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

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-7A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 8
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480434/815-10-50-8

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483466/210-20-50-3

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6B
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6B

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Trading Assets and Liabilities - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading assets, amount offset	$ 1,610		$ 1,610		$ 2,925
Derivatives included in trading liabilities, amount offset	2,057		2,057		1,291
Dividend income on equity securities held for trading	34	$ 45	76	$ 87
Trading Assets
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading assets, amount offset	1,463		1,463		2,813
Trading Liabilities
Debt and Equity Securities, FV-NI [Line Items]
Derivatives included in trading liabilities, amount offset	$ 2,057		$ 2,057		$ 1,291