Financial Instruments (Schedule Of Derivative Instruments) (Details) lb in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2016 USD ($) lb	Mar. 31, 2015 USD ($)	Mar. 31, 2016 USD ($) lb	Mar. 31, 2015 USD ($)
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to earnings	$ (31)	$ 24	$ (42)	$ 4
Gain (loss) to other comprehensive income	(12)	(3)	(17)	(46)
Commodity Contract [Member] | Cash Flow Hedging [Member] | Other Comprehensive Income (Loss) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to other comprehensive income	1	(7)	(10)	(19)
Commodity Contract [Member] | Cash Flow Hedging [Member] | Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	(12)	(8)	(20)	(10)
Foreign Exchange Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Notional amount of foreign currency hedge positions	1,500		1,500
Foreign Exchange Contract [Member] | Other deductions, net [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) to earnings	(10)	31	(7)	14
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	(13)	4	(7)	(27)
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member] | Sales, Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain (loss) reclassified to earnings	(9)	$ 1	(15)	$ 0
All Commodity Hedges [Member] [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of commodities hedged	$ 125		$ 125
Copper and Aluminum [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Weight in pounds of copper and aluminum commodity hedges | lb	54		54