v3.19.3
Cover Page - shares
9 Months Ended
Sep. 30, 2019
Oct. 31, 2019
Cover page.    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2019  
Document Transition Report false  
Entity File Number 001-36384  
Entity Registrant Name RUBICON PROJECT, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 20-8881738  
Entity Address, Address Line One 12181 Bluff Creek Drive,  
Entity Address, Address Line Two 4th Floor  
Entity Address, City or Town Los Angeles,  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 90094  
City Area Code (310)  
Local Phone Number 207-0272  
Title of 12(b) Security Common stock, par value $0.00001 per share  
Trading Symbol RUBI  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Accelerated Filer  
Entity Small Business true  
Entity Emerging Growth Company true  
Entity Ex Transition Period true  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   53,071,171
Entity Central Index Key 0001595974  
Amendment Flag false  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q3  
Current Fiscal Year End Date --12-31