Document and Entity Information - USD ($)	12 Months Ended
	Sep. 30, 2016	Dec. 08, 2016	Mar. 31, 2016
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2016
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Trading Symbol	wmg
Entity Registrant Name	Warner Music Group Corp.
Entity Central Index Key	0001319161
Current Fiscal Year End Date	--09-30
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	No
Entity Voluntary Filers	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		1,055
Entity Public Float			$ 0