Fair Values of Assets and Liabilities - Losses Recognized Related to Nonrecurring Fair Value Measurements (Details) - Fair Value, Measurements, Nonrecurring - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||||
| Losses recognized related to nonrecurring fair value measurements | $ 1 | $ 1 | $ 2 | $ 2 |
| Loans | ||||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||||
| Losses recognized related to nonrecurring fair value measurements | $ 39 | $ 99 | $ 142 | $ 198 |