Quarterly report pursuant to Section 13 or 15(d)

Equity and Mezzanine Equity - Additional Information (Details)

v3.22.2.2
Equity and Mezzanine Equity - Additional Information (Details)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2022
USD ($)
shares
Sep. 30, 2021
shares
Dec. 31, 2021
shares
Sep. 20, 2022
ft²
shares
Feb. 20, 2020
shares
Feb. 19, 2020
shares
Jan. 29, 2020
USD ($)
Class of Stock [Line Items]              
Temporary equity, contract terms, trigger change in control 50.00%            
Common stock, shares outstanding (in shares) | shares 39,607,009   37,473,587   60,290,000 86,290,000  
Units held by noncontrolling owners (in shares) | shares 391,468   256,994        
Fort Payne, Alabama              
Class of Stock [Line Items]              
Aggregate Square Footage | ft²       49,375      
Gladstone Commercial Limited Partnership              
Class of Stock [Line Items]              
Company ownership percentage of voting securities 99.00%   99.30%        
OP units issued | shares       134,474      
Number of units redeemed in acquisition (in shares) | shares   246,039          
Series D Preferred Stock              
Class of Stock [Line Items]              
Temporary equity, contract terms, minimum vote needed to trigger change in control from tender offer 90.00%            
Preferred Stock | Series E Preferred Stock              
Class of Stock [Line Items]              
Redeemable preferred stock, dividend rate 6.625%            
Preferred Stock | Series G Preferred Stock              
Class of Stock [Line Items]              
Redeemable preferred stock, dividend rate 6.00%            
Preferred Stock | Series F Preferred Stock              
Class of Stock [Line Items]              
Redeemable preferred stock, shares issued (in shares) | shares 164,400            
Consideration received | $ $ 3.7            
Maximum remaining capacity to sell common stock under open market sale agreement | $ $ 621.6            
Redeemable preferred stock, shares authorized (in shares) | shares         26,000,000    
Common Stock ATM Program | Common Stock              
Class of Stock [Line Items]              
Universal registration statement, amount authorized | $             $ 63.0
Common Stock ATM Program | Baird, Goldman Sachs, Stifel, Fifth Third, and U.S. Bancorp Investments, Inc. | Common Stock              
Class of Stock [Line Items]              
Redeemable preferred stock, shares issued (in shares) | shares 2,000,000            
Common Stock ATM Program | Baird, Goldman Sachs, Stifel, and Fifth Third | Common Stock              
Class of Stock [Line Items]              
Consideration received | $ $ 40.6            
Maximum remaining capacity to sell common stock under open market sale agreement | $ 26.5            
2020 Universal Shelf              
Class of Stock [Line Items]              
Universal registration statement, amount authorized | $ $ 648.6           800.0
2020 Universal Shelf | Preferred Stock | Series F Preferred Stock              
Class of Stock [Line Items]              
Universal registration statement, amount authorized | $             $ 636.5