XML 17 R23.htm IDEA: XBRL DOCUMENT
v3.20.1

Related-Party Transactions - Additional Information (Detail) |  |  | 3 Months Ended |
--- | --- | --- | --- | ---
Feb. 20, 2020 $ / shares shares | Jan. 10, 2017 quarter | Mar. 31, 2020 USD ($) officer | Mar. 31, 2019 USD ($) | Dec. 31, 2019 USD ($)
Related Party Transaction [Line Items] |  |  |  |  |  |
Number of executive officers | officer |  |  |  | 2 |  |
Amount due to Adviser and Administrator | [1] |  |  | $ 3,152,000 |  | $ 2,904,000
Annual base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses (as percent) |  |  | 1.50% |  |  |
Quarterly base management fee, in percentage of stockholders' equity, adjusted to unrealized gains or losses (as percent) |  |  | 0.375% |  |  |
Base management fee | [2] |  |  | $ 1,412,000 | $ 1,267,000 |
Pre-incentive quarterly fee FFO in percentage of common stockholders' equity that will reward the Adviser (as percent) |  |  | 2.00% |  |  |
Pre-incentive annual fee FFO in percentage of common stockholders' equity that will reward the Adviser (as percent) |  |  | 8.00% |  |  |
Amount to be paid to Adviser in percentage of pre-incentive fee condition one (as percent) |  |  | 15.00% |  |  |
Number of quarters used for the cap of average quarterly incentive fees | quarter |  |  | 4 |  |  |
Incentive fee description |  |  |  | However, in no event shall the incentive fee for a particular quarter exceed by 15.0% (the cap) the average quarterly incentive fee paid by us for the previous four quarters (excluding quarters for which no incentive fee was paid). |  |
Incentive fee | [2] |  |  | $ 1,055,000 | 851,000 |
Portion of incentive fee waived |  |  |  | 0 | 0 |
Capital gains-based incentive fee (as percent) |  |  | 15.00% |  |  |
Capital gain fee |  |  |  | 0 | 0 |
Percentage of independent directors required to terminate the Amended Advisory Agreement (as a percent) |  |  | 66.67% |  |  |
Termination fee payable (as percent) |  |  | 200.00% |  |  |
Notice period for termination of agreement without cause |  |  | 120 days |  |  |
Notice period for termination of agreement with cause |  |  | 30 days |  |  |
Administration fee | [2] |  |  | 438,000 | 413,000 |
Fees paid |  |  |  | $ 90,000 | $ 20,000 |
Financing fee on total secured mortgages percentage (as percent) |  |  |  | 0.25% | 0.15% |
Selling commissions (as percent) |  | 6.00% |  |  |  |
Dealer management fee (as percent) |  | 3.00% |  |  |  |
Minimum |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Percentage of the amount of the mortgage (as percent) |  |  |  | 0.15% |  |
Maximum |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Percentage of the amount of the mortgage (as percent) |  |  |  | 1.00% |  |
Series F Cumulative Redeemable Preferred Stock | Preferred Stock |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Redeemable preferred stock, shares authorized (in shares) | shares |  | 26,000,000 |  |  |  |
Redeemable preferred stock, dividend rate percentage (as percent) |  | 6.00% |  |  |  |
Series F Cumulative Redeemable Preferred Stock | Preferred Stock | Dealer Management Agreement |  |  |  |  |  |
Related Party Transaction [Line Items] |  |  |  |  |  |
Redeemable preferred stock, shares authorized (in shares) | shares |  | 20,000,000 |  |  |  |
Redeemable preferred stock, dividend rate percentage (as percent) |  | 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 |  |  |  |
[1] | Refer to Note 2 “Related-Party Transactions”
[2] | Refer to Note 2 “Related-Party Transactions”

X
- Definition Administration fee. + References No definition available. + Details
Name: | good_AdministrationFee
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount to be paid to adviser in percentage of pre incentive fee condition one. + References No definition available. + Details
Name: | good_AmountToBePaidToAdviserInPercentageOfPreIncentiveFeeConditionOne
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Annual base management fee in percentage of stockholders equity adjusted to unrealized gains or losses. + References No definition available. + Details
Name: | good_AnnualBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Annualized incentive fee per advisory agreement. + References No definition available. + Details
Name: | good_AnnualizedIncentiveFeePerAdvisoryAgreement
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Base management fee. + References No definition available. + Details
Name: | good_BaseManagementFee
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Dealer Management Fee, Gross Proceeds, Percentage + References No definition available. + Details
Name: | good_DealerManagementFeeGrossProceedsPercentage
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Incentive fee. + References No definition available. + Details
Name: | good_IncentiveFee
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Incentive fee on capital gains. + References No definition available. + Details
Name: | good_IncentiveFeeOnCapitalGains
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Incentive Fee Waived + References No definition available. + Details
Name: | good_IncentiveFeeWaived
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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

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 Number of Quarters Used for the Cap of Average Quarterly Incentive Fees + References No definition available. + Details
Name: | good_NumberofQuartersUsedfortheCapofAverageQuarterlyIncentiveFees
Namespace Prefix: | good_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Payment of financing fee. + References No definition available. + Details
Name: | good_PaymentOfFinancingFee
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of financing fee to amount of mortgage. + References No definition available. + Details
Name: | good_PercentageOfFinancingFeeToAmountOfMortgage
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of incentive fees on capital gains. + References No definition available. + Details
Name: | good_PercentageOfIncentiveFeesOnCapitalGains
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of Independent Directors Required to Terminate the Amended Advisory Agreement + References No definition available. + Details
Name: | good_PercentageofIndependentDirectorsRequiredtoTerminatetheAmendedAdvisoryAgreement
Namespace Prefix: | good_
Data Type: | num:percentItemType
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 Quarterly base management fee in percentage of stockholders equity adjusted to unrealized gains or losses. + References No definition available. + Details
Name: | good_QuarterlyBaseManagementFeeInPercentageOfStockholdersEquityAdjustedToUnrealizedGainsOrLosses
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Quarterly incentive fee per advisory agreement. + References No definition available. + Details
Name: | good_QuarterlyIncentiveFeePerAdvisoryAgreement
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Secured mortgages financing fee percent. + References No definition available. + Details
Name: | good_SecuredMortgagesFinancingFeePercent
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Selling Commissions, Gross Proceeds, Percentage + References No definition available. + Details
Name: | good_SellingCommissionsGrossProceedsPercentage
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Termination Fee Payable, Percentage of Average Annual Management Fee and Incentive Fee During Twenty-Four Month Period + References No definition available. + Details
Name: | good_TerminationFeePayableasPercentageofAverageAnnualManagementFeeandIncentiveFeeDuringTwentyFourMonthPeriod
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Carrying amount as of the balance sheet date of obligations due all related parties. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.17) -URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.15(3),(4)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_DueToRelatedPartiesCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Description of the nature of the payments to managing member or general partner for incentive rights held including the fee rate, basis of calculation, relevant accounting period, whether the fee is paid to an entity other than the managing member or general partner, or if the fee is waived. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 + Details
Name: | us-gaap_IncentiveFeeDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The percentage rate used to calculate dividend payments on preferred stock. + References No definition available. + Details
Name: | us-gaap_PreferredStockDividendRatePercentage
Namespace Prefix: | us-gaap_
Data Type: | num: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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num: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://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
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_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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: |

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: | us-gaap_RelatedPartyTransactionAxis=good_DealerManagementAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |