Represents the income recognized during the period arising from equity-based compensation arrangements.

No definition available.

Name:	intg_AllocatedCompensationPercentage
Namespace Prefix:	intg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the excess income recognized during the period arising from equity-based compensation arrangements.

+ References

No definition available.

+ Details

Name:	intg_AllocatedExcessCompensationPercentage
Namespace Prefix:	intg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Reflects the amendment to the limited partnership agreement interests in the reporting period.

+ References

No definition available.

+ Details

Name:	intg_AmendmentToLimitedPartnershipAgreementInterests
Namespace Prefix:	intg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Reflects the annual revenues of the partnership agreement in the reporting period.

+ References

No definition available.

+ Details

Name:	intg_AnnualRevenuesOfPartnershipPercentage
Namespace Prefix:	intg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

General partner contributed revenue to asset manager in the period for performance (incentive) fees based on the investment results achieved for management of certain institutional accounts and hedge funds.

+ References

No definition available.

+ Details

Name:	intg_GeneralPartnerContributionToAssetManagers
Namespace Prefix:	intg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	intg_JusticeInvestorsLineItems
Namespace Prefix:	intg_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the minimum base of annual compensation during the reporting period.

+ References

No definition available.

+ Details

Name:	intg_MinimumAnnualCompensation
Namespace Prefix:	intg_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Reflects the minimum future amendment to the limited partnership agreement interests in the reporting period.

+ References

No definition available.

+ Details

Name:	intg_MinimumFutureAmendmentToLimitedPartnershipAgreementInterest
Namespace Prefix:	intg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the percentage of Partners Capital, Additional Partnership Percent.

+ References

No definition available.

+ Details

Name:	intg_PartnersCapitalAdditionalPartnershipPercent
Namespace Prefix:	intg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

This element represent partners capital tendered percentage.

+ References

No definition available.

+ Details

Name:	intg_PartnersCapitalTenderedPercentage
Namespace Prefix:	intg_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Percentage of voting equity interests acquired at the acquisition date in the business combination.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

+ Details

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
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

Changes in the ownership interest during the period of each class of partners. Partners include general, limited and preferred partners.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

+ Details

Name:	us-gaap_PartnersCapitalAccountPeriodIncreaseDecrease
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Total change in each class of partners' capital accounts during the year due to redemptions and adjustments to redemption value. All partners include general, limited and preferred partners.

+ References

+ Details

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

- Definition

The cash inflow from the capital received in cash from a partner in a partnership during the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

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

- Details

Name:	us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=intg_AltenativeRedemptionStructureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

Name:	dei_LegalEntityAxis=intg_PortsmouthMember
Namespace Prefix:
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Period Type:

JUSTICE INVESTORS (Details Textual) - USD ($)		12 Months Ended
JUSTICE INVESTORS (Details Textual) - USD ($)	Dec. 01, 2008	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2014
Justice Investors [Line Items]
Amendment To Limited Partnership Agreement Interests	98.00%
Minimum Future Amendment To Limited Partnership Agreement Interest	75.00%
Annual Revenues Of Partnership Percentage	1.50%
General Partner Contribution To Asset Managers	$ 75,000
Minimum Annual Compensation	$ 285,000
Allocated Excess Compensation Percentage	50.00%
Business Acquisition, Percentage of Voting Interests Acquired		50.00%
Altenative Redemption Structure [Member]
Justice Investors [Line Items]
Partners Capital Tendered Percentage		1.00%
Partners' Capital Account, Redemptions		$ 1,385,000
Proceeds from Partnership Contribution			$ 16,163,000	$ 2,928,000
General Partner [Member]
Justice Investors [Line Items]
Business Acquisition, Percentage of Voting Interests Acquired		93.00%
Partners Capital Tendered Percentage		1.00%
Partners Capital Additional Partnership Percent		17.146%
Noncontrolling Interest, Ownership Percentage by Parent		29.173%
Partners' Capital Account, Redemptions		$ 1,385,000
Increase (Decrease) in Partners' Capital, Total				$ 64,100,000
Evon [Member]
Justice Investors [Line Items]
Allocated Compensation Percentage	20.00%
Portsmouth [Member]
Justice Investors [Line Items]
Allocated Compensation Percentage	80.00%