Annual report pursuant to Section 13 and 15(d)

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

v2.4.1.9
Borrowings - Summary of Mortgage Note Payable and Line of Credit (Parenthetical) (Detail) (USD $)
12 Months Ended
Dec. 31, 2014
MetLife [Member]  
Debt Instrument [Line Items]  
New MetLife Credit Facility, termination date May 09, 2014
Remaining availability $ 13,800,000land_LongTermDebtAdditionalAvailableAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_MetlifeMember
Farmer Mac [Member]  
Debt Instrument [Line Items]  
Remaining availability $ 0land_LongTermDebtAdditionalAvailableAmount
/ us-gaap_LineOfCreditFacilityAxis
= land_FarmerMacMember