Transactions with Related Parties - Summary of Transactions with Related Parties Reflected in the Partnership's Consolidated Financial Statements (Parenthetical) (Details)	3 Months Ended	9 Months Ended
Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Related Party Transactions [Abstract]
Rate for administration fees receivable	0.45%	0.45%	0.45%	0.45%
Percentage of referral fee to be received in original principal amount	0.25%	0.25%	0.25%	0.25%

Rate for administration fees - rate charged on the bonds and loans collateralized by the underlying properties for administration of the assets

No definition available.

Name:	ghi_RateForAdministrationFees
Namespace Prefix:	ghi_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration