Loans - Impaired Financing Receivables (Detail) - USD ($) $ in Millions |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Financing Receivable, Impaired [Line Items] | ||
| Nonaccrual loans | $ 2,469 | $ 3,552 |
| Nonaccrual loans divided by gross loans at amortized cost | 1.70% | 3.40% |
| Corporate [Member] | ||
| Financing Receivable, Impaired [Line Items] | ||
| Nonaccrual loans | $ 1,559 | $ 2,651 |
| Wealth management [Member] | ||
| Financing Receivable, Impaired [Line Items] | ||
| Nonaccrual loans | 21 | 61 |
| Commercial real estate [Member] | ||
| Financing Receivable, Impaired [Line Items] | ||
| Nonaccrual loans | 841 | 649 |
| Residential real estate [Member] | ||
| Financing Receivable, Impaired [Line Items] | ||
| Nonaccrual loans | 5 | 25 |
| Installment [Member] | ||
| Financing Receivable, Impaired [Line Items] | ||
| Nonaccrual loans | 43 | 44 |
| Other [Member] | ||
| Financing Receivable, Impaired [Line Items] | ||
| Nonaccrual loans | $ 0 | $ 122 |