XML 77 R65.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Variable Interest Entities - Additional Information (Details) $ in Millions | Dec. 31, 2024 USD ($) Property | Dec. 31, 2023 Property
--- | --- | ---
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Number of Variable Interest Entities | Property | 31 | 33
Investments in Unconsolidated Entities [Member] | Non-Consolidated VIEs [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Maximum exposure to loss, funding commitments | $ 18.3 |
Mortgage Revenue Bonds [Member] | Non-Consolidated VIEs [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Maximum exposure to loss, funding commitments | 31.5 |
Taxable Mortgage Revenue Bonds [Member] | Non-Consolidated VIEs [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Maximum exposure to loss, funding commitments | 13.0 |
Governmental Issuer Loans [Member] | Non-Consolidated VIEs [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Maximum exposure to loss, funding commitments | 18.8 |
Taxable Governmental Issuer Loans (Reported Within Other Assets) [Member] | Non-Consolidated VIEs [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Maximum exposure to loss, funding commitments | 46.4 |
Property Loans [Member] | Non-Consolidated VIEs [Member] |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Maximum exposure to loss, funding commitments | $ 28.8 |

X
- Definition The number of variable interest entities owned. + References No definition available. + Details
Name: | ghi_NumberOfVariableInterestEntities
Namespace Prefix: | ghi_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Variable interest entity, maximum loss exposure, funding commitments, amount. + References No definition available. + Details
Name: | ghi_VariableInterestEntityMaximumLossExposureFundingCommitmentsAmount
Namespace Prefix: | ghi_
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/2009/role/commonPracticeRef -Topic 310 -SubTopic 20 -Name Accounting Standards Codification -Section 40 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481628/310-20-40-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 310 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 2 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481990/310-10-45-2 + Details
Name: | us-gaap_AccountsNotesAndLoansReceivableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_EquityMethodInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InformationByCategoryOfDebtSecurityAxis=us-gaap_AvailableforsaleSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_InformationByCategoryOfDebtSecurityAxis=ghi_GovernmentalIssuerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InformationByCategoryOfDebtSecurityAxis=ghi_TaxableGovernmentalIssuerLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InformationByCategoryOfDebtSecurityAxis=ghi_PropertyLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |