Note 11 - Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Net income attributable to SPAR Group, Inc.	$ 639	$ 1,149	$ 1,505	$ 1,821
Weighted-average common shares outstanding – basic (in shares)	23,250	21,808	23,182	21,696
Stock options and unvested restricted shares (in shares)	142	127	155	135
Weighted-average common shares outstanding – diluted (in shares)	23,392	21,935	23,337	21,831
Basic income per common share attributable to SPAR Group, Inc. (in dollars per share)	$ 0.03	$ 0.05	$ 0.06	$ 0.08
Diluted income per common share attributable to SPAR Group, Inc. (in dollars per share)	$ 0.03	$ 0.05	$ 0.06	$ 0.08