Document and Entity Information - USD ($)
$ in Billions
12 Months Ended
Jan. 03, 2016
Feb. 26, 2016
Jun. 28, 2015
Document Document And Entity Information [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Jan. 03, 2016    
Document Fiscal Year Focus 2015    
Document Fiscal Period Focus FY    
Trading Symbol CY    
Entity Registrant Name CYPRESS SEMICONDUCTOR CORP /DE/    
Entity Central Index Key 0000791915    
Current Fiscal Year End Date --01-03    
Entity Well-known Seasoned Issuer Yes    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Large Accelerated Filer    
Entity Common Stock, Shares Outstanding   314,558,619  
Entity Public Float     $ 3.9