Document And Entity Information - USD ($)	Dec. 31, 2021	Apr. 08, 2022	Jun. 30, 2021
Document Information [Line Items]
Entity, Registrant Name	SPAR GROUP, INC.
Document, Type	10-K/A
Document, Annual Report	true
Document, Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document, Fiscal Period Focus	FY
Document, Fiscal Year Focus	2021
Document, Transition Report	false
Entity, File Number	0-27408
Entity, Incorporation, State or Country Code	DE
Entity, Tax Identification Number	33-0684451
Entity, Address, Address Line One	1910 Opdyke Court
Entity, Address, City or Town	Auburn Hills
Entity, Address, State or Province	MI
Entity, Address, Postal Zip Code	48326
City Area Code	248
Local Phone Number	364-7727
Title of 12(b) Security	Common Stock, par value $.01 per share
Trading Symbol	SGRP
Security Exchange Name	NASDAQ
Entity, Well-known Seasoned Issuer	No
Entity, Voluntary Filers	No
Entity, Current Reporting Status	Yes
Entity, Interactive Data, Current	Yes
Entity, Filer Category	Non-accelerated Filer
Entity, Small Business	true
Entity, Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity, Shell Company	false
Entity, Public Float			$ 13,000,000
Entity, Common Stock Shares, Outstanding		21,845,414
Amendment Description	SPAR Group, Inc. (the "Corporation" or "SGRP", and together with its subsidiaries, the "Company") is filing this Amendment No. 1 on Form 10-K/A (this "Amendment") to amend SGRP's Annual Report on Form 10-K for the year ended December 31, 2021 ("Form 10-K"), originally filed with the Securities and Exchange Commission (the "SEC") on April 15, 2022, to include the information required by Part III of our Form 10-K and to make corresponding changes in the table of contents. This information was previously omitted from our Form 10-K in reliance on General Instruction G(3) to Form 10-K, which permits the information in the above referenced items to be incorporated in our Form 10-K by reference from our definitive proxy statement if such statement is filed no later than 120 days after our fiscal year-end. We are filing this Amendment to include Part III information in our Form 10-K because a definitive proxy statement containing such information will not be filed within that period. References to the Annual Report in Form 10-K and in this Amendment shall mean SGRP's 10-K as amended by this Amendment.
Auditor Name	BDO USA, LLP
Auditor Location	Troy, Michigan
Auditor Firm ID	243
Amendment Flag	true
Entity, Central Index Key	0001004989