| Line Item | Jun 30, 2026 | Mar 31, 2026 | Dec 31, 2025 | Sep 30, 2025 | Jun 30, 2025 | Mar 31, 2025 | Dec 31, 2024 | Sep 30, 2024 | Jun 30, 2024 | Mar 31, 2024 | Dec 31, 2023 | Sep 30, 2023 | Jun 30, 2023 | Mar 31, 2023 | Dec 31, 2022 | Sep 30, 2022 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Interest income | ||||||||||||||||
| Interest expense | ||||||||||||||||
| Net interest income | ||||||||||||||||
| Realized gain on sales of investments, net | ||||||||||||||||
| Unrealized (loss) gain on investments, net | ||||||||||||||||
| Gain (loss) on derivative instruments, net | ||||||||||||||||
| Total gains (losses), net | ||||||||||||||||
| Compensation and benefits | ||||||||||||||||
| Other general and administrative | ||||||||||||||||
| Other operating expenses | ||||||||||||||||
| Total operating expenses | ||||||||||||||||
| Net income (loss) | ||||||||||||||||
| Preferred stock dividends | — | |||||||||||||||
| Net income (loss) to common shareholders | ||||||||||||||||
| Net income (loss) per common share-basic (in dollars per share) | ||||||||||||||||
| Net income (loss) per common share-diluted (in dollars per share) |