Quarterly report pursuant to Section 13 or 15(d)

Real Estate and Intangible Assets - Summarized Information of Acquisition of Properties (Parenthetical) (Detail)

v2.4.1.9
Real Estate and Intangible Assets - Summarized Information of Acquisition of Properties (Parenthetical) (Detail) (USD $)
3 Months Ended
Mar. 31, 2015
Parrish Road [Member]  
Real Estate Properties [Line Items]  
Contingent consideration owed in connection with acquisition of real estate property $ 700,000land_AcquisitionOfRealEstatePropertyAdditionalCompensationCommittedUponApprovalOfIncreaseInWaterPermits
/ us-gaap_RealEstatePropertiesAxis
= land_ParrishRoadMember
2015 New Real Estate Activity [Member]  
Real Estate Properties [Line Items]  
Finder's fee 320,905land_CreditToIncentiveFee
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember
Direct leasing costs in connection with acquisitions 2,625us-gaap_AcquisitionCosts
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember
2015 New Real Estate Activity [Member] | New Tenant Lease Agreement [Member]  
Real Estate Properties [Line Items]  
Direct leasing costs in connection with acquisitions $ 2,625us-gaap_AcquisitionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_LeaseAgreementsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember