Other Deductions, Net (Schedule Of Other Deductions, Net) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Mar. 31, 2021	Mar. 31, 2020
Other deductions, net [Line Items]
Amortization of intangibles (intellectual property and customer relationships)	$ 74		$ 59	$ 152	$ 118
Restructuring costs	17		31	83	128
Special advisory fees	0		0	0	13
Other	(58)		(48)	(80)	(39)
Total	33		$ 42	155	$ 220
Gain (loss) from an investment		$ 21
Gain (loss) from acquiring the remaining interest of an equity investment		$ 17
Gain (loss) from sale of equity investment	31
Change in gain (loss) from foreign currency exchange transactions	(22)			(29)
Open Systems International Inc. [Member] | Order or Production Backlog [Member]
Other deductions, net [Line Items]
Backlog amortization	$ 6			$ 17