Revenue Recognition - Narrative (Details) - USD ($)	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Contract with customer, liability, revenue recognized	$ 1,600,000,000	$ 1,500,000,000
Revenue, remaining performance obligation, amount	19,600,000,000
Capitalized contract cost, amortization	251,000,000	191,000,000
Capitalized contract cost, impairment loss	$ 0	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Disaggregation of Revenue [Line Items]
Revenue, remaining performance obligation, percentage	65.00%
Revenue, remaining performance obligation, expected timing of satisfaction, period	2 years