Segment Information - Geographic Information (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 14,535	$ 14,688	$ 15,395
Long-lived assets	1,409	1,410
Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	14,612	14,781	15,500
Inter-segment elimination
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	(77)	(93)	(105)
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	579	588
Americas | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	6,856	6,763	7,220
Americas | Geography Eliminations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	(2,126)	(2,078)	(2,309)
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	416	420
United States | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	6,140	5,893	6,530
Mexico
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	143	151
Mexico | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	2,543	2,634	2,661
Other Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	20	17
Other Americas | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	299	314	338
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	572	550
EMEA | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,773	5,029	5,195
EMEA | Geography Eliminations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	(1,144)	(1,344)	(1,428)
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	122	127
Germany | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	903	942	1,046
Poland
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	155	155
Poland | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	846	939	963
Spain
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	52	39
Spain | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	718	744	725
Czech Republic
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	28	35
Czech Republic | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	694	756	900
Hungary
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	38	31
Sweden | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	545	567	517
Romania | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	500	474	481
Other EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	177	163
Other EMEA | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,711	1,951	1,991
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	258	272
Asia | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	2,983	2,989	3,085
Asia | Geography Eliminations
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	(68)	(53)	(55)
China
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	107	115
China | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	1,286	1,420	1,385
Korea
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	21	23
Korea | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	535	488	534
Thailand
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	50	52
Thailand | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	515	496	564
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	64	62
Japan | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	415	344	373
Other Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	16	20
Other Asia | Reportable Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 300	$ 294	$ 284