XML 47 R27.htm IDEA: XBRL DOCUMENT
v3.23.2

Related-Party Transactions (Details) |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended |
--- | --- | --- | --- | --- | --- | --- | ---
Jul. 11, 2023 | Jul. 14, 2020 | Feb. 20, 2020 $ / shares shares | Feb. 29, 2020 | Jun. 30, 2023 USD ($) | Jun. 30, 2022 USD ($) | Jun. 30, 2023 USD ($) quarter officer | Jun. 30, 2022 USD ($) | Dec. 31, 2022 USD ($)
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Number of executive officers | officer |  |  |  |  |  |  |  | 2 |  |
Base management fee | [1] |  |  |  |  | $ 1,605,000 | $ 1,577,000 | $ 3,210,000 | $ 3,124,000 |
Related Party |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Amount due to advisor and administrator | [2] |  |  |  |  | $ 2,624,000 |  | $ 2,624,000 |  | $ 3,356,000
Advisory Agreement |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Number of quarters used for the cap of average quarterly incentive fees | quarter |  |  |  |  |  |  |  | 4 |  |
Advisory Agreement | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Notice period for termination of agreement without cause |  |  |  |  |  |  |  | 120 days |  |
Percentage of independent directors required to terminate the amended advisory agreement |  |  |  |  |  |  |  | 66.67% |  |
Number of times the sum of the average annual base management fee and incentive fee earned by adviser |  |  |  |  |  | 2 |  | 2 |  |
Period prior to termination |  |  |  |  |  |  |  | 24 months |  |
Notice period for termination of agreement with cause |  |  |  |  |  |  |  | 30 days |  |
Advisory Agreement - Base Rate, Annualized Rate | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, base rate |  |  | 0.425% |  |  |  |  |  |  |
Advisory Agreement - Base Rate, Quarterly Rate | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, base rate |  |  | 0.10625% |  |  |  |  |  |  |
Advisory Agreement - Base Management Fee |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  |  | $ 1,600,000 | 1,600,000 | $ 3,200,000 | 3,100,000 |
Advisory Agreement - Incentive Rate, Quarterly Hurdle Rate | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  |  | 2.00% |  |
Advisory Agreement - Incentive Rate, Annualized Hurdle Rate | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  |  | 8.00% |  |
Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Below Catch-Up Threshold | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  |  | 15.00% |  |
Advisory Agreement - Incentive Rate, Pre-Incentive Fee Net Investment Income Exceeds Catch-Up Threshold | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  |  | 15.00% |  |
Eight Amended Advisory Agreement | Affiliated Entity | Subsequent Event |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  | 15.00% |  |  |  |  |  |  |  |
Advisory Agreement - Incentive Fees | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  |  |  | 1,300,000 |  | 2,700,000 |
Contractual fee waived |  |  |  |  |  | 1,400,000 |  | $ 2,500,000 |  |
Investment company, voluntary fee waived |  |  |  |  |  |  | 0 |  | 0 |
Advisory Agreement - Incentive Rate, Realized Capital Gains |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  |  | 0 | 0 | $ 0 | 0 |
Advisory Agreement - Incentive Rate, Realized Capital Gains | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Management and service fees, incentive rate |  |  |  |  |  |  |  | 15.00% |  |
Advisory Agreement - Termination Fee Payable as a Percentage of Management and Incentive Fees Earned by Adviser | Affiliated Entity |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  |  |  |  | 200.00% |  |
Administrative Agreement - Administrative Fee |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  |  | 500,000 | 400,000 | $ 1,100,000 | 900,000 |
Mortgage Financing Arrangement Agreement - Financing Fees | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  |  | $ 17,500 | $ 100,000 | $ 17,500 | $ 100,000 |
Mortgage Financing Arrangement Agreement - Percentage of Mortgage Principal Secured | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  |  | 0.20% | 0.35% | 0.20% | 0.35% |
Dealer Manager Agreement | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, amounts of transaction |  |  |  |  |  | $ 300,000 | $ 100,000 | $ 400,000 | $ 300,000 |
Dealer Manager Agreement - Selling Commission Percentage of Gross Proceeds From Sales |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  | 6.00% |  |  |  |  |  |
Dealer Manager Agreement - Dealer Management Fee Percentage of Gross Proceeds from Sale of Preferred Stock in Primary Offering |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  | 3.00% |  |  |  |  |  |
Series F Cumulative Redeemable Preferred Stock | Preferred Stock | Dealer Manager Agreement | Affiliated Entity | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Redeemable preferred stock, shares authorized (in shares) | shares |  |  |  | 20,000,000 |  |  |  |  |  |
Redeemable preferred stock, dividend rate |  |  |  |  | 6.00% |  |  |  |  |
Redeemable preferred stock, par value (in dollars per share) | $ / shares |  |  |  | $ 0.001 |  |  |  |  |  |
Redeemable preferred stock, dividend reinvestment plan, shares authorized (in shares) | shares |  |  |  | 6,000,000 |  |  |  |  |  |
Minimum | Mortgage Financing Arrangement Agreement - Financing Fees | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  |  |  |  | 0.15% |  |
Maximum | Mortgage Financing Arrangement Agreement - Financing Fees | Gladstone Securities, LLC |  |  |  |  |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |  |  |  |  |
Related party transaction, rate |  |  |  |  |  |  |  | 1.00% |  |
[1] | Refer to Note 2 “Related-Party Transactions”
[2] | Refer to Note 2 “Related-Party Transactions”

X
- Definition Number of Executive Officers + References No definition available. + Details
Name: | good_NumberofExecutiveOfficers
Namespace Prefix: | good_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Preferred Stock, Shares Authorized, Dividend Reinvestment Plan + References No definition available. + Details
Name: | good_PreferredStockSharesAuthorizedDividendReinvestmentPlan
Namespace Prefix: | good_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Notice period for termination of agreement with cause. + References No definition available. + Details
Name: | good_RelatedPartyTransactionNoticePeriodForTerminationOfAgreementWithCause
Namespace Prefix: | good_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Notice period for termination of agreement without cause. + References No definition available. + Details
Name: | good_RelatedPartyTransactionNoticePeriodForTerminationOfAgreementWithoutCause
Namespace Prefix: | good_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Related Party Transaction, Number of Quarters Used for the Cap of Average Quarterly Incentive Fees + References No definition available. + Details
Name: | good_RelatedPartyTransactionNumberOfQuartersUsedForTheCapOfAverageQuarterlyIncentiveFees
Namespace Prefix: | good_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Related Party Transaction, Number of Times the Sum of the Average Annual Base Management Fee and Incentive Fee Earned By Adviser + References No definition available. + Details
Name: | good_RelatedPartyTransactionNumberOfTimesTheSumOfTheAverageAnnualBaseManagementFeeAndIncentiveFeeEarnedByAdviser
Namespace Prefix: | good_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | instant

X
- Definition Related Party Transaction, Percentage of Independent Directors Required to Terminate the Amended Advisory Agreement + References No definition available. + Details
Name: | good_RelatedPartyTransactionPercentageOfIndependentDirectorsRequiredToTerminateTheAmendedAdvisoryAgreement
Namespace Prefix: | good_
Data Type: | dtr-types1:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Related Party Transaction, Period Prior To Termination + References No definition available. + Details
Name: | good_RelatedPartyTransactionPeriodPriorToTermination
Namespace Prefix: | good_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of fee contractually waived by investment company. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480990/946-20-50-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 + Details
Name: | us-gaap_InvestmentCompanyContractualFeeWaived
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of fee voluntarily waived by investment company. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480990/946-20-50-7 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 + Details
Name: | us-gaap_InvestmentCompanyVoluntaryFeeWaived
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Base rate for management and service fees under arrangement to manage operations, including, but not limited to, investment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 + Details
Name: | us-gaap_ManagementAndServiceFeesBaseRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Rate based on performance for management and service fees under arrangement to manage operations, including, but not limited to, investment. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 + Details
Name: | us-gaap_ManagementAndServiceFeesIncentiveRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense for investment management fee, including, but not limited to, expense in connection with research, selection, supervision, and custody of investment. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 10 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480167/946-830-55-10 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section 45 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483581/946-220-45-3 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483326/850-10-50-1 + Details
Name: | us-gaap_ManagementFeeExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of liabilities classified as other. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 946 -SubTopic 830 -Name Accounting Standards Codification -Section 55 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480167/946-830-55-12 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(12)(b)(2)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(12)(b)(3)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 944 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(15)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(12)(b)(1)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479853/942-210-S99-1 + Details
Name: | us-gaap_OtherLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-13 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.12-12A(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.12-12(Column A)(Footnote 4)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-1 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 3 -Subparagraph (SX 210.12-12B(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-3 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 320 -Name Accounting Standards Codification -Section S99 -Paragraph 6 -Subparagraph (SX 210.12-14(Column A)(Footnote 3)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480032/946-320-S99-6 + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 505 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 13 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org//1943274/2147481112/505-10-50-13 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 210 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-04(16)(a)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147479617/946-210-S99-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of transactions with related party during the financial reporting period. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 850 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483326/850-10-50-1 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 3 -Publisher FASB -URI https://asc.fasb.org//1943274/2147483326/850-10-50-3 + Details
Name: | us-gaap_RelatedPartyTransactionAmountsOfTransaction
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)(2)(i)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(c)(2)(ii)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 946 -SubTopic 220 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.6-07(2)(g)(3)) -Publisher FASB -URI https://asc.fasb.org//1943274/2147483575/946-220-S99-1 + Details
Name: | us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Identify the stated interest rate per the agreement, for example, leasing and debt arrangements between related parties. + References No definition available. + Details
Name: | us-gaap_RelatedPartyTransactionRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_RelatedPartyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=srt_AffiliatedEntityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementBaseRateAnnualizedRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementBaseRateQuarterlyRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementBaseManagementFeeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementIncentiveRateQuarterlyHurdleRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementIncentiveRateAnnualizedHurdleRateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementIncentiveRatePreIncentiveFeeNetInvestmentIncomeBelowCatchUpThresholdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementIncentiveRatePreIncentiveFeeNetInvestmentIncomeExceedsCatchUpThresholdMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_EightAmendedAdvisoryAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementIncentiveFeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementIncentiveRateRealizedCapitalGainsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdvisoryAgreementTerminationFeePayableAsAPercentageOfManagementAndIncentiveFeesEarnedByAdviserMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_AdministrativeAgreementAdministrativeFeeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_MortgageFinancingArrangementAgreementFinancingFeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_MortgageFinancingArrangementAgreementPercentageOfMortgagePrincipalSecuredMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_DealerManagerAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_DealerManagerAgreementSellingCommissionPercentageOfGrossProceedsFromSalesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RelatedPartyTransactionAxis=good_DealerManagerAgreementDealerManagementFeePercentageOfGrossProceedsFromSaleOfPreferredStockInPrimaryOfferingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementClassOfStockAxis=good_SeriesFCumulativeRedeemablePreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_PreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |