Goodwill and Intangible Assets - Schedule of Changes in Goodwill for Each Reportable Segment (Details) $ in Millions	9 Months Ended
Jun. 30, 2026 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 2,061
Acquisitions	76
Other adjustments	(11)
Ending balance	2,126
Recorded Music
Goodwill [Roll Forward]
Beginning balance	1,597
Acquisitions	76
Other adjustments	(11)
Ending balance	1,662
Music Publishing
Goodwill [Roll Forward]
Beginning balance	464
Acquisitions	0
Other adjustments	0
Ending balance	$ 464

Amount, after accumulated impairment loss, of asset representing future economic benefit arising from other asset acquired in business combination or from joint venture formation or both, that is not individually identified and separately recognized.

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+ Details