Annual report pursuant to Section 13 and 15(d)

Real Estate and Lease Intangibles - Fair Value of Acquired Assets and Liabilities Assumed Related to Properties Acquired (Detail)

v2.4.1.9
Real Estate and Lease Intangibles - Fair Value of Acquired Assets and Liabilities Assumed Related to Properties Acquired (Detail) (USD $)
 12 Months Ended
Dec. 31, 2013
Dec. 31, 2014
2014 New Real Estate Activity [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   $ 68,482,397us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   669,210us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Above (Below)-Market Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   (144,957)us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_AboveAndBelowMarketLeasesMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Collins Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   2,596,733us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_CollinsRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Collins Road [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   45,086us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_CollinsRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Spring Valley [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   5,900,500us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Spring Valley [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   83,487us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Spring Valley [Member] | Above (Below)-Market Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   (49,976)us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_AboveAndBelowMarketLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | McIntosh Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   2,667,275us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | McIntosh Road [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   34,674us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | McIntosh Road [Member] | Above (Below)-Market Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   45,674us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_AboveAndBelowMarketLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Naumann Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   6,895,284us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_NaumannRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Naumann Road [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   75,520us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_NaumannRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Sycamore Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   5,803,600us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_SycamoreRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Sycamore Road [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   48,670us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_SycamoreRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Sycamore Road [Member] | Above (Below)-Market Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   (160,184)us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_AboveAndBelowMarketLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_SycamoreRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Wauchula Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   13,897,555us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_WauchulaRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Santa Clara Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   24,593,200us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_SantaClaraAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Santa Clara Avenue [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   310,119us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_SantaClaraAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Dufau Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   6,128,250us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Dufau Road [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   71,654us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Dufau Road [Member] | Above (Below)-Market Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   19,529us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_MajorPropertyClassAxis
= land_AboveAndBelowMarketLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   4,674,065us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member] | Spring Valley [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   200,855us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member] | McIntosh Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   537,254us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member] | Naumann Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   71,586us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_NaumannRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member] | Sycamore Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   67,000us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_SycamoreRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member] | Wauchula Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   3,521,229us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_WauchulaRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member] | Santa Clara Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   187,314us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_SantaClaraAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Irrigation System [Member] | Dufau Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   88,827us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Horticulture [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   520,993us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_HorticultureInventoryMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Horticulture [Member] | Collins Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   520,993us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_HorticultureInventoryMember
/ us-gaap_RealEstatePropertiesAxis
= land_CollinsRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   223,831us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | Collins Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   71,085us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_CollinsRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | Spring Valley [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   17,998us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | McIntosh Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   18,041us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | Naumann Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   41,012us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_NaumannRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | Sycamore Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   7,364us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SycamoreRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | Wauchula Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   5,200us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_WauchulaRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | Santa Clara Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   30,353us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SantaClaraAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Leasing Costs [Member] | Dufau Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   32,778us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Customer Relationships [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   455,857us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Customer Relationships [Member] | Collins Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   24,796us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
/ us-gaap_RealEstatePropertiesAxis
= land_CollinsRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Customer Relationships [Member] | Spring Valley [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   66,217us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Customer Relationships [Member] | McIntosh Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   27,966us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Customer Relationships [Member] | Naumann Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   54,786us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
/ us-gaap_RealEstatePropertiesAxis
= land_NaumannRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Customer Relationships [Member] | Santa Clara Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   229,372us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SantaClaraAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2014 New Real Estate Activity [Member] | Customer Relationships [Member] | Dufau Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   52,720us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= us-gaap_CustomerRelationshipsMember
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
2013 New Real Estate Activity [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 37,783,601land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 110,753land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Below-Market Lease Values [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price (161,547)land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_MajorPropertyClassAxis
= land_BelowMarketLeaseMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | 38th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 1,379,200land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_RealEstatePropertiesAxis
= land_ThirtyEightAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Sequoia Street [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 3,208,210land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_RealEstatePropertiesAxis
= land_SequoiaStreetMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Natividad Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 7,330,035land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_RealEstatePropertiesAxis
= land_NatividadRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Natividad Road [Member] | In-place Leases [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 110,753land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_MajorPropertyClassAxis
= land_InPlaceLeasesMember
/ us-gaap_RealEstatePropertiesAxis
= land_NatividadRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Natividad Road [Member] | Below-Market Lease Values [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price (161,547)land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_MajorPropertyClassAxis
= land_BelowMarketLeaseMember
/ us-gaap_RealEstatePropertiesAxis
= land_NatividadRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | 20th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 2,019,479land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_RealEstatePropertiesAxis
= land_TwentiethAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Broadway Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 3,027,528land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_RealEstatePropertiesAxis
= land_BroadwayRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Oregon Trail [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 14,068,458land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_RealEstatePropertiesAxis
= land_OregonTrailMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | East Shelton [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 6,750,691land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_RealEstatePropertiesAxis
= land_EastSheltonMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 2,833,306land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member] | 38th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 239,768land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_ThirtyEightAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member] | Sequoia Street [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 424,268land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_SequoiaStreetMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member] | Natividad Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 144,915land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_NatividadRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member] | 20th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 441,415land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_TwentiethAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member] | Broadway Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 22,727land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_BroadwayRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member] | Oregon Trail [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 1,118,640land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_OregonTrailMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Irrigation System [Member] | East Shelton [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 441,573land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_IrrigationSystemMember
/ us-gaap_RealEstatePropertiesAxis
= land_EastSheltonMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Horticulture [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 1,038,346land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_HorticultureInventoryMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Horticulture [Member] | 38th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 446,408land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_HorticultureInventoryMember
/ us-gaap_RealEstatePropertiesAxis
= land_ThirtyEightAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Horticulture [Member] | 20th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 488,604land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_HorticultureInventoryMember
/ us-gaap_RealEstatePropertiesAxis
= land_TwentiethAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Horticulture [Member] | Broadway Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 103,334land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_HorticultureInventoryMember
/ us-gaap_RealEstatePropertiesAxis
= land_BroadwayRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Leasing Costs [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 56,649land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Leasing Costs [Member] | 38th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 3,842land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_ThirtyEightAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Leasing Costs [Member] | Sequoia Street [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 9,535land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SequoiaStreetMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Leasing Costs [Member] | Natividad Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 29,941land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_NatividadRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Leasing Costs [Member] | 20th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 2,623land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_TwentiethAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Leasing Costs [Member] | Oregon Trail [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 8,726land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_OregonTrailMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
2013 New Real Estate Activity [Member] | Leasing Costs [Member] | East Shelton [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 1,982land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis
= land_LeasingCostsMember
/ us-gaap_RealEstatePropertiesAxis
= land_EastSheltonMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   58,857,451us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | Collins Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   1,252,388us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_CollinsRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | Spring Valley [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   5,576,138us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | McIntosh Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   1,970,074us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | Naumann Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   6,219,293us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_NaumannRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | Sycamore Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   5,840,750us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SycamoreRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | Wauchula Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   8,466,185us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_WauchulaRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | Santa Clara Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   23,672,902us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SantaClaraAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2014 New Real Estate Activity [Member] | Dufau Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   5,859,721us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 33,102,031land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member] | 38th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 646,522land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_ThirtyEightAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member] | Sequoia Street [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 2,494,911land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SequoiaStreetMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member] | Natividad Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 7,186,774land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_NatividadRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member] | 20th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 805,677land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_TwentiethAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member] | Broadway Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 2,851,353land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_BroadwayRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member] | Oregon Trail [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 12,941,092land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_OregonTrailMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Land and Land Improvements [Member] | 2013 New Real Estate Activity [Member] | East Shelton [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 6,175,702land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_LandAndLandImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_EastSheltonMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   3,225,947us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member] | Collins Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   682,385us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_CollinsRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member] | Spring Valley [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   5,781us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SpringValleyMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member] | McIntosh Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   33,592us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_McintoshRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member] | Naumann Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   433,087us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_NaumannRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member] | Wauchula Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   1,904,941us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_WauchulaRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member] | Santa Clara Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   163,140us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SantaClaraAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2014 New Real Estate Activity [Member] | Dufau Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Acquisition Cost   3,021us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_DufauRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandFourteenNewRealEstateActivityMember
Buildings and Improvements [Member] | 2013 New Real Estate Activity [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 804,063land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Buildings and Improvements [Member] | 2013 New Real Estate Activity [Member] | 38th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 42,660land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_ThirtyEightAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Buildings and Improvements [Member] | 2013 New Real Estate Activity [Member] | Sequoia Street [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 279,496land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_SequoiaStreetMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Buildings and Improvements [Member] | 2013 New Real Estate Activity [Member] | Natividad Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 19,199land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_NatividadRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Buildings and Improvements [Member] | 2013 New Real Estate Activity [Member] | 20th Avenue [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 281,160land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_TwentiethAvenueMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Buildings and Improvements [Member] | 2013 New Real Estate Activity [Member] | Broadway Road [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price 50,114land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_BroadwayRoadMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember 		 
Buildings and Improvements [Member] | 2013 New Real Estate Activity [Member] | East Shelton [Member]    
Business Acquisition Purchase Price Allocation [Line Items]    
Total Purchase Price $ 131,434land_BusinessCombinationConsiderationTransferredIncludingTransactionCosts
/ us-gaap_PropertyPlantAndEquipmentByTypeAxis
= us-gaap_BuildingAndBuildingImprovementsMember
/ us-gaap_RealEstatePropertiesAxis
= land_EastSheltonMember
/ us-gaap_SignificantAcquisitionsAndDisposalsByTransactionAxis
= land_TwoThousandThirteenNewRealEstateActivityMember