Quarterly report pursuant to Section 13 or 15(d)

Real Estate and Intangible Assets - Summary of Lease Expirations by Year for Properties with Leases (Detail)

v2.4.1.9
Real Estate and Intangible Assets - Summary of Lease Expirations by Year for Properties with Leases (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
Lease
acre
Mar. 31, 2014
acre
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 30land_NumberOfExpiringLeases  
Expiring Leased Acreage 8,789us-gaap_AreaOfRealEstateProperty 6,000us-gaap_AreaOfRealEstateProperty
% of Total Acreage 100.00%land_PercentageOfAggregateAcreage  
Rental Revenue for the Three Ended March 31, 2015 $ 2,622,327us-gaap_OperatingLeasesIncomeStatementLeaseRevenue $ 1,495,636us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
% of Total Rental Revenue 100.00%land_PercentageOfAggregateRentalRevenue  
2015 [Member]    
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 4land_NumberOfExpiringLeases
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueRemainderOfFiscalYearMember 		 
Expiring Leased Acreage 405us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueRemainderOfFiscalYearMember 		 
% of Total Acreage 4.60%land_PercentageOfAggregateAcreage
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueRemainderOfFiscalYearMember 		 
Rental Revenue for the Three Ended March 31, 2015 351,496us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueRemainderOfFiscalYearMember 		 
% of Total Rental Revenue 13.40%land_PercentageOfAggregateRentalRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueRemainderOfFiscalYearMember 		 
2016 [Member]    
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 1land_NumberOfExpiringLeases
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueCurrentMember 		 
Expiring Leased Acreage 331us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueCurrentMember 		 
% of Total Acreage 3.80%land_PercentageOfAggregateAcreage
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueCurrentMember 		 
Rental Revenue for the Three Ended March 31, 2015 186,216us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueCurrentMember 		 
% of Total Rental Revenue 7.10%land_PercentageOfAggregateRentalRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueCurrentMember 		 
2017 [Member]    
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 7land_NumberOfExpiringLeases
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearTwoMember 		 
Expiring Leased Acreage 351us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearTwoMember 		 
% of Total Acreage 4.00%land_PercentageOfAggregateAcreage
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearTwoMember 		 
Rental Revenue for the Three Ended March 31, 2015 235,144us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearTwoMember 		 
% of Total Rental Revenue 9.00%land_PercentageOfAggregateRentalRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearTwoMember 		 
2018 [Member]    
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 3land_NumberOfExpiringLeases
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearThreeMember 		 
Expiring Leased Acreage 370us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearThreeMember 		 
% of Total Acreage 4.20%land_PercentageOfAggregateAcreage
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearThreeMember 		 
Rental Revenue for the Three Ended March 31, 2015 92,121us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearThreeMember 		 
% of Total Rental Revenue 3.50%land_PercentageOfAggregateRentalRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearThreeMember 		 
2019 [Member]    
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 0land_NumberOfExpiringLeases
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFourMember 		 
Expiring Leased Acreage 0us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFourMember 		 
% of Total Acreage 0.00%land_PercentageOfAggregateAcreage
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFourMember 		 
% of Total Rental Revenue 0.00%land_PercentageOfAggregateRentalRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFourMember 		 
2020 [Member]    
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 4land_NumberOfExpiringLeases
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFiveMember 		 
Expiring Leased Acreage 1,138us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFiveMember 		 
% of Total Acreage 12.90%land_PercentageOfAggregateAcreage
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFiveMember 		 
Rental Revenue for the Three Ended March 31, 2015 743,216us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFiveMember 		 
% of Total Rental Revenue 28.30%land_PercentageOfAggregateRentalRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueInYearFiveMember 		 
Thereafter [Member]    
Property Subject to or Available for Operating Lease [Line Items]    
Number of Expiring Leases 11land_NumberOfExpiringLeases
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueThereafterMember 		 
Expiring Leased Acreage 6,194us-gaap_AreaOfRealEstateProperty
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueThereafterMember 		 
% of Total Acreage 70.50%land_PercentageOfAggregateAcreage
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueThereafterMember 		 
Rental Revenue for the Three Ended March 31, 2015 $ 1,014,134us-gaap_OperatingLeasesIncomeStatementLeaseRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueThereafterMember 		 
% of Total Rental Revenue 38.70%land_PercentageOfAggregateRentalRevenue
/ us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis
= land_LeaseExpirationsDueThereafterMember