Equity and Noncontrolling Interests - Changes in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	$ 2,718	$ 1,535	$ 2,189
Aggregate adjustment for the period, net of tax	(249)	37	(89)
Current period changes in fair value, net of tax	0	20	(20)
Net reclassifications to AOCI	(1)	(1)	0
Ending balance	2,375	2,718	1,535
Foreign currency translation adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(617)	(634)	(558)
Aggregate adjustment for the period, net of tax	(219)	17	(76)
Ending balance	(836)	(617)	(634)
Realized and unrealized gains (losses) on derivatives
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(8)	(28)	(8)
Current period changes in fair value, net of tax	6	22	(34)
Reclassification to income, net of tax	(6)	(2)	14
Ending balance	(8)	(8)	(28)
Pension plans
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(2)	(3)	(3)
Net reclassifications to AOCI	1	1	0
Ending balance	(1)	(2)	(3)
AOCI attributable to parent
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance	(627)	(665)	(569)
Current period changes in fair value, net of tax		20	(20)
Net reclassifications to AOCI	(1)	(1)
Ending balance	$ (845)	$ (627)	$ (665)