Securitizations and Variable Interest Entities - Schedule of Assets That Relate to Continuing Involvement with Transferred Financial Assets with Servicing Rights and Maximum Exposure to Loss Including the Unpaid Principal Balance (Details) - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items] | ||
| UPB of loans transferred | $ 75,310.2 | $ 64,876.2 |
| Maximum exposure to loss | 76,769.9 | 65,974.0 |
| Ginnie Mae | ||
| Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items] | ||
| UPB of loans transferred | 24,800.0 | 17,500.0 |
| Mortgage Servicing Rights - Fair Value | ||
| Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items] | ||
| Carrying value of assets | 1,341.9 | 978.2 |
| Advances | ||
| Qualitative and Quantitative Information, Transferor's Continuing Involvement [Line Items] | ||
| Carrying value of assets | $ 117.8 | $ 119.6 |