v3.8.0.1
Document and Entity Information - shares
3 Months Ended
Sep. 30, 2017
Nov. 03, 2017
Document And Entity Information [Line Items]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Sep. 30, 2017  
Document Fiscal Year Focus 2018  
Document Fiscal Period Focus Q1  
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   1,054,008,837
Class B Common Stock    
Document And Entity Information [Line Items]    
Trading Symbol FOX  
Entity Common Stock, Shares Outstanding   798,520,953