| 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Revenues: | ||||||||||||||||
| Net premiums earned | ||||||||||||||||
| Net investment income earned | ||||||||||||||||
| Net realized and unrealized investment gains (losses) | ||||||||||||||||
| Other income | ||||||||||||||||
| Total revenues | ||||||||||||||||
| YoY growth | +4.5% | +5.7% | +8.6% | +9.3% | ||||||||||||
| Expenses: | ||||||||||||||||
| Loss and loss expense incurred | ||||||||||||||||
| Amortization of deferred policy acquisition costs | ||||||||||||||||
| Other insurance expenses | ||||||||||||||||
| Interest expense | ||||||||||||||||
| Corporate expenses | ||||||||||||||||
| Total expenses | ||||||||||||||||
| Income (loss) before income tax | ||||||||||||||||
| Income tax expense (benefit): | ||||||||||||||||
| Current | ||||||||||||||||
| Deferred | ||||||||||||||||
| Total income tax expense (benefit) | ||||||||||||||||
| Net income (loss) | ||||||||||||||||
| % of revenue | 9.3% | 7.2% | 11.4% | 8.5% | ||||||||||||
| Preferred stock dividends | ||||||||||||||||
| Net income (loss) available to common stockholders, basic | ||||||||||||||||
| Net income (loss) available to common stockholders, diluted | ||||||||||||||||
| Net income (loss) available to common stockholders - Basic (in dollars per share) | — | |||||||||||||||
| Net income (loss) available to common stockholders - Diluted (in dollars per share) | — |