Investments, at Fair Value - Debt Securities, Allowance for Credit Loss (Details) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
|
| Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward] | ||
| Cumulative losses as of the beginning of period | $ 32,288 | $ 31,290 |
| Credit related losses not previously recognized | 0 | 998 |
| Increase in amounts previously recognized | 0 | 0 |
| Cumulative losses as of the end of period | $ 32,288 | $ 32,288 |