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Borrowings - NMFC Credit Facility (Details) € in Thousands, £ in Thousands, $ in Thousands		3 Months Ended		6 Months Ended
	Sep. 30, 2024 USD ($)	Jun. 30, 2026 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2026 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2026 EUR (€)	Jun. 30, 2026 GBP (£)	Dec. 31, 2025 USD ($)	Dec. 31, 2025 EUR (€)	Dec. 31, 2025 GBP (£)	Jun. 30, 2025 EUR (€)	Jun. 30, 2025 GBP (£)
Line of Credit Facility [Line Items]
Amortization of financing costs				$ 5,062	$ 4,539
NMFC Credit Facility
Line of Credit Facility [Line Items]
Credit facility outstanding balance		$ 30,356		30,356				$ 81,074
Revolving Credit Facility \| NMFC Credit Facility
Line of Credit Facility [Line Items]
Credit facility outstanding balance		30,356		30,356		€ 16,512	£ 8,666	$ 81,074	€ 16,512	£ 8,666	€ 16,512	£ 8,666
Revolving Credit Facility \| NMFC Credit Facility \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 638,500
Commitment fee percentage on unused capacity	0.375%
Interest expense		351	$ 383	1,877	759
Non-usage fee		471	513	858	1,087
Amortization of financing costs		$ 206	$ 187	$ 410	$ 371
Weighted average interest rate		4.50%	5.00%	5.20%	5.20%
Effective interest rate		13.40%	14.30%	8.80%	15.30%
Average debt outstanding		$ 30,824	$ 30,315	$ 72,131	$ 29,314
Extending Lenders \| Revolving Credit Facility \| NMFC Credit Facility \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 527,100	$ 527,100		$ 527,100
Basis spread on variable rate	1.90%
Non-Extending Lenders \| Revolving Credit Facility \| NMFC Credit Facility \| Line of Credit
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 111,400
Basis spread on variable rate	2.10%