XML 59 R47.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Mortgage Notes Payable, Line of Credit and Term Loan Facility - Company's Mortgage Notes Payable and Line of Credit Additional Information (Detail) | 9 Months Ended
--- | ---
Sep. 30, 2016 property mortgage
Debt Instrument [Line Items] |
Weighted average interest rate on debt outstanding | 4.47%
Encumbered properties | 96
LIBOR [Member] |
Debt Instrument [Line Items] |
Variable rate at period end | 0.53%
Fixed Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Number of mortgage notes payable | mortgage | 43
Maturity date of mortgage notes payable, start date | Dec. 01, 2016
Maturity date of mortgage notes payable, end date | Jul. 01, 2045
Encumbered properties | 54
Fixed Rate Mortgage Loans [Member] | Minimum [Member] |
Debt Instrument [Line Items] |
Stated Interest Rates | 3.75%
Fixed Rate Mortgage Loans [Member] | Maximum [Member] |
Debt Instrument [Line Items] |
Stated Interest Rates | 6.63%
Variable Rate Mortgage Loans [Member] |
Debt Instrument [Line Items] |
Encumbered properties | 17
Variable Rate Mortgage Loans [Member] | Minimum [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Spread on LIBOR | 2.15%
Variable Rate Mortgage Loans [Member] | Maximum [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Spread on LIBOR | 2.75%
Mortgage Notes Payable [Member] |
Debt Instrument [Line Items] |
Weighted average interest rate on debt outstanding | 4.71%
Encumbered properties | 71
Variable rate Line of Credit [Member] |
Debt Instrument [Line Items] |
Encumbered properties | 25
Variable rate Line of Credit [Member] | LIBOR [Member] |
Debt Instrument [Line Items] |
Spread on LIBOR | 2.50%

X
- Definition Debt Instrument, Interest Rate, Variable Rate at Period End + References No definition available. + Details
Name: | good_DebtInstrumentInterestRateVariableRateatPeriodEnd
Namespace Prefix: | good_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
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_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: |

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