Derivative Financial Instruments - Gains and Losses on Hedged Items in Fair Value Hedges (Detail) - Net interest income - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives	$ 590	$ 28	$ 1,586	$ 174
Gain (Loss) on Hedged Items	(554)	(34)	(1,526)	(177)
Securities available-for-sale \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives	846	29	2,253	221
Gain (Loss) on Hedged Items	(741)	(4)	(2,062)	(144)
Deposits \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives	(53)	(3)	(138)	(35)
Gain (Loss) on Hedged Items	30	(13)	84	(5)
Long-term debt \| Interest rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) on Derivatives	(203)	2	(529)	(12)
Gain (Loss) on Hedged Items	$ 157	$ (17)	$ 452	$ (28)

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI https://asc.fasb.org/extlink&oid=121577467&loc=d3e76258-113986

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- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

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