Revenue Recognition - Narrative (Details) $ in Millions	12 Months Ended
Sep. 30, 2023 USD ($) source	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)
Disaggregation of Revenue [Line Items]
Refund liabilities	$ 19	$ 19
Uncollectible accounts, reserves	19	19
Deferred revenue increased related to cash received from customers	724	666
Revenue recognized related to deferred revenue	393	274
Revenue recognized from performance obligations satisfied in previous periods	$ 91	$ 59	$ 64
Recorded Music
Disaggregation of Revenue [Line Items]
Number of revenue sources \| source	4
Music Publishing
Disaggregation of Revenue [Line Items]
Number of revenue sources \| source	5

Amount of allowance for credit loss on accounts receivable.

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