XML 12 R52.htm IDEA: XBRL DOCUMENT
v3.19.3

Subsequent Events - Monthly Distributions Declared by Company's Board of Directors (Detail) - $ / shares |  |  |  |  |  |  |  |  |  | 1 Months Ended |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Jan. 07, 2020 | Dec. 31, 2019 | Dec. 19, 2019 | Dec. 06, 2019 | Nov. 29, 2019 | Nov. 19, 2019 | Nov. 07, 2019 | Oct. 31, 2019 | Oct. 22, 2019 | Dec. 31, 2019 | Nov. 30, 2019 | Oct. 31, 2019 | Oct. 08, 2019 | Oct. 04, 2019
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) |  |  |  |  |  |  |  |  |  |  |  |  | 0.404861 |
Subsequent event | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.2625
Subsequent event | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  |  |  |  |  |  | $ 0.375 |
Subsequent event | October 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  |  |  |  |  |  |  | Oct. 22, 2019 |  |  |  |  |
Forecast | October 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payment Date |  |  |  |  |  |  |  | Oct. 31, 2019 |  |  |  |  |  |
Forecast | October 2019 | Series D Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  | $ 0.1458333 |  |  |  | $ 0.1458333 |  |
Forecast | October 2019 | Series E Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  | 0.128819 |  |  |  | $ 0.128819 |  |
Forecast | October 2019 | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payable to the Holders of Record During the Month of: |  |  |  |  |  |  |  |  |  |  |  | October |  |
Payment Date |  |  |  |  |  |  | Nov. 07, 2019 |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  | $ 0.0875 |  |  |  |  |  |  |
Forecast | October 2019 | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  |  |  |  | $ 0.125 |  |  |  | $ 0.125 |  |
Forecast | November 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  |  |  |  | Nov. 19, 2019 |  |  |  |  |  |  |  |
Payment Date |  |  |  |  | Nov. 29, 2019 |  |  |  |  |  |  |  |  |
Forecast | November 2019 | Series D Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  | $ 0.1458333 |  |  |  |  |  |  |  |  |
Forecast | November 2019 | Series E Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  | 0.138021 |  |  |  |  |  |  |  |  |
Forecast | November 2019 | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payable to the Holders of Record During the Month of: |  |  |  |  |  |  |  |  |  |  | November |  |  |
Payment Date |  |  |  | Dec. 06, 2019 |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  | $ 0.0875 |  |  |  |  |  |  |  |  |  |
Forecast | November 2019 | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  |  |  |  | $ 0.125 |  |  |  |  |  |  |  |  |
Forecast | December 2019 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Record Date |  |  | Dec. 19, 2019 |  |  |  |  |  |  |  |  |  |  |
Payment Date |  | Dec. 31, 2019 |  |  |  |  |  |  |  |  |  |  |  |
Forecast | December 2019 | Series D Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  | $ 0.1458333 |  |  |  |  |  |  |  | $ 0.1458333 |  |  |  |
Forecast | December 2019 | Series E Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  | 0.138021 |  |  |  |  |  |  |  | $ 0.138021 |  |  |  |
Forecast | December 2019 | Senior Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Payable to the Holders of Record During the Month of: |  |  |  |  |  |  |  |  |  | December |  |  |  |
Payment Date | Jan. 07, 2020 |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) | $ 0.0875 |  |  |  |  |  |  |  |  |  |  |  |  |
Forecast | December 2019 | Common Stock |  |  |  |  |  |  |  |  |  |  |  |  |  |
Dividends Payable [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |
Distribution per share (in dollars per share) |  | $ 0.125 |  |  |  |  |  |  |  | $ 0.125 |  |  |  |

X
- Definition Distributions payable to holders of records, months. + References No definition available. + Details
Name: | good_DistributionsPayableToHoldersOfRecordsMonths
Namespace Prefix: | good_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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=98513485&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=98513485&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: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
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_StatementEquityComponentsAxis=us-gaap_CommonStockMember
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: |

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_DividendsAxis=good_DividendDeclaredPeriodThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |