XML 69 R54.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Mortgage Notes Payable, Revolving Credit Facility, and Term Loan Facility Narrative (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2016 property mortgage
Debt Instrument [Line Items] |
Libor rate (as percent) | 0.77%
Weighted average interest rate on debt outstanding (as percent) | 4.48%
Encumbered properties | 94
Revolving Credit Facility [Member] |
Debt Instrument [Line Items] |
Encumbered properties | 24
Fixed Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Encumbered properties | 52
Mortgage Notes Payable [Member] |
Debt Instrument [Line Items] |
Number of mortgage notes payable | mortgage | 44
Maturity date of mortgage notes payable, start date | Mar. 01, 2017
Maturity date of mortgage notes payable, end date | Jul. 01, 2045
Weighted average interest rate on debt outstanding (as percent) | 4.69%
Encumbered properties | 70
Variable Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Encumbered properties | 18
Variable rate Line of Credit [Member] | Revolving Credit Facility [Member] |
Debt Instrument [Line Items] |
Libor rate (as percent) | 2.25%
Encumbered properties | 24
Minimum [Member] | Fixed Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Debt instrument stated percentage (as percent) | 3.75%
Minimum [Member] | Variable Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Libor rate (as percent) | 2.15%
Maximum [Member] | Fixed Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Debt instrument stated percentage (as percent) | 6.63%
Maximum [Member] | Variable Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Libor rate (as percent) | 2.75%

X
- Definition Number of existing encumbered properties. + References No definition available. + Details
Name: | good_NumberOfExistingEncumberedProperties
Namespace Prefix: | good_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of mortgage notes payable. + References No definition available. + Details
Name: | good_NumberOfMortgageNotesPayable
Namespace Prefix: | good_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
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_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Latest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDateRangeEnd1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Earliest date the outstanding debt instruments are required to be repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentMaturityDateRangeStart1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average interest rate of debt outstanding. + References No definition available. + Details
Name: | us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=good_FixedRateMortgageLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=good_MortgageNotesPayableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=good_VariableRateMortgagesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=good_VariableRateLineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |