v3.8.0.1
Document and Entity Information - shares
9 Months Ended
Mar. 31, 2018
May 04, 2018
Document And Entity Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2018  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q3  
Entity Registrant Name TWENTY-FIRST CENTURY FOX, INC.  
Entity Central Index Key 0001308161  
Current Fiscal Year End Date --06-30  
Entity Filer Category Large Accelerated Filer  
Class A Common Stock    
Document And Entity Information [Line Items]    
Trading Symbol FOXA  
Entity Common Stock, Shares Outstanding   1,054,032,541
Class B Common Stock    
Document And Entity Information [Line Items]    
Trading Symbol FOX  
Entity Common Stock, Shares Outstanding   798,520,953