Annual report pursuant to Section 13 and 15(d)

Document and Entity Information Document

Document and Entity Information Document - USD ($)
12 Months Ended
Sep. 30, 2018
Nov. 05, 2018
Mar. 25, 2018
Document Information [Line Items]      
Entity Registrant Name QUALCOMM INC/DE    
Entity Registrant State of Incorporation Delaware    
Entity Address 5775 Morehouse Dr.    
Entity City San Diego    
Entity State California    
Entity Zip Code 92121-1714    
Entity Phone Number (858) 587-1121    
Entity Employer ID 953685934    
Entity Central Index Key 0000804328    
Current Fiscal Year End Date --09-30    
Entity Filer Category Large Accelerated Filer    
Document Type 10-K    
Document Period End Date Sep. 30, 2018    
Document Fiscal Year Focus 2018    
Document Fiscal Period Focus FY    
Amendment Flag false    
Entity Common Stock, Shares Outstanding   1,212,162,586  
Entity Emerging Growth Company false    
Entity Small Business false    
Entity Shell Company false    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Public Float     $ 79,468,272,443