Annual report pursuant to Section 13 and 15(d)

DEI Document

DEI Document - USD ($)
$ in Millions
12 Months Ended
Jun. 30, 2018
Jul. 13, 2018
Dec. 31, 2017
DEI [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Jun. 30, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Entity Registrant Name KLA TENCOR CORP    
Entity Central Index Key 0000319201    
Entity Filer Category Large Accelerated Filer    
Current Fiscal Year End Date --06-30    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Well-known Seasoned Issuer Yes    
Trading Symbol klac    
Entity Common Stock, Shares Outstanding   156,126,508  
Entity Public Float     $ 16,430