Document And Entity Information - USD ($)
$ in Billions
12 Months Ended
Jun. 30, 2018
Aug. 09, 2018
Dec. 29, 2017
Document And Entity Information [Abstract]      
Document Type 10-K    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity well-known seasoned issuer Yes    
Amendment Flag false    
Document Period End Date Jun. 30, 2018    
Entity Registrant Name CDK Global, Inc.    
Entity Central Index Key 0001609702    
Current Fiscal Year End Date --06-30    
Entity Filer Category Large Accelerated Filer    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Entity Common Stock, Shares Outstanding   129,440,956  
Public Float     $ 9.6