Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

v3.20.2
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2020
Jul. 22, 2020
Cover [Abstract]    
Document Type 10-Q  
Amendment Flag false  
Document Period End Date Jun. 30, 2020  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q2  
Trading Symbol BBSI  
Entity Registrant Name BARRETT BUSINESS SERVICES INC  
Entity Central Index Key 0000902791  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Current Reporting Status Yes  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   7,635,723
Entity Interactive Data Current Yes  
Title of 12(b) Security Common Stock, Par Value $0.01 Per Share  
Security Exchange Name NASDAQ  
Entity Incorporation, State or Country Code MD  
Document Quarterly Report true  
Document Transition Report false  
Entity File Number 0-21886  
Entity Tax Identification Number 52-0812977  
Entity Address, Address Line One 8100 NE Parkway Drive  
Entity Address, Address Line Two Suite 200  
Entity Address, City or Town Vancouver  
Entity Address, State or Province WA  
Entity Address, Postal Zip Code 98662  
City Area Code 360  
Local Phone Number 828-0700