Note 2 - Correction of Prior Period Financial Statements - Adjustments to Prior Period Financials (Details) - USD ($) $ in Thousands	3 Months Ended					6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2017	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016		Jun. 30, 2016	Sep. 30, 2016	Dec. 31, 2016
Accumulated other comprehensive loss	$ (2,341)	$ (1,991)	$ (2,091)	$ (2,025)		$ (2,091)	$ (1,991)	$ (2,407)	[1]
Total SPAR Group, Inc. equity	19,561	19,945	19,809	19,495		19,809	19,945	19,677	[1]
Non-controlling interest	3,820	5,201	4,549	4,376		4,549	5,201	5,405	[1]
Comprehensive (loss) income attributable to non-controlling interest	(516)	(651)	(172)	17	[2]	(156)	(807)	(1,011)
Comprehensive loss attributable to SPAR Group, Inc.	(178)	42	217	(312)	[2]	(96)	(54)	(381)
Comprehensive (loss) income attributable to non-controlling interest	$ (516)	(651)	(172)	17	[2]	(156)	(807)	(1,011)
Scenario, Previously Reported [Member]
Accumulated other comprehensive loss		(3,364)	(3,570)	(3,357)		(3,570)	(3,364)	(3,995)
Total SPAR Group, Inc. equity		18,572	18,330	18,163		18,330	18,572	18,089
Non-controlling interest		6,574	6,028	5,708		6,028	6,574	6,993
Comprehensive (loss) income attributable to non-controlling interest		(546)	(320)	(298)		(618)	(1,164)	(1,583)
Comprehensive loss attributable to SPAR Group, Inc.		147	69	(627)		(558)	(411)	(953)
Comprehensive (loss) income attributable to non-controlling interest		(546)	(320)	(298)		(618)	(1,164)	(1,583)
Restatement Adjustment [Member]
Accumulated other comprehensive loss		1,373	1,479	1,332		1,479	1,373	1,588
Total SPAR Group, Inc. equity		1,373	1,479	1,332		1,479	1,373	1,588
Non-controlling interest		(1,373)	(1,479)	(1,332)		(1,479)	(1,373)	(1,588)
Comprehensive (loss) income attributable to non-controlling interest		(105)	148	315		462	357	572
Comprehensive loss attributable to SPAR Group, Inc.		(105)	148	315		462	357	572
Comprehensive (loss) income attributable to non-controlling interest		$ (105)	$ 148	$ 315		$ 462	$ 357	$ 572

[1] See Note 2 Correction of Prior Period Financial Statements.

[2] See Note 2 Correction of Prior Period Financial Statements.