Restructuring and Impairment Costs - Schedule of Restructuring Reserve (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
2024 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve beginning balance	$ 51
Plan charges	11
Utilized - cash	(9)
Noncash and other adjustments	1
Restructuring reserve ending balance	54
2023 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve beginning balance		$ 60
Plan charges		7
Utilized - cash		(27)
Noncash and other adjustments		5
Restructuring reserve ending balance		45
Employee Severance and Termination Benefits | 2024 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve beginning balance	56
Plan charges	11
Utilized - cash	(9)
Noncash and other adjustments	0
Restructuring reserve ending balance	58
Employee Severance and Termination Benefits | 2023 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve beginning balance		69
Plan charges		7
Utilized - cash		(27)
Noncash and other adjustments		0
Restructuring reserve ending balance		49
Currency Translation | 2024 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve beginning balance	(5)
Plan charges	0
Utilized - cash	0
Noncash and other adjustments	1
Restructuring reserve ending balance	$ (4)
Currency Translation | 2023 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve beginning balance		(9)
Plan charges		0
Utilized - cash		0
Noncash and other adjustments		5
Restructuring reserve ending balance		$ (4)