XML 61 R46.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Real Estate and Intangible Assets - Summary of Estimated Aggregate Rental Income (Detail) - Above and Below Market Leases [Member] $ in Thousands | Dec. 31, 2016 USD ($)
--- | ---
Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items] |
2017 | $ 743
2018 | 743
2019 | 743
2020 | 797
2021 | 705
Thereafter | 5,594
Total | $ 9,325

X
- Definition Schedule Of Operating Leases Future Minimum Payments Receivable [Line Items] + References No definition available. + Details
Name: | good_ScheduleOfOperatingLeasesFutureMinimumPaymentsReceivableLineItems
Namespace Prefix: | good_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Future minimum rental payments in aggregate as of the balance sheet date under operating leases. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
Name: | us-gaap_OperatingLeasesFutureMinimumPaymentsReceivable
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Future rental payments receivable within one year of the balance sheet date under an operating lease. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
Name: | us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Future rental payments receivable within the fifth year from the balance sheet date under an operating lease. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
Name: | us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFiveYears
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Future rental payments receivable within the fourth year from the balance sheet date under an operating lease. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
Name: | us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInFourYears
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Future rental payments receivable within the third year from the balance sheet date under an operating lease. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
Name: | us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInThreeYears
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Future rental payments receivable within the second year from the balance sheet date under an operating lease. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
Name: | us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableInTwoYears
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Future minimum lease payments receivable under operating leases for periods greater than five years following the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6454179&loc=d3e41551-112718 + Details
Name: | us-gaap_OperatingLeasesFutureMinimumPaymentsReceivableThereafter
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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