Income Taxes (Schedule Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Period over which the amount of unrecognized tax benefits are not expected to significantly increase or decrease	12 months
Unrecognized tax benefits, beginning	$ 132	$ 86
Additions for current year tax positions	13	54
Additions for prior year tax positions	8	4
Reductions for prior year tax positions	(8)	(6)
Acquisitions and divestitures	21	9
Reductions for settlements with tax authorities	(3)	(4)
Reductions for expiration of statutes of limitations	(5)	(11)
Unrecognized tax benefits, ending	$ 158	$ 132