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Fair Value of Financial Instruments - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Sandoval Flats [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Unrealized gains (losses) from property loan held for sale	$ 0
Governmental Issuer Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available for Sale Security and Property Loan Receivable, Maximum Exposure	226,700,000	$ 225,700,000
Taxable Governmental Issuer Loan [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Available for Sale Security and Property Loan Receivable, Maximum Exposure	$ 13,900,000	$ 12,100,000

X

- Definition

Available for Sale Security and Property Loan Receivable, Maximum Exposure - This represents the maximum exposure to loss related to the Available for Sale Securities and Property Loan Receivables.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Unrealized gains (losses) from property loan held for sale.

+ References

No definition available.

+ Details

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Namespace Prefix:	ghi_
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Period Type:	duration

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

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
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X

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

X

- Details

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X

- Details

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