Face (par) amount of debt instrument at time of issuance.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph e
-URI http://asc.fasb.org/extlink&oid=75038535&loc=d3e64711-112823

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Balance Type:	na
Period Type:	duration

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Debt instrument remaining outstanding amount.

+ References

No definition available.

+ Details

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Namespace Prefix:	wmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=wmg_AcquisitionCorpIssuerMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Subsequent Events (Details) - Acquisition Corp. - USD ($) $ in Millions	Apr. 15, 2021	Apr. 14, 2021	Mar. 31, 2021	Mar. 08, 2021
Senior Term Loan Facility \| Subsequent Event
Subsequent Event [Line Items]
Face or principal amount of debt instrument	$ 1,145	$ 325
5.500% Senior Notes due 2026
Subsequent Event [Line Items]
Interest rate			5.50%	5.50%
5.500% Senior Notes due 2026 \| Subsequent Event
Subsequent Event [Line Items]
Interest rate	5.50%
Debt instrument remaining outstanding amount	$ 343
Redemption price, percentage of principal amount redeemed	102.75%