Securities - Realized Gains and Losses on Investment Securities Transactions Attributable to Available-for-sale Securities (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
---|---|---|---|---|
Jun. 30, 2025 |
Jun. 30, 2024 |
Jun. 30, 2025 |
Jun. 30, 2024 |
|
Investments, Debt and Equity Securities [Abstract] | ||||
Gross realized gains | $ 7 | $ 12 | $ 10 | $ 14 |
Gross realized losses | (1) | (4) | (1) | (4) |
Net realized gains | $ 6 | $ 8 | $ 9 | $ 10 |