Equity - Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ 17,402
Other comprehensive income	72	$ 92
Ending Balance	17,243	18,490
AOCI Attributable to Parent
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(911)	(434)
Ending Balance	(864)	(347)
Foreign currency translation adjustments
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(901)	(421)
Other comprehensive income	59	84
Other comprehensive income, tax effect	0	0
Ending Balance	(842)	(337)
Realized and unrealized gains (losses) on derivatives
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(11)	(17)
Other comprehensive income, before reclassifications	(9)	4
Reclassification to income	(2)	0
Other comprehensive income, tax effect	(2)	3
Reclassification to income, tax effect	(1)	0
Ending Balance	(22)	(13)
Pension and postretirement plans
Increase (Decrease) in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	1	4
Reclassification to income	(1)	(1)
Reclassification to income, tax effect	0	0
Ending Balance	$ 0	$ 3