Restructuring and Impairments - Schedule of Restructuring Accrual Activity (Details) $ in Millions	12 Months Ended
	Sep. 30, 2024 USD ($)
Restructuring Reserve [Roll Forward]
Restructuring and impairments	$ 135
Strategic Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0
Restructuring and impairments	121
Cash payments	(17)
Ending balance	104
Severance Costs
Restructuring Reserve [Roll Forward]
Beginning balance	19
Restructuring and impairments	(1)
Cash payments	(15)
Ending balance	3
Severance Costs | Strategic Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0
Restructuring and impairments	116
Cash payments	(17)
Ending balance	99
Contract Termination Costs | Strategic Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0
Restructuring and impairments	5
Cash payments	0
Ending balance	$ 5