Consolidations and Transfers of Financial Assets - Transfers of Financial Assets and Portfolio Securitizations (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
Dec. 31, 2024 |
|
| Transfers of Financial Assets [Line Items] | |||||
| Portfolio securitizations: unpaid principal balance | $ 30,900 | $ 35,500 | $ 66,400 | $ 66,700 | |
| Unconsolidated VIEs | |||||
| Transfers of Financial Assets [Line Items] | |||||
| Retained interests: principal and interest received | 66 | $ 63 | 123 | $ 127 | |
| Unconsolidated VIEs | Single Class MBS, REMIC & Megas | |||||
| Transfers of Financial Assets [Line Items] | |||||
| Retained interests: unpaid principal balance | 610 | 610 | $ 661 | ||
| Retained interests: fair value | $ 950 | $ 950 | $ 1,000 | ||