Financial Instruments (Schedule Of Amounts Included In Earnings And Other Comprehensive Income) (Details) lb in Millions, $ in Millions	12 Months Ended
	Sep. 30, 2016 USD ($) lb	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Financial Instruments [Line Items]
Notional value of foreign currency hedge positions	$ 1,400
Gain (Loss) to earnings	(103)	$ (22)	$ (5)
Gain (Loss) to other comprehensive income	(47)	(104)	(1)
Foreign currency [Member] | Other deductions, net [Member]
Financial Instruments [Line Items]
Gain (Loss) to earnings	$ (27)	14	(3)
Copper and aluminum [Member]
Financial Instruments [Line Items]
Weight of copper and aluminum for commodity hedges, in pounds | lb	51
Derivative, amount of aluminum and copper hedged	$ 103
Cash Flow Hedging [Member] | Commodity [Member] | Cost of sales [Member]
Financial Instruments [Line Items]
Gain (Loss) to earnings	(35)	(24)	(12)
Cash Flow Hedging [Member] | Foreign currency [Member] | Sales, cost of sales [Member]
Financial Instruments [Line Items]
Gain (Loss) to earnings	(41)	(12)	10
Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member] | Commodity [Member]
Financial Instruments [Line Items]
Gain (Loss) to other comprehensive income	(9)	(43)	(16)
Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member] | Foreign currency [Member]
Financial Instruments [Line Items]
Gain (Loss) to other comprehensive income	$ (38)	$ (61)	$ 15