Gain loss recognized on sale of third party property.

No definition available.

Name:	ghi_GainLossRecognizedOnSaleOfThirdPartyProperty
Namespace Prefix:	ghi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Partial principal payment of loan.

+ References

No definition available.

+ Details

Name:	ghi_PartialPrincipalPaymentOfLoan
Namespace Prefix:	ghi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Partnership Maturity Extended Date

+ References

No definition available.

+ Details

Name:	ghi_PartnershipMaturityExtendedDate
Namespace Prefix:	ghi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Proceeds from acquisition of mortgage loans real estate.

+ References

No definition available.

+ Details

Name:	ghi_ProceedsFromAcquisitionOfMortgageLoansRealEstate
Namespace Prefix:	ghi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Maturity date of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Subsection 29
-Paragraph Column C
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 948
-SubTopic 310
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column C))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479628/948-310-S99-1

+ Details

Name:	srt_MortgageLoanOnRealEstateFinalMaturityDate
Namespace Prefix:	srt_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of contractual principal due at origination of mortgage loan within investment in mortgage loan on real estate by entity with substantial portion of business acquiring and holding investment real estate or interest in real estate.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name Regulation S-X (SX)
-Number 210
-Section 12
-Subsection 29
-Paragraph Column F
-Publisher SEC

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 948
-SubTopic 310
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29(Column F))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479628/948-310-S99-1

+ Details

Name:	srt_MortgageLoansOnRealEstateFaceAmountOfMortgages
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in YYYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(a)(2))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 4: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-1B

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

This is the principal amount outstanding for securitized loans only (across all types of loans).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Subparagraph (a)
-Paragraph 4
-SubTopic 20
-Topic 860
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481326/860-20-50-4

+ Details

Name:	us-gaap_PrincipalAmountOutstandingOnLoansSecuritized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow associated with principal collections from a borrowing supported by a written promise to pay an obligation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-12

+ Details

Name:	us-gaap_ProceedsFromCollectionOfNotesReceivable
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://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482740/230-10-45-14

+ Details

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

- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 830
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481674/830-30-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 855
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483399/855-10-50-2

+ Details

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

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ghi_GovernmentalIssuerLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_PoppyGroveIGilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_LegacyCommonsAtSignalHillsGilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_VantageAtTomballMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MortgageLoansOnRealEstateDescriptionTypeOfPropertyAxis=ghi_ForwardPurchaseCommitmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_FreddieMacMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=ghi_TOBTrustMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_PoppyGroveIPoppyGroveIIAndPoppyGroveIIIMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_WillowPlaceApartmentsGilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_SupplementalGILMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_OspreyVillageGilMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_SandyCreekApartmentsGILMember
Namespace Prefix:
Data Type:	na
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Period Type:

Subsequent Events - Additional Information (Details) - USD ($)	1 Months Ended			3 Months Ended	12 Months Ended
	Feb. 28, 2025	Jan. 31, 2025	Feb. 29, 2024	Mar. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Subsequent Event [Line Items]
Principal Funded					$ 56,050,000	$ 108,005,034
Governmental Issuer Loans [Member]
Subsequent Event [Line Items]
Outstanding principal					$ 128,900,000
Poppy Grove I GIL [Member] \| Governmental Issuer Loans [Member]
Subsequent Event [Line Items]
Principal Funded			$ 5,200,000
Acquisition proceeds			$ 5,200,000
Scenario Forecast [Member] \| Legacy Commons at Signal Hills GIL [Member]
Subsequent Event [Line Items]
Partnership maturity extended date	August 1, 2025
Scenario Forecast [Member] \| Vantage At Tomball [Member]
Subsequent Event [Line Items]
Gain loss recognized on sale of third party property				$ 0
Forward Purchase Commitments [Member] \| Scenario Forecast [Member] \| Freddie Mac [Member]
Subsequent Event [Line Items]
Maturity date	Oct. 01, 2025
TOB Trust [Member] \| Poppy Grove I, Poppy Grove II, and Poppy Grove III [Member] \| Governmental Issuer Loans [Member]
Subsequent Event [Line Items]
Maturity Date					Apr. 01, 2025
TOB Trust [Member] \| Scenario Forecast [Member]
Subsequent Event [Line Items]
Partnership maturity extended date	January 2028
TOB Trust [Member] \| Scenario Forecast [Member] \| Poppy Grove I, Poppy Grove II, and Poppy Grove III [Member] \| Governmental Issuer Loans [Member]
Subsequent Event [Line Items]
Maturity Date	Oct. 01, 2025
Subsequent Event [Member] \| Vantage At Tomball [Member]
Subsequent Event [Line Items]
Cash received by partnership		$ 14,200,000
Subsequent Event [Member] \| TOB Trust [Member] \| Willow Place Apartments GIL [Member]
Subsequent Event [Line Items]
Principal Proceeds		17,700,000
Outstanding principal		20,700,000
Subsequent Event [Member] \| TOB Trust [Member] \| Supplemental GIL [Member]
Subsequent Event [Line Items]
Principal Proceeds		17,700,000
Outstanding principal		1,500,000
Subsequent Event [Member] \| TOB Trust [Member] \| Osprey Village GIL [Member]
Subsequent Event [Line Items]
Principal Proceeds		49,500,000
Outstanding principal		60,000,000
Subsequent Event [Member] \| TOB Trust [Member] \| Sandy Creek Apartments G I L [Member]
Subsequent Event [Line Items]
Partial principal repayment		7,200,000
Principal Proceeds		$ 5,800,000