Fair Value Option - Additional Information (Detail) - USD ($) |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| Fair Value [Line Items] | |||||
| Total contractual amount of unfunded commitments for which the fair value option was elected | $ 905,000,000 | $ 905,000,000 | $ 944,000,000 | ||
| Net gain/(loss) attributable to changes in instrument-specific credit spreads on loans and lending commitments for which the fair value option was elected | 0 | $ 0 | 0 | $ 0 | |
| Secured long term borrowings | |||||
| Fair Value [Line Items] | |||||
| Difference between aggregate contractual principal amount of long-term debt instruments for which the fair value option was elected and related fair value | 0 | 0 | 0 | ||
| Unsecured long-term borrowings | |||||
| Fair Value [Line Items] | |||||
| Difference between aggregate contractual principal amount of long-term debt instruments for which the fair value option was elected and related fair value | $ 3,820,000,000 | $ 3,820,000,000 | $ 2,860,000,000 | ||