SEGMENT INFORMATION (Details) (USD $)	3 Months Ended	6 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Jun. 30, 2014
Segment Reporting Information [Line Items]
Revenues	$ 18,074,000us-gaap_Revenues	$ 16,432,000us-gaap_Revenues	$ 37,101,000us-gaap_Revenues	$ 33,815,000us-gaap_Revenues
Segment operating expenses	(15,185,000)us-gaap_OperatingExpenses	(20,622,000)us-gaap_OperatingExpenses	(29,944,000)us-gaap_OperatingExpenses	(32,959,000)us-gaap_OperatingExpenses
Segment income (loss) from operations	1,657,000us-gaap_OperatingIncomeLoss	(5,474,000)us-gaap_OperatingIncomeLoss	4,699,000us-gaap_OperatingIncomeLoss	(1,612,000)us-gaap_OperatingIncomeLoss
Interest expense - mortgage	(2,517,000)us-gaap_InterestExpenseDebt	(1,529,000)us-gaap_InterestExpenseDebt	(5,175,000)us-gaap_InterestExpenseDebt	(2,936,000)us-gaap_InterestExpenseDebt
Interest expense - occupancy tax	0intg_InterestExpensesForOccupancyTax	(328,000)intg_InterestExpensesForOccupancyTax	0intg_InterestExpensesForOccupancyTax	(328,000)intg_InterestExpensesForOccupancyTax
Loss on extinguishment of debt	0	(3,910,000)	0	(3,910,000)
Loss on disposal of assets	(51,000)us-gaap_GainLossOnDispositionOfAssets1	(1,092,000)us-gaap_GainLossOnDispositionOfAssets1	(51,000)us-gaap_GainLossOnDispositionOfAssets1	(1,092,000)us-gaap_GainLossOnDispositionOfAssets1
Other real estate income			458,000us-gaap_OtherRealEstateRevenue	0us-gaap_OtherRealEstateRevenue
Gain on sale of real estate	1,742,000	0	1,742,000	0
Depreciation and amortization expense	(1,232,000)	(1,284,000)	(2,458,000)	(2,468,000)
Gain(Loss) from investments	(1,456,000)	688,000	(3,443,000)	385,000
Income tax benefit	17,000us-gaap_IncomeTaxExpenseBenefit	2,477,000us-gaap_IncomeTaxExpenseBenefit	258,000us-gaap_IncomeTaxExpenseBenefit	2,017,000us-gaap_IncomeTaxExpenseBenefit
Net income (loss)	(608,000)us-gaap_ProfitLoss	(9,168,000)us-gaap_ProfitLoss	(1,512,000)us-gaap_ProfitLoss	(7,476,000)us-gaap_ProfitLoss
Total assets	146,650,000us-gaap_Assets	166,698,000us-gaap_Assets	146,650,000us-gaap_Assets	166,698,000us-gaap_Assets	165,460,000us-gaap_Assets
Hotel Operations [Member]
Segment Reporting Information [Line Items]
Revenues	14,044,000	12,274,000	28,874,000	25,579,000
Segment operating expenses	(12,033,000)	(17,872,000)	(23,871,000)	(27,404,000)
Segment income (loss) from operations	2,011,000	(5,598,000)	5,003,000	(1,825,000)
Interest expense - mortgage	(1,769,000)	(767,000)	(3,665,000)	(1,402,000)
Interest expense - occupancy tax		(328,000)		(328,000)
Loss on extinguishment of debt		(3,910,000)		(3,910,000)
Loss on disposal of assets	(51,000)	(1,092,000)	(51,000)	(1,092,000)
Other real estate income			0
Gain on sale of real estate	0		0
Depreciation and amortization expense	(714,000)	(747,000)	(1,405,000)	(1,396,000)
Gain(Loss) from investments	0	0	0	0
Income tax benefit	0	0	0	0
Net income (loss)	(523,000)	(12,442,000)	(118,000)	(9,953,000)
Total assets	51,234,000	68,141,000	51,234,000	68,141,000
Real Estate Operations [Member]
Segment Reporting Information [Line Items]
Revenues	4,030,000	4,158,000	8,227,000	8,236,000
Segment operating expenses	(2,192,000)	(2,266,000)	(4,332,000)	(4,544,000)
Segment income (loss) from operations	1,838,000	1,892,000	3,895,000	3,692,000
Interest expense - mortgage	(748,000)	(762,000)	(1,510,000)	(1,534,000)
Interest expense - occupancy tax		0		0
Loss on extinguishment of debt		0		0
Loss on disposal of assets	0	0	0	0
Other real estate income			458,000
Gain on sale of real estate	1,742,000		1,742,000
Depreciation and amortization expense	(518,000)	(537,000)	(1,053,000)	(1,072,000)
Gain(Loss) from investments	0	0	0	0
Income tax benefit	0	0	0	0
Net income (loss)	2,314,000	593,000	3,532,000	1,086,000
Total assets	61,429,000	64,581,000	61,429,000	64,581,000
Investment Transactions [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Segment operating expenses	0	0	0	0
Segment income (loss) from operations	0	0	0	0
Interest expense - mortgage	0	0	0	0
Interest expense - occupancy tax		0		0
Loss on extinguishment of debt		0		0
Loss on disposal of assets	0	0	0	0
Other real estate income			0
Gain on sale of real estate	0		0
Depreciation and amortization expense	0	0	0	0
Gain(Loss) from investments	(1,456,000)	688,000	(3,443,000)	385,000
Income tax benefit	0	0	0	0
Net income (loss)	(1,456,000)	688,000	(3,443,000)	385,000
Total assets	27,737,000	28,373,000	27,737,000	28,373,000
Other [Member]
Segment Reporting Information [Line Items]
Revenues	0	0	0	0
Segment operating expenses	(960,000)	(484,000)	(1,741,000)	(1,011,000)
Segment income (loss) from operations	(960,000)	(484,000)	(1,741,000)	(1,011,000)
Interest expense - mortgage	0	0	0	0
Interest expense - occupancy tax		0		0
Loss on extinguishment of debt		0		0
Loss on disposal of assets	0	0	0	0
Other real estate income			0
Gain on sale of real estate	0		0
Depreciation and amortization expense	0	0	0	0
Gain(Loss) from investments	0	0	0	0
Income tax benefit	17,000	2,477,000	258,000	2,017,000
Net income (loss)	(943,000)	1,993,000	(1,483,000)	1,006,000
Total assets	$ 6,250,000	$ 5,603,000	$ 6,250,000	$ 5,603,000

Represent interest expenses for occupancy tax.

No definition available.

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

- Definition

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.18)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 12

-Article 7

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 18

-Article 5

+ Details

Name:	us-gaap_Assets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

+ Details

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

- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=8077374&loc=d3e2443-110228

+ Details

Name:	us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

+ Details

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The net gain (loss) resulting from sales and other disposals of other real estate owned, increases (decreases) in the valuation allowance for foreclosed real estate, and write-downs of other real estate owned after acquisition or physical possession.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.14(d))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 14

-Subparagraph d

-Article 9

+ Details

Name:	us-gaap_GainsLossesOnSalesOfOtherRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 9

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35755396&loc=d3e33749-111570

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.12)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 11

-Article 7

+ Details

Name:	us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Income Tax Expense (or Benefit)

-URI http://asc.fasb.org/extlink&oid=6515339

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a),(b)

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

+ Details

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

- Definition

Amount of the cost of borrowed funds accounted for as interest expense for debt.

+ 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 210.5-03.8)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 8

-Article 5

+ Details

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

- Definition

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Includes selling, general and administrative expense.

+ References

No definition available.

+ Details

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

- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingIncomeLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Other real estate revenue not otherwise specified in the taxonomy.

+ References

+ Details

Name:	us-gaap_OtherRealEstateRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4K

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591552-111686

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 45

-Paragraph 19

-URI http://asc.fasb.org/extlink&oid=7656940&loc=SL4569616-111683

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 1A

-Subparagraph (a),(c)

-URI http://asc.fasb.org/extlink&oid=18733093&loc=SL4573702-111684

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 55

-Paragraph 4J

-URI http://asc.fasb.org/extlink&oid=35736750&loc=SL4591551-111686

+ Details

Name:	us-gaap_ProfitLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ 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 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

Name:	us-gaap_Revenues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_SegmentReportingInformationLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=intg_InvestmentTransactionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_ApartmentBuildingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_HotelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=us-gaap_OtherPropertyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: