Investments - Industry and Geographic Dispersion of Investment Portfolio as Percentage of Total Fair Value of Investments (Detail)	Sep. 30, 2025	Dec. 31, 2024
Investment Holdings [Line Items]
Percentage of total fair value of investment	100.00%	100.00%
Healthcare Supplies
Investment Holdings [Line Items]
Percentage of total fair value of investment	14.50%	17.00%
Insurance Services
Investment Holdings [Line Items]
Percentage of total fair value of investment	12.00%	0.00%
Commercial and Professional Services
Investment Holdings [Line Items]
Percentage of total fair value of investment	11.50%	13.00%
Engineered Products
Investment Holdings [Line Items]
Percentage of total fair value of investment	10.30%	12.40%
Retirement Plan Services
Investment Holdings [Line Items]
Percentage of total fair value of investment	10.30%	10.10%
Legal Services
Investment Holdings [Line Items]
Percentage of total fair value of investment	9.50%	0.00%
Visual Safety Solutions
Investment Holdings [Line Items]
Percentage of total fair value of investment	9.30%	7.90%
Franchise Consulting Services
Investment Holdings [Line Items]
Percentage of total fair value of investment	8.40%	0.00%
Information Services and Advisory Solutions
Investment Holdings [Line Items]
Percentage of total fair value of investment	6.20%	12.20%
Real Estate Services
Investment Holdings [Line Items]
Percentage of total fair value of investment	5.40%	6.30%
Hobby Goods and Supplies
Investment Holdings [Line Items]
Percentage of total fair value of investment	2.00%	2.50%
Restaurant and Food
Investment Holdings [Line Items]
Percentage of total fair value of investment	0.60%	0.00%
Business Services
Investment Holdings [Line Items]
Percentage of total fair value of investment	0.00%	13.90%
Sanitation Products
Investment Holdings [Line Items]
Percentage of total fair value of investment	0.00%	4.70%