XML 14 R1.htm IDEA: XBRL DOCUMENT v3.21.1
Document And Entity Information - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Mar. 23, 2021
Document Information [Line Items]    
Entity Registrant Name SPAR GROUP, Inc.  
Entity Central Index Key 0001004989  
Trading Symbol sgrp  
Current Fiscal Year End Date --12-31  
Entity Filer Category Non-accelerated Filer  
Entity Current Reporting Status Yes  
Entity Voluntary Filers No  
Entity Well-known Seasoned Issuer No  
Entity Emerging Growth Company false  
Entity Small Business true  
Entity Interactive Data Current Yes  
Entity Common Stock, Shares Outstanding (in shares)   21,253,483
Entity Public Float $ 9.6  
Entity Shell Company false  
Document Type 10-K  
Document Period End Date Dec. 31, 2020  
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus FY  
Amendment Flag false  
Title of 12(b) Security Common Stock, par value $.01 per share