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v3.25.3

Comprehensive Income (Loss) - Narrative (Details) $ in Millions | 12 Months Ended
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Sep. 30, 2025 USD ($)
Equity [Abstract] |
Changes in accumulated other comprehensive loss, net of related tax benefit | $ 1

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- References No definition available. + Details
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- Definition Changes in accumulated other comprehensive income loss net of related tax. + References No definition available. + Details
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Namespace Prefix: | wmg_
Data Type: | xbrli:monetaryItemType
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