XML 62 R50.htm IDEA: XBRL DOCUMENT
v3.21.1

Subsequent Events - Monthly Distributions Declared by Company's Board of Directors (Detail) - $ / shares | Jul. 06, 2021 | Jun. 30, 2021 | Jun. 28, 2021 | Jun. 18, 2021 | Jun. 04, 2021 | May 28, 2021 | May 26, 2021 | May 19, 2021 | May 06, 2021 | May 05, 2021 | Apr. 30, 2021 | Apr. 28, 2021 | Apr. 23, 2021 | Apr. 13, 2021
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Forecast | February 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  |  |  |  |  |  | May 19, 2021 |  |  |  |  |  |
Payment Date |  |  |  |  |  | May 28, 2021 |  |  |  |  |  |  |  |
Forecast | February 2021 | Series D Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  | $ 0.1458333 |  |  |  |  |  |  |  |
Forecast | February 2021 | Series E Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  | 0.138021 |  |  |  |  |  |  |  |
Forecast | February 2021 | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment Date |  |  |  |  | Jun. 04, 2021 |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  | $ 0.0875 |  |  |  |  |  |  |  |  |
Forecast | February 2021 | Series F Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  |  |  |  |  | May 26, 2021 |  |  |  |  |  |  |
Payment Date |  |  |  |  | Jun. 04, 2021 |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  | $ 0.125 |  |  |  |  |  |  |  |  |
Forecast | February 2021 | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  | $ 0.12515 |  |  |  |  |  |  |  |
Forecast | March 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  |  | Jun. 18, 2021 |  |  |  |  |  |  |  |  |  |
Payment Date |  | Jun. 30, 2021 |  |  |  |  |  |  |  |  |  |  |  |
Forecast | March 2021 | Series D Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  | $ 0.1458333 |  |  |  |  |  |  |  |  |  |  |  |
Forecast | March 2021 | Series E Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  | 0.138021 |  |  |  |  |  |  |  |  |  |  |  |
Forecast | March 2021 | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment Date | Jul. 06, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) | $ 0.0875 |  |  |  |  |  |  |  |  |  |  |  |  |
Forecast | March 2021 | Series F Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  | Jun. 28, 2021 |  |  |  |  |  |  |  |  |  |  |
Payment Date | Jul. 06, 2021 |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) | $ 0.125 |  |  |  |  |  |  |  |  |  |  |  |  |
Forecast | March 2021 | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  | $ 0.12515 |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event | Series D Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.4374999
Subsequent Event | Series E Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.414063
Subsequent Event | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.2625
Subsequent Event | Series F Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  | 0.375
Subsequent Event | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.37545
Subsequent Event | January 2021 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  |  |  |  |  |  |  |  |  |  |  | Apr. 23, 2021 |
Payment Date |  |  |  |  |  |  |  |  |  |  | Apr. 30, 2021 |  |  |
Subsequent Event | January 2021 | Series D Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  | $ 0.1458333 |  |  |
Subsequent Event | January 2021 | Series E Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  | 0.138021 |  |  |
Subsequent Event | January 2021 | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment Date |  |  |  |  |  |  |  |  | May 06, 2021 |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  | $ 0.0875 |  |  |  |  |
Subsequent Event | January 2021 | Series F Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  |  |  |  |  |  |  |  |  |  | Apr. 28, 2021 |  |
Payment Date |  |  |  |  |  |  |  |  |  | May 05, 2021 |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  | $ 0.125 |  |  |  |
Subsequent Event | January 2021 | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  | $ 0.12515 |  |  |

X
- Definition Date the declared dividend will be paid, in CCYY-MM-DD format. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4304-108586 + Details
Name: | us-gaap_DividendPayableDateToBePaidDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition The per share amount of a dividend declared, but not paid, as of the financial reporting date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=121583591&loc=d3e4304-108586 + Details
Name: | us-gaap_DividendsPayableAmountPerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format. + References No definition available. + Details
Name: | us-gaap_DividendsPayableDateOfRecordDayMonthAndYear
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
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 No definition available. + Details
Name: | us-gaap_DividendsPayableLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_StatementScenarioAxis=srt_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DividendsAxis=good_DividendDeclaredPeriodTwoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

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

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

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

X
- Details
Name: | us-gaap_DividendsAxis=good_DividendDeclaredPeriodThreeMember
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_DividendsAxis=good_DividendDeclaredPeriodOneMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |