Fair Value Hierarchy - Trading Cash Instruments, Additional Information (Detail) - USD ($) $ in Millions |
12 Months Ended | |
|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Trading cash instruments, fair value disclosure | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Net realized gains/(losses) | $ 93 | $ 168 |
| Net realized gains / (losses) on assets | 104 | 161 |
| Net unrealized gains/(losses) | (11) | 7 |
| Trading cash instruments, fair value disclosure | Market making | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Net realized gains/(losses) | 14 | 100 |
| Trading cash instruments, fair value disclosure | Interest income | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Net realized gains/(losses) | 79 | 68 |
| Trading cash instruments assets | ||
| Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items] | ||
| Net realized gains / (losses) on assets | 104 | 161 |
| Net unrealized gains/(losses) | $ (11) | $ 7 |