Quarterly report pursuant to Section 13 or 15(d)

Equity - Additional Information (Details)

v3.20.2
Equity - Additional Information (Details)
1 Months Ended 3 Months Ended 9 Months Ended 12 Months Ended 42 Months Ended
Apr. 03, 2020
$ / shares
shares
Apr. 01, 2020
USD ($)
security
Mar. 05, 2020
USD ($)
shares
Feb. 20, 2020
$ / shares
shares
May 31, 2018
$ / shares
shares
Apr. 12, 2017
USD ($)
security
Nov. 04, 2020
USD ($)
Sep. 30, 2020
USD ($)
$ / shares
shares
Sep. 30, 2019
USD ($)
shares
Sep. 30, 2020
USD ($)
$ / shares
shares
Sep. 30, 2019
USD ($)
shares
Dec. 31, 2019
$ / shares
shares
Sep. 30, 2020
USD ($)
$ / shares
shares
Jun. 30, 2020
shares
May 12, 2020
USD ($)
Feb. 19, 2020
shares
Jun. 30, 2019
shares
Dec. 31, 2018
shares
Aug. 07, 2015
USD ($)
Subsidiary, Sale of Stock [Line Items]                                      
Stock authorized and unissued (in shares)       26,000,000                              
Common stock, shares authorized (in shares)       65,500,000       65,543,935   65,543,935   91,514,600 65,543,935     91,500,000      
Common stock, par value (in dollars per share) | $ / shares               $ 0.001   $ 0.001   $ 0.001 $ 0.001            
Common stock, shares issued (in shares)               22,204,906   22,204,906   20,936,658 22,204,906            
Common stock, shares outstanding (in shares)               22,204,906   22,204,906   20,936,658 22,204,906            
Proceeds from issuance of preferred and common equity | $                   $ 55,231,000 $ 86,070,000                
Payments of stock issuance costs | $                   3,636,000 $ 6,551,000                
2017 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Maximum number of securities that can be sold (in securities) | security           2                          
Proceeds from issuance of preferred and common equity | $                         $ 117,400,000            
2020 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Maximum number of securities that can be sold (in securities) | security   2                                  
Proceeds from issuance of preferred and common equity | $                   9,200,000                  
Allowance for credit loss, writeoff | $                   $ 29,000                  
Common Stock                                      
Subsidiary, Sale of Stock [Line Items]                                      
Common stock, shares outstanding (in shares)               22,204,906 20,888,075 22,204,906 20,888,075 20,936,658 22,204,906 21,534,739     20,532,770 17,891,340  
Common Stock | 2017 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Common stock, shares issued (in shares)               9,495,834   9,495,834     9,495,834            
Securities allowed for issuance (amount up to) | $           $ 300,000,000.0                          
Shares of common stock issued (in shares)                         1,215,565            
Common Stock | 2020 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Common stock, shares issued (in shares)               570,145   570,145     570,145            
Securities allowed for issuance (amount up to) | $   $ 1,000,000,000.0                                  
Shares of common stock issued (in shares)                   288,303                  
Series B Preferred Stock                                      
Subsidiary, Sale of Stock [Line Items]                                      
Preferred stock, shares authorized (in shares)               6,456,065   6,456,065   6,485,400 6,456,065            
Preferred stock, par value (in dollars per share) | $ / shares               $ 0.001   $ 0.001   $ 0.001 $ 0.001            
Preferred stock, shares issued (in shares)               5,956,065   5,956,065   4,755,869 5,956,065            
Preferred stock, shares outstanding (in shares)               5,956,065   5,956,065   4,755,869 5,956,065            
Redemptions of Series B Preferred Stock | $               $ 371,000 $ 48,000 $ 680,000 $ 214,000                
Series B Preferred Stock | 2017 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Proceeds from issuance of preferred and common equity | $                         $ 147,500,000            
Series B Preferred Stock | Preferred Stock                                      
Subsidiary, Sale of Stock [Line Items]                                      
Dividend rate (as percent)         6.00%                            
Preferred stock, shares outstanding (in shares)               5,956,065 3,465,527 5,956,065 3,465,527 4,755,869 5,956,065 5,972,482     2,636,068 1,144,393  
Average sales price of common stock sold (in dollars per share) | $ / shares         $ 25.00                            
Stock redeemed (in shares)               16,417 2,120 29,335 9,520                
Redemptions of Series B Preferred Stock | $               $ 372,000 $ 48,000 $ 681,000 $ 214,000                
Maximum amount of securities can be sold under shelf registration statement (in shares)         6,000,000                            
Gross proceeds | $                 20,487,000 30,148,000 57,529,000                
Net proceeds from issuance of stock | $                 18,711,000 $ 27,664,000 52,440,000                
Series B Preferred Stock | Preferred Stock | 2017 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Common stock, shares issued (in shares)               6,000,000   6,000,000     6,000,000            
Series B Preferred Stock | Preferred Stock | Series B Termination                                      
Subsidiary, Sale of Stock [Line Items]                                      
Securities allowed for issuance (amount up to) | $     $ 147,500,000                                
Maximum amount of securities can be sold under shelf registration statement (in shares)     6,000,000                                
Gross proceeds | $     $ 133,400,000                                
Net proceeds from issuance of stock | $     $ 1,600,000                                
Series C Preferred Stock                                      
Subsidiary, Sale of Stock [Line Items]                                      
Preferred stock, shares authorized (in shares)               26,000,000   26,000,000   0 26,000,000            
Preferred stock, par value (in dollars per share) | $ / shares               $ 0.001   $ 0.001   $ 0.001 $ 0.001            
Preferred stock, shares issued (in shares)               420,230   420,230   0 420,230            
Preferred stock, shares outstanding (in shares)               420,230   420,230   0 420,230            
Series C Preferred Stock | 2020 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Proceeds from issuance of preferred and common equity | $                   $ 10,400,000                  
Series C Preferred Stock | Preferred Stock                                      
Subsidiary, Sale of Stock [Line Items]                                      
Dividend rate (as percent)       6.00%           6.00%                  
Preferred stock, shares authorized (in shares) 20,000,000     120,000                              
Preferred stock, par value (in dollars per share) | $ / shares       $ 0.001                              
Preferred stock, shares outstanding (in shares)               420,230   420,230     420,230 130,702          
Average sales price of common stock sold (in dollars per share) | $ / shares $ 25.00     $ 25.00                              
Preferred stock, shares authorized, pursuant to DRIP (in shares) 6,000,000                                    
Maximum amount of securities can be sold under shelf registration statement (in shares) 26,000,000     400,000                              
Gross proceeds | $               $ 7,184,000   $ 10,444,000                  
Net proceeds from issuance of stock | $               $ 6,586,000   9,559,000                  
Sale of stock pursuant to DRIP (in dollars per share) | $ / shares $ 22.75     $ 22.75                              
Net proceeds from issuance of stock, excluding selling commissions and dealer-manager fees | $                   $ 225,000                  
Series C Preferred Stock | Preferred Stock | 2020 Registration Statement                                      
Subsidiary, Sale of Stock [Line Items]                                      
Common stock, shares issued (in shares)               420,196   420,196     420,196            
Series C Preferred Stock | Preferred Stock | Series C Termination                                      
Subsidiary, Sale of Stock [Line Items]                                      
Preferred stock, shares authorized (in shares) 20,000,000                                    
Common Stock | ATM Program                                      
Subsidiary, Sale of Stock [Line Items]                                      
Gross proceeds | $               $ 8,483,000 937,000 $ 14,638,000 1,830,000                
Net proceeds from issuance of stock | $               $ 8,398,000 $ 923,000 $ 14,491,000 $ 1,802,000                
Common stock, value authorized | $                             $ 100,000,000.0       $ 30,000,000.0
OP Unit Holder                                      
Subsidiary, Sale of Stock [Line Items]                                      
Company's ownership percent (as percent)               100.00%   100.00%   98.60% 100.00%            
Minimum period required to exercise, in months                   12 months                  
Gladstone Land Limited Partnership                                      
Subsidiary, Sale of Stock [Line Items]                                      
OP units held by non-controlling limited partners (in shares)                   0   288,303              
Subsequent Event | Series C Preferred Stock | Preferred Stock                                      
Subsidiary, Sale of Stock [Line Items]                                      
Proceeds from issuance of preferred and common equity | $             $ 4,638,000                        
Subsequent Event | Common Stock                                      
Subsidiary, Sale of Stock [Line Items]                                      
Proceeds from issuance of preferred and common equity | $             $ 26,094,000