Document and Entity Information
3 Months Ended
Dec. 31, 2013
Feb. 06, 2014
Document Document And Entity Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Dec. 31, 2013  
Document Fiscal Year Focus 2014  
Document Fiscal Period Focus Q1  
Trading Symbol wmg  
Entity Registrant Name Warner Music Group Corp.  
Entity Central Index Key 0001319161  
Current Fiscal Year End Date --09-30  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   1,055