v3.26.1
Borrowings - BANA Credit Facility - Narrative (Details) - USD ($)
$ in Thousands
May 09, 2025
Jun. 30, 2026
Sep. 30, 2025
Debt Instrument [Line Items]      
Debt   $ 5,170,226 $ 4,699,707
Revolving Credit Facility | BANA Credit Facility | Line of Credit      
Debt Instrument [Line Items]      
Debt   $ 310,900 $ 310,000
Revolving Credit Facility | BANA Credit Facility | Line of Credit | GCRED Funding LLC      
Debt Instrument [Line Items]      
Maximum borrowing capacity $ 500,000    
Revolving Credit Facility | BANA Credit Facility | Line of Credit | GCRED Funding LLC | Component One      
Debt Instrument [Line Items]      
Commitment fee percentage on unused portion 0.25%    
Revolving Credit Facility | BANA Credit Facility | Line of Credit | GCRED Funding LLC | Minimum      
Debt Instrument [Line Items]      
Debt instrument, basis spread on variable rate 1.70%    
Revolving Credit Facility | BANA Credit Facility | Line of Credit | GCRED Funding LLC | Minimum | Component Two      
Debt Instrument [Line Items]      
Commitment fee percentage on unused portion 0.50%    
Revolving Credit Facility | BANA Credit Facility | Line of Credit | GCRED Funding LLC | Maximum      
Debt Instrument [Line Items]      
Debt instrument, basis spread on variable rate 1.95%    
Revolving Credit Facility | BANA Credit Facility | Line of Credit | GCRED Funding LLC | Maximum | Component Two      
Debt Instrument [Line Items]      
Commitment fee percentage on unused portion 1.75%