Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Detail)

v3.8.0.1
Subsequent Events - Additional Information (Detail)
 1 Months Ended 3 Months Ended 9 Months Ended
Oct. 17, 2017
USD ($)
farm
Oct. 13, 2017
USD ($)
shares
Oct. 06, 2017
shares
Oct. 02, 2017
USD ($)
a
option
farm
Sep. 20, 2017
shares
Nov. 07, 2017
USD ($)
$ / shares
shares
Sep. 30, 2017
a
shares
Sep. 30, 2017
USD ($)
a
farm
shares
Sep. 30, 2016
a
farm
Subsequent Event [Line Items]                  
Number of farms | farm               72 56
Area of real estate property (in acres) | a             61,794 61,794 33,800
ATM Program                  
Subsequent Event [Line Items]                  
Sale of common stock sold under sale agreement (in shares) | shares             434,401 434,401  
Limited Partner | Gladstone Land Limited Partnership                  
Subsequent Event [Line Items]                  
OP units redeemed (in shares) | shares         221,875        
2017 New Real Estate Activity                  
Subsequent Event [Line Items]                  
Number of farms | farm               14  
Area of real estate property (in acres) | a             11,202 11,202  
Price of acquisition               $ 121,847,000  
Subsequent event | ATM Program                  
Subsequent Event [Line Items]                  
Sale of common stock sold under sale agreement (in shares) | shares   121,875       31,038      
Average sales price of common stock sold (in dollars per share) | $ / shares           $ 13.39      
Gross proceeds from issuance of common stock           $ 416,000      
Proceeds from issuance of common stock           $ 409,000      
Subsequent event | Limited Partner | Gladstone Land Limited Partnership                  
Subsequent Event [Line Items]                  
OP units redeemed (in shares) | shares     121,875            
Subsequent event | Term loan | Rabo Agrifinance LLC Loan                  
Subsequent Event [Line Items]                  
Proceeds from notes payable   $ 540,000              
Interest rate (as percent)   4.59%              
Subsequent event | Unsecured promissory note | TRS                  
Subsequent Event [Line Items]                  
Interest rate (as percent) 5.00%                
Face amount of debt $ 1,700,000.0                
Subsequent event | 2017 New Real Estate Activity | Baca County, Colorado                  
Subsequent Event [Line Items]                  
Number of farms | farm       1          
Area of real estate property (in acres) | a       1,280          
Price of acquisition       $ 900,000          
Lease expiration period       4 years          
Number of renewal options | option       1          
Renewal term       5 years          
Annualized straight-line cash rent       $ 52,000          
Subsidiaries | Subsequent event | TRS                  
Subsequent Event [Line Items]                  
Number of farms | farm 1                
Reduction in lease term 2 years