v3.19.1
Document And Entity Information - $ / shares
6 Months Ended
Mar. 29, 2019
Apr. 26, 2019
Sep. 28, 2018
Entity Registrant Name DOLBY LABORATORIES, INC.    
Entity Central Index Key 0001308547    
Current Fiscal Year End Date --09-27    
Entity Filer Category Large Accelerated Filer    
Document Type 10-Q    
Document Period End Date Mar. 29, 2019    
Document Fiscal Year Focus 2019    
Document Fiscal Period Focus Q2    
Amendment Flag false    
Entity Emerging Growth Company false    
Entity Small Business false    
Class A Common Stock [Member]      
Entity Common Stock, Shares Outstanding   64,255,607  
Common stock, par value (usd per share) $ 0.001   $ 0.001
Class B Common Stock [Member]      
Entity Common Stock, Shares Outstanding   37,393,979  
Common stock, par value (usd per share) $ 0.001   $ 0.001
Subsequent Event [Member] | Class A Common Stock [Member]      
Common stock, par value (usd per share)   $ 0.001  
Subsequent Event [Member] | Class B Common Stock [Member]      
Common stock, par value (usd per share)   $ 0.001