Settlement and Other Risk Management - Estimated Settlement Exposure (Details) - Guarantee Obligations - USD ($) $ in Millions |
Sep. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Risks Inherent in Servicing Assets and Servicing Liabilities | ||
| Gross settlement exposure | $ 94,646 | $ 89,599 |
| Risk mitigation arrangements applied to settlement exposure | (16,870) | (16,722) |
| Net settlement exposure | $ 77,776 | $ 72,877 |