Annual report pursuant to Section 13 and 15(d)

Document and Entity Information

v3.20.4
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2020
Feb. 16, 2021
Jun. 30, 2020
Cover [Abstract]      
Document Type 10-K    
Amendment Flag false    
Document Period End Date Dec. 31, 2020    
Document Fiscal Year Focus 2020    
Document Fiscal Period Focus FY    
Trading Symbol BBSI    
Entity Registrant Name BARRETT BUSINESS SERVICES INC    
Entity Central Index Key 0000902791    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Accelerated Filer    
Entity Shell Company false    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Common Stock, Shares Outstanding   7,593,383  
Entity Public Float     $ 397,266,232
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    
Entity File Number 0-21886    
Document Annual Report true    
Document Transition Report false    
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    
Documents Incorporated by Reference

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the definitive Proxy Statement for the 2021 Annual Meeting of Stockholders are hereby incorporated by reference in Part III of Form 10-K.