Quarterly report [Sections 13 or 15(d)]

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

v3.26.1
RELATED-PARTY TRANSACTIONS - Schedule of Management Fees, Incentive Fees and Associated Credits and Administration Fees (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Adviser    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities $ 1,945 $ 2,246
Base management fee | Adviser    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities 1,945 2,058
Capital gains fee credit | Adviser    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities 0 188
Administration fee    
Related Party Transaction [Line Items]    
Total fees to Gladstone Securities $ 720 $ 642