Quarterly report pursuant to Section 13 or 15(d)

Equity - Additional Information (Detail)

v3.7.0.1
Equity - Additional Information (Detail)
 3 Months Ended 12 Months Ended 36 Months Ended
Apr. 12, 2017
USD ($)
security
Mar. 22, 2017
USD ($)
shares
Mar. 13, 2017
USD ($)
$ / shares
shares
Apr. 02, 2014
USD ($)
security
Mar. 31, 2017
USD ($)
$ / shares
shares
Mar. 31, 2016
USD ($)
Dec. 31, 2016
USD ($)
$ / shares
shares
Mar. 31, 2017
USD ($)
$ / shares
shares
Dec. 31, 2015
shares
Aug. 07, 2015
USD ($)
Subsidiary, Sale of Stock [Line Items]                    
Common stock, shares authorized (in shares) | shares         18,000,000   18,000,000 18,000,000    
Common stock, par value (in dollars per share) | $ / shares         $ 0.001   $ 0.001 $ 0.001    
Common stock, shares issued (in shares) | shares         11,850,624   10,024,875 11,850,624    
Common stock, shares outstanding (in shares) | shares         11,850,624   10,024,875 11,850,624    
OP units held by non-controlling interest limited partners         $ 745,879     $ 745,879    
Maximum number of securities that can be sold (in securities) | security       2            
Proceeds from issuance of equity         $ 20,722,000 $ 0        
Subsequent Event                    
Subsidiary, Sale of Stock [Line Items]                    
Maximum number of securities that can be sold (in securities) | security 2                  
Registration Statement                    
Subsidiary, Sale of Stock [Line Items]                    
Proceeds from issuance of equity               $ 73,100,000    
Number of shares issued (in shares) | shares         0          
Registration Statement | General and administrative expenses                    
Subsidiary, Sale of Stock [Line Items]                    
Professional fees and stockholder-related expenses         $ 46,000          
Public offering                    
Subsidiary, Sale of Stock [Line Items]                    
Sale of common stock sold under sale agreement (in shares) | shares     1,680,000              
Average sales price of common stock sold (in dollars per share) | $ / shares     $ 11.35              
Gross proceeds from issuance of common stock     $ 19,100,000              
Net proceeds from issuance of common stock     $ 18,000,000              
Over-allotment option                    
Subsidiary, Sale of Stock [Line Items]                    
Sale of common stock sold under sale agreement (in shares) | shares   145,749                
Gross proceeds from issuance of common stock   $ 1,700,000                
Net proceeds from issuance of common stock   $ 1,600,000                
ATM Program                    
Subsidiary, Sale of Stock [Line Items]                    
Common stock, shares issued (in shares) | shares         64,561     64,561    
Common stock, value authorized                   $ 30,000,000.0
Average sales price price (in dollars per share) | $ / shares         $ 10.23     $ 10.23    
Common stock, value, outstanding         $ 660,000     $ 660,000    
Common stock, value, issued             $ 650,000      
Common Stock                    
Subsidiary, Sale of Stock [Line Items]                    
Common stock, shares outstanding (in shares) | shares         11,850,624   10,024,875 11,850,624 9,992,941  
Number of shares issued (in shares) | shares         1,825,749   31,934      
Common Stock | Registration Statement                    
Subsidiary, Sale of Stock [Line Items]                    
Common stock, shares issued (in shares) | shares         4,013,763     4,013,763    
Securities allowed for issuance (amount up to)       $ 300,000,000            
Common Stock | Registration Statement | Subsequent Event                    
Subsidiary, Sale of Stock [Line Items]                    
Securities allowed for issuance (amount up to) $ 300,000,000                  
Preferred Stock | Registration Statement                    
Subsidiary, Sale of Stock [Line Items]                    
Common stock, shares issued (in shares) | shares         1,150,000     1,150,000    
Gladstone Land Limited Partnership                    
Subsidiary, Sale of Stock [Line Items]                    
Company's ownership percent (as percent)         89.10%   87.40% 89.10%    
OP units held by non-controlling limited partners (in shares) | shares         1,449,258   1,449,258