v3.26.1
Cover Page - shares
 6 Months Ended
Jun. 30, 2026
Aug. 03, 2026
Class of Stock [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2026  
Document Transition Report false  
Entity File Number 001-38434  
Entity Registrant Name Dropbox, Inc.  
Entity Incorporation, State or Country Code NV  
Entity Tax Identification Number 26-0138832  
Entity Address, Address Line One 50 Hawthorne Street  
Entity Address, City or Town San Francisco  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94105  
City Area Code 415  
Local Phone Number 930-7766  
Title of 12(b) Security Class A Common Stock, par value $0.00001 per share  
Trading Symbol DBX  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Central Index Key 0001467623  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2026  
Document Fiscal Period Focus Q2  
Amendment Flag false  
Class A common stock    
Class of Stock [Line Items]    
Entity Common Stock, Shares Outstanding   150,561,680
Class B common stock    
Class of Stock [Line Items]    
Entity Common Stock, Shares Outstanding   75,147,605
Class C common stock    
Class of Stock [Line Items]    
Entity Common Stock, Shares Outstanding   0