Income Tax - Schedule of Aggregate Unrealized Gains and Losses on Investments Based on Cost for U.S. Federal Income Tax Purposes (Detail) - USD ($) $ in Thousands |
Mar. 31, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Investment Company, Disclosure Items [Abstract] | ||
| Tax cost | $ 733,924 | $ 589,625 |
| Gross unrealized gains | 731 | 1,931 |
| Gross unrealized losses | $ (8,812) | $ (286) |