Restructuring and Related Costs - Schedule of Restructuring Reserve by Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Mar. 31, 2026	Mar. 31, 2025
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	$ 57	$ 62	$ 144	$ 95
Current Restructuring Plans
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	36		73
Restructuring and related cost, cost incurred to date	237		237
Current Restructuring Plans \| Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	4		18
Restructuring and related cost, cost incurred to date	65		65
Americas \| Current Restructuring Plans \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	23		32
Restructuring and related cost, cost incurred to date	83		83
EMEA \| Current Restructuring Plans \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	7		18
Restructuring and related cost, cost incurred to date	67		67
APAC \| Current Restructuring Plans \| Operating Segments
Restructuring Cost and Reserve [Line Items]
Restructuring costs and asset impairment charges	2		5
Restructuring and related cost, cost incurred to date	$ 22		$ 22

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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