Quarterly report pursuant to Section 13 or 15(d)

Real Estate and Intangible Assets - Summary of Total Revenue and Earnings Recognized on Properties Acquired (Detail)

v2.4.1.9
Real Estate and Intangible Assets - Summary of Total Revenue and Earnings Recognized on Properties Acquired (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Real Estate Properties [Line Items]    
Rental revenue $ 2,622,327us-gaap_OperatingLeasesIncomeStatementLeaseRevenue $ 1,495,636us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
2015 New Real Estate Activity [Member]    
Real Estate Properties [Line Items]    
Rental revenue 200,432us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember 		 
Earnings 104,237land_RealEstatePropertiesEarningsRecognized
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember 		 
2015 New Real Estate Activity [Member] | Espinosa Road [Member]    
Real Estate Properties [Line Items]    
Acquisition Date Jan. 05, 2015  
Rental revenue 186,216us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_RealEstatePropertiesAxis
= land_EspinosaRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember 		 
Earnings 97,058land_RealEstatePropertiesEarningsRecognized
/ us-gaap_RealEstatePropertiesAxis
= land_EspinosaRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember 		 
2015 New Real Estate Activity [Member] | Parrish Road [Member]    
Real Estate Properties [Line Items]    
Acquisition Date Mar. 10, 2015  
Rental revenue 14,216us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_RealEstatePropertiesAxis
= land_ParrishRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember 		 
Earnings $ 7,179land_RealEstatePropertiesEarningsRecognized
/ us-gaap_RealEstatePropertiesAxis
= land_ParrishRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFifteenNewRealEstateActivityMember