Comprehensive Income (Loss) - Schedule of Accumulated Other Comprehensive Income Loss (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014
Accumulated Other Comprehensive Income Loss [Line Items]
Foreign currency translation adjustments included intra-entity foreign currency transactions	$ 2

Intra-entity foreign currency transactions included in foreign currency translation adjustments.

No definition available.

Name:	wmg_IntracompanyForeignCurrencyBalanceAmount
Namespace Prefix:	wmg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant