Fair Value Option - Summary of DVA Losses on Financial Liabilities (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
|
| Fair Value, Option, Quantitative Disclosures [Line Items] | |||
| DVA (net of tax) | $ (261) | $ (2,079) | $ 2,553 |
| Other Financial Liabilities [Member] | |||
| Fair Value, Option, Quantitative Disclosures [Line Items] | |||
| DVA (pre-tax) | (347) | (2,763) | 3,389 |
| DVA (net of tax) | $ (261) | $ (2,079) | $ 2,553 |