Income Taxes - Schedule of Taxable income and Taxable Net Realized Gains Losses (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Income Tax Disclosure [Abstract] | ||||
| Taxable income | $ 74.0 | $ 85.7 | $ 247.8 | $ 230.4 |
| Taxable income, per share (in dollars per share) | $ 0.40 | $ 0.47 | $ 1.34 | $ 1.31 |
| Taxable net realized gains (losses) | $ 9.4 | $ 5.1 | $ 30.4 | $ (30.6) |
| Taxable net realized gains (losses) per share (in dollars per share) | $ 0.05 | $ 0.04 | $ 0.16 | $ (0.17) |
| Weighted average shares outstanding (in shares) | 185,989 | 180,360 | 184,767 | 175,633 |