XML 147 R113.htm IDEA: XBRL DOCUMENT
v3.22.4

Derivative Instruments - Additional Information (Details) - USD ($) | 1 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2022 | Dec. 31, 2022
Derivative [Line Items] |  |
Derivative notional amount |  | $ 194,656,088
Mizuho Capital Markets [Member] |  |
Derivative [Line Items] |  |
Derivative notional amount |  | 102,690,670
Total Return Swap One [Member] | Mizuho Capital Markets [Member] |  |
Derivative [Line Items] |  |
Derivative notional amount |  | $ 102,700,000
Required cash collateral percentage |  | 35.00%
Total Return Swap Two [Member] | Mizuho Capital Markets [Member] |  |
Derivative [Line Items] |  |
Required cash collateral percentage | 100.00% |
Amount of obligation to return cash collateral under swap arrangement | $ 63,500,000 |
Increase in unrestricted cash | $ 41,300,000 |

X
- Definition Increase in unrestricted cash. + References No definition available. + Details
Name: | ghi_IncreaseInUnrestrictedCash
Namespace Prefix: | ghi_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Required cash collateral percentage. + References No definition available. + Details
Name: | ghi_RequiredCashCollateralPercentage
Namespace Prefix: | ghi_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of obligation to return cash collateral under master netting arrangements that have not been offset against derivative assets. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 20 -URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226038-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 13 -URI https://asc.fasb.org/extlink&oid=99393222&loc=SL20226016-175313 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (d)(2) -URI https://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 8 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=125515794&loc=d3e41678-113959 + Details
Name: | us-gaap_DerivativeCollateralObligationToReturnCash
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Nominal or face amount used to calculate payments on the derivative liability. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1B -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5580258-113959 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 1A -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=125515794&loc=SL5579245-113959 + Details
Name: | us-gaap_DerivativeLiabilityNotionalAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
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 No definition available. + Details
Name: | us-gaap_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_CounterpartyNameAxis=ghi_MizuhoCapitalMarketsLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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