XML 11 R1.htm IDEA: XBRL DOCUMENT v3.7.0.1
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2017
Jul. 28, 2017
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2017  
Document Fiscal Year Focus 2017  
Document Fiscal Period Focus Q2  
Trading Symbol ghc  
Entity Registrant Name GRAHAM HOLDINGS CO  
Entity Central Index Key 0000104889  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Class A Common Stock [Member]    
Entity Common Stock, Shares Outstanding   964,001
Class B Common Stock [Member]    
Entity Common Stock, Shares Outstanding   4,628,229