Financial Instruments (Schedule Of Derivative Instruments) (Details) lb in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2018 USD ($) lb	Dec. 31, 2017 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	$ 10	$ 5
Gain (loss) to other comprehensive income	(19)	1
Commodity Contract [Member] | Cash Flow Hedging [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to other comprehensive income	(7)	13
Commodity Contract [Member] | Cash Flow Hedging [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	(3)	5
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of foreign currency hedge positions	2,300
Foreign Exchange Contract [Member] | Other deductions, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	11	0
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	(12)	(12)
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Sales, Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	2	$ 0
All Commodity Hedges [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of commodities hedged	$ 126
Copper and Aluminum [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weight in pounds of copper and aluminum commodity hedges | lb	47