Document And Entity Information (USD $)
12 Months Ended
Jun. 26, 2011
Aug. 12, 2011
Dec. 26, 2010
Document And Entity Information      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Jun. 26, 2011    
Document Fiscal Year Focus 2011    
Document Fiscal Period Focus FY    
Trading Symbol lrcx    
Entity Registrant Name LAM RESEARCH CORP    
Entity Central Index Key 0000707549    
Current Fiscal Year End Date --06-26    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   123,785,429  
Entity Well-known Seasoned Issuer Yes    
Entity Public Float     $ 5,116,431,866
Entity Current Reporting Status Yes    
Entity Voluntary Filers No