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, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| Transfers of Financial Assets [Line Items] | |||||
| Portfolio securitizations: unpaid principal balance | $ 49,400 | $ 30,900 | $ 97,700 | $ 66,400 | |
| Unconsolidated VIEs | |||||
| Transfers of Financial Assets [Line Items] | |||||
| Retained interests: principal and interest received | 129 | $ 66 | 200 | $ 123 | |
| Single Class MBS, REMIC & Megas | Unconsolidated VIEs | |||||
| Transfers of Financial Assets [Line Items] | |||||
| Retained interests: unpaid principal balance | 6,400 | 6,400 | $ 1,000 | ||
| Retained interests: fair value | $ 6,700 | $ 6,700 | $ 1,300 | ||