Quarterly report [Sections 13 or 15(d)]

RELATED-PARTY TRANSACTIONS - Schedule of Management Fees, Incentive Fees and Associated Credits and Administration Fees (Details)

v3.25.1
RELATED-PARTY TRANSACTIONS - Schedule of Management Fees, Incentive Fees and Associated Credits and Administration Fees (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Adviser    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities $ 2,246 $ 2,156
Base management fee | Adviser    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities 2,058 2,156
Capital gains fee | Adviser    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities 188 0
Administration fee    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities 642 603
Financing Fees and Selling Commissions and Dealer Management Fees | Gladstone Securities    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities 0 28
Selling Commissions and Dealer Management Fees | Gladstone Securities    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities $ 0 $ 28