XML 74 R67.htm IDEA: XBRL DOCUMENT
v3.25.2

Mortgage Revenue Bonds - Additional Information (Details) - USD ($) | 1 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Mar. 31, 2025 | Jun. 30, 2025 | Jun. 30, 2024 | Dec. 31, 2024
Mortgage Revenue Bond [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Accrued interest receivable |  | $ 5,400,000 |  | $ 5,300,000
Variable interest rate | 3.60% |  |  |
Investment, Variable Interest Rate, Type [Extensible Enumeration] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] |  |  |
Investment owned, redemption month |  | March 2026 |  |
Outstanding principal |  | $ 175,300,000 |  |
Taxable MRB [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Outstanding principal |  | 9,000,000 |  |
Brookstone [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Realized a gain on sale |  |  | $ 1,000,000 |
Residency at the Mayer [Member] | Mortgage Revenue Bond [Member] | Series A Mortgage [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Maximum balance of MRB stabilization | $ 18,000,000 |  |  |
Fixed interest rate | 4.90% |  |  |
Residency at the Mayer [Member] | Mortgage Revenue Bond [Member] | Series M Mortgage [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Maximum balance of MRB stabilization | $ 5 |  |  |
Fixed interest rate | 3.50% |  |  |
Investment, Variable Interest Rate, Type [Extensible Enumeration] | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate [Member] |  |  |
Residency at the Entrepreneur MRBs and Residency at Mayer MRBs and Residency at the Entrepreneur MRBs | Mortgage Revenue Bond [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Partnership recognized loan fee |  | $ 565,000 |  |
Companion at Thornhill Apartments [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Redeemed percentage of par value plus accrued interest |  | 102.00% |  |
Companion at Thornhill Apartments [Member] | Contingent Interest Income [Member] |  |  |  |
Schedule Of Available For Sale Securities [Line Items] |  |  |  |
Redemption premium amount |  | $ 208,000 |  |

X
- Definition Accrued interest receivable + References No definition available. + Details
Name: | ghi_AccruedInterestReceivable
Namespace Prefix: | ghi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Investment owned, redemption month. + References No definition available. + Details
Name: | ghi_InvestmentOwnedRedemptionMonth
Namespace Prefix: | ghi_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Loan Financing Fixed Interest Rate. + References No definition available. + Details
Name: | ghi_LoanFinancingFixedInterestRate
Namespace Prefix: | ghi_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Maximum balance of MRB stabilization. + References No definition available. + Details
Name: | ghi_MaximumBalanceOfMRBStabilization
Namespace Prefix: | ghi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Mortgage loans on real estate, redemption premium amount. + References No definition available. + Details
Name: | ghi_MortgageLoansOnRealEstateRedemptionPremiumAmount
Namespace Prefix: | ghi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Mortgage revenue bond, redeemed percentage of par value. + References No definition available. + Details
Name: | ghi_MortgageRevenueBondRedeemedPercentageOfParValue
Namespace Prefix: | ghi_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Partnership recognized loan fee. + References No definition available. + Details
Name: | ghi_PartnershipRecognizedLoanFee
Namespace Prefix: | ghi_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net gain (loss) resulting from the sales of securitized, pay-through debt securities collateralized by real estate mortgage loans (mortgages). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 942 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(13)(h)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147478524/942-220-S99-1 + Details
Name: | us-gaap_GainLossOnSalesOfMortgageBackedSecuritiesMBS
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Indicates type of variable interest rate of investment. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.12-12A(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column A)(Footnote 4)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-3 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147477271/946-320-S99-6 + Details
Name: | us-gaap_InvestmentVariableInterestRateTypeExtensibleEnumeration
Namespace Prefix: | us-gaap_
Data Type: | enum2:enumerationSetItemType
Balance Type: | na
Period Type: | instant

X
- 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

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (aaa) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-3 + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=ghi_MortgageRevenueBondMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=ghi_TaxableMortgageRevenueBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_BrookstoneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_ResidencyAtTheMayerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=ghi_SeriesAMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_MortgageLoansOnRealEstateDescriptionLoanCategoryAxis=ghi_SeriesMMortgageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_ResidencyAtTheEntrepreneurMrbsAndResidencyAtMayerMrbsAndResidencyAtTheEntrepreneurMrbsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis=ghi_CompanionAtThornHillApartmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=ghi_ContingentInterestIncomeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |