Note 9 - Segment Information - Segment Reporting Information (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue:	$ 67,333			$ 69,832			$ 197,649	$ 196,626
Operating income (loss):	1,541			1,720			6,688	6,143
Interest expense (income):	380			270			1,248	595
Other expense (income), net:	(164)			(126)			(347)	(363)
Income before income tax expense:	1,325			1,576			5,787	5,911
Income tax expense:	227			676			1,806	1,942
Net income (loss):	1,098	$ 1,106	$ 1,777	900	$ 1,614	$ 1,455	3,981	3,969
Net income attributable to non-controlling interest:	(839)			(932)			(2,217)	(2,180)
Net (loss) income attributable to SPAR Group, Inc.:	259			(32)			1,764	1,789
Depreciation and amortization:	548			506			1,574	1,524
Capital expenditures	365			463			1,083	1,237
Americas [Member]
Revenue:	53,796			53,738			154,457	149,992
Operating income (loss):	1,328			1,441			5,894	5,862
Interest expense (income):	264			203			895	399
Other expense (income), net:	5			(12)			22	(24)
Income before income tax expense:	1,059			1,250			4,977	5,487
Income tax expense:	(163)			467			1,068	1,346
Net income (loss):	1,222			783			3,909	4,141
Net income attributable to non-controlling interest:	604			(582)			1,484	(1,660)
Net (loss) income attributable to SPAR Group, Inc.:	618			201			2,425	2,481
Depreciation and amortization:	472			482			1,402	1,456
Capital expenditures	286			433			946	1,214
Asia Pacific [Member]
Revenue:	5,674			7,147			17,432	19,351
Operating income (loss):	(218)			(341)			(510)	(1,491)
Interest expense (income):	31			6			47	24
Other expense (income), net:	(59)			(50)			(69)	(62)
Income before income tax expense:	(190)			(297)			(488)	(1,453)
Income tax expense:	45			(145)			8	(104)
Net income (loss):	(235)			(152)			(496)	(1,349)
Net income attributable to non-controlling interest:	(5)			(45)			11	476
Net (loss) income attributable to SPAR Group, Inc.:	(230)			(197)			(507)	(873)
Depreciation and amortization:	36			15			60	39
Capital expenditures	30			0			37	14
EMEA [Member]
Revenue:	7,863			8,947			25,760	27,283
Operating income (loss):	431			620			1,304	1,772
Interest expense (income):	85			61			306	172
Other expense (income), net:	(110)			(64)			(300)	(277)
Income before income tax expense:	456			623			1,298	1,877
Income tax expense:	345			354			730	700
Net income (loss):	111			269			568	1,177
Net income attributable to non-controlling interest:	240			(305)			722	(996)
Net (loss) income attributable to SPAR Group, Inc.:	(129)			(36)			(154)	181
Depreciation and amortization:	40			9			112	29
Capital expenditures	$ 49			$ 30			$ 100	$ 9