XML 51 R39.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Real Estate and Intangible Assets - Carrying Value of Intangible Assets and Accumulated Amortization (Detail) - USD ($) $ in Thousands | Sep. 30, 2016 | Dec. 31, 2015
--- | --- | ---
Finite-Lived Intangible Assets [Line Items] |  |
Below market leases and deferred revenue, gross | $ (19,813) | $ (17,951)
Below market leases and deferred revenue, accumulated amortization | 8,538 | 8,294
Above and Below Market Leases and Deferred Revenue [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets (liabilities), gross | (9,521) | (7,775)
Finite-lived intangible assets (liabilities), accumulated amortization | 1,363 | 1,476
Above Market Leases [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets, gross | 10,292 | 10,176
Finite-lived intangible assets, accumulated amortization | (7,175) | (6,818)
In-Place Leases [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets, gross | 68,681 | 66,244
Finite-lived intangible assets, accumulated amortization | (26,469) | (22,679)
Leasing Costs [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets, gross | 45,555 | 44,360
Finite-lived intangible assets, accumulated amortization | (17,320) | (14,774)
Customer Relationships [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets, gross | 48,774 | 46,485
Finite-lived intangible assets, accumulated amortization | (16,456) | (14,722)
Lease Intangibles [Member] |  |
Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets, gross | 163,010 | 157,089
Finite-lived intangible assets, accumulated amortization | $ (60,245) | $ (52,175)

X
- Definition Finite lived intangible assets (liabilities) accumulated amortization. + References No definition available. + Details
Name: | good_FiniteLivedIntangibleAssetsLiabilitiesAccumulatedAmortization
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Finite lived intangible assets (liabilities) gross. + References No definition available. + Details
Name: | good_FiniteLivedIntangibleAssetsLiabilitiesGross
Namespace Prefix: | good_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life. + References No definition available. + Details
Name: | us-gaap_BelowMarketLeaseAccumulatedAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before amortization of leases acquired as part of a real property acquisition at below market lease rate with a finite life. + References No definition available. + Details
Name: | us-gaap_BelowMarketLeaseGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275 + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275 + Details
Name: | us-gaap_FiniteLivedIntangibleAssetsGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_FiniteLivedIntangibleAssetsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=good_AboveAndBelowMarketLeasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_AboveMarketLeasesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_LeasesAcquiredInPlaceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=good_LeasingCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerRelationshipsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=good_LeaseIntangiblesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |