Interest Expense - Schedule of Components of Interest Expense (Details) - USD ($) $ in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2026 |
Sep. 30, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Debt securities: | ||||
| Interest expense | $ 115.5 | $ 82.9 | $ 301.2 | $ 225.6 |
| Mortgage warehouse facilities | ||||
| Debt securities: | ||||
| Interest expense | 28.5 | 23.5 | 76.7 | 61.2 |
| MSR financing facilities | ||||
| Debt securities: | ||||
| Interest expense | 28.0 | 23.0 | 74.2 | 63.1 |
| Advance match funded liabilities | ||||
| Debt securities: | ||||
| Interest expense | 5.6 | 7.8 | 17.7 | 23.4 |
| Escrow and other | ||||
| Debt securities: | ||||
| Interest expense | 3.5 | 2.3 | 7.2 | 5.6 |
| Senior Notes Due 2029 | ||||
| Debt securities: | ||||
| Interest expense | 17.7 | 12.9 | 51.5 | 38.6 |
| Secured Debt | Securitization Notes | ||||
| Debt securities: | ||||
| Interest expense | $ 32.2 | $ 13.5 | $ 73.9 | $ 33.7 |