Financial Instruments (Schedule Of Derivative Instruments) (Details) lb in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2019 USD ($) lb	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) lb	Jun. 30, 2018 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	$ 5	$ 29	$ 45	$ 28
Gain (loss) to other comprehensive income	(8)	(18)	5	(18)
Commodity Contract [Member] | Cash Flow Hedging [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to other comprehensive income	(8)	(3)	(5)	1
Commodity Contract [Member] | Cash Flow Hedging [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	(2)	2	(8)	13
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of foreign currency hedge positions	2,200		2,200
Foreign Exchange Contract [Member] | Other deductions, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	3	28	43	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	0	(15)	10	(19)
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Sales, Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	4	$ (1)	10	$ (1)
All Commodity Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of commodities hedged	$ 117		$ 117
Copper and Aluminum [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weight in pounds of copper and aluminum commodity hedges | lb	45		45