Trading Assets and Liabilities - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading assets, amount offset	$ 2,797	$ 4,079
Derivatives included in trading liabilities, amount offset	1,296	3,377
Dividend income on equity securities held for trading	157	78	$ 37
Trading Assets
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading assets, amount offset	1,419	2,763
Trading Liabilities
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading liabilities, amount offset	$ 1,296	$ 3,377

Amount of obligation to return cash collateral under master netting arrangements offset against derivative assets.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=117331979&loc=d3e41228-113958

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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-Topic 815
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=117331979&loc=d3e41228-113958

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