Quarterly report pursuant to Section 13 or 15(d)

Borrowings - Summary of Mortgage Note Payable and Line of Credit (Detail)

v2.4.1.9
Borrowings - Summary of Mortgage Note Payable and Line of Credit (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
Dec. 31, 2014
May 09, 2014
Debt Instrument [Line Items]      
Principal Outstanding $ 106,666,803us-gaap_LongTermDebt $ 86,417,361us-gaap_LongTermDebt  
Undrawn Commitment 108,015,002us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount 125,993,002us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount  
MetLife [Member]      
Debt Instrument [Line Items]      
Initial Commitment     125,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
MetLife [Member] | Mortgage Note Payable [Member]      
Debt Instrument [Line Items]      
Issuer MetLife    
Dates of Issuance May 09, 2014    
Initial Commitment 100,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember 		  100,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember
Maturity Date Jan. 05, 2029    
Principal Outstanding 66,331,998us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember 		66,331,998us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember 		 
Stated Interest Rate 3.61%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember 		3.61%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember 		 
Undrawn Commitment 33,668,002us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember 		33,668,002us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableToBanksMember 		 
MetLife [Member] | Line of Credit [Member]      
Debt Instrument [Line Items]      
Issuer MetLife    
Dates of Issuance May 09, 2014    
Initial Commitment 25,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember 		  25,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember
Maturity Date Apr. 05, 2024    
Principal Outstanding 11,800,000us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember 		4,000,000us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember 		 
Stated Interest Rate 2.76%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember 		2.75%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember 		 
Undrawn Commitment 13,200,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember 		21,000,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_LineOfCreditMember 		 
Farm Credit [Member] | Mortgage Notes Payable [Member]      
Debt Instrument [Line Items]      
Issuer Farm Credit    
Dates of Issuance, Start Sep. 19, 2014    
Dates of Issuance, End Mar. 10, 2015    
Initial Commitment 14,888,280us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmCreditMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableOtherPayablesMember 		   
Maturity Date, Start May 01, 2020    
Maturity Date, End Aug. 01, 2034    
Principal Outstanding 14,681,805us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmCreditMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableOtherPayablesMember 		12,410,363us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmCreditMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableOtherPayablesMember 		 
Stated Interest Rate 3.48%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmCreditMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableOtherPayablesMember 		3.53%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmCreditMember
/ us-gaap_LongtermDebtTypeAxis
= us-gaap_NotesPayableOtherPayablesMember 		 
Farmer Mac [Member] | Bond Payable [Member]      
Debt Instrument [Line Items]      
Issuer Farmer Mac    
Dates of Issuance Dec. 11, 2014    
Initial Commitment 75,000,000us-gaap_DebtInstrumentFaceAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember
/ us-gaap_LongtermDebtTypeAxis
= land_BondsPayableMember 		   
Maturity Date, Start Dec. 11, 2019    
Maturity Date, End Jan. 06, 2020    
Principal Outstanding 13,853,000us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember
/ us-gaap_LongtermDebtTypeAxis
= land_BondsPayableMember 		3,675,000us-gaap_LongTermDebt
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember
/ us-gaap_LongtermDebtTypeAxis
= land_BondsPayableMember 		 
Stated Interest Rate 3.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember
/ us-gaap_LongtermDebtTypeAxis
= land_BondsPayableMember 		3.25%us-gaap_DebtInstrumentInterestRateStatedPercentage
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember
/ us-gaap_LongtermDebtTypeAxis
= land_BondsPayableMember 		 
Undrawn Commitment $ 61,147,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember
/ us-gaap_LongtermDebtTypeAxis
= land_BondsPayableMember 		$ 71,325,000us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember
/ us-gaap_LongtermDebtTypeAxis
= land_BondsPayableMember