The parent entity's majority interest in net assets of the subsidiary, expressed as a percentage.

No definition available.

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Namespace Prefix:	sgrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of available field merchandising specialists.

+ References

No definition available.

+ Details

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Namespace Prefix:	sgrp_
Data Type:	xbrli:integerItemType
Balance Type:	na
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- Definition

Number of full-time national, regional, and district administrators.

+ References

No definition available.

+ Details

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Namespace Prefix:	sgrp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents number of vehicles leased under lease arrangement.

+ References

No definition available.

+ Details

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Namespace Prefix:	sgrp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents number of vehicles subleased.

+ References

No definition available.

+ Details

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Namespace Prefix:	sgrp_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent of service provided by related party.

+ References

No definition available.

+ Details

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Namespace Prefix:	sgrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of ownership by a related person in a related entity.

+ References

No definition available.

+ Details

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Namespace Prefix:	sgrp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of expense provided in the period for legal costs incurred on or before the balance sheet date pertaining to resolved, pending or threatened litigation, including arbitration and mediation proceedings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.3)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Term of the lessee's leasing arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

Name:	us-gaap_LesseeLeasingArrangementsOperatingLeasesTermOfContract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Identify the stated interest rate per the agreement, for example, leasing and debt arrangements between related parties.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_SBSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=sgrp_DomesticMerchandisingSpecialistsFieldForceMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=sgrp_DomesticFieldManagementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=sgrp_CostPlusFeeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_SbsAndSasMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_SasMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_NRSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=sgrp_Plus2CompensationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_CMRMeridienMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LeaseArrangementTypeAxis=sgrp_LeaseArrangementWithMcptMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_MrBrianMasonMrGarryBristowAndMrAdrianWingfieldMember
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Data Type:	na
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Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_MrMasonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=sgrp_MerholdHoldingTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_MrBristowMember
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Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_MrWingfieldMember
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Data Type:	na
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- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_NDSMember
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Data Type:	na
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- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_MrAndMsYilmazMember
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Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=sgrp_AffinityInsuranceMember
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Note 5 - Related-Party Transactions (Details Textual)	1 Months Ended	3 Months Ended			5 Months Ended	6 Months Ended
Note 5 - Related-Party Transactions (Details Textual)	Jun. 30, 2016	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015	May 31, 2016	Jun. 30, 2016 USD ($)	Jun. 30, 2015 USD ($)
SBS [Member] \| Domestic Merchandising Specialists Field Force [Member]
Percent Of Service Provided By Related Party						80.00%	85.00%
SBS [Member] \| Domestic Field Management [Member]
Percent Of Service Provided By Related Party						92.00%	90.00%
SBS [Member] \| Cost Plus Fee [Member]
Related Party Transaction, Rate						2.96%	2.96%
SBS [Member]
Number of Merchandising Specialists						5,000
Number of National, Regional, and District Administrators						50
Legal Fees		$ 88,699	$ 143,463			$ 442,915	$ 267,335
SBS And SAS [Member] \| Domestic Field Management [Member]
Related Party Transaction, Expenses from Transactions with Related Party		$ 6,400,000	6,500,000			$ 12,500,000	$ 13,300,000
SAS [Member] \| Cost Plus Fee [Member]
Related Party Transaction, Rate	2.00%				4.00%
NRS [Member] \| Domestic Merchandising Specialists Field Force [Member]
Percent Of Service Provided By Related Party							4.00%
NRS [Member] \| Plus2 Compensation [Member]
Related Party Transaction, Rate				2.00%
Related Party Transaction, Amounts of Transaction							$ 11,000
NRS [Member]
Majority Interest Ownership Percentage By Parent	51.00%	51.00%				51.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%	49.00%				49.00%
C M R Meridien [Member] \| Lease Arrangement With MCPT [Member]
Number Of Vehicles Subleased						2
Number Of Vehicles Leased						126
Lessee Leasing Arrangements, Operating Leases, Term of Contract						4 years
C M R Meridien [Member]
Majority Interest Ownership Percentage By Parent	51.00%	51.00%				51.00%
Mr. Brian Mason Mr. Garry Bristow And Mr. Adrian Wingfield [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%	49.00%				49.00%
Mr. Mason [Member] \| Merhold Holding Trust [Member]
Related Party Ownership Percentage						46.70%
Mr. Mason [Member]
Related Party Ownership Percentage						50.00%
Mr. Bristow [Member] \| Merhold Holding Trust [Member]
Related Party Ownership Percentage						20.00%
Mr. Wingfield [Member] \| Merhold Holding Trust [Member]
Related Party Ownership Percentage						33.30%
NDS [Member]
Majority Interest Ownership Percentage By Parent	51.00%	51.00%				51.00%
Mr And Ms Yilmaz [Member]
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%	49.00%				49.00%
Related Party Ownership Percentage						40.00%
SPAR Todopromo [Member]
Majority Interest Ownership Percentage By Parent	51.00%	51.00%				51.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	49.00%	49.00%				49.00%
Mr. Juan F. Medina Domenzain [Member] \| CON [Member]
Related Party Ownership Percentage						90.00%
Affinity Insurance [Member] \| Maximum [Member]
Noncontrolling Interest, Ownership Percentage by Parent	1.00%	1.00%				1.00%
Related Party Transaction, Expenses from Transactions with Related Party		$ 6,694,000	$ 7,353,000			$ 13,079,000	$ 14,793,000