v3.19.3
Document And Entity Information - USD ($)
$ in Billions
12 Months Ended
Sep. 27, 2019
Oct. 25, 2019
Mar. 29, 2019
Entity Information [Line Items]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Sep. 27, 2019    
Document Transition Report false    
Entity File Number 001-32431    
Entity Registrant Name DOLBY LABORATORIES, INC.    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 90-0199783    
Entity Address, Address Line One 1275 Market Street    
Entity Address, City or Town San Francisco    
Entity Address, State or Province CA    
Entity Address, Postal Zip Code 94103-1410    
City Area Code 415    
Local Phone Number 558-0200    
Title of 12(b) Security Class A common stock, $0.001 par value    
Trading Symbol DLB    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Shell Company false    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
Entity Public Float     $ 3.2
Entity Central Index Key 0001308547    
Current Fiscal Year End Date --09-27    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus FY    
Amendment Flag false    
Class A Common Stock [Member]      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   63,971,315  
Class B Common Stock [Member]      
Entity Information [Line Items]      
Entity Common Stock, Shares Outstanding   36,229,820