Financial Instruments (Schedule Of Derivative Instruments) (Details) lb in Millions, $ in Millions	3 Months Ended
	Dec. 31, 2017 USD ($) lb	Dec. 31, 2016 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to earnings	$ 5	$ (6)
Gain (loss) to other comprehensive income	1	12
Commodity Contract [Member] | Cash Flow Hedging [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to other comprehensive income	13	10
Commodity Contract [Member] | Cash Flow Hedging [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	5	(2)
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of foreign currency hedge positions	1,600
Foreign Exchange Contract [Member] | Other deductions, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to earnings	0	6
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)	2
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	$ (10)
All Commodity Hedges [Member] [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of commodities hedged	$ 124
Copper and Aluminum [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weight in pounds of copper and aluminum commodity hedges | lb	49