XML 53 R41.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Real Estate Dispositions, Held for Sale and Impairment Charges - Additional Information (Detail) |  |  | 3 Months Ended | 9 Months Ended
--- | --- | --- | --- | ---
Aug. 24, 2016 USD ($) property | May 16, 2016 USD ($) | Sep. 30, 2016 USD ($) property | Sep. 30, 2015 USD ($) | Sep. 30, 2016 USD ($) property | Sep. 30, 2015 USD ($)
Real Estate Properties [Line Items] |  |  |  |  |  |
Loss on sale of real estate |  |  | $ (24,000) | $ 0 | $ (24,000) | $ 0
Number of real estate properties, held for sale | property |  |  | 5 |  | 5 |
Impairment loss |  |  | $ 1,786,000 | $ 622,000 | $ 2,016,000 | 622,000
Dayton Ohio [Member] |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Property held for sale |  | $ 200,000 |  |  |  |
Loss on sale of real estate |  | 0 |  |  |  |
Impairment loss |  | 40,000 |  |  | 40,000 | $ 600,000
Angola, Indiana [Member] |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Number of properties sold | property | 2 |  |  |  |  |
Rock Falls, Illinois and Angola, Indiana [Member] |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Property held for sale | $ 3,000,000 |  |  |  |  |
Loss on sale of real estate | $ 20,000 |  |  |  |  |
Impairment loss |  | 20,000 |  |  | $ 20,000 |
Montgomery, AL [Member] |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Impairment loss |  | 200,000 |  |  |  |
Hazelwood, MO [Member] |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Impairment loss |  | 700,000 |  |  |  |
South Hadley, MA [Member] |  |  |  |  |  |
Real Estate Properties [Line Items] |  |  |  |  |  |
Impairment loss |  | $ 1,100,000 |  |  |  |

X
- Definition Number of real estate properties held for sale. + References No definition available. + Details
Name: | good_NumberOfRealEstatePropertiesHeldForSale
Namespace Prefix: | good_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Properties Sold + References No definition available. + Details
Name: | good_NumberofPropertiesSold
Namespace Prefix: | good_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of write-down of assets recognized in the income statement. Includes, but is not limited to, losses from tangible assets, intangible assets and goodwill. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2420-110228 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 + Details
Name: | us-gaap_AssetImpairmentCharges
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount classified as property, plant and equipment attributable to disposal group held for sale or disposed of. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=51717284&loc=SL51721673-107760 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 10 -URI http://asc.fasb.org/extlink&oid=51716988&loc=d3e1107-107759 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=51719941&loc=d3e2941-110230 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=51716988&loc=SL51721533-107759 + Details
Name: | us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585 + Details
Name: | us-gaap_GainLossOnSaleOfProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
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_RealEstatePropertiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementGeographicalAxis=good_DaytonOhioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=good_AngolaIndianaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=good_RockFallsIllinoisandAngolaIndianaMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=good_MontgomeryALMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=good_HazelwoodMOMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementGeographicalAxis=good_SouthHadleyMAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |