v3.19.1
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2019
Apr. 26, 2019
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Mar. 31, 2019  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q1  
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  
Entity Small Business false  
Entity Emerging Growth Company false  
Class A Common Stock [Member]    
Entity Common Stock, Shares Outstanding   964,001
Class B Common Stock [Member]    
Entity Common Stock, Shares Outstanding   4,350,929