Note 4 - Earnings Per Share - Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Net income attributable to SPAR Group, Inc.	$ 674	$ 917
Shares used in basic net income per share calculation (in shares)	21,583	21,188
Stock options and unvested restricted shares (in shares)	146	393
Shares used in diluted net income per share calculations (in shares)	21,729	21,581
Basic income per common share: (in dollars per share)	$ 0.03	$ 0.04
Diluted income per common share: (in dollars per share)	$ 0.03	$ 0.04