Other Assets - Additional Information (Details)	Dec. 31, 2022 USD ($)
Other Assets [Abstract]
Taxable mortgage revenue bonds with fair value, held in trust	$ 9.0

Taxable mortgage revenue bonds with fair value, held in trust.

No definition available.

Name:	ghi_TaxableMortgageRevenueBondsWithFairValueHeldInTrust
Namespace Prefix:	ghi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant