positions	1,400		1,400
Foreign Exchange Contract [Member] | Other deductions, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to earnings	(22)	(9)	(22)	(16)
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to other comprehensive income	10	(18)	32	(25)
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Sales, Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	0	$ (12)	(17)	$ (27)
All Commodity Hedges [Member] [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of commodities hedged	$ 98		$ 98
Copper and Aluminum [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weight in pounds of copper and aluminum commodity hedges | lb	45		45