Quarterly report pursuant to Section 13 or 15(d)

SUBSEQUENT EVENTS - Narrative (Details)

v3.24.0.1
SUBSEQUENT EVENTS - Narrative (Details) - USD ($)
 1 Months Ended
Jan. 24, 2024
Jan. 31, 2024
Jan. 17, 2024
Dec. 31, 2023
Subsequent Event [Line Items]        
Sale of stock, aggregate value of securities authorized       $ 300,000,000.0
Adviser | David Gladstone        
Subsequent Event [Line Items]        
Noncontrolling interest, ownership percentage by parent       100.00%
Adviser | Gladstone Companies, Inc        
Subsequent Event [Line Items]        
Noncontrolling interest, ownership percentage by parent       100.00%
The Gladstone Companies, Ltd | David Gladstone        
Subsequent Event [Line Items]        
Noncontrolling interest, ownership percentage by parent       100.00%
Gladstone Companies, Inc | The Gladstone Companies, Ltd        
Subsequent Event [Line Items]        
Noncontrolling interest, ownership percentage by parent       100.00%
Subsequent Event        
Subsequent Event [Line Items]        
Sale of stock, aggregate value of securities authorized     $ 700,000,000  
Subsequent Event | Adviser | David Gladstone        
Subsequent Event [Line Items]        
Noncontrolling interest, ownership percentage by parent 100.00%      
Subsequent Event | Adviser | Voting Trust Board        
Subsequent Event [Line Items]        
Ownership percentage of voting rights 20.00%      
Effective period after agreement is entered into 1 year      
Subsequent Event | CHA Holdings, Inc.        
Subsequent Event [Line Items]        
Net proceeds from the sale of investments   $ 3,000,000